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Gift of
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APPLETONS’
CYCLOPEEDIA OF APPLIED
MECHANICS
REVISED AND IMPROVED EDITION
A DICTIONARY OF MECHANICAL ENGLN'EERING AND THE MECHANICAL ARTS
ILLUSTRATED WITH NEARLY SEVEN THOUSAND EN GRAVIN GS
EDITED BY
PARK BENJAMIN, PH. D., LL. B.
EDITOR OF”APPLETONS’ CYCLOPEDIA OF APPLIED MECHANICS, EDITION OF 1880
MEMBER OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS
OF THE AMERICAN INSTITUTE OF ELECTRICAL ENGINEERS, AND
OF THE BRITISH CHARTERED INSTITUTE OF PATENT AGENTS
IN TWO VOLUMES
WITH A SUPPLEMENTARY VOLUME (MODERN MECHANISM)
VOLUME I.
N E W Y O R K
D. APPLETON AND COMPANY
1895
COPYRIGHT, 1880, 1892,
BY D. APPLETON AND COMPANY.
“’4‘
Q 17,. //._33/7 62 b"
r—7-33
PREFACE.-

THE world’s progress in the mechanical arts has been so rapid during the
twelve years which have elapsed since the last edition of this Cyclopaedia
appeared, that a complete revision has been found necessary. It was evident
that any mode of accomplishing this must provide not only for the addition
of all the latest and most important achievements in the great field to be
covered, but for retaining the large mass of valuable 'information which has
rendered this publication the standard of American mechanical practice.
The plan which has been adopted has included, first, the preparation of a
supplemental and new volume (“MODERN MECHANISM”), which enlarges the
entire work one-third, adding to it nearly 1,000 pages and 2,000 engravings ;
and, second, the removal from the existing volumes of about one-seventh Of
their contents, and replacing the same with fresh matter and illustrations. It
has thus been made possible to restrict the third volume to articles in continu-
ation of those in Volumes I. and II. which relate to the more important stand-
ard subjects, such, for example, as the Steam-Engine, Lathe, etc.; and to
articles on topics not before treated, such as the Development of Niagara,
the Electric Motor, the Storage-Battery, and Modern Means of Power-Trans-
mission. The removal of the large percentage above noted of the contents of
Volumes I. and II. has eradicated descriptions of many now Obsolete devices,
and, has given opportunity for the making of additions directly to the articles
bearing on subjects not included in Volume III.
The work, therefore, retains all its former valuable features, and the infor~
mation it afiords is brought up to its new date of publication. ~
CONTRIBUTORS.
.,.. ._.__.._ _.-~___._.---_' h --~-~~‘
l
The initials of Contributors are amended to the articles written by them,
either wholly or in part.
by the Editor.
RICHARD II. BUEL, C. E.
Articles on BOILERS, ENGINES, PUMPS, PRO-
PELLERs, etc.
JOIIN BIRKINBINE, C. E.
BLAST-FURNACES.
Lieut. A. A. BOYD, U. S. N.
Articles on ORDNANCE (in part).
HENRY L. BREVOORT, C. E.
MILLING.
GEORGE H. BENJAMIN, M. D.
CARTRIDGE, LAMPS, ORGANS, PIANos, etc.
IIon. ORESTES CLEVELAND.
Articles relating to GRAPHITE.
THOMAS A. EDISON, Ph. D.
T ELEGRAPII.
CHARLES E. EMERY, C. E.
DYNAMOMETER, INDICATOR.
S. W. GREEN.
TYPE-SETTING MACHINERY.
ALEXANDER L. IIoLLEY, C. E.
STEEL.
GEORGE W. W. HOIICIITON.
WAGON AND CARRIAGE BUILDING.
T. F. KRAJEWSKI, C. E.
Articles relating to LOCOMOTIVES, RAILROADS,
and SIGNALS.

Articles that are unsigned have been prepared
WILLIAM KENT, C. E.
Articles relating to IRON-MAKING.
Prof. C. W. MAOCORD, A. M.
GEARING.‘
F. H. MCDOWELL, E. M.
Articles on MINING MACIIINERY and IIYDRAII-
LIC MINING. ,‘
HENRY A. MOTT, Jr., E. M., Ph. D.
DAIRY APPARATUS, GAE.
WILLIAM H. PAINE, C. E.
BRIDGES.
PIERRE DE P. RIOKETTS, E. M., Ph. D.
ASSAI 1N0.
J OSIIUA ROSE.
Articles on Tome and MECHANICAL OPERA-
“'I'IO'N-S.
IRVING M. SCOTT.
COINING MACHINERY, MINING APPLIANCES. etc.
COLEMAN SELLERS, J r., M. E.
COUPLINGS AND CLUTCHES, SHAFTING.
F. T. TIIIIRSTON, C. E.
PAPER-MAKING.
SAMUEL WERBER, C. E.
Articles on TEXTILE MACHINERY.
Prof. DE VOLSON WOOD, A. M., C. E.
DYNAMICs.

REVISERS OF EDITION OF 1892.
THE EDITOR.
Lieut. A. P. NAZRO, U. S. N.
E. ll. KIERNAN, M. E.
CYCLOPAL‘DIA
OF
APPLIED MECHANICS.

ABACUS. An instrument employed by the ancients for facilitating calculations; similar to that
now frequently employed for teaching children the rudiments of arithmetic, and which is commonly
sold in our stationers’ shops. It usually consists of twelve parallel wires, fixed in a light rectangu-
lar frame; each wire carrying 12 beads or balls. There are thus 12 times 12, answering to the
common multiplication-table, all the results of which it demonstrates to the dullest capacity. All
the operations of addition or subtraction are likewise performed by it, by merely moving the
beads from one side to the other of the frame. By thus smoothing the difficulties of acquiring
arithmetical knowledge at the very outset, and rendering it quite obvious and amusing at the same
time, the apparatus becomes one of considerable importance in education.
Another kind of abacus consists of a series of parallel wires fixed in a frame like the former.
On each wire there are nine little balls; the lowest stand for units, the next above for lens, the next
1.
b l. a

Millions . . . . . . . . . . . . . . . .
Hundreds of thousands... .
Tens Of thousands... .
Thousands.. . . .. .. .....
Hundreds. . . . . . . . . . . . . .
Units..................





hundreds, and so on up to any number. The frame is divided into two compartments, a and b, by
a cross-wire at c, which is sufficiently raised above the wires to allow the little balls to slide under it.
Suppose the whole 63 balls to be placed in the compartment a, and it be proposed to note the sum of
4,346,072, it is effected by sliding the balls shown in b from their previous situation in a. See CAL-
CULATING-MACRINES.
ACCUMULATOR. An apparatus used for working hydraulic cranes, lifts, and other machines
where a steady, powerful pressure of water is required. Fig. 2 represents the portable accumulator
used in connection with other hydraulic machinery at the St. Gothard Tunnel. It is interposed
between the pump and the lift. It consists of a vertical cylinder, in which a piston travels, and which
has to be loaded to a weight equivalent to 450 lbs. per square inch. When the lift is not in opera-
tion, the piston is raised to an extent proportionate to the quantity of water introduced, which it
returns to the lift when the ingress-cock of the latter is opened. The diameter of the piston is
11.81 inches, and the stroke is 66.93 inches. The volume of water contained is 26.2 gallons, and
the pressure on the piston should be 21.18 tons; the piston and cross-head weigh 1.18 ton. A
load of 20 tons of lead-ingots is suspended to the cross-head at the top of the piston. These can be
removed at will to facilitate the moving of the apparatus from place to place on the works.
The accumulator illustrated in Fig. 3 admits of the use of a long cylinder of small diameter. The
1
2 ADDRESSING—MACHIN E.

weight of masonry M, rests upon the cylinder 0, and entirely surrounds the same. No guide is
therefore needed to control the vertical movement of the weight, and the centre of gravity of the
‘2. ' 8.
lL
H_ I?
N







latter is situated low down. The plate F is in two portions, consolidated by the fscrew-rods Z. The
upper joint has a stuffing-box, to which access may be had through the cover K.
ADDRESSING-MACHINE. An apparatus used for affixing the addresses on a large number of
missives, such as newspapers, upon which the same series of names must be inscribed as the day
of issue recurs. There are two general forms of this machine. .In one the addresses are separately
printed on slips of gummed paper, which are fed from the apparatus, which cuts ofi each address
in turn, and allows the latter to remain attached to the wrapper. The other mode is to set up the
type of each address in a form, and so to arrange the forms that they are successively presented at
a spot to which the enveloped papers are consecutively fed. A large number of these machines
have been patented.
ADHESION is the molecular attraction exerted between bodies in contact. It occurs between
. solids and solids, liquids and solids, liquids and liquids, gases and solids, gases and gases, and gases
and liquids. The adhesion between two plates of the same material is the same as that between
one of the plates and any material which possesses a less adhesive property. Adhesion is supposed
to manifest itself at an appreciable distance before actual contact of bodies. The ascent of liquids
in capillary tubes is a result of adhesion, as well as the spreading out of liquids between two sur-
faces kept in close proximity. The chain-pump, in which the water is carried up by a simple chain
in a tube, is a practical example of adhesion of liquids to solids. The adhesion of gases and solids
is illustrated by the adhesion of air around a piece of solid iron, which causes it to float on melted
iron. In the Gifl’ard injecter a blast of steam is used to carry water by its adhesion to it into the
boiler against its own pressure.
The adhesive force on railroads may be estimated approximately by multiplying the weight of
the locomotive in tons which rests on the driving-wheels by a coefficient of adhesion for said
wheels. This coefficient is with dry rails 670; very dry rails 560; under ordinary circumstances
450; wet rails 314; in snowy or frosty weather 225. On horse-railroads the coefficient varies from
300 to 400 in snow and frost.
ADIT. The horizontal opening by which a mine is entered, or by which water and ores are car-
ried away. An adit is termed a cross-cut when run for purposes of exploration in a direction trans-
verse to the general bearings of the veins or lodes. The great adit in Cornwall, Wales, drains the
waters from the Gwennap and Redruth mines, and is nearly thirty miles in length.
AGRICULTURAL MACHINERY. Agricultural machines and implements are so multifarious
that to facilitate their consideration a system of classification is necessary. Such a system may be
based on the history of every crop ; hence we have—
1. Implements for clearing ground, breaking it, and otherwise preparing it for the reception of
the seed. , '
2. Implements for depositing the seed.
3. Implements for the cultivation of the plant.
4. Implements for gathering crops.
5. Implements for preparing the crops for market.
6. Miscellaneous implements applicable to various farm-uses.
These classes will be considered in their order, and examples of machinery given under each divi-
sion. Dairy implements are principally referred to under DAIRY APPARATUS, CHURNS, and CHEESE-
MAKING; farm-engines, under ENGINES, STEAM, Foams OF. See also DRAINAGE, IRRIGATION,-and MILLS.
1. Implements for clearing, breaking Ground, etc. »
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AMERICAN HARVESTING MACHINERY.
AGRICULTURAL MACHINERY. 3

Stump-Pullers.—-The primitive method of extracting stumps is to hitch on a yoke of oxen, and-
after cutting away the earth from around the stump as much as possible, drag the latter from the
soil by main strength. Explosives are frequently employed to blow the stump to pieces. A
mechanical apparatus for stump-extraction is represented in Fig. 4. It consists of two beams
placed at right angles, and carrying each a wheel at their outer ends. The journal of the larger
wheel on the right is hinged to its beam so that the
wheel may be turned back parallel to the beam for con-
venience in drawing the machine from place to place.
A loop secured to the ends of the hinged journal carries
a hook, to which the harness of the horse is hitched.
Near the intersection of the beams is placed a guide for
a knife, which may be adjusted by a lever as deep in the
ground as is desired. To the rear of the beam on the
left is attached a loop that encircles the stump. The
horse is hitched to the apparatus as shown.
In operating the machine the loop is first dropped in
place, and a ring is placed above it. A wedge is then
driven into the top of the stump so as to fasten the ring,
the latter serving both to prevent the loop from slipping
OE, and also as a band to keep the wedge from spreading
the lower part of the stump so as to tighten the loop. The knife is next forced into the ground for
five or six inches, so that, on driving the horse around the stump, it cuts off such side roots as may
lie in its path. At each round the knife is driven in deeper until all the roots are divided. The hook
shown is then dropped and held down by the foot until it catches upon a root. A few rounds twist
off this last, and the stump may then be easily raised from the ground.
Ploughs.-—The plough is primarily designed to prepare the ground for cultivation by turning it over,
thus burying the weeds and loosening the earth. Modifications of the plough, however, have of late
been contrived to assist in cultivating operations, such as the destruction of weeds, loosening the
surface of the earth, or casting the same against the rows of the grain or plant, as the case may be,
and ploughs of this description will be treated of under the head of Cultivators, by which term they
are now generally known. The modern plough consists of a frame, to which horses may be attached,
and to which is fastened a device to detach (in advance of the share) the furrow from the un-
ploughed land; a share to sever the bottom of the furrow from the land beneath, a gauge-wheel to
regulate the depth to which the share shall enter the soil, and a mould-board to invert the furrow.
In Fig. 5 is represented an improved form of plough, made by the Ames Plough Co. A is the frame;
B B are the handles by which the operator guides the plough; C is the gauge-wheel, which runs upon
the surface of the soil and determines by the distance
between its perimeter at the bottom and the bottom
of the ploughshare the depth of the furrow; D is
the coulter which severs the furrow-slice from the land
in advance of the share; E is the mould-board, and F
is the clevis to which the draught is applied.
The manner in which the furrow is turned by the
plough is of considerable importance. Greensward land
may be ploughed with the furrows turned completely
over so as to kill the herbage, as shown in Fig. 6;
or it may be lap-furrowed, as shown in Fig. 7. The
difference is, that in the former case the ploughed land lies solid, and is difficult to break up, whereas
in the latter the land will break somewhat of itself, while there will remain at the same time beneath




6.
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the furrows the hollow triangular spaces shown in Fig. 7. Hence, when the cultivator, or elod-
crusher, is passed over the land, the soil will be more thoroughly broken up. In arable land—that
is, land that has been well ploughed before, and is not of a very clayey nature—the furrows may be




4 AGRICULTURAL MACHINERY.

turned completely over with such a short turn that the twisting of the soil itself will cause it to break
up, as shown in Fig. 8. Still another kind of ploughing is performed by the double Michigan plough,
the furrows of which are shown in Fig. 9. The upper furrow merely skims or pares ofl’ the upper
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portion of the sod and inverts it in the bottom of the furrow—a trench left by the bottom plough in
its previous traverse. By this method the soil is well broken up. The ploughing may be deep, and
the roots of grass, weeds, etc., are thoroughly buried.
The amount of twist given to the furrow is determined by the form of the mould-board. All other
things being equal, a long twist will require the least power to draw, while a short onerwill more
thoroughly break up the soil. The manner in which the furrows will lie depends upon the angle at
which the cutter or coulter is set. Thus in Fig. 10 the cutter, being set at an angle as shown, is










proper for ploughing flat furrow-slices, and stands as much inclined toward the mould-board side as
the land-side (as the side of the plough next to the unploughcd land is termed) does, and it is gen-
erally considered best to incline it even a little more, in order to obtain that beveled edge of the
furrow-slices so essential to their sure and finished matching, side by side, as they come from the
plough, and to do per ectly flat work.
In Fig. 11 Band are the furrows, and the dotted lines denote the direction in which the furrow B
will fall, D being the mould. In order to plough lap-furrowed slices, the cutter or coulter is adjusted
as shown in Fig. 12, in which A represents the land-side, or unploughcd land, B the coulter or cutter,
C the mould, and D, E, and F the furrows already turned. The forward inclination of the coulter
or cutter may be made greater or less, but it is always set with the point in advance. In
some cases a circular cutter takes the place of the knife-coulter, because it will sever fibrous roots
the more readily. The width of the furrow depends upon the position of the plough with reference
AGRICULTURAL MACHINERY. 5

to the line of draught of the horses, and is usually adjusted through the medium of either the draught-
rod or of the clevis, and examples of each of these methods will be found in our illustratlons. To
illustrate the influence of the line of draught upon the plough, however, let 6 in Fig. 13 represent the


13.
f/
f
T' c
6
d v \ ' e




forward end of the plough-beam, and c the centre of resistance on the plough, which may be
assumed at two inches above the plane of the base of the plough, (l e, though it is liable to constant
changes, from the depth of the furrows and constant inequalities in the soil. _ _
We have first to consider the particular form of those parts through which the motive power is
brought to bear upon the plough. It is evident that the motive force acts in a direct line from the
hook or ring at the shoulder of the animal, to the centre of resistance, and a straight bar or beam,
lying in the direction 0 b, and attached firmly to the body at a, would answer .all the purposes of
draught, perhaps better than the present beam, but for considerations of convenience. The draught,
however, not being the end in view, but merely the means by Wl'llCh the end 1s accomplished, the
former is made to subserve the latter; and, as the beam, if placed in the direct line a to 6, would
obstruct the proper working of the plough, we are compelled to resort to an indirect action to obtain
the desired effect. This indirect action is accomplished by means of an angular framework, consist-
ing of the beam, and the body of the plough, so strongly connected together as to form an unyielding
structure. The effect of the motive force applied to the framework at the point b, and in the line b
to f, produces the same results as if c b were firmly connected by a bar in the position of the line a
to b, or as if that bar alone were employed.
The average length of the trace-chains being ten feet, including all that intervenes between the
clevis of the plough at b, and the horse’s shoulders, let that distance be set off in the direction b to f;
and the average height at the horse’s shoulders, where the chains are attached, being four feet and
two inches, let the point f be fixed at that height above the base-line cl e. Draw the line from f to c,
which is the direction of the line of draught acting upon the assumed centre of resistance c ; and if
the plough is in proper trim it will coincide also with the ring of the clevis, e c f being the angle of
draught and equal to 20°. It will be readily perceived that, with the same length of hames, the
angle e c f is invariable; and if the plough has a tendency to rise at the heel, or run on the point
under this arrangement, it indicates that the ring at b is too high in the clevis. Shifting the ring
one or more holes downward will bring the plough to work evenly upon the base of the land-side, or
work flat.
If the plough has a tendency to rise at the point of the share, the ring b is too low, and must be
moved by raising it one or more holes in the clevis. If a pair of taller horses be harnessed to the
plough, the draughhehains, depth of furrow, and soil remaining the same, we should have the point
f raised, suppose to f ' ; by drawing the line f ' to c, we have e c f' as the angle of draught, which
will be 22°, and the ring will be found to be below the line of draught f’ c; and if the draught~
chains were applied at b, in the direction f’ b, the plough would have a tendency to rise at the point
of the share, by the action of that law of forces which obliges the line of draught to coincide with
the line which passes through or to the centre of resistance ; hence the ring would be found to rise
from b to b', which would raise the point of the share out of its proper direction. To rectify this,
the ring must be raised in the clevis by a space equaling that between I) and b’, causing it to coincide
with the true line of draught, which would again bring the plough to work evenly on the base of the
land-side and run flat.
The foregoing principles are substantially such as are adopted by the most experienced plough-
men, and, if properly applied, will not only do the best work, but accomplish it with the greatest
ease to themselves and their team. If the power (or team) is not rightly applied, good work cannot
easily be done ; for if the plough inclines in or out of the ground too much, or takes too wide or too
narrow a furrow-slice, the ploughman must exert force to direct it properly, in addition to that re-
quircd to overcome the obstacles and inequalities in the soil; but if the power he rightly applied,
the plough will move so accurately as not only to perform good work with more case to both plough
man and team, but, in soils free from obstructions, even without a guide.
To effect a proper horizontal movement, the clevis at b or draught-rod (if one is used instead of a
clevis) must be adjusted and confined at that point, moving it to the right or left, if necessary.
This will cause the plough to take the proper width of furrow-slice, which, in sod, should be wider
or narrower according to the depth of furrow, or, rather. the thickness of the furrow-slice required ;
for as the thickness is increased, so also must be the width in proportion, in order to turn it easily
and perfectly over, particularly when the furrow-slices are required to be laid over level, and side bv
side. The proportion in ordinary sod should be seven by ten, or the width or depth should be varied
only in this preportz'on.
6 AGRICULTURAL MACHINERY.

\
In determining the width of furrow-slice, some regard must be had to the strength of the particu-
lar sod to be turned; for the plough will turn over a wider slice in a strong, stifl’ sod than when
running in one more easily broken, or it will cripple and double when raised to a perpendicular posi-
tion, thus only doing the work called “cut and cover.”
When the slices are required to be laid at an angle and lapped each one upon the preceding, the
proportion of width should be as seven to ten, thus setting the furr‘ows at an angle of 45°, which is
the position of furrow presenting the greatest attainable surface to the action of the atmosphere,
and the greatest cubical contents of soil to the action of the harrow in preparing a seed-bed.
In Fig. 14 is shown a prairie-breaking plough. The furrows in this class of ploughing are usually
about 4 inches deep, and from the fibrous roots in and compact nature of the soil the duty is very
heavy; hence the length of the plough is increased, and a wheel-coulter is employed. The line of


draught is regulated by the clevis being moved laterally to the width of the furrow, and vertically
to steady the plough as regards depth.
The double Michigan or “ sod and subsoil ” plough, Fig. 18, has some important advantages. The
forward or skim plough pares off a sod a few inches in thickness, and inverts it into the bottom of
the previous furrow. The second or main plough follows, and throws up the lower soil, completely
burying the inverted sod, and giving a loose, mellow surface to the field. This forms an excellent
preparation for all crops, particularly carrots and other roots, which grow best in a deep, loose bed
of earth ; and, where a portion of the subsoil improves the top-soil by being mixed with it,’ a perma-
nent advantage results. A greater depth may be attained by the use of this double plough than


with one having a single mould~board, in sod-ground, because the inversion will be complete even if
the width of the furrow is only one-half the depth. But, with a single plough, the width must be con-
siderably greater than the depth, or the sod will be thrown on its side or edge, and cannot be in-
verted. There is one disadvantage, however, in the use of the double plough. A greater force is
required to make two outs in the soil, one above the other, than one cut with a single share. For
this reason more force must be used to plough a field to a given depth, say one foot, with the double



than with the single plough. But the single plough, in order to reach this depth, would require to
be so large, and to turn so wide a furrow, that no ordinary amount of team could be had to do the
AGRICULTURAL MACHINERY. 7

work. And, in addition to this difficulty, the inverted surface Would not be so well pulverized as by
the use of the double plough.
Side-hill or swivel ploughs are designed to throw the furrow-slice down-hill, whichever way the
plough may be moving. The plough is pivoted so that it may be moved from side to side of the
beam when at the end of the furrow. The ploughing may then be done across and across the field
instead of around it or in sections. Fig. 16 is an Ames side-hill plough. Another variety of the
swivel or “turn-wrist ” plough is shown in Fig. 17. It is so constructed that two ploughs attached
to one beam are readily changed from one side to the other, turning the furrow-slices either to the
right or left as desired. The forward plough turns the sod to the depth of about three inches, de-
positing it at the bottom of the channel; and the rear plough works to the depth of five to seven
inches, raising and pulverizing the under or subsoil, and depositing it upon the forward furrow-slice,
burying the sod below the reach of the barrow or cultivator.
Fig. 15 is a plough designed for deep tilling, and it may be taken as a representative of the class
of ploughs used in sugar-cultivation. The line of draught is adjustable by the clevis, as shown.
In the New York plough, Fig. 19, the line of draught for regulating the width of the furrow is
adjusted at the end of the beam where it connects with the handle-frame. The handles may be
kept nearly equidistant laterally from the share, giving a central draught.
Fig. 20 is a Scotch subsoil plough, which is used for
following directly after the turning-plough, and in the
same furrow, breaking up, lifting a few inches, and
pulverizing the subsoil. For making roads, the class
of plough shown in Fig. 21 is used. Strength and du-
rability are here prime requisites, as the principal duty
is simply to loosen the ground, cutting a width of from
seven to nine inches at a traverse.
As regards the tractile power required to draw a
plough, from experiments in England it appears that
about 35 per cent. of the whole required draught is ex-
pended in overcoming the friction of the implement on
its bottom and sides, about 55 for cutting the furrow-
slice, and only about 10 per cent. for turning the sod.
Hence the exclusive attention formerly given to forming the mould-board, as a means of reducing
the draught, should have been directed more to lessening the force required for cutting the hard soil:
These data are not wholly satisfactory for the light ploughs of the United States.
To ascertain the amount of friction, suppose the plough weighs 100 lbs. Half its weight would be
501bs., the friction on the sole of the plough. The friction of the sides would vary/greatly with
ploughs, being very small with those having a perfect centre-draught, or with no tendency to press
against the land on the left. The whole friction and force for lifting the sod would therefore be
about 150 lbs.; leaving 250 lbs. as the force for cutting the slice. A very easy-running plough
would leave a much smaller force—some as low as 200 lbs.
This estimate is liable to great variation. A wet and clayey soil would double the friction ; a very
hard piece of ground would add
much to the force required for out-
U= ting the slice; if loose, 'the force
would be comparatively small; or if
i 3 quite moist, this force would be also
@ C @ much diminished; while the great
difference in the draught of ploughs
B B would vary the results still further.
Us {I {I The estimate, however, for soil dry
A U: enough to be friable, and of medium
tenacity, is probably not far from
correct, for ploughing in this country—showing that most of the force required is for the act of cut.
tin", and indicating the importance of giving special attention to the cutting edge.
cam-Ploughz'ng.—This answers the use of a gang-plough hauled across and across or else around
the field by means of wire ropes, the 23
steam-engine remaining stationary. '
In Fig. 22 is represented Fowler’s dou-
H]
ble-engine system,* which requires W
two engines, one on each headland, C @
each of which alternately draws the
cultivating implement across the '13 8
field. Each engine is provided with A
a winding or hauling drum, which in
turn pulls the implement and pays
out the slack rope. This system is
both simple and effective. The im-
plement is drawn with considerable
velocity—often much faster than a
man can walk—and the steam drag L
or harrow will pass over from fifty J
to sixty acres of land per day. Fow- D
* From “ British Manufacturing Industries," article Agricultural Machinery, by G. P. Bevan, F. G. S.










A








8 AGRICULTURAL MACHINERY.

ler’s double-engine system appeals to large capitalists, but the same firm also provides good single-
engine sets for the use of smaller employers. The single-engine system (Fig. 23) requires an engine
on one headland and a self-moving windlass on the other. The engine is provided with the patent
Burton clip-drum, capable of hauling the cultivating implement backward and forward between the
engine and windlass. Both engine and windlass travel along the two headlands opposite each other.
A third system is offered in Fig. 24, in which the engine remains stationary, and the rope is
arranged in an irregular triangle or square, while the implement passes to and fro between two
fixed anchors, rendered movable at pleasure. This is called the “ round-about system,” because the
rope is carried around anchors and ineloses the space to be cultivated. The several systems thus
slightly described will be more easily understood by reference to the accompanying diagrams. One
of the main advantages of the “round-about ” plan is that it enables the farmer to employ any ordi-
nary traction-engine for ploughing purposes, and thus reduces the amount of capital required in
commencing steam-cultivation.
The following particulars, taken from one of the Royal Agricultural Society’s Implement Catalogues,
will give the reader a good idea of what is
24- included in a set of steam-cultivating im-
plements. Messrs. J. Fowler and Co.’s
double engine, 20 horse-power set, consists
of a pair of 20 horse-power self-moving
engines with single cylinders, fitted with
single winding drums, 800 yards of best
steel-wire rope, and works a thirteen-tined
cultivator. There may be a six-furrow bal-
ance combined plough and digger in addi-
tion.
It appears from a test of Messrs. Fowler
and Co.’s apparatus, made by the Royal
Agricultural Society, that the machine was
able to turn over soil in an efficient man-
ner at a saving as compared with horse-
labor on light land of 2% to 25 per cent.;
on heavy land 25 to 30 per cent; and in





l



. A. trenching 80 to 85 per cent.
-_© {-5551 Gcmg-Ploughs.——The nans-plough has a
gm framework to which arte3 afiaehed two or
more ploughs, together with a seat for the
driver. Mechanical means are provided whereby the ploughs mayr be lifted entirely clear of or be
adjusted to any required depth in the ground. The smaller and lighter gang-ploughs may be drawn
‘25.










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by horses after the manner of sulky-ploughs; but in many cases, and especially in England, gang-
ploughs are employed for steam-ploughing, as previously described. _
In Figs. 25 and 26 are given two views of an improved Enghsh gang cultivator-plough.
AGRICULTURAL MACHINERY. 9

The frame, to which the ploughs are attached, stands on three wheels, of which the middle one is
a caster-wheel, while the two end-wheels revolve in turn-tables, which lift or lower the main frame ,
exactly by the depth of the furrow, according to the direction which is given to the wheel. The
plough-skifes turn in sockets, and are connected by a long red, working short levers, so that the
turning round of one plough causes all the others to turn as well. There are, further, two con-
nected horizontal pulling levers, by turning which either backward or forward the ploughs are
also turned completely round, and locked. The ploughs themselves are shaped so as to cut with
either end. While at work the main frame travels in a slanting position over the land, the front-
wheel running in the preceding furrow, the hind-wheel on /the unploughcd ground, the ploughman
steering the furrow-wheel.
Table showing Dynamomctric Tests of Gang-Ploughs at Paris Exposition, 1878. (1)

















'
_ Mean Power
3:; width necessary I
Length Mean Mean of Section to dis- .
names or CON- Trial Mx' of ordi- 0°25” depth furrow of place 35.3 Len?!“ Th,“ ‘we‘fbtl
'rns'raurs. " b trace. mte. P2; mg of slice laud cubic feet f ° t °vl in ° ,1
P13“- (2) (3) o furrow. of the turned. of earth. mom raw ' l (mg 'I'
mew gang- Mean of i
" % plough. two trials. 1
l I
Square Foot- 1 Square ’ Foot- Min. I
Malia Feet. Inches. pounds. Inches.l Inches. feet-
Pounds' Feet. a Sec'irounasn
Mfimnbfgg’mggml Going. 178.5 7.97 1.92 3595.5 5.9 26.4 1.098l . . . . . .. 524 g 4 s '5434
France .. Returning. 174.7 7.75 1.85 3616.8 6.2 24.4 1.080,35421.2 524 ' 4 42 . . . . __l
Deere & (10., MW} Going. 187.3 8.24 1.87 3651.9 6.3 ; 27.1 .213 -. . . . . . . . 5‘24 4 l2 >572
line, Ill . . . . . . . . . . Returning.‘195.2 7.79 2.06 4023.8 6.5 i 27.6 ‘1269 I 32851.? 524 4 22 g . . . .


(1) The ground was slightly inclined. (2) The base line on the paper ribbon of the dynamometer. (3) Mean dis-
tance between the base and profile lines on paper ribbon.
See Scienitgfic American, xxxix., 162.
27.






In Fig. 27 is represented the Collins Gang and Sulky Plough, in which the depth of fu'row is regu-
lated by the adjustment of the slide upon the are shown. The ploughs are raised above the ground
by throwing the left-hand lever forward, causing the clamp attached thereto to engage the rim of the
wheel which carries it over, lifting the frame and ploughs. To take the first furrow, the right-hand
lever and its rear sliding clamp are drawn back on the
arc and fastened at the point necessary to give the
required depth of furrow. The left-hand lever is
then retracted, depressing the ploughs into the
ground.
Sulky-Plougk.—This name is given to single ploughs,
which are mounted upon a frame on which a seat for
the ploughman is arranged. The sulky-plough shown
in Fig. 28 is arranged for three draught-horses. By
applying the brake to the wheel the horses raise
the plough out of the ground instead of the driver
having to pull it out by main force. The team is
hitched to the end of the beam instead of to the
tongue or carriage, thus avoiding side-draught and
relieving the weight from the horses’ necks. Owing
to the peculiar construction of the axle, the lower-
ing of the plough into the ground throws the furrow-
wheel down and the land-wheel up, keeping the plough



' 10 AGRICULTURAL MACHINERY.

level, thereby avoiding all the trouble of leveling up with levers or screws. The depth of furrow
can be instantly changed by the driver without getting off or stopping the horses. It can also be
readily adjusted to take more or less land.
Clod-Ormlzer.——This machine is used to break up the land which is of such a stiff nature as to
remain in lumps or clods after ploughing. In the implement illustrated in Fig. 29, it consists of about
two dozen circular cast- iron disks, placed loosely upon an axle, so as to revolve
separately. Their outer circumference is formed into teeth, which crush and
disintegrate the elods as they roll over the surface of the field. Every alter-
nate disk has a larger hole for the axle, which causes it to rise and fall while
turning over, and thus prevent the disks from clogging.
This elod-crusher can be used only where the ground and the clods have
become quite dry. Even then it packs the soil, and if followed by a harrow
with scarifier teeth, to loosen it again, it would prove an advantage. It is
' only in certain seasons that it is most successfully employed, or when quite
dry weather follows a wet spring. As thorough tile-draining is generally adopted, it becomes less
necessary.
Harrows are used to disintegrate and pulverizc the ground after ploughine. Several forms of
these implements are presented herewith.





Fig. 30 is the ordinary square harrow; Fig. 31, the Friedmann harrow; and Fig. 32, the Scotch
harrow. For land containing many fibrous roots, or much stiff clay, the disk or wheel harrow rep-


resented in Fig. 33 is used. The wheel-gangs (that is to say, the shafts to which each row of disks
is fixed) are attached to the pole and draught-bars by the ball-joint shown at A, so that each gang is
free to conform by its own weight to the shape of the ploughed land-surface. The operation of this
harrow is that of cutting and separating rather than of scratching, as in the case of spike-harrows.
The shares harrow (Fig. 34) is especially adapted for pulverizing the freshly-inverted surface of
award-land, to a depth two or three times as great as the common barrow can effect. The teeth,
being sharp, fiat blades, cut with great efficiency; and as they slope like a sled-runner, they pass over
the sod, and instead of tearing it up like the common barrow or gang-plough, they tend to keep it
down, and in its place, while the upper surface of the sod is sliced up and torn into a fine, mellow soil.


Rollers crush all sods and lumps that remain on the top of the ground after the barrow has passed,
and force down small stones level with the surface. They render the field smooth for the cradle,
AGRICULTURAL MACHINERY. 1 1

scythe, and rake, press the earth close about the seed, and secure a more sure and quick. germination.
0n light and sandy lands they are invaluable, and in all cases their use has greatly increased the
product. Much benefit is undoubtedly found in compressing the surface of such light sods, by pre-
venting the escape of those gases from the manure so essential to vegetation, and WhlCh are so rapidly
extracted by the sun and winds. Great advantage is gained by rolling early in the spring while the
ground is yet soft. Clay lands, by heaving, pull to pieces and displace the roots of gram and grasses
sown the previous autumn, and the heavy roller presses the roots and earth together to their proper
position, when vegetation goes on again, and thus, in a measure, prevents what 18 termed Winter-
killing. Fig. 35 represents an approved form constructed wholly of iron, except the tongue and
box, which are of wood. These rollers are made of various diameters, from twenty to thirty-six
inches, in separate sections, each one foot long, placed on a wrought-iron shaft independently of each
other.
Fig. 36 is a hand-roller used upon lawns and gardens. Additional weight is supplied by iron
weights pivoted as shown to the axle.
2. 1m laments for depositing Seed, etc.
Seed-giw'ing Machines—Drills—These machines are mainly distinguished by the mechanical de-
vices by which the drills are opened, seed fed, and drills reelosed upon the seed. Of these the feed-
ing-device is the essential feature, and this usually involves either means for varying the quantity of
seed fed by varying the escape-openings, or by positive mechanical movements variable in speed.
The principal requirements are capability of distributing seed with a continuous and regular dis-
charge from each distributor or grain-tube; accuracy in quantity of seed discharged; efficiency in
regulating the same under all circumstances on inclined, level, or irregular land; changeability of the
feed-apparatus to suit coarse or fine seed, and facility of adjustment.
Fig. 37 represents a sowing-machine to which a horse may be attached, or it may be pushed by
hand. A is the seed-box, in the bottom of which is the seed-delivering device, which consists either
of a brush D, or a revolving cylinder 0. The
former is employed for small, the latter for 37-
large seed. To change the quantity of seed
sown, the speed of either of these feed-devices
is increased as follows: B is a casting contain-
ing several diameters of gears upon one east-
ing, which is either fast to the wheel or the
axle. Into one of these gears is meshed a
pinion fast upon an horizontal shaft or spindle,
which by means of bevel-gears at the other
end rotates the brush or cylinder as the case
may be. Hence by changing the pinion at B
from meshing into the larger or smaller gear
at B, the rotations of the brush or cylinder may be increased or diminished, and the quantity of seed
sown varied in consequence. The grain-spout enters the ground at its point, and therefore opens the
drill ready to receive the seed, while the swing-board beneath the handles closes the earth over the
sown seed, and the roller following compacts and levels the same over the seed.
Fig. 38 is a Bickford and Huffman grain-drill. It contains eight dropping-tubes. The mode by
which the, grain is discharged from the hopper down these tubes is exhibited in section in Fig. 39,






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which shows the interior of the hopper, and a revolving
wheel, the projecting rims of which form the bottom of the ~ s '- ~ - r j
seed-holder; the axle causes this wheel to revolve, and the
small projections on the interior of the rim carry the seed to where it drops through an opening in
the plate which forms the side of the seed-holder. The rapidity of discharge is perfectly controlled
by wheel-work, which causes the axle to revolve slowly or fast at pleasure. The seed-holder is
divided into two parts by the wheel, as shown by cross-section in Fig. 40; one part containing wheat,
barley, and other medium-sized grains, and the other for corn, peas, and the larger seeds. This
figure shows the opening in the side-plates, through which the grain is discharged. As these two
divisions must be used on separate occasions, the apertures between them and the hopper are opened
and closed at pleasure by a sliding bottom with a single movement of the hand. This sliding bottom
is shown in Fig. 41, and forms hoppers with sloping sides down which the grain passes. The ends of
the tubes, which are shed with steel, are made to pass any desired depth into the mellowed soil, and
term the drills for the seed, which is immediately covered by the falling earth as the drill passes.
12
AGRICULTURAL MACHINERY.
In Figs. 42 and 43 is shown the“ force-feed ” device.
_
The seed is delivered from the internal flange
of the feed-wheel. Fig. 42 exhibits the feed for wheat and small grain, and Fig. 43 the same for


corn or coarse grain.
consequently, when the wheel is revolved, the seed travels exactly with it, thereby insuring the flow
of grain to be in a steady, unbroken stream. The two casings, as shown by the cuts, between which
the feed-wheel revolves, forms the outer walls of a complete measuring channel, or throat, through
which the grain is carried by the rotary motion of
the wheel, thus providing the means of measuring
the seed with as much accuracy as could be done
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with a small measure. The quantity sown per acre
is governed by simply increasing or diminishing the
speed of the feed-wheel.
In Fig. 44 is represented Kuhn’s grain-drill, in
which the change of speed in the feeding-device is
altered by a system of cone-gearing shown in Fig.
45. The lower gear-wheel may be adjusted to
mesh into such of the cone-gears as is required in
accordance with the amount of seed to be deposited.
The mode in which the grain is fed by a positive
mechanical movement is exhibited in Figs. 46 to 49.
Fig. 46 shows a feed-wheel, Fig. 47 a sectional
view of wheel and cap, and Figs. 48 and 49 the de-
livery of the grain. In Fig. 50 is represented a
potato-planting machine. The cut potatoes are
placed in the hopper shown. Secured upon the
axle is a cast-iron disk, around the periphery of
which a number of holes are made in order that
the cups may be fastened thereon, at any points
or at any distances apart. As this disk revolves,
the cups, which are turned rearward, enter the
hopper from beneath, passing through an orifice
protected by bristles, which serve to prevent the
escape of the seed. The cups thus become filled As they are carried on out of the hopper by
the disk, they pass through a box, also shown larger at one side.


4S.


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The sides of this attachment are
46. 49.
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fitted with bristles, which, while offering no resistance to the passage of the cup, retain the seed in
the same as it is reversed by the rotation of the disk. As soon, however, as each cup emerges from
AGRICULTURAL MACHINERY. 13

a.
between the bristles, its contents drop out—directly, however, into the drill made by the opening
plough. Wings in rear of the latter, as the machine advances, replace the soil in the furrow, com-
pleting the planting. The knives in the cutter divide
the seed into pieces of uniform size, and thus the con- 50.
stant filling of the cups is rendered more certain.
Figs. 51 and 52 represent an apparatus for cutting
potatoes before planting. They are placed in the tubes ,
shown on the table, across which a strap passes, thence
ever a pulley, and finally is attached to a treadle. 0n
the up er side of the strap are bolted horizontal ‘
blades see enlarged view, Fig. 52), which carry one or ‘ ©
more vertical cutters on the portions contained within
the peripheries of the tubes. These tubes, it will be
seen, are slotted in order to allow all the blades to be
drawn through them, an operation effected through the
strap and treadle already referred to. By increasing 7 __
the number of vertical cutters in any tube, the number ‘ .._
of pieces into which the potato is divided is of course
augmented. The system of knives is connected by bars underneath the table, secured to vertical
arms extending down through slots in the same.
In operation, after the potatoes are deposited, one in each tube, pressure upon the treadle carries
the knives through them; and thus divided, they fall through
51- apertures beneath the tubes, upon an inclined plane, and into
any vessel placed for their reception.
3. Implements for the Cultivation of the Plant.
Cultivators.—The name cultivator has been applied to a class
of implements which is adapted to perform the various agricult-
ural operations necessary to the cultivation of the crop. Prop-
erly speaking, the term should imply that its duties commence
after the crop is above the ground; but, unfortunately, it has
been applied to machines employed in preparing the ground for
the reception of seed, which, so to speak, trench upon the duty of
the barrow. The ordinary duty of the cultivator, however, is to ,
loosen the earth, destroy weeds, and in some cases to gather the
surface earth and leave it around the growing plants or crop.
It follows, then, that to admit of the use of the cultivator, the
crop must be sewn or planted in drills or rows. Cultivators are
made in various forms to suit the duty required. When they
operate between two rows they are termed single, and when
between three rows, double cultivators. Those which provide
a seat for the driver are termed sulky-cultivators, while those
not so provided are simply “ cultivators,” and are usually distin~
guished by an additional term indicating the kind of crop they
are intended to cultivate. Thus we have “ corn-cultivators,”
“cotton-cultivators,” etc. Double cultivators are arranged so
that the outside teeth may be adjusted in width to suit the
width of the rows of the crop. In Fig. 53 is shown a hand—
cultivator, the two outside rows of teeth being adjustable in
width to suit the width of the crop-rows by means of the slotted
stays in the rear, which are held by the set screw shown.
In Fig. 54 is represented a cultivator having a gauge-wheel
adjustable upon the draught-beam, and also a roller. By these
devices the depth at which the implement works in the ground is
adjusted. The cultivator shown in Fig. 55 has iron sidebeams
_ so curved that, as they are expanded or contracted by loosening
the iron keys that confine the teeth in their places, the latter are moved forward or back to a point
$121121? will again cause them to work parallel with the centre-beam, and at equal distances from the
0 ers.

















There is also one pair of moulds calculated to work in the rear, in form like small ploughs, throw-
ing the earth in opposite directions and fittimr alike both side beams - the ma be la ‘
_ eed to throw
the earth to or from the centre, or ’rows of vegetables. , y y p
\
14 AGRICULTURAL MACHINERY.

The cultivator shown in Fig. 56 is adapted to loosen the surface of the soil and destroy weeds.
The draught-rod is connected to the centre of the beam to render the operation of the machine steady,


and facilitate the regulation of the depth to which the teeth enter the soil. Fig. 57 is a cultivator
and hiller. The soil loosened by the teeth is thrown against the plants by a rear-share. The width of
the hiller and of the teeth is adjustable to suit the
duty. Fig. 58 represents an improved wheel-culti-
vator operating between rows of corn. The shovel-
frame is pivoted to the axle, and the handles are at-
tached on each side the ploughs, when not in op-
eration are suspended from the hooks shown. For
ploughing out between narrow rows the ridging
or double-mould plough represented in Fig. 59 is
used. It is also employed for opening drills to
plant potatoes. fig. 60 is a double-mould plough
or cultivator for sugarcane. The mould-boards are
made to expand to suit the width of the rows.
The double share cuts off a surface-slice of the
soil, and the wings or mould- boards throw the
same up to the cane_plants. Fig. 61 is a four-fur-
row plough of English construction, designed for
steam-cultivation, and the notable feature in it is the admirably simple means provided for adjusting
the widths of the furrows. The implement has the rigid frame which is so essential in steam culti-






AGRICULTURAL MACHINERY. 15

F-
vating implements, while the alteration of the width of the furrows is effected by means of wedges,
which throw the ploughs at different angles to the frames. The employment of wedges in this way
does away with the necessity for belts or screws, and makes a thoroughly rigid fastening, while at the
same time every facility is afforded for adjusting the width of furrow very quickly.
61.






Fig. 62 is a type of the cultivators similar in construction to the double-mould-board plough. The
object is to throw the earth on each side, the wings A B at the sides being provided to alter the
width of the mould to suit that of the cross'rows. The
piece 0 is also removable, so that part of the earth 62-
may, if desired, fall between the moulds instead of being
delivered at the sides.
4. Implements for gathering Crops.
Mowers—The essential parts of a mower are suitable
driving- wheels upon which it travels, and from which
motion is transmitted to the cutting apparatus; a main
frame supporting the mechanical movements; the cutting
apparatus consisting of a finger or cutter bar and a recip-
rocating scythe; levers or handles by means of which the
driver can put the machine in or out of gear, and lift the
cutting apparatus to pass obstructions; jointed or flexible connections between the finger-bar and
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1 6 AGRICULTURAL MACHINERY.
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frame, allowing the cutting apparatus to conform to the undulations of the surface of the ground in-
dependently of the main frame, and admitting of the folding over of the cutting apparatus on to the
frame when traveling on the road so as to stow it out of the way in a compact shape; appliances at
each end of the finger-bar for regulating the height of the stubble, and mechanical means of throw-
ing the mechanism operating the cutter-bar in or out of motion. The diameter of the driving-wheels
(A, Fig. 63) is usually about 30 inches. Hence it follows that one revolution of the wheel carries the
machine forward 94.28 inches. The scythe sections project forward 2 inches, so that they must have
a sufficient number of vibrations, which (multiplied by the 2 inches) will cut over all the ground trav~
crsed. N ow, as the machine represented has 51.6 vibrations to one revolution of the driving-wheel, the
cut made equals (51.6 multiplied by 2 equals 103.2, which less 94.28 equals) 8.92 inches more than the
actual distance traveled by the machine. These vibrations are obtained by multiplying-gear which
cause the shaft driving the scythe (through the medium of a crank-disk and connecting-rod) to re-
volve the necessary number of revolutions faster than the wheels A.
In Fig. 63, A A are the wheels upon which the machine travels, the lugs or projections shown
upon the periphery of each being provided for the purpose of enabling the wheels to take a firm
hold of the ground. This is necessary, because the reciprocating motion necessary to the cutting-
knives is obtained either by gear-wheels attached to the shaft upon which the wheels A A revolve,
or by the said wheels themselves containing an internal gear-wheel. In either case the gear or tooth
wheel actuates the parts which operate the cutter-scythe. Hence it follows that if the wheels A A
were to slide over the ground and not revolve, the operation of the scythe would cease, and the ma-
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chine would pass over the herbage without mowing it. The framework carrying the mechanical move-
ments necessary to the operation of the machine is carried by means of suitable bearings upon the
axle connecting the wheels A A, and upon this framework there is provided a seat for the operator.
The levers, or handles, by which the operator
65- throws the cutting-knives into or out of opera-
tion, or raises or lowers the cutting-device, are
convenient to the hand. The machine shown
in Figs. 63, 64, 65, and 66, is known as the
Buckeye mower, the driver’s seat being re-
moved to show the arrangement of the mechan-
ical parts the more distinctly. The wheels A
‘v A are not, in the mower under consideration,
~ \ fast upon the axle B, so that when the ma
"av-v . \ chine is in transit to or from the field of opera
§\ \ / ‘ \ \\\\\ \\ \: . _
E; I / /2' vi trons the wheels revolve independently, and are,
K‘sWM/MW7/WW/W2MWWM/MMWWW" therefore, the only parts in motion. When,
"—vmmw ————=~—— however, the machine is in position ready to
”"' ’"lTI/ZZ/ llg'n/j/l/h/fl/I/W .
operate they are connected to the axle B, in
// ,
1' // / n
\ _/
the following manner: Fast to the axle B are



the ratchet-wheels C, and attached to the side
of each of the wheels A A are two pawls or
catches, each pivoted at one end, so that the
other end may engage or disengage with.the
teeth of the ratchet. To retain the pawl in fixed, engaged, or disengaged position there 1s prowdcd
a spring which is shown at E. Another advantage of this arrangement is, that when the horses are
backing (in which operation they cannot exert much power), they are relieved of the duty of movmg
the working-gear of the machine. . _ _
To drive the shaft I (Fig. 63) two methods of gearing have been applied. In_ the first (Fig. 63)
the bevel-gear D drives a pinion upon a short shaft having at its other end a pinion geared to the
AGRICULTURAL MACHINERY. 17


'—
pinion G in Fig. 67, which figure is a plan .view of the part H, in Fig. 63. In the second method
(Figs. 65 and 66) the bevel-wheel D gears direct to the pinion 6.
Fast upon the axle B is the bevel-
gear wheel 1) (Fig. 66), which engages 66-
with the bevel-pinion G, the latter being
formed in one casting with the internal
gear H. This ar- g -
rangemcnt is con-
structed in order 1' I
that, the bevel-gear
having 71 teeth, or I ,
cogs, and the bev-
el-pinion having 12 _ [F/
teeth, the revolu- 7 Q '
tions of the latter may be 5.91 to one |, l
of the former; and the internal gear H '
having 48 cogs, and the spur-pinion hav- ‘ ,9
ing 11 cogs, the revolutions of the lat-
ter are 4.36 times those of the former.
Upon the shaft 1, Fig. 63, at the end K, @
is a crank-disk shown, carrying a crank-
pin which communicates reciprocating
motion to the rod which is pivoted at \,
that end of the scythe-bar, thus also im-
parting a reciprocating motion to the
latter. Thus it will be noted that the
multiplication of scythe rcciprocations \ 6)
over the wheel revolutions is obtained f ~
in two places: first between the wheels I _I
D and G, and next between the wheel H
and its pinion. All these wheels are cased in to prevent them from becoming clogged or entangled with
herbage. N N, Fig. 63, is the iron frame swung by bearings upon the axle B, and carrying the parts so
far described; M is a wrought-iron hinge-bar connecting the cutting-device to the frame N, to which
it is hinged beneath; while 0 is a brace attached rigidly to J1, and hinged to the frame N at its other
end. The joints of the hinges by which both M and 0 respectively are attached to the frame N are
parallel one with the other and also with the shaft 1, an arrangement which permits of the cutting-device
being raised and lowered without the intervention of a double or universal joint. It is obvious that
the cutting-device (as we have termed that part of the machine which consists of the finger-bar,
scythe-bar, and the attachments at each end thereof) must be lifted out of the way when it is re-
quired to pass over an obstruction, and for this purpose the lever Q and its attachments are provided.
Upon the draught-pole P is the ratchet casting shown in Fig. 68, and upon the projecting pin shown






\
\\\\ \ \\ \\\\\\ -.-











therein fits the hole shown in the lever Q, illustrated in Fig. 69; the catch R engages and discngages
G (by operating the latch S) with the teeth of the ratchet shown in Fig. 68: To the eve shown
at T a chain is attached, the lower end of the chain being fast to the hinge-bar M, in Fig. 63, so that,
by operating the lever Q, the bar ill may be raised to the requisite height and detained“ there by the
catch R engaging with the ratchet.
We now come to the cutting-device, which consists essentially of a bar of iron, to which are fixed
the cutting-knives, and which is termed the scythe; a bar to which are fixed the stationary cutters,
and which is termed the finger-bar; a mechanical device at each end whereby to regulate the height
of the scythe from the ground, and means of permitting the scythe to lay in a plane parallel with the
surface of the ground. ~
In Fig. 70 is shown the scythe, the eye at A being that to which the rod If in Fig. 63 is attached,
so as to impart the reciprocating motion ; and in Fig. -0 k
71 (foreground) is shown the finger-bar, formed of ‘ '
a series of fingers attached to a bar. These fingers A / I /
serve a fourfold purpose. They are stationary, tand Q o A o b \o [0/—
have a slot which forms a guide, wherein the scythe rcciprocates, and is thus maintained in proper posi-
tion; the finger-points passing in advance of the knives into the herbage hold the same while it is be-
ing cut, and they act as guards to protect the knives from becoming damaged by contact with stones
or other foreign substances, while at the same time they hold the lower or stationary knives.
The finger-bar and the scythe are held at each end by castings termed shoes, of which the one nearest
the bar 111, in Fig. 63, is called the inside, and the one at the other end the outside shoe. To these
shoes are attached the devices which, when adjusted, keep the guard-fingers the desired height from

2
18 AGRICULTURAL MACHINERY.

the ground. This is accomplished on the inside shoe of the wheel IV, shown in Fig. 63, which is ad-
]ustable for vertical height in a slot provided in the shoe. By raising the wheel Wthe vertical
71.
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._ _. V v v > , <,_/~ I
(fr / ,/_/_,_
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11


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height between the bottom of that wheel which runs upon the ground, and the guard-fingers, is dimin-
ished, and vice versa. The same result is attained on the outside shoe by adjusting the height of the
foot of the same from the finger-bar.
In the outside shoes are also carried the track-clearers shown in Fie'. '71, at the end of the bar.
These cause the herbage, when mown, to fall clear of that uncut, thus leaving a clear space between the
two. In addition, however, the inside shoe performs another and an important duty, as follows : The
cutting-device requires to cant or tilt to suit the conformation of the land beneath the guard~fingers,
and it follows that the connection between this device and the bar must be such that while the former
can follow the above conformation it can yet be lifted bodily to pass an obstruction. These two ends
are attained as shown in Fig. 7 2, in which A is a section of the shoe, Bis the end of the finger-bar
72 attached to the shoe, it! is an edge-view of
‘ the bar M shown in Fig. 63, C' is the chain
A to raise the same, and G is 2. lug or gag.
Now, the distance allowed between the top
of the gag G and the underneath face of
the bar .M is sufficient to permit the finger-
bar to lie at any angle necessarv to suit the
slope of the land ; but when it is intended
to raise the same to pass an obstruction,‘
the following action takes place : The
weight of the cutter-bar is in the direction
of the arrow D ; hence, when the bar M is
raised (in the direction of the arrow E) by
the chain 0, the outside shoe remains upon
the ground until the top of the gag G con-
tacts with the face of the bar ill, whereupon the whole cutting-device raises up to a height deter-
mined by the distance the lever Mr is moved.
The cutting-device or mowing-part of the machine is shown in Fig. 71. The scytheknives operate
laterally on the finger-guards and above the lower knives. A cutting-edge is given to the knives held
in the fingers by beveling off the bottom-face edge, while the cutting-edge for the upper or scythe
knives is formed by beveling off the top face at the edges. For cutting grass or other green herb-
age, the edges of the knives are plain, but for cutting grain the knives are given a sickle-edge—that
is to say, the beveled face of the knife is serrated to form fine teeth. The sickle-edged knife will
not serve for grass-mowing, but is preferred for grain, because it retains its cutting-edge without grind~
ing, thus saving that labor. ‘
When, however, .the grain is to be cut sufficiently near the ground that the knives come into con-
tact with weeds or other green herbage, plain knives must be used, as sickle-knives would become
clogged. The cutting angle for scythe sections or knives is about 60°, and for sickle-edges about 40°
The variations in the construction of all mowing-machines consist of mechanical devices and move-


AGRICULTURAL MACHINERY. 1 9

ments, designed to effect the objects herein described. In the machine here illustrated, the mowing
is performed in front of the driving-wheels A A, while in others it is performed in a line with the
axle B, and in yet others still farther to the rear of the side. In some cases, also, the frame N N,
Fig. 63, is made to adjust out of the line of draught, so that the points of the finger-guards may depress
toward or cant from the surface of the sward. In all mowing-machines the cutting-device is either
made to lift and stand vertical, or else to fold over to the frame of the mower, in order to be out of
the way during transportation from place to place.
73.


In Fig. 73 is shown Wm. Anson \Vood’s mower, in which an internal gear-wheel provided upon the
main wheel, drives the cutter-bar. ’
Reapers or harvesting-machines are used for cutting grain-crops. They either deliver the 0'rain to
one side in gavels ready to bind into sheaves, or elevate the gavels upon a platform where tw?) opera-
tors bind them into sheaves by hand. An attachment is often provided whereby the machine suc-
cessfully performs the binding of the sheaves automatically with wire before delivering them.
The essential parts of a reaper are: the cutting arrangement, similar in design to that of mowing-
machmes (except that in many cases sickle-knives in place of plain knives are used); sweep or tabIe
rakes to convey the grain to and from the machine; and mechanical means to regulate the delivery of
the gavels, so that the size of the same shall be sufficient for binding even in spots or places upon the
land where the crop is very light. Many of these machines are constructed so that the various devices
for raking, sweepmg, gathering, or delivering, may be detached, leaving the machine a simple mower.
IThe term “ Harvester” originated in the \Vestern States, and was applied to distinguish machines
which bound the grain from those which simply delivered it in gavels. In Figs. 74 aid 7 5 is shown
the Champlon mower and reaper, with the names of the various parts marked thereon. The reapinir
part of the machine consists of the device above the large shoe, which is for operating the rake-arm?
and the wooden framework, and its attachments whereon and whereby the grain is gathered and de-
livered 1n gavels. rIthe chain-wheel is fast to the upright spindle, to which the rake-arms are pivoted
or hinged, and 1s drlven by a chain passing around another chain-wheel attached to the main axle
74.


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20 AGRICULTURAL MACHINERY.

of the machine. To the rake-arms are attached rollers running upon an inclined pathway termed a
cam. The plane of this pathway is arranged so as to lower the rake-arm to, and lift it from, the
75.




Q
as o 0 0 oaw'
SEAT smm m“... ' '
RATCHET —
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9 F5
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table, to rake the grain on to and off from the table—the rake—guide being provided to prevent the
rake from contact with the finger-bar.
The rakearms may be permitted to sweep a gavel of grain from the table at each descent, or may
be made to carry the grain on to the table, and allow it to remain there until sufficient is accumulated
to form a gavel, when the rake may be allowed to sweep it off. The arrangement by means of which
this is accomplished is the switch shown in Fig. 75, operated by means of the treadle-crank and trip-
chain shown in F ig. 74. The sw.tch acts to raise the roller-path, lifting the rake-arm and rake before
it has time to rake the gavel from the table. When, howevcr,.suffieicnt grain has accumulated to




76.
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“'14 --~ 5 he» // M/MMZ/Z/l/UUUUUUL
form a proper-sized gavel, the switch moves out of the way, and the rake sweeps the gavel from the
table ; and in this manner the size of the delivered gavel can be regulated by the operator.
/ '-
.4-
AGRICULTURAL MACHINERY. 21

Mr. John Coleman, an English judge at the Centennial Exhibition, says, referring to this class of
machines, in his report to the English Government: “A word or two as to table-rakes may not be out
of place, seeing that this form of reaper is unknown in England. The ordinary sweep-rake is replaced
by a jointed rake, which travels in a given orbit on the table or platform, being driven by universal-
joint-and-bevel gearings, the direction of travel being regulated by a cam screened from the grain by
a shield. The advantages claimed for this invention are reduction of draught and superior form of the
grain for binding. The rake, when uncontrolled, works continuously but can be arrested at any
point by a leverage from the driver’s feet. This is a desirable feature, allowing of uniform sheaves
for a variable crop. The disadvantages appear to be that, as the rake compresses at the corner of
the table, there is some risk of shedding when over-ripe; also, that the compact nature of the sheaf
interferes with the drying influence of sun and wind, so important when grain is cut in a green con-
dition; and, lastly, the table-rake is not suitable for very heavy crops, especially if the straw is long.”
In Fig. ’76 is shown the Buckeye mower and reaper, with dropping attachment. In machines of
this class a revolving reel instead of sweep-rakes is employed, and the gavels are dropped in the rear
of the machine. The duty of the reel is to press the grain to the knives, and hold it while being cut
by the scythe. The dropper, as the slotted frame behind the cutter-bar is called, is raised at an angle
to collect the grain, and is lowered by hand to deposit the gavel.
The Walter A. Wood binder makes a bundle or sheaf to every ten feet, if allowed to work auto-
matically. The binder can be removed from the machine, and the grain bound by hand upon tables
77.

|i












attached for the purpose. The amount of duty claimed for :1 Walter A. Wood harvester with bindin!r
attachment is, with fair grain on fair ground, from ten to fifteen acres per dav. a
In Figs. 77 and 78 is shown the ‘
McCormick harvester with self-bind- Ts.
ing attachment, the latter showing the
binding attachment detached.
The details of the McCormick sheaf- '
binder are represented in Figs. 79-86.
The binding apparatus is fixed at
the side of the reaping machinery.
The grain as cut is delivered by an
endless band to the elevators, shown
in Fig. '79, by which it is raised and
delivered under the guard on to the
platform. Fig. '7 9 also shows the
general form of the binding-arms
and their position before inclosing a
sheaf. The standard carrying the
binding-arm has a reciprocating move-
ment imparted to it, by which it is
moved from the position shown in
Fig. 79 to the various other positions
shown successively in Figs. 80, 81, 82,
etc. To put the machine into work, the
wire from the upper spool is thread-
ed into the main arm, as shown, and
Jomted to the wire from.the lower spool brought up from under the twister, as shown in the upper
part of 85. The mam arm may now be supposed to have moved to the position shown in Fig.
81, and is about to descend through the slot in the platform, and to take the position shown in Fig.
82, at which posxtion the thumb I—seen also in other figures—has moved and passed the other part






22 AGRICULTURAL MACHINERY.

of the wire, or that from the upper spool, in between the teeth of the twister, so that the two parts
of the Wire are between opposite teeth in the twister. The standard now begins to return to the
79.
Old CRAM SHOUINC POSITION 0P
ARMS BEFURE ENCLOSIMB CORN


80.
DIACIAII INJUIMO POSITION
0P ARMS AFIIR GUIDING Ill”






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BUNDLE ENCLWED
PWMING TO nws'r
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CUTTING THE WIRE
MAINTAIN A CDNYINUO
U. Wlflfi H'TEH EOMPU‘TINQ Tlll' TWIST
position shown in Fig. 79, and in its rectilinear movement the teeth of two wheels shown in Fig.
86 engage in a rack by which they are revolved, and in their revolution they move the two steel
wheels which form the twister and the cutter, a difierential movement being given to them by the
difference in the number of teeth in the main wheels, so that the twister-teeth gradually overlap after
several revolutions by one revolution of the main wheels. As seen in Fig. 82, the sheaf is inclosed,
both parts of the wire are in the twister-teeth, and the latter now begin to revolve.
Fig. 83 shows the position after the first twist, and Fig. 84 shows the twist completed, and the
wire cut off, the wheels having assumed the position shown in Fig. 86, and the standard having
nearly returned to the position of Fig. 79. Fig. 80 shows the position of both arms after the sheaf
is bound, but before it is released. Each successive sheaf passes the last one off the platform.
Now, it will have been seen that the wire has been joined by twisting both above and below the
twister, so that, though out off in one place, the wire is by the join continuous from lower to upper
spool, as seen in Fig. 84. When the arm begins to rise again, the lower wire, as seen in Fi". 79, is
pulled to the position seen in the lower part of Fig. 85, and as the arm still rises, the wire is
pulled in between the twister-teeth, as shown by the light-dotted lines. Now it becomes necessary
to get the wire to the position shown in the dark-dotted lines, or to that shown in Fig. 81, and to
efiect this the twister-wheels receive a half-revolution, obtained by the meeting of a projecting arm
and two studs on the main cog-wheels, during the latter part of the return-movement of the stand-
ard, which it will be seen carries all this mechanism. The projecting arm thus gives the wheels '3.
push farther round. The wire is now in the position shown in Figs. '79, 81, and 85, and the whole
is ready to recommence the binding operation.
AGRICULTURAL MACHINERY. 23

The following is a summary of the dynamomcter tests of sheaf-binders made at the Royal Agri-
cultural Society in August, 187 7 :




Name of Exhibitor in Order of Trial.
0. H. McCormick. Walter A. Wood. D. M. Osborne 6: Co. Averages.
l . . .
Width of cut, with buy .................. .. 581,11- ~29 tn- 52,22,131. ,
“ against lay . . . . . . . . . . . . . . . .. 52 m. 113' . _ ,- y
“ average . . . . . . . . . . . . . . . . . . . . . ' 552 in-
m. 55; m-
Height of stubble . . . . . . . . . . . . . . . . .1 . . . . . . . $5111 1651'?)- 3‘511115 ,
Side-draught, with lay . . . . . . . . . . . . . . . . . . . . . , ‘3') lb- - 3_ 5- l
“ against lay . . . . . . . . . . . . . . . . . .. I 25 lb- 25,11» - '83 :
Mean draught (in lbs.). with lay. . . . . . . .. . . g 464 408 210
“ against lay . . . . . . . . . . . . . . . . . . ‘ 471 460 2
“ average . . . . . . . . . . . . . . . . . . . . . 467 -5 464 45-1 461
Mean draught (in lbs), per inch width of cut, z, 8 ]b_ 93 _6 1b, 8.85 lb_ 5
with lay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,
Mean draught (in lbs), per inch width of cut, { 9_06 1b_ 7_ 54 1b_ 635 "l
again lay . . . . . . . . . . . . . ._ . . . . .._ . . . . . . . . . . ,
Mean draught (in lbs.), per inch Width of cut, 8.53 lb_ 8‘ 45 lb. 7.8 lb. 8. 26 :
average . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ ,
d~ m'les er hour . . . . . . . . . . . . .. . 3-10 3-00 3-22 3.12
asserts...'-£ .................. .. l m... i... 1 l '
No. of sheaves cut . . . . . . . . . . . . . . . . . . . . . . . .. 17 21 16 [34 ..- - 250 ,
Total weight of sheaves ............... .. 2w lb. 3‘1 lb. $73 i423 .
.. 1' .9
Mean weight of each sheaf . . . . . . . . . . . . . . . . . l 10.6 17.7 10$}12A ,
Foot- ounds of work per lb. of corn cut, or a
height to which corn must be raised to rep- P 423.5 420.7 468 l
resent work done in cutting and binding it. 1



Lawn-Mowers.—The use of these machines is indicated by the name. The essential parts of the
apparatus, a representative of which is shown in Fig. 87, consist in the wheels and frame, the rotary
cutters, and a stationary knife below, and multiplying gearing for transmitting motion from the
wheels to the cutters. The construction is such that, when the machine travels in one direction, the
87.




cutters are operated, and when moved in the other they are not. The machine is made in various
sizes to adapt it for hand-use, or to enable it to be drawn by a horse.
Potato-Digger.—One form of this apparatus is illustrated in Fig. 88. On the under and near
side of the centre plough A is an adjustable bar of steel, having sharp-edged wings, and fastened to
this throughout its whole length, which is more than the full breadth of the furrow, are a number of
looped and branched chains, two feet or more in length, which drag on the bottom of the furrow,
breaking up and stirring the earth that falls upon and through them, and bringing the potatoes to
the surface. This chain-bar may be placed higher or lower, as may be desired. A coulter, blunt-
pointed and round-edged, is attached to the beam, and opens the bills at the right-hand side, clearing
away the bines, and placing them over to the left of the plough, which follows, turning the hills up.
The two rods B C are sufficiently high to permit the earth to pass between them, while they cause
the weeds to pass to one side. The wheels D D steady the implement, and also serve as gauge“
wheels to regulate the depth to which the plough enters the soil.
Hay~tedders are used to turn the hay as it lies on the meadow, in order to dry it preparatory to
stacking. In the tedder illustrated in Fig. 89 the main wheels contain a gear-wheel driving, through
the medium of pinions, cranked shafts carrying forks. Each fork is connected at its centre and at
its end to a crank upon the upper, and one upon the lower, shaft. The upper shaft is operated by
gears connected with the lower one. The whole framework carrying the forks and gearing swings
upon the bearing, supporting it on the axle. The draught-frame is secured to the latter by separate
24 AGRICULTURAL MACHINERY.

bearings ; hence .to alter the distance at which the forks approach the surface it is necessary only to
change the posmon of the fork-carrying frame with relation to the draught-frame. This is accom-


plished by the lever shown above the driver’s seat. The motion of the forks is closely similar to
that performed by hand in tossing the hay. English machines usually have two separately-rotating
90.




57,1/‘1‘94


21%
‘ s
frames carrying forks, each fork occupying
one-half of the width between the wheels.
The direction of motion of the forks may
be reversed, so that, after the hay has been
strewed in the usual way, it may be thrown
backward. A machine of this class is shown
in Fig. 90.
Fig. 91 represents an American hay-ted-
der having revolvinrr forks. The fork-shaft
is revolved by mu tiplying gear from the
wheel-axle. It is furnished with sixteen
forks, attached to a light reel in such a man-
ner that they revolve rapidly, with a rotary,
continuous, and uniform motion. It never
clogs, may be easily backed, and readily
passes over ordinary obstructions, without any attention on the part of the driver.
Hay-tedders should be used on the meadow about three times a day, which will enable the farmer
\
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_\\§/'=" M ‘
Y
Q
\
v


AGRICULTURAL MACHINERY. 25

to cut his crop in the morning, and draw it in the same day; giving him, also, more uniformly dried
and better hay.
Horse hay-rakes gather the hay preparatory to its removal from the meadows. That repre-
sented in Fig. 92 may be used without lifting the rake or stopping the horse. It has a double row
of teeth, pointing each way, which are brought alternately into use as the rake makes a semi-revolu-
tion at each forming windrow, in its onward progress. They are kept fiat upon the ground by the
pressure of the square frame on their points, beneath the handles; but, as soon as a load of bay
has collected, the handles are slightly raised, throwingr this frame backward off the points, and rais-
ing them enough for the forward row to catch the earth. The continued motion of the horse causes
the teeth to rise and revolve, throwing the backward teeth forembst, over the windrow. In this
way each set of teeth is alternately brought into operation.
An improved form of rake is represented in Fig. 93. It is arranged with a sulky, so that the
operator can ride. The spring-teeth gather the hay and retain it until the driver, by pulling the
vertical lever, lifts the teeth and discharges it. The horizontal bars projecting through the teeth
keep the hay from rising with them, thus insuring its complete discharge. Fig. 94 shows another
form of spring-tooth rake, the teeth of which are made of stiff, elastic wire, on the points of which




the rake runs; they bend in passing an obstruction, and spring back into their place again. The
rake is unloaded by simply lifting by the lower handles, the upper ones being intended for holding
and guiding; the rake is light, and about one-half the weight sustained by the horse.
Hay—sweeps are essentially large, stout, coarse rakes, with teeth projecting both ways, like those
of a common revolver; a horse is attached to each end, and a boy rides each horse. A horse passes
along each side of the windrow, and the two thus draw this rake after them, scooping up the hay as
they go. When 500 lbs. or more are collected, they draw it at once to the stack or barn, and the
horses turning about at each end, causing the gates to make half a circle, draw the teeth backward



from the heap of “hay, and go empty for another load—the teeth on opposite sides being thus used
alternately. In 1* 1g. 95 the apparatus is shown separate, and in Fig. 96 in operation.


l
ifélki» ‘
26 AGRICULTURAL MACHINERY.

Hayloade'np machines lift the hay upon vehicles. The Douglas machine, shown in Fig. 97, consists
of a frame lunged to the rear of the wagon, and suspended by chains, by which it can be raised and
lowered at will. Upon the hinged frame stands an upright frame, carrying rollers at its top and bot-
tom. Around the rollers pass leather belts, armed with steel spurs, which pick up the hay as the
wagon passes over it. The lower rollers are rotated by chain-gear from the rear axle of the wagon.
Horse hay-forks are also used to facilitate the loading and unloading of hay. Fig. 98 shows Glad-
ding’s fork, in which a hinge-joint is placed at the connection of the head and handle, so that at any
moment, by a jerk on the cord which passes through a bore in the handle, the fork is dropped, and
the load allowed to fall on the stack or wagon, as shown in the lower figure. Another form of fork
adapted for lifting hay into barn-win-
dows, etc., is represented in Fig. 99, in
which the mode of operation is plainly
shown.
A double hay-fork is represented in
Fig. 100, and another in Fig. 101, which
consists of two three-pronged forks con-
nected by a hinge. Fig. 102 shows a
simple clamp for attaching this fork to
a beam. It is raised and lowered by the
double ropes passing over two fixed pul-
leys and the one on the elevator—the
horse moving twice as fast as the load is
raised.
For pitching hay, or any material
which hangs well together, harpoon-
forks work most rapidly, but they are obviously not suited for short straw.
Walker’s harpoon is a straight bar of metal, appearing almost as simple as a crowbar (Fig 103).
Its point is driven into the hay as far as desired, when a movement at the handle is made, which
turns up the point at right an-
101- gles (Fig. 104), enabling it to
lift a large quantity of hay.
A modification has spurs,
which are thrown out on op-
posite sides. The combined
fork and knife invented by
Kniifcn and Harrington is an
excellent hay-knife when fold-
ed, as shown in Fig. 106, and
an efficient elevator when
opened, as shown in Fig. 105.
At a trial in Auburn, New
York, this fork discharged a
load of hay weighing 2,300
pounds, over a beam, in two
minutes.
Fig. 107 represents a hay-
stacker, which first elevates
the hay, and then swings it
around over the stack, dropping it where desired. The horizontal motion of the
crane is effected as follows: Two ropes are attached to the whippletree; one, a
strong one, to elevate the hay, running on the pulleys at B, C, and D ,' and the
other, a smaller one, passing the swivel-pulley at A, on the end of the lever B, ex~
tending from the foot of the upright shaft. This cord then passes up and over a
pulley above the weight E. The weight is about four pounds, and is attached to
the end of the smaller cord. At the same time that the horse, in drawing, ele-
vates the fork with its load of hay, the weight E is raised until it strikes the pulley, when the power
of the horse becomes applied to the end of the level B, causing it to revolve, and swing the hay over
the stack. As the horse backs, the weight drops again to the ground, taking up the slack rope
from under the horse’s feet, and the weight of the fork causes the arm of the derrick to revolve
back over the load. The intended height for raising the hay, before swinging, is regulated by
lengthening or shortening the smaller cord, as the arm will not revolve until the weight strikes the
pulley under the head-block.
5. Implements for preparing Crops.
Tiaras/ting~Maclzine.—-Thrashing and cleaning machine. Threshing and separating machine.
Threshing and winnowing machine. All the above terms are applied to the same class of implement.
The operation of simply thrashing is rarely resorted to, since the additional parts necessary to perform
the winnowing add but very little to the cost, while increasing vastly the utility of the machine. The
term cleaning, as applied to thrashing machines, is synonymous with the term winnowing. The term
separating, however, is applied to such processes as separate the grain from the straw, and all such
other purifying and assorting as cannot be performed by the simplest process of winnowing. Hence
processes which separate the grain into divisions of equal gravity are separating processes, while
those intended simply to remove matter foreign to the grain itself are termed cleaning processes.
The first and simplest processes of cleaning and separating only are performed in the thrashing





AGRICULTURAL MACHINERY. 27

,__
machine—the further cleaning, polishing, and separating processes being done by the miller. See
MILLS.
104. 103. 105. 106.











_ __.i
i623?"
%


In Fig. 108 is represented a sectional view of an excellent thrashing and cleaning machine, the de-
sign of Minard Harder, of Cobleskill, New York. In this machine the grain is fed into the machine as
denoted by the arrow marked 1, the thrashing operation being performed conjointly by the roller A
and the concave; thence it passes to the separator O, which allows the loose grain to fall through, while
the straw passes along, finding exit as denoted by the arrow 2. The grain and chaff passing through the
108.









z.:.;.:.:.:.;,r;.:.:.;.:.:.;.;.:.:.:.:.:.


separator fall into a trough and thence to three sieves marked respectively D, E, and F. G is a re-
volvmg fan which forces a current of air between the sieves, the grain falling through while the chaff
and dust are carried away with the air-current produced by the fan. The revolving cylinder A is pro-
28 AGRICULTURAL MACHINERY.

vided with a series of spikes arranged spirally in rows around its circumference. The concave is a
bar standing parallel with the axis of the cylinder A, and contains stationary spikes, and in the pas-
sage of the straw through these spikes the thrashing is performed. The spikes beat the grain-ears,
loosening the grain therefrom. The rotary motion of the cylinder A throws the grain and straw to
the separator O, and to maintain an even feed of the same to the separator the beater H is provided,
consisting of a revolving shaft carrying three wings. This serves also to prevent the grain-straw from
being thrown by the cylinder A too far forward upon the separator G. In the rear of the beater or
feeder, and equalizer, as it may be more properly termed, is hinged a light board marked J, whose
duty is to force the straw lightly down, and prevent its being thrown too far forward by the beater.
The separating device is shown in Fig. 109, in which K K K K K are perforated boards between
each of which are situated the blades 0. These perforated boards and the blades are operated recipro-
cally, the motion of the boards being in a direction opposite to that of the blades c ,' the motions are
slightly vertical as well as lateral, so that during the reciprocating movement the blades rise and fall
through the separator-boards. When the motion of the blades is toward the arrow 2, in Fig. 108, the
blades lift, thus carrying the straw toward that end of the machine. The blades 1 are not level
upon their upper edges, but are serrated with teeth similar to saw-teeth, the front of the teeth facing
the rear of the machine so as to hold the straw on the one stroke, and allow it to pass over the slop-
ing back of the teeth during the backward motion. In addition to this, the upper edge of the blades
has a wave-like form, and the highest part of one blade is opposite laterally to the lowest part of the
next one, so that they impart to the straw a combined zigzag, vertical, and horizontal movement tow-
ard the arrow marked 2, affording ample disturbance to the straw to insure the falling of the grain
therefrom. The double crank denoted by L is employed to operate the rod .41, which is attached to the
separator, and also the rod N attached to the trough O. The separator and the trough are suspended
by links. By suitable construction, while a reciprocating mbvement is given to the separator in nearly
an horizontal plane, the blades are made to receive, in addition to this horizontal movement, simultane-
ously with the separator, a vertical movement (up and down) at nearly right angles in relation to the
separator. The grain after falling through the separator to the reciprocating trough O traverses by
reason of the motion of the trough and its own gravity to the end P, and thence falls to the delivery-
board Q. Upon the end of the board Q is a row of forks f, whose duty is to prevent foreign sub-
stances from falling in a body upon the first sieve D, which is termed the chaffing-sieve. The middle
sieve E carries the operation of cleaning still further. The sieveD is coarsest, and has its square
meshes of the same size for all kinds of grain, while the mesh of the middle sieve is varied in the
size and shape of its mesh to suit the grain. For buckwheat and barley a square mesh, and for
wheat, rye, and oats, a mesh longer than it is wide, are employed. The lower screen F has more slant-
than the others, in order to separate seeds and small grain. The cleaned grain falls from the sieves
into the grain-spout, and the screenings into the screening-drawer at V, while the chaff and dust pass
out with the air-current as shown by the arrow 3. The capacity of this machine, as determined by a
test in Auburn, New York, in 1866, is 250 bundles of wheat-straw, producing 11 bushels of very
clean wheat, thrashed in 40 minutes.
In Figs. 110 and 111 are represented an English thrashing-machine. Fig. 110 is a side elevation,
showing the framing, stiffened around the edges, and at intervals in the length, by plates. It also
110.


shows the arrangement of the pulleys for drivingr the drum, shakers, fan, etc. The other view is of
a longitudinal section through the centre of the machine, and shows clearly the arrangement of drum,
shakers, shoes, barley-awners, and fan. The engravings explaln‘the arrangement of the machine
thoroughly, and we need not, therefore, attempt any detailed description, but confing ourselves to the
special features of this machine, other than the iron framework mentmned above. fhe drum~spmdle _
is of. steel, and the rings placed upon it are slotted out, as shown 1n Fig. 111, to receive a number of
iron bars, to which the beater-plates are attached, this arrangement bemgfound preferable to intro-
ducing wood beneath the heaters. The concave at the back of the drum is entirelyof wrought-iron.
AGRICULTURAL MACHINERY. 29

The shakers consist of four boxes, the straw~platforms being arranged as shown. They are actuated
by two crank-shafts, one at each end, connected with the shakers by brackets. The cranks are pro~_
vided with long bearings, and a collar at each end, over which the top bearing-block overlaps, to keep
out the dirt. The reciprocating dressingshoes are hung on spring rods, as shown, and are worked by
a crank-shaft similar to those for the shakers. The whole of the blast employed in the machine is
taken from one fan, shown in Fig. 111, one part being taken under the riddle of the main dressing~
shoe, and the other thrown upward to act on the corn as it passes from the cleaner to the screen.
111.


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The elevators are entirely within the machine, and lift the grain from the reservoir. It will be noted.
that the main difference between the English and American machines consists in that, in the former,
revolving flails are employed instead of a spiked roller and concave. In England, however, the straw
is used for thatching barns and stacks, so that it is desirable that it should leave the machine un-
broken. This object is better served with the revolving flails than with the spiked rollers.
Figs. 112 to 114 represent Ber-dsell’s improved machine for thrashing and hulling clover. The


62
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thrashing-cylinder D has four rows of wedge-shaped teeth set spirally on its surface, as shown in Fig.
112, which take the clover-stalks from the seed-board A, and carry them up as indicated by the arrow
113.
C23:


CID
under the concave I, which is provided with three rows of teeth. As the teeth in the concave are
only half as far apart as the teeth in the cylinder, the latter are so arranged as to pass alternately
through the spaces between' the teeth in the concave.
30 AGRICULTURAL MACHINERY.

The vibrating-board E conducts the thrashed clover on to the upper bolt B, which is made of thin
boards, perforated with holes one and one-eighth inch in diameter; and in the same frame is a screen











114.
I '37-'37"? .‘I?..~r.'.'_?'~::
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/ I
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B', with holes three-fourths of an inch in diameter. When the screen moves toward the thrashing-
cylinder, it descends and slips forward under the straw, and rises as it moves back, carrying the straw






















from the thrashing-cylinder, and itipasses ofi at the end of the screen, while the bolls and seed pass
through the screen on the table T. A belt of slats, b b, carries the bolls and seed off of the table
AGRIOULTURAL MACHINERY. ' 31

,._..—
T on to the inclined feed-board P, which conducts them on to the hulling-cylinder L. The shaft of
this cylinder may be provided with a pulley or gear to turn it and operate the machine, as the pulley
1 on this shaft is connected by belt to pulley 2 on the thrashing-cylinder. The cylinder L is covered with
iron roughened like a rasp, and case-hardened. It is provided with a concave of iron, having a rasp-
surfacc similar to that of the cylinder L, and the bolls and seed fed to the cylinder off the board 1’
are carried up as indicated by the arrow, and over between the cylinder and concave which separates
the bolls from the seed, both falling to the board M '. They are then carried by the belt of slats, b b,
to the screens of woven wire Q Q, to the shoe 0, which screens and separates the hulls from the
seed, the latter passing through the screens, while the bulls pass 01f at the end of the screen.
The case F’ around the fan compels the blast to pass between the end of the board M and the
screen, so as to pass among the seed; and the blast also passes between the screens and under the
lower screen, thus mingling with the falling seed. The screens B traverse so fast that they slip forward
under the straw as they descend, and, as they rise and move back, they lift the straw and carry it
back. This operation being continued, the straw passes off at the rear end of the screens.
A bran-separator is illustrated in Figs. 115 to 117. Fig. 115 is a sectional view, and Fig. 117 a sec-
tional plan, with the top parts removed, in order more plainly to show the parts represented in Fig.
116. A is the shaft: .3, the cylinder; (1', the inner revolving shell; and I), the outer or stationary
shell. The cylinder is made by framing staves of the form and in the position represented at 1, 2,
3, etc., Fig. 117, into corresponding cast-heads; the staves thus forming the longitudinal and work-
ing surface, and which may be covered with any kind of material that will make it rough and durable.
Air is let into the cylinder at the lower end, through holes around the centre, and spaces between the
staves emit it to carry the flour and other stuffs through the several qualities of wire-cloth with which
the inner surface of the revolving shell is covered. The cylinder is driven by a belt and pulleys, as
is represented at the bottom of Fig. 116. The inner surface of the revolving shell is covered with
the above-named wire-cloth. Thus, the space between the top and the beveled dividing ring E, Fig.
116, is covered with a quality that will let through little else but pure flour, which falls, and by the
dividing ring is conducted into an endless trough I, attached to the inner and sheet-iron or zinc-lined
surface of the stationary shell, and by the sweepers F,
attached to the revolving shell, is brought around and
discharged at the spout G. The space between the di-
viding rings E and H is covered with a quality that will
discharge an inferior quality to the above, which falls, as
above, into the endless trough J, and by the sweepers K
is. brought around and discharged at the spout L. The
space between the dividing rings H and 11! is covered
with a quality that will take out the fine particles of the
bran, called dusting, which falls, as above, into the end-
less trough N, and by the sweepers O is discharged at
the spout P. The space between the dividing ring ill
and the .bottom is covered with a quality that will sepa-
rate the shorts from the bran, the shorts falling to the
bottom, or into the endless trough R, and by the sweepers
S is discharged at the spout T, the bran passing down
the inside of the revolving shell, and by the arms U of
its east-head is swept around to and discharged at the spout V. The revolving shell is driven by a
combination of gear-wheels. o '
Fanning-mills or winnowing-machines clean eoifce, grain, etc., from chaff, dirt, and other light impuri-


119.
. ' 7
...,.__ _‘; W. :4.-










ties The apparatus shown in Fig 118 is designed for hand use Multi ' ~ '
_ \ . . . g - . . pl_vm_n “car 1s laced be-
tween the crank-handle and bar shown. The sreves are vibrated by means of acraiikodiskmod) and bell-
32 AGRICULTURAL MACHINERY.

crank. The grain is fed in at the top, and passes through the sieves, the uppermost of which is coarse,
while the lower ones are of varying degrees of fineness, the object being to distribute the fanning
duty, by arresting the motion of the grain, so that the coarser impurities pass out between the up-
per and the finer ones between the lower sieves.
6. Miscellaneous Agm'wltw'al Implmnents.--Of these there is a large number variously adapted to
special uses. As a representative of a very important class, we introduce Fig. 119, which is a clz'tclwr,
designed by ex-Govcrnor Randolph, of New Jersey. In this machine the flange-wheel A cuts the
ground upon each side ready for the cutter O to slice out the soil, which is elevated and delivered
at the side of the machine at Z. The screw-gearing serves to regulate the depth, etc., of the trench.
This machine has dug a ditch 1,000 feet long, 2 feet deep, and 6 inches wide, in one hour, the soil
being heavy muck and blue clay.
122.













Feed-cutters are employed to cut feed for cattle. Fig. 120 is an apparatus having a simple lever
carrying a knife. To the end of the trough is attached a stationary blade. The fodder is fed through
the trough by hand between the knives. Fig. 121 shows a geared stalk and straw cutter, having
self-feeding spiked rollers. It has two revolving knives and a fixed knife. The apparatus shown in
Fig. 122 has spiral knives, above which is a roller composed of disks of raw-hide closely compressed
upon a mandrel. 3etween the roller and knives the material passes. Fig. 123 represents a machine
124.
Q



ll;






3;.-
illllllh‘
M”;-
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,
for mixing corn and cobs for feed. It is driven by power, the operation being performed by the _re-
volving hooked teeth. The speed should be about 600 revolutions per minute. Fig. 124 1s a machine
AIR-COMPRESSORS. 33

. for cutting vegetables for fodder. The cutting-wheel is made of cast-iron, through which are inserted
three knives similar to plane-irons; these out the vegetables into thin slices with great rapidity, and
the cross-knives operate to cut and break them into irregular pieces of convenient form and size for
cattle or sheep. . _
Corn-shellers remove the grain of Indian-corn or maize from the cob. The general principle fol-
lowed is that of scratching off the corn by means of short spike projections upon a cylindrical or
flat surface. The operation of the apparatus shown in Fig. 125 is evident. In the machine shown
in Fig. 126 the spiked teeth are arranged radially upon a rotating disk, the cobsbeing fed smgly, and
presented lengthwise to the face of the disk. .
05dcr-Mills.-—These usually consist of a grinding-mill and a press, for crushing apples and ex-
pressing the juice. The apples are placed in the hopper, as shown, and the pulp, after grinding, is
placed in the press (Fig. 127). _
lncubators.-—The essential elements involved in hatching eggs by artificial means are that the eggs
shall be kept for 21 days at a temperature of about 102° Fahr., and that in no case shall that tem-
perature fall below 100° or rise above 106°, while the eggs should be carefully turned over once in
every 24 hours. '









' \\,',\



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(2‘

H“
In Fig. 128 is shown a simple form of this apparatus known as Corbett’s incubator, which con-
sists of a cylindrical wooden box, in which are placed two sieves containing the eggs. During the
process of hatching, the box is buried to its upper edge in horse-manure, which must, however, be the
product of grain-fed (not grass-fed) horses, and must not be over two months old. The ventilator
shown at the top is opened to reduce the temperature as desired. After the eggs are hatched the
chicks are removed to what is termed the “artificial mother,” shown in Fig. 129. This is a box
exactly the same as the incubator, but provided with an horizontal disk, covered on the underside with
a piece of sheep-skin from a long-wool sheep, and arranged to be moved up and down by a screw.
The manure is heaped partly around the box, to provide the needed warmth; the door is let down for
a pathway in and out for the chicks (see Fig. 129), and in this they are placed as soon as ready to be
removed from the incubator. After having been fed a few times, the chicks will learn to come out
from beneath the wool to feed when the platform is tapped.
Cow-Milkm'.—An apparatus for milking cows is shown in Fig. 130. It consists of a glass receiver,
having a cover which may be closed air-tight. Through this cover extend four rubber tubes, which ter-
minate in metal tubes attached to the teats. Air is ex- 3.
hausted from the receiver by the pump shown, and the 1 0'
milk thus drawn down. The device may be suspended by
the books on a strap over the cow’s back. J. ll.
AIR—COMPRESSORS. Machines for compressing air,
which is afterward to be used in suitable engines as a
motor, or through its expansion as a means of reducing
the temperature of adjacent bodies, or as a blast for
forges, etc. The machines performing the last-men-
tioned duty are known as blowing engines and blowers.
The name “blower” is more commonly applied to re-
tary machines, either force, blast, or fan, and “blow-
ing engine” to piston apparatus. The former, having
a wide range of uses, are separately treated under BLOW-
nus. For mechanical applications of compressed air,
sec BRAKES, Oiiissoss, DIVING, Fousnarioivs, HAMMER,
LOCOMO'I‘lVE, RAILROAD, REFRIGERATING MACHINERY, and
TELEGRAPH. For theoretical considerations, see STEAM.
Apparatus for compressing air includes, first, a. mo-
tor; second, a machine wherein the air is compressed.
Compressors may be classified as follows: 1. With re-
gard to air-pressure generated. Low - pressure com-
pressors are those in which air is compressed to a




3
34 AIRFOOMPRESSORS.

pressure not‘exceeding 2 absolute atmospheres—that is to say, to less than one effective atmosphere.
.Medium-pressurc compressors are those in which the pressure attained is compressed between'2 and
4 absolute atmospheres, or between 1 and 3 effective atmospheres. High-pressure compressors are
those in which the air is compressed to between 4 and 8 absolute atmospheres—that is to say, below
2 effective atmospheres. ' Very high-pressure compressors are those in which the air is compressed to
pressures above 8 absolute atmospheres. .
2. With regard to volume furnished at a given pressure, each one of the foregoing classes may be
diVided into low-duty and high-duty machines. Each of these subdivisions may be again divided into
pisiowcompressm's, the primitive type of which is the blast-machine of blast-furnaces, in which the air
contained in a cylinder is brought to the desired pressure by means of a piston which gradually
decreases the volume of the cylinder to that which corresponds to the pressure desired ; and compres-
sors without pistons, the primitive type of which is the trompe or water~bellows of Catalan forges, and
which includes all other machines not coming under the piston-compressor class. .
In piston-compressors the piston may act on the air either directly or by the intermediary of water,
.which serves as packing. Hydraulic piston-compressors, as the last-mentioned class may be termed,
may be again divided in accordance with the means used for cooling the air and the cylinder. As
each class above mentioned will be considered in turn, for the convenience of the reader the various
groupings are reeapitulated as follows in their proper connection: ’
- I. Low-PRESSURE Conrnnssoss.
A. Low-duty ilfachincs.
B. High-duty Machines.
1. Exhaustiiig and compressing apparatus for sugar-weiks.
2. Blowing-engines for blast-furnaces, which include (a) walking-beam engines, (6) horizontal
_ engines, (0) vertical engines. ' -
3. Compressing and exhausting machines for pneumatic telegraphs.
G. Compressors without Pistons, which include-—
1. W titer-machines. 2. Steam-machines.
II. MEDIUM-PRESSURE COMPRESSORS.
A. LozL'-(Ziczfy"Macltincs.
1. Forcing-pumps, for diving apparatus.
2. Compressors for compressed-air wells.
8. Compressors for pneumatic foundations and caissons.
B. High-duty llfachincs.
131- 1. Blast-engines for Bessemer converters.
III. HIGH-PRESSURE Cournnssons.
A. Low-duty lilachincs.
1. Piston-compressors acting directly on the air to be
compressed. '
2. Hydraulic piston-compressors.
B. High-duty Machines.
1. Compressors in which there is no refrigeration.
2. Compressors in which the refrigeratory apparatus is
purely exterior, and is a water-envelope, or a jacket
in which there is water in circulation.
3. Compressors in which refrigeration is effected by
water maintained on the piston.
4. Compressors wherein refrigeration is received by
water introduced at the periphery of the compress-
ing piston.
5. Compressors wherein refrigeration is effected by in-
jection of water in the eompressory cylinder.
6. Compressors wherein refrigeration is effected by in-
jection of water in spray in the compressing cylin-
der, and by circulation of water in a jacket about
the same, and also within the piston.
’7. Hydraulic piston-compressors.
8. Impact compressors.
7..
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I IV. VERY HIGH-PRESSURE Comrniissons.
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t \\ 1. Compressors having pistons acting directly on the
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air to be compressed.
2. Hydraulic piston-compressors.
B. High-duty machines subdivided in the same manner.
I. LOW-PRESSURE COMPRESSORS. A. Low-duty Appara-
. tus.-—-'l‘his class includes hand and forge bellows; also,
forcing-pumps for supplying air to respiratory apparatus used by firemen, etc. The Fayal pump,
'Fig. 131, consists of a leather bellows, fixed between heads, in which are inlet and delivery valves.
In the centre of the bellows is a piston of wood, connected by a split connecting-rod with the crank-
\









.E OWWMEQZQOLHTQ Q Z41



AIR-COMPRESSORS. Y 35



shaft and wheel. The air is driven into a sheet-iron reservoir in the lower portion of the machine,
which communicates with the delivery-valve, and by a lateral tube with the air-conduit. This appw
ratus furnishes air under pressure of from 11.7 to 15.6 inches of water, and this excess of pressure
of from .04 to .03 atmosphere is sufficient to supply fresh air to five or six miners with their lamps
at a distance of some 300 feet from the compressor.
13. High-duly Apparatus. 1. .Machincs for Sugar-Worka—Fig. 132 represents the blowing and
exhausting machine used in the large German sugar-works for injecting carbonic acid into the
defecating apparatus. The air-cylinder is in line with the steam-cylinder, the piston-rods being
I
182.

7" I“ > fie-s ‘
c. ._l_.__!_r!.__-_--:.——v———-i.
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connected and guided as shown. The diameter of the air-piston varies according to the power
of the machine from 17.5 to 31.2 inches, the stroke generally being equal to the diameter. The
revolutions vary from 35 to 60 per minute. The valve-mechanism is clearly shown in the en-
gravmg.
2. Blast-Furnace Blowing-Engines.—(a) Walking-beam Machines. Fig. 133 shows the dispo-
sition of the machine used at Ebbw Vale, Wales. This engine, owing to its size, is probably the
most powerful of its class extant. The dimensions are as follows : Motor, diameter of steam-piston, 71.5
inches; stroke, 142.7 inches; length of walking-beam, 35 feet 7 inches; fly-wheel, diameter, 30 feet 7
inches; weight, 85 tons; air-cylinder, diameter of piston, 142.7 inches; area of same, 112 square feet
86 square inches; stroke, 142.7 inches; volume of cylinder, 1,358 cubic feet 818 cubic inches; revolutions
per minute, 16; velocity of piston per second, 6 feet 4 inches; theoretic volume generated per minute,
43,496 cubic feet; absolute pressure of blast, 1.3 atmosphere; volume of air theoretically furnished
at this pressure, 33,458 cubic feet. (6) Horizontal Machines. Fig. 134 represents the blowing-engine
at Georgs-Marien I-Iiitte, near Osnabriick. The steam-piston has two rods, one attached to the cons
necting-rod of the crank-shaft and fly-wheel,
the other communicating with the air-pump 133-
piston. The principal dimensions, etc., are
as follows: Absolute air-pressure, 1.33 at-
mosphere; volume of air furnished at this
pressure, 15,421 cubic feet. Motor: Diam-
eter of steam-piston, 4 feet 4 inches; stroke,
85 inches, cut-off at 5’; stroke. Diameter of
fly-wheel, 30 feet 4 inches. Weight, 28
tons. Normal steam pressure, 4.5 atmos-
pheres. Air-cylinder: Diameter of piston,
9 feet; stroke, 85 inches; useful volume of
cylinder, 487 cubic feet; revolutions per
minute, 21 ; theoretic volume generated per
minute, 20,516 cubic feet. As will be seen
from Fig. 135, the air-valves are disposed on
the cylinder-heads. The inlet-valves, seven
in number, are placed in three vertical lines
in the upper half of the heads, and are of
iron, with leather packing. Their mode of
support by articulated rods is clearly shown.
The total opening is .19 the piston-surface.
The delivery-valves, 16 in number, are placed
in six vertical lines, and are formed of leaves
of rubber fixed at one side. Their total
opening is .156 that of the piston-surface. The piston is hollowed. (c) Vertical Blowing-Engines.
Fig. 136 represents a type of compressor employed in many localities in Pennsylvania. The inlets
valves are placed in the extremities of the cylinders, and are provided with sprines so as to insure
their rapid closing. The delivery-valves are of leather. The cylinder is surrounded by an annular
chamber. The dimensions, etc., are as follows: Absolute air-pressure, 1.3 atmosphere. Volume of
air at the pressure, 11,804 cubic feet. Motor: Diameter of steam-piston, 43 inches; stroke, 47.1
inches; two fly-wheels of 20 feet 4 inches diameter. Air-cylinder: Diameter of piston, 83 inches;
stroke, 46.8 inches; useful volume of cylinder, 151 cubic feet; revolutions per minute, 50; volume
generated per minute, 15,345 cubic feet.







36 AIR-COMPRESSQRS,

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3. Compressors for Pneumatic Telegraphs.-—These machines are used in large citiesfor producing
the pressure or vacuum for impelling packets through underground systems of pneumatic tubes (sec











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Pneumatic Zielcgraphy, in TELEGRAPH). Fig. 137 represents the machine used in the Post-Office, L0!“
don, England. The walking-beam is connected with two compressing cylinders, also to steam-cylin-
137.




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AIR-COMPRESSORS. 37

'7
ders built on the compound system, and to the fly-wheel. The absolute pressure of the compressed
air is 1.7 atmosphere, and the corresponding volume of air furnished is 588 cubic feet when cylin-
ders are single-acting; when double-acting, twice this total. The dimensions are as follows: Motor:
Diameter of small piston, 16.7 inches ; large piston, 24.9 inches; stroke of small piston, 48.7 inches;
of large piston, 65.1 inches. Cut-off at % stroke; condensing; steam-pressure, 75 lbs. Air-cylin-
ders: Diameter of air-piston, 34.7 inches; stroke, 35.5 inches; useful volume of cylinder, 20 cubic
feet 22 cubic inches; revolutions per minute, 25; volume generated per minute, one cylinder, 998
cubic feet ; two cylinders, 1,996 cubic feet. The cylinders are made as shown in Fig. 137, so as to be
both exhausting and compressing, or either exhausting or compressing. To this end the~valves
are placed in chambers on each side of the cylinder, as shown. The inlet-valves are on the left,
the delivery-valves on the right. The two upper ones communicate with the atmosphere; the lower
pair communicate, one with the receiver to be exhausted, the other with the compressed-air reservoir.
It will readily be seen how, by suitable adjustment of these valves, the apparatus may be made to
act in the diiferent ways above described. The total valve openings aggregate air-area .0087 that of
the piston-surface.
C. Compressors without Pistons. 1. lVater-Apparatus.—Of this variety they are two types, that in
which the compression is produced only by the progressive reduction of the volume occupied by the
air in a reservoir in which water is admitted; and that in which the compression is produced by the
’ entrainment of the air by means of a liquid vein escaping under a given pressure. The first may be
termed: (1.) Simple Displacement Apparatus. Machines of this description are used in some of the
pneumatic-dispatch stations of Paris. An example is given in Fig. 138. The machine consists of a
water-reservoir 5 feet 2 inches in diameter,
12 feet 2 inches in length, and 64.7 cubic
feet in capacity, and two air-chambers, 208
cubic feet volume. One tube connects the
reservoir with the city water-mains, anoth-
er serves for emptying the reservoir, and
a third on the upper portion of the latter
communicates with the air-chambers. The
air-chambers are connected as shown, and
from one a tube leads directly to the
pneumatic conduit. If the three recep-
tacles be filled with air, and placed in
communication with one another, but shut
off from the pneumatic pipe, water enter-
ing the reservoir at a pressure of about >
35 feet drives out the air, and compresses it in the two chambers. When the reservoir is filled, the
air is reduced from a volume of 663 cubic feet to one of 416 cubic feet, and the pressure amounts to
1.59 absolute atmosphere. (2.) Entrainment Apparatus. To this class belongs the well-known
water-bellows or trompe of the Catalan forges. An improved device on the same principle has been
invented by M. Romilly, and- is illustrated in Fig. 139. This apparatus is formed of a conical tube
a, having a valve S, which prevents the air escaping from the reservoir to which the tube is attached.
Water is led in the compressing reservoir through an ajutage O, in the form of a liquid vein at a given
pressure which entrains air with it, and so effects compression of the latter in the reservoir V.
The reservoir is 282.4 cubic feet in capacity, and M. Romilly has determined that with water at 35
feet pressure a quantity of air can be introduced equal to .465 of the volume of the water employed
raising the air-pressure to 1.6 atmosphere.
2. Steam Apparatus. Injectors. (See also same general heading.)—Mr. Siemens has investigated
the application of the steam-injector to the propulsion of gases, and he has constructed an injector
which, with steam at 45 lbs. pressure, produces a vacuum of 23.7 inches of mercury. Fig. 140 is








a section of the apparatus. The injection-pipe is slightly conical in form, maintaining the conver-
gences of the concentric air and steam jets toward the axis of the tube on a length compressed be-
tween twelve and twenty times the breadth of the annular air-induction aperture. The object of this
convergence is to secure complete mingling of steam and air. Mr. Siemens has applied this apparatus
to the production of a vacuum in 21,369 feet of pneumatic-dispatch tubes in London. Three injectors
38
AIR—COMPRESSORS.

maintained in pipes of the above length and 2.9 inches in diameter a vacuum of 9.8 inches of mercury,
with steam at a pressure of 29 lbs. per square inch, and a consumption of coal of about 56 lbs. per hour.



.3 ‘
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passing through the valve into the compressor at each
The same apparatus has been used for blast in
the Siemens furnace and in sugar-works. It
cannot be practically employed as a rule to cf-
feet compressions over 25.5 inches of mercury.
3. Apparatus has been produced wherein
compressed air itself has entrained the sur-
rounding atmosphere. Experiment on this sub-
ject has not resulted in the invention of any
practicable machine based thereon.
II. MEDIUM-PRESSURE Cournrzssous. A. Low-
(Zutg/ Apparatus—1. Fig. 141 represents a com-
pressor of the Sommeiller type designed for
low duty. The piston-plunger moves in an
horizontal pump-body, while the valves are
placed in a vertical chamber connecting with
the pump-cylinder. This column is filled with
water, so that when the piston is- at the end
of its stroke the water covers the valve above.
As at each impulsion a portion of the water is
entrained by the compressed air, there is placed
around the chamber a water-jacket into which
a stream of water constantly enters, the liquid
aspiration. The dimensions, etc., are as fol-
lows: Absolute pressure of air, .5 atmosphere; volume of air furnished per minute, 278 cubic feet.
Motor of any type: Compressor single-acting;
diameter of compressing piston, 5.8 inches;
stroke, same; useful volume of cylinder, 91 cu-
bic feet; revolutions per minute, 15; theoretic
volume generated by the piston at this velocity,
1,403 cubic feet.
2.‘ Compressors for supplying Air under
Pressure in "fella—Fig. 142 is a double-acting
compressor used in sinking wells near Liege,
Belgium. It is driven by a vertical engine, as
shown. The aspiration-valves are fixed on the
upper half of each head of the air-cylinder and
open directly into the atmosphere. The com-
pressing valves open into a chamber communica-
ting with the lower section of each cylinder-
head. This chamber is connected by a tube with
the well. The following are the dimensions,
etc.: Absolute air-pressure, 3 atmospheres; vol-
g§\\\\ \\
ume of air furnished at this pressure, 12 cubic feet. Motor: Diameter of piston, 14.9 inches;
142.
R=aJJI
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stroke,
27.5 inches; normal steam-pressure,52.5 lbs. Air-cylinder: Diameter of piston, 23.6 inches; stroke,
148.
'_.‘ .e-v
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same; useful volume of cylinder, 6 cubic feet; revolutions per minute, 30; theoretic volume gene-
rated per minute,_35.5 cubic feet.
AIR-COMPRESSORS. 39

8. Compressors for Bridge-Foundationa—These are mainly employed for forcing air into bridge-
caissons. The disposition of the Gail compressor used at Kehl Bridge is the plan for Fig. 143. The rods
of the cylinders are connected. The compressing cylinder is at the base of an iron box, so that the
intermediate space between its outer periphery and the box may be filled with water. In this box also
are the aspiration and compression valves. The dimensions, etc., are as follows: Absolute air-pres-
sure,“8.5 atmospheres; volume furnished at this pressure, 60 cubic '
feet. Motor: Diameter of piston, 12.5 inches; stroke, 23.6 inches; 144,
fly-wheel, 6.5 feet in diameter; steam-pressure, 75 lbs. Compression
cylinder: Diameter of piston, 15.7 inches; stroke, 23.6 inches; use-
ful volume of cylinder, 4,561 cubic inches ; revolutions per minute,
40; theoretic volume generated per minute, 213 cubic feet.
The caissons of the East River Bridge, New York City, were sup-
plied-with compressed air by six steam-engines driving two single-
acting compressors, with cylinders 14.9 inches in diameter by 13.7
inches stroke. Sec (Lussoxs.
B. Highduty llfachines. Fmgz'ne for Bessemer Converters—Fig.
144 represents an engine of this class, employed in Pittsburg. ' The
cylinders are disposed vertically, the air-cylinder being uppermost
and inverted. Around this cylinder is a water-jacket, and the valves
are placed in, the ends, which, divided by a diametrical partition,
constitute inlet and delivery chambers. The valves are formed of
very light disks of vulcanized India-rubber, supported by disks of
brass. They move on bronze seats inserted in the cylinder-ends, and
are held thereon by spheral springs. The dimensions, etc., are as
follows: Absolute air-pressure, 2.66 atmospheres ; volume of air
furnished at this pressure, 2,389 cubic feet. Motor: Diameter of
piston, 41 inches; stroke, 47 inches. Air-cylinder: Diameter of
piston, 53.4 inches; stroke, 47 inches; useful volume of cylinder,
63.7 cubic feet; revolutions per minute, 50; theoretic volume of air
delivered per minute, 6,356 cubic feet.
III. HIGH-PRESSURE Couranssons.-Machines of this class are by
far the most numerous. Air employed as a means of transmission of power over long distances is
compressed to a pressure of from 4 to 8 atmospheres, in order to enable it to overcome friction of
pipes, etc., and to reach the apparatus of which it is the motor with eifective working energy.


145. _ 146.
































Ia\\\
A. Low-duty Apparatus.—1. Under this heading may be classed the compressors used for supply-
ing air as motive-power for rock-drills, where but small volume is required. The general construction
of the Burleigh compressor is shown in Fig. 145. There are two vertical inverted air-cylinders, the
pistons of which are moved by cranks, on a shaft which carries at one extremity the fiyavheel, and
40 ' AIR-COMPRESSORS.


at the other the crank which is connected with a direct-acting inverted engine mounted on the
same support. The delivery-valves are placed in a chamber which connects the upper parts of the
two cylinders. They are cooled by a stream of water, regulated to quantity by a suitable valve. The
machine may be said to furnish 35.3 cubic feet of air, at 4 atmospheres and at 90 revolutions per
minute. This is one of the most successful compressors for supplying power to drills yet constructed.
2. Hydraulic Piston-Compressors.—-Thc compressor used in the mines of Perscbcrg, Sweden (Fig.
146), is connected with and actuated by the pumping-engine. It consists of two vertical cylinders
connected by a cast~iron bed below,-and carrying a valve-box above. In one of the cylinders is the
piston which, surrounded by water, causes the liquid at each stroke to rise in one vessel and descend
in the other. In order to facilitate the descent of the piston, a cross-head is attached to the piston-
rod from the arms—bars extend
down on each side and below
the apparatus. These bars sus-
tain a counterweight which cqui-
librates the water in the second
cylinder. Simple flap-valves of
leather backed with metal are
employed. The inlet-valves are
counterweighted. The dimen~
sions and data are as follows:
Absolute air-pressure, 2.5 atmos-
pheres; volume of air furnished
at this pressure, 32.1 cubic feet.
Compressor (double-acting) : Di-
ameter of piston, 15.6 inches;
stroke, 85.8 inches; useful vol-
ume of cylinder, 10 cubic feet;
number of double strokes per
minute, 4; theoretic volume de-
livered at this velocity, 80 cubic
feet.
B. High-duty Apparatus.-To
this claSs belong the permanent
machines for distributing air-
pressure as motive-power to nu-
merous points. .
l. Compressors with no Re-
fi'igm-atz'on.—-When no means
of cooling is employed, compres-
sors cannot be advantageously
used except for low pressures,
and at velocities so far reduced
that the heat developed by the
compression may be dissipated
as fast as generated. It is rare-
ly that a pressure above 2 at-
mospheres can be reached, work-
ing at high speed, as dry air
compressed to this degree at
tains a temperature of 165°
Fahr.; or 3 atmospheres work-
ing at low velocity as the final
temperature of ‘air compressed
under this pressure exceeds 266°
Fahr. The Sachs compressor
(Fig. 147) is an example. In
this case the motor (at Vicillc
Montague) is an 8-horsc-p0wer
hydraulic wheel. The useful
effort applied to the compressor
is 6-liorse power, the remainder
being otherwise utilized. The
piston acts in its horizontal cylinder directly on the air. The three inlet-valves at one end of the
cylinder open into the atmosphere; the three delivery-valves in the other end open into chambers
which communicate with a cast-iron tube placed parallel to the cylinder. On this is a safety-valve
and the connection for the air-conduit. Dimensions and data: Absolute air-pressure, 3 atmos-
pheres; volume of air furnished at this pressure, 47 cubic feet. Air-cylinder. Diameter of piston,
9.7 inches ; stroke, 35.8 inches ; useful volume of cylinder, 2,730 cubic inches; revolutions per minute,
45 ; theoretic volume delivered per minute, 143 cubic feet. As compression is not carried to a high
degree, the heat generated causes no difficulty.
2. Compressors cooled by Water-Envelope—In the majority of compressors the refrigeration is
accomplished by jacketing the cylinder and causing a circulation of water in the annular space
between. Failure of this means is mostly due to the fact that the air remains dry, and in this,










AIR—COMPRESSORS. 41

condition the compression causes a development of heat which increases rapidly with the pressure.
This heat is incompletely absorbed by the water because of the high velocity with which the air
traverses the cylinder, and the consequence is that piston-packing and valves speedily deteriorate.
These machines are most advantageously employed for pressures between 3 and 4 atmospheres.
One of the most successful compressors of this class is that constructed by Mr. Sturgeon, in Eng-
land, the disposition of which is shown in Fi". 148. The air-cylinder is attached to one side of a


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hollow bed or receiver, and is worked by a steam-engine
attached to the other side through a crank-shaft carrying a
fly-wheel at each‘end. To these fiy-wheels the crank-pins are
attached at right angles to each other, so that the piston of
the steam-engine may be at the middle of its stroke and the
best point of its power, when the piston of the air-engine is
approaching the end of its stroke, where it meets the great;
est resistance from the compression of the air. The valve-
boxes of the air-cylinder (Fig. 149) serve as covers, and are
bolted to the receiver. The inlet-valves are at the centre of
the boxes. The construction is such that, as the piston begins
to recede, the rod carries the valve with it until its progress
is checked by a stop, it then being full open, and the rod, continuing its movement through the valve,
holds the latter open until the end of the stroke. On the commencement of the return-stroke the
valve is at once closed in the same manner. The delivery-valves consist of a number of small valves
distributed over the surface of the cylinder-cover or valve-box, and afiording a large area of outlet
opposite the direction of movement of the piston. The following data relate to one of these com-
pressors exhibited at the Manchester (England) Exhibition of 1874: Absolute air-pressure, 3 atmos-
pheres; volume of air furnished at this pressure, 35 cubic feet. Motor: Diameter of piston, 11.7
inches; stroke, same ; diameter of fly-whecls, 3 feet 10 inches. Compressor (double-acting): Diameter
of piston, 10.4 inches; stroke, 11.7 inches; useful volume of cylinder, 1,037 cubic inches; revolu-
tions per minute (average), Pie—these have been carried as high as 440; theoretic volume deliv-
ered per minute, 174 cubic feet.
3. Compressors refrigerated by Layer of W'ater on the Fatima—This mode of cooling is much more
efficacious than a simple outside water circulation, because the inner
periphery of the cylinder which is in contact with the heated air is kept 150'
wet, as a quantity of water passes around the piston which may be suf- q
ficient to saturate the air with watery vapor during its compression. In
this state, air may be compressed to 7.5 atmospheres without its tempera-
ture exceeding 194° Fahr. The portable compressor of MM. Saultier
and Lemonnier. a section of which is given in Fig. 150, belongs to this _ _
class. It is a small, strong machine, built of sufficiently light weight to i '- \
be carried bya mule. The cylinders, of which there are two, are open _
above. A thin stream of water passes to a circular channel in the
upper part of the cylinders, by which it is distributed around their





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inner portion to the pistons, through the inlet-valves, in which it enters '1:
into the space in which the air is compressed, so that it comes in direct I;
contact with the air. There are three valves in each cylinder: two inlets in the piston, and one delivery at the cylinder-bottom. They i

are simply bronze cups on seats of the same metal, provided with suit-
able springs, and guided by stems, dimensions, data, etc. Absolute air-
pressure, 5 atmospheres; volume of air furnished at this pressure by
both cylinders, '5 cubic feet 269 cubic inches. Motor of 10-horse power,
any form. Compressor: Diameter of pistons, 9.3 inches; stroke, 11.7 \_
inches; useful volume of cylinders, 479 cubic feet; revolutions per ,
minute, 27 ; theoretic volume delivered by the pistons at this velocity, is
26 cubic feet. “i
4. Compressors refr'igm'ated by l'Valer introduced at the Pcfipherg/ of
the Compressing 1’ist0n.—-In 1872 Messrs. Benjamin lloy 8t 00., who .\\\\\\ \
built the first air-compressing machines for the St. Gothard Tunnel,
adopted a system of construction which involved a hollow compressingr piston, receiving by its red
water under pressure which it distributed uniformly over the piston by means of a channel at the
A“


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42
AIR—COMPRESSORS.


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middle. This disposition is analogous to the water-layer on the piston in the preceding class of ma-
clnnes, but it is considered preferable because it is applicable to double-acting, to horizontal, and
to fast-runnmg compressors, since the piston is no longer formed of two independent portions, of
151.




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which one (the. liquid packing) may be disadvantageously affected by high velocities. In Fig. 151
is given a sectlon of the air-cylinder and pump of a compressor of this type, made for mining
purposes by the French Compagnie de l’Horme.
_ The piston is hollow, and has on its periphery
five channels, of WhlCh one communicates by apertures with its interior, and serves as an escape for
the water. The others receive the metal packing-rings. In rear of the piston is a hollow rod which
is screwed in the piston-rod, and which, passing through the rear cylinder-head, connects with a
pump. The latter is composed of two small barrels and a spring accumulator. The pistons consist
of two solid rods connected by a cross-piece and a sleeve to the prolonged hollow piston-rod. These
plungers pump the water from a reservoir into the accumulator chamber, whence it is forced through
the piston-rod and out through the piston, as already described. The water then escapes into a reser-






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voir, in which is an automatic valve,
which opens when a certain level is
reached, and allows the water to pass
into the receptacle, from which it is
pumped. Dimensions and data: Abso-
lute air-pressure, 6 atmospheres ; volume
of air furnished at this pressure by two
cylinders, 142 cubic feet. Motor, two
direct-acting horizontal cylinders. Di-
ameter of pistons, 19.5 inches; stroke,
31.2 inches. Variable cut-off. Conden-
sing. Fly-wheels, 11 feet 5 inches in
diameter. Two double-acting a"-com-
pressing cylinders. Diameter of pistons,
15.6 inches; stroke, 31.2 inches; useful
volume of cylinders, 3,547 cubic feet;
revolutions per minute, 60. Volume de-
livered at this velocity, one cylinder, 422
cubic feet; two cylinders, 844 cubic feet.
5. Compressors rqfhigerated by Injec-
tion of Water/in the Cylinder.——T his sys-
tem is better than the foregoing, because
the air becomes more perfectly saturated
with watery vapor. The compressing
cylinder of the Windhausen machine (see
REFRIGERATING Mach-INERY) is of this
class, and is represented in Fig. 152. The
cylinder has a double envelope in which
cold water circulates. In order to aug-
ment the surface exposed to the action
of the water, grooves are made close
together on the outside of the interior
shell. Four valves, placed in each end
of the cylinder, are contained in the
covers, which form chambers, and are
connected by horizontal tubes, whence
lead the air-ducts. The two inlet-valves
placed at the upper part of the cover
are guided by stems which carry small
pistons moving in closed cylinders, in which the air forms an, elastic cushion. A lever, actuated
by traverse-guides on the piston-rod, moves these stems so as completely to close the inlet-valves
when the piston reaches the end of its stroke. The two delivery-valves at the lower part of the



AIR-OOMPRESSORS. 43

cylinder are composed each of a cylinder of bronze closed bya lightly concave bottom. This cylinder
travels in another closed cylinder in which the air-spring tends to maintain the valve upon its seat.
These valves are also guided by stems terminated by a projection with which a lever comes in contact
so as to lift the traverse guide of the piston at the end of each aspirating stroke. The cooling of
the air is directly effected in the cylinder by a jet of cold water which enters at the upper portion
of eaclrend of the cylinder through an aperture made between the two inlet-valves. This injection
is produced by small pumps placed laterally at each end of the cylinder, the pistons of which are
actuated by the air compressed in the cylinder, so that the intensity of the jet increases with the
degree of compression of the air. Dimensions and data: Absolute air-pressure, 5 atmospheres; vol-
ume of air per minute furnished at this pressure, 371 cubic feet. Motor, single horizontal cylinder
communicating with compressor; compressor horizontal, double-acting. Diameter of piston, 43.6 inch-
es; stroke, 41 inches; useful volume of cylinder, 37.1 cubic feet; revolutions per minute, 25; theo-
retic volume at this velocity, 1,858.5 cubic feet.
6. Compressors refrigerated by Injection of 153.
Water in Form of Spray into the Cylinder (Fig.
153).--Four sets of compressing cylinders, three 8?
in each group, and all belonging to this type, are in use at Airolo, St. Gothard Tunnel. To
each group motive power is communicated from ,
gearing connected with the shaft of a turbine i
wheel. There is a circulation of water in the
head and around each cylinder, and also in the
piston and rod, besides an injection of spray at
each end. The circulation around the body and
ends of the cylinders is obtained from small
pumps operated from the rod of the compress-
ing piston. This pump injects water into the
hollows in the cylinder-ends and into the annu-
lar space formed around the cylinder by a
sheet-iron envelope. The piston-rod, which is
of steel, is bored through to receive a copper
tube of smaller diameter. This tube is nearly
as long as the rod, and is connected to it at the
rear end- by a screw-threaded bronze plug.
The mode of connection at the opposite ex-
tremity is clearly shown in the drawing. The
water injected by the pump passes through
this tube and returns by the annular space be-
tween the tube and piston-rod, as far as a dia-
phragm which is formed of a bronze ring fixed
on the rod just inside the piston, and which
compels the water to penetrate the latter, cool-
ing the two faces as indicated by the arrows.
This water then escapes by the rubber tube


11
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attached to the rear end of the piston-rod. \s... The water which enters at each end of the , w.
cylinderidoes so through spouts so constructed ‘. 5,3-
that two fine streams are emitted by each, and i the two jets on escaping are caused to meet at ‘ \\ i nearly a right angle, so that the water becomes turned to spray by the impact. The quantity of \ as. , 5 _~
water introduced 1s regulated so as to maintain ;\\\ x ‘ was; __


the air completely saturated. Under these con-
ditions, even when circulation inside the piston
is not continuous, it has been found possible to maintain the temperature of the entire apparatus at
about 86° Fahr. Three valves are placed at each end of the cylinder, two inlet and one delivery.
The total area of the inlet-valves is .11, and of the delivery-valves .04, that of the piston~surface.
Dimensions and data: Absolute air-pressure, 6 atmospheres; volume of air furnished at this pressure
by the three compressors of a group, 236.9 cubic feet. Motor for each group turbine of 46.8 inches
diameter, under 528 feet head velocity, 390 turns per minute. Transmission by gearing in ratio of l
to 4.35. Triple compressors, double-acting. Diameter of pistons, 17.9 inches; stroke, 17.5 inches;
useful volume of cylinders, 26.4 cubic feet; revolutions per minute, 90; theoretic volume delivered
at this velocity for each compressor, 47 5.2 cubic feet. Final temperature of air on leaving cylinders,
104°. It will be seen that the four groups of compressors employed produce at the above average
velocity of 90 revolutions 947,600 cubic feet of air at a pressure of 6 absolute atmospheres.
7. Hydraulic Piston-Compressors—An example of this type is the improved Sommeiller com-
pressor used in the tunneling of Mont Ccnis, as shown in Fig. 154. The two cylinders of each com-
pressor are isolated, and each has its own piston, only one of the faces of which (th. t in contact with
the water, and which, by the intermediation of the latter, acts on the air) is concealed, while the other
is easily accessible in the pump-body in which it moves. The piston is very long, so that it guides
itself. The valves consist of four circular leaves of leather with metallic backing, resting on an
inclined bronze seat. These are disposed, two by two, along the vertical column of the compressor,
as shown in the engraving. The upper ones are the inlet-valves, and take air from a cylindrical iron
44 AIR—OOMPRESSORS.

envelope which communicates with the atmosphere. The lower valves open into a water-box, and
serve tor the 411tl‘0dl10t1011 of water to replace that entrained by the compressed air. The delivery
154.


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valve is of bronze, and conical. Dimensions and data: Absolute air-pressure, '7 atmospheres;
volume of air furnished at this pressure by the two compressors connected to a single hydraulic
wheel, 68.4- cubic feet. Motor, hydraulic wheel, 216 inches in diameter, and 163.8 inches in breadth,
discharging 35.3 cubic feet of water per second, under a head of 216 inches. Direct crank-connec-
tion. Compressor: Piston-diameter, 23.4 inches; stroke, 58.5 inches; useful volume of cylinders,
14.9 feet; number of turns per minute, 8 ; theoretic volume of air delivered at this velocity, 476.55
cubic feet. Final temperature of air on leaving compressors, 104° Fahr.
8. Sltock-Oompressors.—These machines are not used industrially, on account of their inefficiency.
They are really nothing but hydraulic rams of large size. They were used for a time at the Mont
Conis Tunnel, but were removed to give place to piston-compressors.
IV. VERY HIGH-PRESSURE COMPRESSORS.—C0mpl‘OSSOl‘S belonging under this division are not largely
employed for indus-


















m" trial purposes. 'Ihey 15¢
are utilized for com-
© © @ pressing air to a great , “ ,r
_ M, degree in small reser-
aw
i]. ____ "'1 voirs, such as are car- ‘ \§ §
1 ma 2: *"v ~ -. i. _. ‘ \ \
18 a el. a e “1.1 5 5 them their own air- % :7.
~ supply, instead of de- é pending on pumps at g z
i the surface. They are ¢ also used for com-
< pressing gases in eyl-
@ indors which are de- é
1 livered to consumers, /
\ for the oxyhydrogen ?
light, etc.; also for '3' filling the air-reservoirs of compressed-air locomotives and of tor- ._ .. pedoes, and for forcing air into gaseous waters. /' Z
A. Low-duty Apparatus.——M. Rouquayrol’s pump (Fig. 155) is g g
adapted to filling reservoirs of air for divers, of a capacity of some-
é
thing less than a cubic foot, with air under 40 atmospheres’ press- 52
ure. The apparatus is composed of two pump-bodies of unequal
diameter. The first has large diameter and long stroke; the second,
._
m“


a much smaller diameter, and a stroke reduced, so that the volume ii.
delivered by the piston of the large body may be five times 0'rcatcr H i" . M’
' i' - h 4,2: s??? ‘~ \\\\\\\\ \l
than that delivered by the small piston. The air compressed by the
large piston is forced into a small reservoir forming the upper por- -/ " ‘
tion of the pump-body ; and it is in this reservoir that the small pis- k ‘\\
ton carries the pressure from 5 atmospheres to 25. With an appa-
ratus of four such differential bodies, a pressure of 100 atmospheres
may be obtained by man-power. The valves have water-joints, and
all the connections are made with great aceuracyl
B. High-duty Apparalus. 1. Direct-action Machines—The I-Iurcourt compressor (Fig. 156) is used
in Paris for compressing gas, at a pressure of 11 atmospheres, into cylinders holding 247.1 cubic feet
AIR.
45

7.
each. The apparatus consists of two single-acting pumps, disposed on each side of a pyramidal
support, which carries at its summit a shaft with cranks at right angles, and a belt-pulley be-
tween the two standards. The cylinder is of cast-iron, with no exterior envelope, and no means
of refrigeration.
At the base is a tube, in which is the conical inletvalve. Opening into the
piston is a conical valve which communicates by three openings leading through the rod, and
just above the piston-packing, with the annular space between rod and cylinder. The piston,
on descending, compresses the gas contained in the pump-body, until a pressure is reached
sufficient to enable the gas to lift the valve in the piston and pass into the annular space
above. On the up-stroke of the pump the gas is again compressed, and at the same time a new
supply is drawn in through the valve in the cylinder~bottom.
Dimensions and data: Absolute air-
pressure, 11 atmospheres; volume of compressed gas furnished at this pressure by the two pumps,
2,939.7 cubic feet.
Motor, horizontal non-condensing engine—no steam expansion—connects with
6 compressors by belting. Diameter of piston, 13.26 inches; stroke, 24.9 inches; steam-pressure,
_ 6 atmospheres; revolutions per minute, 70. Compressor: Diameter of piston, 7.02 inches; stroke,
23.4 inches; useful volume of cylinder, 538.6 cubic feet; revolutions per minute, 30; theoretic
volume generated at this velocity by each compressor, 32,3376 cubic feet.
. 2. Hydraulic PistomCompressors.—The machines under this class are but two: one, a very old
apparatus, not used at present; in the second, in which the air is compressed to 25 atmospheres, the
refrigeration is accomplished by injection, and the compression effected in two unequal cylinders. This
machine has not been subjected to sufficient practical tests to admit any authentic data being presented.
Summary—In the construction of air-compressors, the present tendency is to use metal through-
out.
For piston-packing, rings or segments in cast-iron or bronze are employed; for stuffing boxes,
soft alloys, and for valves in machines for distributing power, plates of steel, resting in bronze seats,
either with or without springs, are recommended. With regard to dimensions, starting with the vol-
ume of compressed air to be furnished per minute under a given pressure, the useful volume to be
given to the compressor is first to be calculated, keeping in view the fact that the compressing piston,
if on the hydraulic system, should not travel faster than 15 revolutions per minute; or, if direct-act~
ing, not more than 60 revolutions.
The useful volume determined, the stroke of the piston is fixed so
that the velocity per second shall not exceed 29.25 inches for hydraulic piston-compressors, or 58
inches for direct-acting compressors. If the diameter is too large, two cylinders are employed.
Results of Tesla—From the records of a large number of experimental investigations, the following
results are selected: I. Apparatus without piston—1. Machines acting by simple displacement of
water: useful effect, 6 to 40 per cent—Experiments of MM. Romilly and i.Vorms (Annelcs (Ics
Mines).
2. Entrainment apparatus: useful effect, 41.50 per cent—Same experimenters.- II. Hy-
draulic piston apparatus—Sommeiller compressor improved: useful effect, 84 per cent.--Daxhelct’s ex-
periments (Revue [Miocrsclle the filters).
III. Apparatus with piston acting directly on air—London
Pneumatic Telegraph compressor: useful effect, 87 per cent—Tested by constructor (Engineering,
1874)
Schaeht compressors, Saarbriick mines: air compressed to 4 atmospheres, 80 per cent.
In
power u'tilizahle at driven shaft of compressor, with expansion of one-half, about 40 per cent. ; at 3
atmospheres, 841} per cent. ; at 1 atmosphere, 91 per cent.—-Hasslacher’s experiments (Annafcs dos
Jlh'ncs Prussimmes, vol. xvii).
Ryhope Colliery compressor: average useful effect, 66 per cent.—Ta_\-=
lor’s experiments (’li'cmsact'ions of North of England Inst-iiute of dialing and JIcc/mnical Engineers,
vol. xxi.).
per cent. at average rate of travel.
DISTRIBUTION or Conrnnsssn Am.
As a rule, it may be stated that the useful effect of the most improved compressors is 80
Tubing—Tubes are usually of cast or wrought iron, the former
being preferable for large diameters, and the latter for those below 3.9 to‘5.7 inches. \Vrought-iron has
the advantage of lightness and flexibility.
mitting blast to furnaces.
Tubes of riveted sheet-iron are sometimes used for trans-
Copper tubing is employed where flexible joints and sections of peculiar
shape are needed. Lead tube is of little value, and rubber tubes are used for flexible connections.
The latter are usually lined with wire-spiral, and covered with canvas.
Diameter of Timing—The
following table shows the losses of pressure in millimetres of mercury which occur in conduits 1,000
metres in length, and of diameters increasing from .1 to .35 metre, velocity of air from 1 to 6 metres:



Velocity of‘ the air
at opening of con-
duits, in metres,
per second.


Ciasfi‘vwi-i

LOSSES OF PRESSURE IN MILLIMETRRS OF MERCURY OBSERVED IN CONDUITS OF
1,660 nurses in LENGTH we or INTERIOR DIAMETERS or

awn—“F... . A...
.l metro.



.15 metre. .9 metre. .95 metre. .3 metre.
4 3 3 2
18 13 11 9
42 31 25 ‘21
7 '3. 54 4t 36
112 S4 67 56
156 | 117 94 7 S
.35 metre.
2
8
18
31
48
67


The results of practice at the tunnels of Mont Oenis and St. Gothard, Saarbriick mines, and elsewhere
in Europe, show the following diameters of pipes to be advisable: For principal conduits, cast-iron,
from 5.8 to 9.7 inches; for secondary conduits (generally drawn tubing), 2.9 to 5.8 inches; for extreme
branches (always drawn tubing), 1.9 to 2.9 inches; for flexible connections (rubber), 0.9 to 1.9 inch.
Resmwoirs.-—Under ordinary conditions, the capacity of the reservoir should represent 10 or 15
times the consumption of air in cubic feet per minute when the air is used variably, as in rock
drills; in cases of regular employment, 4 or 5 times the consumption per minute may be taken as the
rule. In a large number of instances, reservoirs ranging from 706 to 2,824 cubic feet have been found
of ample size.
Duty of Air-llfotors.—-In many English mines experiments have been conducted with a view to
46 AIR-CHAMBER.

determining the fraction of absolute: work theoretically transmitted by air delivered, which machines,
driven by said air, return in the form of effective work. This work has always represented 55 to 7 5
per cent. of' the absolute work, which corresponds to the consumption of compressed air. At St.
Gothard Tunnel, M. Rebourt, by direct experiment upon compressed-air locomotives, determined that
the relation of tractile work to the theoretic work of air expended was comprised between .50 and
.60. If, instead of seeking a ratio between the effective work and the theoretic work contained in the
air expended, we determine the same between the first and the work expended to compress the air
so as to obtain the total useful effect of the entire system, or, in other words, for the fraction of work
expended by primary motor which is returned from the shaft of the compressed-air engine, the relation
is found to be between 20 and 25 per cent. at high pressure, or 35 and 40 per cent. at low pressure.
Works for Reference—The foregoing article is translated'and abridged from L’At'r Comprt'mé,
by A. Pernolet (Paris, 1876), to which the reader is referred for complete discussion of the subject.
For a full list of all the authorities on compressed air, reference may be had to “ Tunnelling, Explo-
sive Compounds, and Rock-Drills,” by H. S. Drinker, E. M. (New York, 1878).
AIR-CHAMBER. See PUMPS.
AIR-ENGINE. See ENGINES, Am.
AIR-ESCAPE. A simple and ingenious eontrivance for letting off the air from water-pipes. If a
range of water-pipes be led over a rising ground, it will be found that air will collect in the higher
parts and obstruct the progress qf thewater, to remedy which inconvenience the air-escape is em-
ployed. A hollow vessel is attached to the upper part of the pipe, in the top of which vessel there is
fixed a ball cock, adjusted in such a way that, when any air collects in the pipe, it will ascend into
the vessel, and, by displacing the water, cause the ball to descend, and thus open the cock, when the
air is allowed to escape. N 0 water, however, can escape, for, when that fluid rises in the vessel above
a certain height, the ball rises and shuts the cock; new air then collects, displaces the water, lowers
the ball, the cock is opened, and it again escapes.
AIR-GUN. A machine in which highly-compressed air is substituted for gunpowder to expel the
ball, which will be projected forward with greater or less velocity, according to the state of conden-
sation and the weight of the body projected.
It consists of a lock, stock, barrel, ramrod, etc., of about the size and weight of a common fowling-
piece. Under the lock at b is screwed a hollow copper ball 0, perfectly air-tight. This ball is fully
charged with condensed air, by means of the syringe B, previous to its being applied to the tube at b. Being charged and screwed on as above stated, if a bullet be rammed down in the barrel, and the
trigger a be pulled, the pin in b will, by the spring-work in the lock, forcibly strike out into the ball,
and thence, by pushing it suddenly, a valve within it will let out a portion of the condensed air, which,
rushing through the aperture in the lock, will act forcibly against the ball, impelling it to the distance
of 60 or 70 yards, or farther if
the air be strongly compressed.
At every discharge only a portion
of the air escapes from the ball ;
therefore, by re-cocking the piece
another discharge may be made,
which may be repeated for a num-
ber of times proportioned to the
size of the ball. The air in the
copper ball is condensed by the
syringe B in the following man-
ner: The ball is screwed quite
close on the top of the syringe;
at the end of the steel-pointed
rod a is a stout ring, through
which passes the red It ,' upon
this red the feet should be firmly
set; then the hands are to be
applied to the two handles a 5
fixed, on the side of the barrel
of the syringe, when, by moving
the barrel B steadily up and
down on the rod a, the ball 0
will become charged with condensed air, and the progress of condensation may be estimated by the
increasing difficulty in forcing down the syringe. At the end of the red It is usually a square hole,
that the rod may serve as a key for attaching
















the ball to either the gun or syringe. In the 158-
inside of the ball is fixed a valve and spring, which gives way to the admission of the air, ' _____________ “
, ‘ . . ‘ \ :1--Tsaa-ggqgiég§§:zz;:x:zzz;:s :
but upon its emissmn comes close up to the orifice, shutting out the external air. The p1s¢ "mm mm”, m- /t____




"A: -rnap----.--
ton-rod works air-tight by a collar of leather on
it, in the barrel B ,' it is therefore obvious that,
when the barrel is drawn up, the air will rush
in at the hole It; when it is pushed down, it
will have no other way to pass from the press-
ure of the piston but into the ball 0 at the top. The barrel being drawn up, the operation is re-
peated, until the condensation is so great as to resist the action of the piston.


AIR—PIPES. 47

In Gifford’s air-gun, Fig. 158, the barrel is in communication with the inside of the trigger-box,
in the interior of which is a valve-piston, consisting of a steel rod carrying a ring fitted with a caou-
tehouc disk for closing communication. Air enters the barrel by a bell-shaped chamber. By pressing
strongly on the extremity of the rod, the disk is compressed and closes the reservoir-orifice. By sud-
denly releasing the piston-valve, the elasticity of the rubber, combined with the pressure of the air,
causes the sudden opening of the reservoir-orifice, and emits a blast of air to the rear of the projec-
tile. The air is compressed into a-reservoir beneath the barrel by means of a piston working longi-
tudinally in a valved interior tube.
AIR-PIPES. An invention for clearing the holds of ships and other close places of their foul air.
The eontrivance is simply this: A long tube, open at both ends, is placed with one end opening into an
apartment to be ventilated, and the other out of it. The air in the outer end of the tube is rarefied
by heat, and the dense air from the hold comes in to supply the partial vacuum, the escape of the
foul air in the hold being supplied by fresh air introduced through an opening above; and this pro-
cess is carried on until the air becomes everywhere equally elastic.
AIR-PUMP. The air-pump is an instrument by which a vacuum can be produced in a given
space, or rather by which air can be greatly rarefied, for an absolute vacuum cannot be produced by
its means. Fig. 159 represents a simple form of this machine. Through the centre of the brass
plate there is drilled an orifice A, from which orifice there is led a pipe A B, forming a communication
between the receiver R and the interior of the cylinder B P V, which communication may be opened
or closed by means of a stopcock at G. The cylinder or barrel B P V is furnished with a piston BP
accurately fitted to the cylinder, but capable of free motion up and down, which motion is effected
by means of a piston-rod D C, which moves through a stuffed or air-tight collar at D. The bottom
of the cylinder or barrel is furnished with a valve V opening outward. This cylinder communicates
with anotherB X P V, constructed and furnished in a similar
manner; and the two piston-rods are provided with racks (7 C 159-
at the top, the teeth of which are acted upon by those of a
wheel placed between them, as may be seen in the figure.
Let us now attend to the mode of action. Suppose the stop-
cock at G open, and the pistons as they are in the figure.
The piston 131’ being at the top, a free communication is
' formed between the receiver R and the first cylinder, and the
piston being pushed down past the orifice at B, the air con-
tained in the cylinder ‘or barrel will be forced into less space
or compressed, and, of course, its elastic force increased. In
consequence of this increased elasticity, the valve at Vwill
be opened and the air expelled. When the piston is lifted,
this valve will be shut by the pressure of the atmospheric
air without; thus a portion of the air which was contained
in the receiver, communication-pipe, and barrel, has been
expelled, and that which remains will consequently be less
dense; another stroke of the piston will diminish the density
still more; and this process may be continued until the den-
sity be so diminished that, when compressed by the descent
of the piston to the bottom of the barrel, its elastic force is 1’
only sufficient to open the valve V. It will be easily seen that the exhaustion of the air in the receiver depends on the '
elasticity of the air; for when the piston descends and expels the air contained within the barrel,
which it will do completely if it go to the bottom, and then, in returning, the valve V being shut, a
vacuum will be formed in the barrel until the piston in its ascent
passes the orifice B, when the air within the receiver will expand
and fill the whole cavity. The operation of the second barrel and
piston is precisely similar to that of the first, so that when the one
is understood, the other requires no explanation.
The degree of exhaustion will depend upon the workmanship of
the pump, the number of strokes of the piston, and the relative.
capacities of the receiver and barrels; but perhaps in no case can
the vacuum in the receiver be made perfect. For the purpose of
determining the degree of exhaustion, a mercurial gauge is em-
ployed, which acts on a similar principle with the common barom-
eter. A glass tube EF rests in a basin of mercury F, and its up-
per orifice opens into the brass plate 8' S. When the exhaustion of
the receiver has commenced, the pressure of the air in the receiver
must be less than that of the atmosphere without. \Vhereforc,
since the air in the receiver presses the mercury down the tube,
and the atmosphere pressing on the mercury in the basin forces it
up the tube, with the greater force the mercury will rise in the
tube, and it will rise the higher according to the difference of the
5' density, and consequently elastic force, of the air in the receiver,
and that of the atmosphere.
Two examples of the latest improved air-pumps are given here-
_ _ with. Fig. 160 is the free-piston air-pump of M. J. A. Deleuil.
The peculiarity of the machine is that the piston works out of contact with the barrel of the pumn,
and, of course, without friction. The film of air between piston and cylinder-wall forms a kind of

















48 . AIR-PUMP.

lubricating cushion. The piston is driven by an epicycloidal combination operated by crank and
fly-wheel, and is guided by its red, as shown. There are two valves at each end of the cylinder, one
opening inward, the other outward. The outward-opening valves both com-
municate with the same tube, which is secured and united with the cylinder
at both extremities. At the middle point of this tube a branch leading
from it may be connected with a condensing apparatus; so that the pump
may be used for condensation as well as rarefaction. When used for. the
ordinary purposes of an air-pump this branch is open to the atmosphere.
On the other side, the two inward-opening valves are similarly connected,
and the branch tube on that side establishes communication with the receiver
to be exhausted. The valves are opened and shut mechanically by the pis-
ton itself in a manner not shown in the figure. For this purpose twQ cylin-
drical rods are introduced passing through the piston, and reaching from
end to end of the cylinder, but capable of a slight longitudinal movement
as the piston changes its direction. This movement opens a valve at one
end, and simultaneously closes the corresponding one at the opposite end ;
but this change having been efiected, the rod remains stationary, the piston
sliding on it in continuing its movement. With a machine of this kind,
having a cylinder 4% inches in diameter, a 20-gallon receiver may be ex-
hausted down to a pressure of less than half an inch of mercury in five
minutes.
Fig. 161 represents an air-pump devised by M. do las Marismas, which may
be cheaply constructed. Two reservoirs A A counterpoise each other, and
are supported by the pulley B. They communicate uith two glass balloons
O by means of the glass tubes D, and of the India-rubber tubes E. They
are filled with mercury, which, when one of the reservoirs is lifted, passes into
the balloon and drives the air out of it through the capillary tube F, which
is soldered to the top, at the same time that the other reservoir, in falling
lower than 29.64 inches, causes the mercury to quit the other balloon, thus
forming a barometric vacuum. The balloons communicate with the plate G
- by the glass tubes H, which plunge to within 0.39 inch of the bottom of the
balloons. They are automatically closed as soon as the mercury rises within
the balloons to drive out the air, and opened as soon as it retires to produce
L a vacuum. The air cannot re'énter the balloons by the tubes F after having
been once driven out, because, in order to escape by the orifice 1, it is obliged
to pass through a slight layer of mercury contained in the curved tube J; and when the vacuum is
formed in the balloons, the atmospheric pressure causes the mercury to mount up again in the
tubes, and thus prevents the return of air. In order to receive the air or gas contained in the plate,
all that is to be done is to place the required recipient in communication with the orifice J. The
degree of vacuum produced is indicated by the barometer K, which communicates with the plate by
tube L. The return of the air is effected through the tube 11!, which communicates on one side with
the plate, and on the other plunges into the mercury contained in the bent tube N.
Bmzscn’s Air-Pump is represented in Fig. 162. Falling water is employed to carry the surrounding
air with it, and in this way a steady exhaustion is produced. The device consists of a wide glass tube
D in which a narrower tube reaches downward to N, connected at
the top by a well-fitting cork M'. \Vater is carried in by a side 1R2-
branch 0, connected by means of an India-rubber tube B, closed by \ .
a spring [-1, with a tube A drawing water from a reservoir. The
current of this water going down in the tube D around the inner
tube draws the air from T and S and from any vessel connected
with S. To increase the effect, the wide tube D is connected below
with a lead tube F which reaches 20 or 30 feet down ; so that this
long descending column of water acts like a powerful continuous
piston.
illcr-curial Air-Pampa—All true mercurial air-pumps are, of
course, based upon the principle of the barometer. That is to say,
in all of them the vacuum is constituted in the manner invented.
by Torricelli, namely, in an inclosed space above a barometric col-
umn. In all of them the object is to render the Torricellian vacuum
as perfect as possible. In some of them the object is effected by
driving the air upward out of the barometer~head by raising the
barometric column. In others the air is forced downward by the
injection of more mercury into the barometer-head. In others,
again, the air is pushed up one barometric column and down an-
other. In some recent kinds of mercurial pump several of these
forms are combined. Other pumps again depend on the injection
of mercury at high pressure through an orifice. These distinctions
are used by Prof. Silvanus P. Thompson (see Journal of the Society of
Arts, November, 1887) as the basis for the following classification:
1. Those which drive the air up a barometric tube. 2. Those which drive the air down a baro-
metric tube. 3. Those which drive the air up one barometric tube and down another. 4. Combina-
tion-pumps. 5. Injection-pumps, dependent in their action upon the velocity of efilux vof a stream of
mercury. 6. Mechanical mercurial pumps.
161.














Mfg .Fmz.
Cigars“ “56
“i”
, v H’- _, _. : at: a...”
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.-. .. - \ ;_ . l - 4.,


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gig


AIR-PUMP. 49

The famous pump of Dr. H. Geissler, of Bonn, devised in 1855, is a well-known example of the
first class. As originally constructed, this apparatus consisted of a vessel containing a supply of mer-
cury connected to the lower end of a barometric column by a flexible tube. The pump-head was
provided at the top with a large 3-way tap. The operation is described as follows: The airin the pump-
head is repelled by raising the supply-vessel, while the tap is in such a position that the pump-head
communicates with the outer air. The tap is then turned so that the
communication with the outer air is cut off, and communication is 162a.
established with the vessel to be exhausted. This being done, the
supply-vessel is again lowered, when the mercury in the pump-head
sinks, and draws in air through the exhaust-tube. The tap is then
turned, and the supply-vessel is again raised to expel the air that has
been drawn in; then the tap is turned, and the supply-vessel again
lowered.
A modern form of this pump devised by Mr. A. Geissler is repre-
sented in Fig. 162 A. The 3-way tap is here replaced by two auto-
matic valves, one of which, V, opens from the top of the pump-head
into the outer air. The other, U, admits air from the vessel to be
exhausted into the pump just below the pump-head. These valves
are hollow tubes of glass, with spindle ends to guide their motion,
which float in the mercury when it reaches them. They are provided
with accurately ground glass collars instead of conical ends, to {it
against the ends of the tubes which they respectively close. An
additional tap, T, is interposed for safety between the pump and the
vessel to be exhausted. Other tubes lead to the manometric gauge
and to the drying apparatus. This form of pump is intended for
industrial use, where power is available to keep the supply-vessel
slowly rising and falling. '
The length of the pump-shaft in this type of apparatus renders it
more or less unwieldy. Although a column of mercury 7 6 cm. high
is a necessity for working between vacuum within and atmospheric
pressure without, no such length is required when working between vacuum and a reduced pressure.
The length of the pump may be shortened by reducing the air-pressure above the surface of the mer
cury in the supply-vessel, for which purpose an auxiliary pump is employed. A recent pump in this
category has an ordinary 3-way tap at the top of the pump-head communicating with the open air.
Below, at the lower end of the pump-shaft, is a closed vessel com-
162 a. municating by another 3-way tap with a water aspirator and with a
source of pressure, by means of which the mercury is alternately
raised and lowered.
In the second class, or downward driving-pumps, the best-known
type is that devised by Dr. Hermann Sprengel in 1865. It is based
on the principle of the water trombe or aspirator, and in its simplest
form consists of a funnel or supply-vessel from which mercury flows
downward through a narrow India-rubber tube, which is nipped by
an adjustable pinch-cock. After passing this constricted point the
mercury falls in drops down a glass tube of narrow bore commonly
called the “fall-tube,” and in so doing sweeps out the air, so to
speak, in the tube. For rapid partial exhaustions, a tube having
an internal bore of from 2 to 3 mm. is best. For slower exhaus-
tions carried to the highest degree of rarefaction, a diameter of bore
of from 1.4 to 1.8 mm. is preferable. At the bottom of the fall-
tube the air and mercury are received in a vessel from which the
air may be collected. In most of the modern forms of Sprengel
pumps the mercury is introduced into the pump-head by a jet tube
with a narrow orifice, whence it spurts in a fine stream and falls
into the widened fall-tube. In other forms it merely breaks away
in drops over a bend in a wider tube.
By removing a portion of the extreme pressure the fall-tube of
the Sprengel pump may be shortened. A shortened Sprengel pump
devised by Dr. \V. \V. J. Nicol is represented in F ig. 162 B. An
auxiliary water dropping aspirator (not shown in the figure) is
used to draw in air at the aperture A, regulated by a tap. This air
draws up the fallen mercury in drops through the, return-tube,
on the left, and returns it into the supply-chamber, S, at the top,
whence it passes downward through a rubber tube, squeezed be-










‘LU tween the jaws of a regulating pinch-cock, and rises through an
L UL air-trap, i, into the pump-head. The distributor is simply a horizontal
\J glass tube, sealed into the pump-head, and pierced with small holes
above the openings of each fall-tube. The fall~tubes, F FF, are con-
nected to the pump-head in the following manner: Below the pump-head are sealed, on short pieces
of glass, tubing of at least 5 mm. bore. These are provided with small flanges, and drawn out coni-
cal below, so that they can be pushed very tightly through small India-rubber plugs, p p p, which are
firmly fixed in mercury cups. These mercury cups, which are strangulated, so as to nip the rubber
plugs, are sealed to the fall-tubes. The lower ends of the fall-tubes pass into the collecting vessel,
4
50 AIR-SHIP.

K, through simple packing, s s s, of rubber tube. The arrow shows the course of the mercury. The
tube, al, leads to the drying apparatus, and to the vessel to be exhausted. This pump can, of course,
be used for exhausting only, not for collecting the gas for analysis. The entire height of the appa-
ratus is less than 1 metre. A very small quantity of mer-
cury—only 300 cub. cm.—is required. The entrance of
water vapor at S or a is prevented by the use of tubes con-
taining calcium chloride. The upward and downward class
of pumps include those which drive the air up one baromet-
ric column and down another. The Toepler pump is sub-
stantially a combination of the Sprengel and Geissler prin-
ciples. The external cistern is lifted, so raising the mer-
cury in the tube and pump-head, whence it flows over and
into the fall-tube. An improved shortened pump of this
class devised by Neesen is represented in Figs. 162 c and
162 n, Fig. 1621) being an enlarged view of the valve. At
the lower portion air-tight connections are being formed at
the three necks of the bottle, L. The tube, Y, is put into
alternate communication with the atmosphere and with a
good mechanical air-pump, so as to raise and lower the
mercury alternately in the pump-head, A. There is an
automatic valve, U, in the exhaust-tube, which leads up to
the drying flask and to the lamp or other vessel that is to
be exhausted. This valve, Fig. 162 D, is made with a
small glass disk about 2 cm. in diameter, cut from thin
plate-glass, which, as the mercury rises under it, is pressed
up against a flat flange, fashioned on the lower end of
the upper tube. This pump is further provided with a
chamber, ill, and a siphon trap, Q, down which the re-
sidual air from the pump-head is expelled into a moder-
ately perfect vacuum.
Various combination pumps have been suggested, such as that of Mr. J. T. Bottomley, who pro-
poses to utilize the Geissler arrangement to exhaust the chamber, into which the foot of the fall-tube
of the Sprengel pump is led, thus putting the two pumps in series. Injector and mechanical mercurial
pumps have been devised, but have not come into use. The following table shows results obtained
by various pumps, the vacua produced being specified both in mm. and in millionths of one atmos-
phere:
162 o.

u
@m
n














Pressure in milli- Pressure in
NATURE OF PUMP. millionths of
metres of mercury.
one atmosphere.
Improved Sprengel (maximum result) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.000046 _ 11,,
Single-fall Sprengel, 1.1 millimetre diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.00051 %
Five-fall Sprengel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.000006 fig
l’lain Sprengel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.000152 §
Itoocl’s Sprengel, heated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.000002 mtg,
Old Geissler, after 25 strokes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.110 140
New Geissler (2 taps). after ditto (average) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0 0085 11
" (2 tape) (maximum result) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.008" 101}
Old Toepler, after 5 strokes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0075 10
“ after 5 more . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.0064 8
Modified Toepler (average) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.000012 E13
" (maximum result) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.000008 51,;





Vacua are now obtainable in advance of ordinary requirements by the absorption of the residual
gas after the exhaustion has been pushed as far as possible by the mercury-pump. This is done
either mechanically or by using some substance with which the air-particles combine chemically.
Dewar has obtained a vacuum of $51; mm. by heating charcoal to redness in the vessel exhausted by
the Sprengel pump, and Mr. WV. Crookes has produced one of T51; of a millionth of an atmosphere,
equivalent to 1'7; in. at the top of a barometer-tube 200 miles in length.
AIR-SHIP. A vessel adapted to the navigation of the air. The subject will be considered under
the two heads of Balloons and Flying-Machines.
The Balloon is a bag or hollow vessel of light impermeable material, which, when filled with
a gas lighter than air, ascends. The theoretical considerations governing this result are as
follows: ,
1. If a body is wholly immersed in any fluid, it will be pressed upward by a force equal to the
weight of a volume of the fluid equal to the volume of the body.
2. If the upward pressure is less than the weight of the body, the latter will have no tendency to
fall, under the action of a force equal to the difierence between the body’s weight and the weight of
an equal volume of the fluid.
3. If the upward pressure is equal to the weight of the body, the body will have no tendency either
to fall or rise.
4. If the upward pressure is greater than the body’s weight, the body will have a tendency to rise,
due to a force equal to the difierence between the weight of a volume of fluid equal to the volume of
the body, and the weight of the body. These principles are a concise statement of the theory of
a balloon’s action. If we have a body whose weight per cubic foot is less than the weight of a
*4
AIR-SHIP. 51

cubic foot of air, the body will rise with a force equal to the difference between the body’s weight
and the weight of an equal volume of air. For instance, if a ballodn is filled with hydrogen, the air
will exert a lifting force of about 75-5 of a pound for each cubic foot in the volume of the balloon, so
that, if the weight of the balloon and car is less than this lifting force, the balloon will ascend. If
common illuminating gas is used in the balloon, the lifting force will be about one-twenty-fifth of a
pound hr each cubic foot of the balloon’s volume. The weight of the material in a balloon varies
greatly, of course, according to the construction, some balloons only weighing, with the network, about
onc~twentieth of a pound per square foot of surface, or even less, and others weighing as much as
one-eighth of a pound per square foot of surface. The ordinary shape of a balloon approximates
closely to that of a sphere, which it is commonly assumed to be in making calculations.
These rules may be applied in examples in order to exhibit the calculations involved in the design-
ing of a balloon. A balloon has a diameter of 40 feet; the weight of the material and netting is one-
eighth of a pound per square foot of surface; the weight of the car and contents is 6001bs.; and
the gas which distends the balloon is subject to an upward pressure of one-twenty-fifth of a pound
per cubic foot. ‘
The volume of the balloon is 33,510 cubic feet, so that the upward pressure due to the air is about
1,340 lbs. The surface of the balloon is 5,026.5 feet, so that the weight of material and netting
is about 628 lbs., to which must be added the weight of the car, making a downward pressure of
1,228 lbs.; hence the unbalanced upward pressure, which causes the balloon to ascend, is about
112 lbs. It will now be evident that the lifting force of a balloon is entirely due to the air, and
is impeded, instead of being assisted, by the gas ; so that it would be better, if it were practicable, to
make a balloon with a vacuum in the interior. It must be remembered that, as a balloon ascends
above the earth’s surface, the air in which it is immersed grows continually less dense, so that the
lifting force becomes less and less, unless the volume of the balloon is increased. Thus, at about
18,000 feet elevation, the air is only about half as dense as at the sea-level , at 36,000 feet elevation,
} as dense, and so on. Hence balloons are rarely filled at the surface.
In making the estimate for a balloon, one can generally ascertain the weight of the car and con-
tents, the difference of weight of a cubic foot of air and of the gas to be employed (which may be
called the buoyant effort), and the weight of the balloon with its ropes and network per square foot
of surface. It is then required to find the diameter of a balloon which will have a tendency to rise
with a given force. The calculation by which this is determined is somewhat complex, but it will be
found explained at length below, an example being added for the purpose of further illustration.
The following quantities must first be ascertained : 1. The buoyant effort, or difference between the
weight of a cubic foot of air and of gas. 2. The weight, which includes the weight of everything
except the material of the balloon and the netting, together with the lifting force. 3. The superficial
weight, or weight of the material and netting, per square foot of the balloon’s surface.
The operations for finding the required diameter are as follows: (a) Divide twice the superficial
weight by the buoyant effort. (6) Divide 8 times the cube of the superficial weight by the cube of
the buoyant effort. (0) Divide 0.95493 times the weight by the buoyant effort. ((1) Multiply
15.27888 times the cube of the superficial weight by the weight, and divide the product by the fourth
power of the buoyant effort. (e) Divide 0.91188 times the square of the weight by the square of
buoyant effort. (f) Add together the quantities obtained by rules (d) and (e), and take the square
root of the sum. (g) Add together the quantities obtained by rules (6), (c), and (f), and take the
cube root of the sum. (h) Add together the quantities obtained by rules (6) and (c), subtract the
quantity obtained by rule (f), and take the cube root of the difference. (2') Add together the quan-
tities obtained by rules (a), (g), and (h). The sum will be the diameter required.
Earanqale: It is required to find the necessary diameter of a balloon,'the following data being
given: -
The weight of the car and contents is 4'75 lbs., of the valve 25 lbs., and the air is to exert a
lifting force of 100 lbs. The gas in the balloon is to be such that the difference between its
weight and that of a cubic foot of air shall be 0.04 lb. The weight of the material and netting
is to be 0.12 lb. per square foot of balloon-surface.
Pursuing the same steps as indicated in the preceding rules, we find: 1. The buoyant effort
2 0.04 lb. 2. The weight : 475 + 25 + 100 z 600 lbs. 3. The superficial weight : 0.12 lb.
(a) 2 x 0.12 + 0.04 = 6. (b) 8 x 0.001728 -:— 0.000064 : 216. (c) 0.95498 x 600 —:- 0.04 : 14,324.
(cl) 15.27888 X 0.001728 -:-— 0.00000256 : 6,187,946. (0) 0.91188 x 360,000 -:— 0.0016 2 205,173,000.
(f) V(205,173,000 + 6,187,946) : 14,538. (g) a y(216+14,324 + 14,5ss = 30.75. (ll) 3 y(216
+ 14,324—14,538) :: 1.26. (i) 6 + 30.75 +- 1.26 = 38.01 feet, required diameter.
As there are many who like to know the reasons for a result, we have added the method by which
the rules are obtained, which can readily be verified by those who are familiar with algebra. Let
b :2 buoyant effort, W : weight, and a : superficial weight.
The balloon is to have sufficient volume that the upward pressure of the air, which is the volume
of the balloon multiplied by the buoyant effort, shall be equal to the weight, increased by the product
of the superficial weight and the surface of the balloon. Assuming that the balloon is in the form of
a sphere, this condition is expressed by the following equation, calling :c the diameter of the balloon :



o 3 ~ 1'
0.5236 x b x x3 :: IV + 3.1416 x a X .132. From which we deduce: a' : if} + %- “090493 “ +
(15.27888 a3 VV+ 0.91188 W 9>1-]1} + + 0.95493 W __ 15.2788 a “V + 0.91188 W 3%]1;
()4 b2 b3 b b4 b"2
the same value as was given in the foregoing rules.
It will be evident, by inspecting the equation of condition, that the same method can be applied to
any form of balloon whose volume and surface can be expressed algebraically.
52 AIR—SHIP.

In Fig. 163 is represented M. Dupuy de Lbmes’s great balloon, remarkable alike for its peculiar con-
struction and from the fact that it has been found possible to cause it to move slowly in a desired
direction by means of the screw-propeller. The balloon consists of white silk taffeta lined with India-
rubber, and again with nainsook. To the last a varnish is applied. I
In order that the plane of the movement shall be more directly under the control of the aeronaut,
the following dimensions have been adopted : Length, 118 feet 6 inches; diameter at centre, 48feet
8 inches; area through the centre, 1,862 square feet; volume, 121,983 cubic feet; height from top
of balloon to keel of car, 951} feet; distance between screw-shaft and major axis of balloon, 67.1 feet.
The rudder is a triangular sail of 1614; square feet area, and is manipulated by cords from the car. In
Fig. 163,11 is the balloon; B the car, with D network; a a, taffeta covering; 6 b, collar attaching
the upper netting to the covering of the balloon ; d d, silken ropes suspending the car; e e, balance-







163 .
d
5‘ s
a '_ A I
6 ' 6'
V V
\ l?
I)
Q \ ,'
‘T. /
\ Q I
\\ J
I L__ .. _ L-D'“
/ 165.
Q
“200 Feat .



ropes for the car; 8, small internal balloon, with line of intersection with the balloon; E, gaff-sail or
rudder; H, pendent tubes for securing a constant degree of inflation. These are filled with hydrogen,
which gas alone is used in the balloon, and hung down for a distance of 25 feet. As the gas expands
it forces itself down these tubes, while its own pressure in the tube reacts upon the main body of the
gas in the balloon, preserving such an excess of interior pressure as prevents the shape of the outer
' covering being altered by the wind. The small internal balloon 8, or ballonet, still further serves to
maintain a constant surface. As the gas escapes through diminution of pressure in the primary bal-
loon, it becomes filled with air. At J are the cords regulating the valves 8; T is the tube for filling
the ballonet with air ; M is a crank for working the screw Q; I are stays for strengthening the
screw. Experiment with this air-ship has given results in remarkable accordance with the inventor’s
calculations. Eight men, rotating the screw at 25 revolutions per minute, caused the aérostat to
travel at the rate of 52.5 feet per second. This speed was augmented to 55.8 feet per second with
27.5 rotations. The ballonet was found to maintain the exterior surface; no rocking motion was im-
parted by persons in the car, and it was reported that the head of the aérostat was readily kept in any
desired direction at an angle to the wind, by the labor of 8 men upon the screw-crank.
It having been shown, by the experiments of M. Paul Bert and others, that animal life may be ex-
tinguished in a too rarefied atmosphere, on account of the insufficient supply of oxygen, attempts have
been made to reach exceedingly high altitudes by carryinga supply of oxygen gas, which the a'éronauts
inhaled when the atmosphere became unbearable. The last effort in this direction was that of MM.
Sivel, Spinelli, and Tissandier, in 1875. At 23,000 feet the aéronauts, despite the oxygen, relapsed
into a kind of stupor, and it is supposed that, in partial delirium, one of them cut away the oxygen-
bags, with other objects, in his intense desire to mount upward. MM. Spinelli and Sivel were suffo-
cated, and the third revived from his insensibility after the balloon had sunk to a lower altitude. The
maximum height attained, shown by the barometers, was 27,500 feet. Previously, and without the
aid of oxygen, Goxwcll and Glaisher reached an altitude estimated at 37,000 feet.
Two automatic devices for adjusting the elevation of a balloon, and for giving warning of a descent,
are illustrated in Figs. 164 and 165. The ballast-regulator, Fig. 164, is a bladder A inflated with air
before ascending, and placed between two boards, one of which is fixed upright and the other hinged.»
thereto. A rubber spring keeps the movable piece up against the bladder, and by suitable connection
the moving-board is attached to the handle of a water-barrel, so as to turn a stream on or off in
accordance with its motion. When the bladder swells, as the balloon rises into an atmosphere of
AIR-SHIP. 53

greater tenuity, the handle of the spigot is moved so as to diminish gradually or check the escape of
water; while the descent of the balloon causes the contraction of the bladder and the opening
of the spigot. This device was intended to relieve the aéronaut from the necessity of watchfulness
during a brief period, so that he might sleep. The second apparatus, Fig. 165, is an ordinary barom-
eter-tube, into which are led wires from a battery. The ends of the wires are connected by an insu-
lated substance, and are adjusted at any desired mark on the barometer corresponding to a given alti-
tude, and above the mercury. Should the balloon descend, the mercury rises, touches the wires,
establishes the electric circuit, and a bell is sounded. Mr. Donaldson, the inventor of these devices,
also succeeded in directing the course of his balloon, in some measure, by large kites lowered into
currents of air of favorable direction. He also found that low-flying balloons were preferable to
balloons at high elevations for purposes of traveling. By so adjusting his ballast that his air-ship
floated at about four feet above the ground, he was able to impel himself by a pole, and by vigorous
pushes on the same to cause his balloon to leap over low houses, trees, etc.
In Fig. 166 are represented Sivel’s sounding balloons, for recOgnizing the presence of currents of air
above or below the main aerostat. A red 30 feet in length was projected from the car, and held in
equilibrium by the upper balloon, which was 19 feet 7
in diameter, and which was filled with gas. This 166.
was attached to a rope 3,000 feet long, and allowed
to ascend that distance above the car. The other
small balloon was filled with air, and, being attached
to a line of similar length, fell far below. After
many experiments and no small amount of costly
investigation, the Aeronautical Society of Great
Britain, so long presided over by the Duke of Ar-
gyll, has pronounced decisively against the balloon
as incapable of being made useful for the purpose
' of locomotion, except in the way of waftage; and
in a report (1876), the secretary of the Society de-
clares that the sole improvement of which the bal-
loon is capable is the invention of some means to
secure its ascent and descent without the expendi-
ture of gas or ballast.
Suppose we have, for example, a balloon so
weighted that it would float on the discharge of
35 lbs. of ballast, or on receiving an additional
thousand cubic feet of gas. It is plain that, if
some mechanical means (say a screw acting verti-
cally) were added, capable of exerting a lifting force
of 35 lbs. more than its own weight—a light 2-horse-
power engine would drive it—the voyager would
be able to rise without discharging ballast, or sink
without discharging gas, and so be able to avoid
obstacles while drifting over the surface, or to rise
above adverse currents to such as might be more fa-
vorable. .
But, for the purposes of real aerial navigation,
such drifting is wholly inadequate. The work to be
accomplished is not the floating of a relatively light
body in more or less favorable air-currents, but the
propulsion of a heavy body with a force sufficient to
overcome all aerial resistance, and with velocity
enough to make the, inevitable driftage relatively
unimportant. This has not yet been achieved, though
the efforts toward it have shown some very encouraging results. Certain experiments made at the
expense of the Aeronautical Society, to determine the exact lifting pressure of air-currents against
a plane inclined at different angles, obtained results which are especially promising. The plane used
was a steel plate a foot square, and the substitute for wind or the resistance, occasioned by the pas-
sage of a body at high speed through the air, was the blast of a powerful fan-blower. Placed at
right angles to this blast, the pressure on the plate was 3}; lbs., indicating a wind-velocity of
about 25 miles an hour. Inclined at an angle of 15°, the plate received a direct pressure of
only one-third of a pound, while the lifting pressure amounted to 11} lb. In other words, a plane
of 1 square foot, held at an angle of 15° against a current of air having the velocity of 25 miles an
hour, will carry four times as much weight as it meets resistance. A less angle than 15° could not
be tried, owing to some obstruction to the action of the apparatus. The experiments showed, how-
ever, that the ratio of the lift to the thrust greatly increased as the inclination of the plane dimin-
ished, and also that the lifting power of the current, per square foot of plane, increased with the
extension of the sustaining surface, probably on the same principle that makes a large sail on a ship
so much more efficient than an equal area of small sails.
Regarding the power required to lift a weight in the air by means of vertical screws, in a “Report
on the English Aeronautical Exhibition of 1868,” by Mr. Wenham, the following paragraph appears:
“The Society has brought out the remarkable fact that a l-horse-power engine can be made to
weigh only 13 lbs., thus showing the possibility of obtaining flight by the repudiated system of verti-
cal serews, even with the enormous expenditure of power that this plan is known to require.” In


54 AIR—SHIP.

order to ascertain what actual lifting power could be obtained with planes moving in horizontal
orbits, Mr. Moy constructed new aero-plane wheels, 12 feet in diameter, with 12 planes to each
wheel, the whole presenting 160 square feet of surface, driven by a steam-engine weighing 80 lbs.
By placing the whole acting surface on these two wheels, an interesting experiment was carried out.
It was palpable, however, that, from the conditions of the actual trial, the full lifting power due to
166A.
A
\







Er)




the surface, angle, and velocity could not be hoped for. These revolving planes were traveling all
the time in one circle. They had not the advantage of obtaining an abutment upon a previously
undisturbed body of air. The experiment was in an inclosed part of the building. A great part of
its power was expended in drawing downward a body of air. The whole weight of the machine was
186 lbs. Levers were attached to the spindle of the aero-plane wheels, which were weighted to take
1663 elf allover 120 lbs. This latter weight
' was raised from the floor as much as 6
‘ ‘ Q \_ . I I ' inches under one a'e'ro-plane and 2 inches
‘ - a 7" I under the other, this inequality being due
to one wing-plane having broken.
The engine, therefore, was proved capa-
ble of raising itself, and 40 lbs. additional
weight, under great disadvantages. The
I __ _. revolutions of these two 12-feet aero-
..\,“\\~\,\ "x "'7, ,r .-
I planes were 67 per minute.
“‘“ullllluh: “ The largest and probably the most per-
_ \ feet balloon which has been made is that
' " ‘ “ designed by M. Henri Gitfard, and exhib-
ited by him in the City of Paris during the
continuance of the French International
\ Exposition of 1878. The following is a
summary of someof the principal figures
\-, connected with this interesting aerostat:
—Dimensions: Diameter of the spherical
envelope, 118 feet 1 inch; height above
the ground when at its moorings, 180 feet








. s ‘ 5 inches; capacity of envelope, 882,915
9' "3, - '\ ‘r“ ,‘_ a . . - o
" g3? , j cubic feet. Weights: Material of the bal-
‘W" loon with its two valves, 5 tons 3 cwt.;
" netting, 3 tons 5 cwt.; ropes attached to

the nets, rings, pulleys, etc., 3 tons 12
, cwt.; car and its appurtenances, 1 ton 11
1 RN cwt.; total weight of materials, 13 tons
11 cwt. Weight of cable supported by
the balloon, 2 tons 9 cwt.; fifty passen-
gers and two aeronauts, 3 tons ;'ballast,
grapnels, etc., 3 tons; total weight lifted,
22 tons.
The shape of this balloon, Fig. 166 A,
is perfectly spherical, the object of thus
departing from the usual pear-shaped form
being to obtain a greater capacity with the same weight of material, and hence greater lifting
power. The sphere is constructed of 104 gores, each measuring 3 feet 6 inches at its widest
part. The material is a compound fabric composed of layers: 1, muslin; 2, pure India-rubber;
3, linen canvas; 4, pure India-rubber; 5, canvas; 6, vulcanized rubber; 7, muslin. The surface
:9.
AIR—SHIP. , 55
is covered with a mixture of boiled linseed-oil and litharge, and afterward with a coat of white
paint. The method of making the seams is as follows: The edges of two gores having been
sewn together by two undulating lines of stitches, a strip of material consisting of a thickness of
vulcanized India-rubber between two layers of muslin is laid over the outside of the seam, being
made to adhere by a coat of India-rubber varnish previously applied; and the inside of the seam is
covered\in the same way with a strip of muslin saturated with the same solution of India-rubber.
No knots are used in the netting, seizings being applied at the intersection of the ropes, and the
junctions covered with goat-leather. The car, Fig. 166 B, is suspended by 16 cords from a strong
steel ring A, of small diameter, and this ring is in its turn suspended at a distance of about 4 feet
from a second and larger ring B, which is hollow, and is constructed of steel plates having an ex-
ternal diameter of 5 feet 3 inches. The upper ring is attached by 16 ropes to as many sheave-
blocks 0. Through each of these blocks passes a smaller rope carrying a smaller block at each end.
Consequently, there are 64 of these latter blocks supporting the weight of the car, and communica-
ting the lifting strain of the balloon to the cable by which it is attached to the ground. At D are the
moving ropes. The valve consists of a metallic disk 21%; inches in diameter, which is maintained in
close contact with a seat of vulcanized rubber by a series of spiral springs fixed above it. It is ar-
ranged in the centre of a large circle of a similar material to that of which the balloon is con-
structed, but somewhat thicker, and is held between two flanges of wood 8 feet in diameter, which
are held together by screws. In and closing the neck of the balloon is a second valve, which con-
sists of a circular metallic plate 31?; inches in diameter, which is kept pressed against its seat by a
set of very delicate springs, so that upon the slightest increase of pressure within the balloon the
valve opens, and a quantity of gas proportional to the excess escapes. The car consists of an orna-
mental annular balcony, 19 feet 8 inches in external diameter, the floor being 3 feet 3 inches wide.
In Fig. 166A is given an elevation of M. Giifard’s balloon, showing it as arranged in the court
of the Tuileries, Paris. A is the balloon; B, the car suspended over the conical pit with the em-
barking bridge in position. At 0 is the winding machinery to which the retaining cable of the
balloon is brought. This cable is nearly 3,000 feet long, weighs over 2% tons, and is tapered from
a diameter of 3.35 inches at its upper end to 2.56 inches at its lower extremity. At its point of
connection with the aerostat the cable is secured to a dynamometer, by which the strain on the cable
and the lifting power of the balloon are determined. The small balloon marked I) represents an
ordinary aérostat of 35,000 cubic feet capacity, capable of carrying 3 or 4 persons. (See Ifrzgz'mer-
ing, xxvi., 658.)
Mr. C. F. ltitchel has devised an aerial machine wherein is employed a balloon 25 feet in length
and 13 in diameter, weighing 66 lbs., and charged with hydrogen gas. Broad worsted bands extend
over that and down to a rod of brass tubing, from which the machine is suspended by slender cords.
The after portion of the machine is at the base a parallelogram of rods, from which rise, lengthwise,
curved rods, drawn near together at the top. All these reds are of mandrel-drawn brass, light and
very strong. Above the apex of this form rises a cog-edged steel wheel, with double handles so
geared to a four-bladed fan moving horizontally directly beneath, that the operator can give the fan
2,000 revolutions per minute. The extreme diameter of this revolvingr fan is 24 inches. The blades
are set like those of the screw of a propeller. Just behind the wheel is a very small seat, upon which
the operator perches. His feet rest upon two light treadles above and in front of the fan. F mm
the front of this form spring other rods, carrying at their extremity a vertically-working revolving
fan, 22 inches in diameter. It is so geared to the main fan that it may be operated or not, at the
pleasure of the driver, and can be made to turn from one side to the other, so as to deflect the course
of the machine in the air. This fan makes 2,800 revolutions per minute when the other is making
2,000. The total weight of the apparatus is 114 lbs. For particulars of trial of this machine, which
seemingly worked quite satisfactorily in still air, see Scientific American, xxxviii., 405.
THE FLYING MACHINE—Human muscular power being proportionately very much inferior to that
of the bird, it follows that no eontrivance of the nature of wings can be successfully operated by the
unaided strength of a man’s muscles. Either some motor must be employed to drive the lifting
mechanism, or an auxiliary balloon, as already pointed out, must be used. In view of the fact that
a kite is sustained in the air by the pressure of the wind against it, provided the direction of the
wind is oblique to its surface, some authorities consider the moving plane to be the simplest mech_
anism that can be devised for the flying-machine, in connection with two propeller-wheels, turning in
opposite directions, so as to keep the machine in an upright position. The best angle of inclination
of the fixed plane—that is, the angle in which the least amount of surface is required—is 54° 10'
with ,a horizontal line; but the power required for motion in this case is very great. By reducing
the angle between the fixed surface and a horizontal line, the power required for propulsion is dimin-
ished ; but it is necessary to give the machine a much higher velocity, in order that it may be sus
tained in the air; or, if the original velocity is retained, the area of fixed surface must be largely
increased, which will, of course, add to the weight. It must be remembered also that the macnine
will not be sustained unless it is in motion, so that it cannot rise from the ground, but must be
launched from an elevation. M. Bruignac considers that, by attaching balloons to flying-machines,
they can be propelled by the aid of less power than in the case where a sustaining plane surface is
used. The best form of balloon, according to M. Bruignac, is that of a horizontal cylinder with coni-
cal ends, the slant height of the cones being equal to the diameters of their bases. It is found by
experiment that, if three bodies having the same cross-section are moved through the air at the same
velocity, having the forms respectively of a circular plane, a sphere, a cone with slant height equal
to diameter of bases, the resistances to motion in the two latter cases will be (calling the resistance
R P
of the plane R) for the sphere ~23 and for the cone 3:.
The most favorable form of aerial machine, according to l! Bruignac, is a combination of a balloon
56 AJUTAGE.

with a sustaining plane. By his calculations, it appears that the most advantageous design, for a
speed of 20 miles an hour in a calm, must not weigh, with engines, navigators, fuel, stores, etc., more
than 2,200 lbs., and must have the following dimensions: There must be a balloon, filled with hydro-
gen, 22 feet in diameter and 91 feet long, together with a sustaining plane 94 feet long and 16 feet
wide; and an engine capable of exerting from 6 to 7 horse power. This is equivalent to saying that
the problem is impossible with our present means of construction, and would seem to settle the matter
conclusively, unless it can be shown that a more favorable plan than the best one discussed by M.
Bruignac can be designed. It is pretty evident that, if a machine is not practicable even in theory,
there is little hope of its actual success.
Dr. F. A. P. Barnard has published a paper, entitled “Aérial Navigation” (1875), in which M.
Bruignac’s investigations are reviewed. Dr. Barnard offers the following suggestion: “If it is possible
to lift a given weight into the air and make it move in any desired direction, it is certainly easier to
do the same with a part of that weight. Let the inventor, then, attach his lifting apparatus to some
vehicle on land—as, for instance, a railroad-train—and, by sustaining some of the weight, make it move
more easily; let him remove the locomotive, and put in its place his aerial propeller. If this works
well, there is some hope of actually getting into the air; but should it fail, it would seem advisable
for him to abandon his experiments.”
The reader is referred to the “ Patent-Ofice Reports of the United States ” for descriptions of hun-
dreds of devices whereby it has been hoped to solve the problem of aerial navigation. The quest
has a singular fascination, but it has ruined thousands, and teems with examples of misdirected
energy and genius. In conclusion, it may be added that the problems to be solved before aerial
navigation takes its place among human achievements are consequently these two: the invention of
an apparatus to accomplish the work of the bird’s wings and tail, and an engine capable of develop-
ing great power with comparatively little weight of machinery and fuel. For the purpose of naviga-
tion, the flying-ship must be, however, like the bird, heavy in comparison with air, that it may not be
at the mercy of every gust of wind; and it must be strong enough to withstand the pressure of
strong gales, or, what is equivalent, the resistance due to rapid motion. Hence it is evident that,
whatever it may be, the successful air-ship will not be and will not contain a gas-bag. For the prac-
tical navigation of the air, the balloon is and will ever be a delusion and a snare; and the general
recognition of this truth by intelligent workers in this field is one of the most encouraging features
of modern aeronautics.
It is quite possible that ae'rial rafts, supported by balloons, may sometimes be useful in regions
favored with winds which blow steadily in a fixed direction for months at a time; but in ordinary
climates they cannot but be as useless for commercial purposes as log-rafts in a sea everywhere as
vexed by conflicting currents as Hell Gate was in its worst days. A self-propelling vessel supported
by a balloon would be little, if any, better. N o balloon light enough to sustain such a vessel could
bogin to withstand the pressure it would meet in stemming or crossing the current of a moderate
wind, or in being driven through still air at the rate of 20 or 30 miles an hour; and unless it can
do this, and much more, it is out of the question for practical navigation.
lVor/cs 0fRsfcrenca—A very large and complete list of works on aéronautics will be found in
"‘ Aiirial Navigation,” a fragmentary volume written by Charles 13. Mansfield in 1851, and published
in London and New York in 1877. The rules and theoretical discussion in this article are by Mr. R.
II. Buel, in Scientific American, vol. xxii., 64. See also vol. xxix. of same journal.
AJ U PAGE. A tube fitted to the mouth of a vessel for the purpose of modifying the discharge of wa-
ter. If cylindrical or conical, it considerably increases the efflux of water. In the former case, when
the length of the ajutage does not exceed four times its diameter, the increase is in the proportion of
1.33 to 1. “With an ajutage composed of two conic frustrums on a horizontal axis, the bases open-
ing respectively into the vessel and into the atmosphere, the length of the outer frustrum being three
times that of the inner one, and the opening into the vessel being seven-eighths the size of the deliv-
ery-opening, the proportion of 3 to 2 has been obtained.
ALARMS. Machines for giving warning of danger or calling attention. For boiler-alarms, for
indicating low water or an over-high pressure of steam in steam-generators, see BOILERS. For marine-
alarlns, including fog-whistles, etc., see Lren'rnousa and Buovs.
Fire-Alarms, as a rule, depend for their operation upon the increased temperature of the air in the
vicinity of the fire, or upon the burning away of certain connecting-cords which are stretched in
exposed situations. Of the first of these, the simplest form is a gun loaded with blank cartridge
and suspended near the ceiling. The increased heat determines the explosion. Of the second, a
simple arrangement is a weight hung by a cord. When the cord burns, the weight falls, the crash
giving the alarm. Another device consists of a series of tubes which proceed from each floor to a
central office. The occurrence of fire in the edifice produces a blast of air (due to its expansion)
from the tubes. In another invention the increased heat of the apartment causes expansion of a
body of mercury, and brings it in contact with a wire of a metal which readily amalgamates. The
wire then breaks with the strain, and releases a clock-work, which sounds a bell and opens a cock,
allowing the escape of an extinguishing agent. Another device involves a thermostatic arrangement,
by which a closing of an electric circuit is made when the metal expands with the heat. The ther-
mostat is a column of mercury which ascends in a tube and makes the electric connection, or a plate
or coil of two metals on the principle of the chronometer-balance, or it is an elongating-rod. The
connection made, an armature in the telegraphic wire circuit is attracted by its magnet, and releases a
clock-work alarm. The Tunnicliffe alarm is a small cylindrical metal barrel, attached by a screw to
any part of the room. It is loaded with a small charge of powder, and provided with a fuse con-
taining a chemical mixture, which ignites whenever the surrounding atmosphere is heated to 200°
Fahr. The explosion follows, making a loud noise, and, if desired, a small plug is ejected so as to
strike and release a detent in a clock-work, which sounds a bell. Fig. 167 represents a fire-alarm
ALARMS. 57

lpw“ -_..._._,.__. ._.._..._..~-. ...._._ ._.._..r._.._._- _. .- ....m__
which, when acted upon by heat, causes a bell to ring, and which may be ordinarily employed in lieu
of the common press-button as a means of sounding electric hells for calls. To the two metal col-
umns to which the battery-wires are fastened are attached two thin elastic plates of metal tipped
with steel. Their tendency, when heated, is to curve inward, come in contact, and establish electric
communication, thus sounding a gong elsewhere situated. Between the plates is a rod supported by
a sprifig. When the rod is pulled down, a metal part on its end touches both plates, and the current
passes. The plates, when the rod is held up by its spring, are separated by a piece of insulating
material on the rod. This device is very sensitive, and may be adjusted
by moving one of the plates by the screw shown on the side.
Earthquake-Alarms have been made, based on the supposition or dis-
covery that a few seconds previous to an earthquake the magnet tempo-
rarily loses its power. To an armature is attached a weight, so that,
upon the magnet becoming paralyzed, the weight drops, and, striking a
bell, gives the alarm.
Gas-Alarms are employed to give warning of fire-damps in mines,
and also of dangerous leakage of illuminating gas. Chuard’s device con-
sists of a light metallic stem, surmounted by a thin glass globe filled with
atmospheric air. On the lower end of the stem is a ball which gives the
device buoyancy, and also a weight, so that the apparatus is maintained
in vertical position in a vessel of distilled water. The weight is gradu-
ated so that the normal condition of the air causes the finger to indicate
zero on the scale. When the surrounding air becomes mixed with hydro-
gen, the relative weight of the glass globe is changed, and, its contained
air being heavier than the surrounding atmosphere, it sinks, and thus
moves a pointer on a scale. At a certain point on the latter is a mark
indicating that the mingled air and gas has become dangerously cxp10~
sive, and when the pointer reaches this mark it comes in contact with a
magnet, by which a lever is moved and an alarm sounded. Several other
devices founded upon endosmotic action have been proposed. A bladder
of air is placed in a position exposed to the action of escaping hydrogen,
and, by the absorption of gas, its form or specific weight becomes changed,
and by this means a mechanical device for sounding an alarm is actu-
ated. Another gas-alarm for mines or rooms consists of a galvanic battery with a bell, and a glass
tube filled with chloride of palladium. This metallic salt is extremely sensitive to the presence of
carbonic-acid gas, a small quantity of which at once throws down some of the metal from the solu-
tion, and this precipitate, collecting in the bettom of a tube, at once establishes a connection in a
current of electricity, and an electric bell is sounded.
Ansell’s Fire-Damp Alarm consists of a small tube bent in the form of a U, one of the branches of
which ends in a funnel closed by porous earthenware. The tube contains mercury, and, in ordinary
circumstances, when the apparatus, full of air, is placed in pure air, the surfaces of mercury in the two
branches are on the same level. But this is not the case when the air is vitiated by prom-carbonate
of hydrogen. This gas will filter through the earthen partition, penetrate into the funnel, increase
the pressure, and make the column of mercury rise in one branch of the bent tube so as to cause a
contact between two platinum wires which terminate in the two poles of an electric battery. The
current is thus established, and, if an electric bell is placed in the circuit, a signal will be given, which
can be conveyed to any distance.
illill-Hoppor Alarms are attachments to grinding-mills to indicate that the hopper is nearly empty
of grist. Mills have been burned by sparks and heat generated by the stones when running empty;
and there are numerous devices for giving timely notice of the fact, and also for stopping the ma-
chinery thereupon. In one apparatus of this kind, which may serve as an example, a bell is so ar-
ranged within the hopper that, when surrounded by the grain, it is held stationary, but when uncovered
is caused to ring by the tremulous motion of the hopper. The grain rests upon a float hinged near
the bottom of the hopper. When the grain is about expended, the float is raised by a weighted lever,
and the spout of an upper hopper is opened to supply the lower one with grain.
llfoney-Drawer Alarms are devices which strike a bell when the till-drawer is opened. A cleat on
the lower portion of the drawer engages a latch, and rings the bell when the drawer is opened or
closed. .
A Pocket-Alarm is shaped like a watch, and has a chain attached to the hook at its upper end.
In case a pickpocket attempts to take the chain, his pulling on the same turns a spring-wheel and
moves a hammer in the apparatus which sounds a bell. Another device is designed to be attached
to the watch, and also to the chain. On the latter being jerked, a spring hammer inside the apparatus
is freed, and a percussion-cap is struck and exploded.
Clock-Alarms usually consist of a bell or wire coil and hammer, which is set in motion by a recoil
escapement. Devices are provided so that whatever figure on a small movable dial is made to come
to a small pointer set as a tail to the hour-hand, the alarm is let ed at that hour, and operates until
the spring which actuates it runs down. Alarms are also arranged in connection with the mechanism
of watches, to sound at certain fixed times.
Bilqe-W'atm' Alarms are used on ships to indicate an excessive depth of water in the hold, and a
possible leak. One form has a rectangular box, placed vertically near the bottom of the vessel. As
the water rises in the box a float therein is lifted, and the rod of the latter connects with clock-work,
so that the same may be released and allowed to sound a bell when the float reaches a certain height.
A dial is provided in connection with the rod, so as to indicate the height of the float at all times.
In another form a tube is bent to conform to the transverse sectional shape of the vessel, and is pro-


58 ALCARAZA.

vided with a whistle at each end. At the lowest midship portion the bilge-water is admitted at a
gauze-covered opening. When a considerable amount of water has collected in the pipe, the rolling
of the vessel causes the water to eXpcl the air in the tube through the whistles, which thus sound an
alarm. A form of leak-alarm is represented in Fig; 168. The water rising in the hold elevates the
float, permitting the spring-drum to revolve and wind up the chain. This rings the alarntbell, and
169.
ll
.2.
168. “A,”
l







§ff¥ ; - I?



7//
Q.


moves the index, which signifies the depth. As the water falls the float rewinds the spring. An ice-
berg-alarm is a thermometrical device. '
Burglar-Alarms are devices to be attached or connected with doors or windows, so as to give
warning of the attempted entrance of an intruder. Fig. 169 shows one of the numerous forms of
the application of the electric circuit and apparatus to the above purpose. Copper wires running
through the house connect with a battery, and have circuit connections attached to the doors or win-
dows, so that, when one of the latter is opened, the armature is released from the magnets and causes
a bell to strike, and also ignites a fluid-lamp or candle, or turns on the gas, left burning low. The
circuit being completed by the motion of the door or window, the magnet B attracts the armature C,
and sets free a detent, so that a weight runs an alarm-hammer, while the match-puller reciprocates
and lights the lamp or gas. Portable burglar-alarms are constructed in the form of wedge-shaped
eases having clock-work and a gong inside. These are placed on the floor, so that the door of a room,
on being opened, strikes the device and moves a detent, which allows the clock-work to run down and
sound the bell.
Alarm-Funnels are used to indicate that liquid in a barrel has risen to a certain point. The fun-
nel being placed over the bung-hole of the barrel, the rising liquid raises the float, which detaches
the button from its stop and rings the alarm-bell.
A Hot-Bearing Alarm, for giving warning of an overheated journal, is illustrated in Fig. 170. It is the
invention of Mr. S. Alley. The alarm is given by a tappet fixed to the revolving-shat t striking against the
clapper of a bell. This bell, as will be seen from the engraving, Fig. 170, is hung from the end of a
lever which is supported in a raised position by resting on a knife-edge formed at the side of a hollow
spindle which rests on the top of a hollow fusible plug A, inserted in a casting which can be screwed
into the top of the bearing. The plug A is made of hard lubricant, and, on its melting, the hollow
plunger on the spindle 0 falls, thus lowering the bell so that its clapper is acted upon by a wooden
striker fixed to the revolving-shaft. When the plunger 0 falls the
glass globe containing oil falls with it, until the collar a of its
mounting comes into contact with the tubular part b of the main
casting. This arrests the further fall of the globe, and the plunger
a, continuing to fall, parts the conical joint shown, and allows any
oil that may be in the glass globe to fall at once through the holes
(I on to the bearing.
ALCARAZA. A vessel of porous earthenware, used for cooling
the contained liquid by evaporation from the exterior surface—popu-
larly called a “ water-monkey.” The vessel is usually enveloped in
I a light cord net, and, after being filled, is suspended in a draught of
air.
ALLOYS. Antimony Alloys—All the antimony-metal of com-
merce may be considered an alloy. It is never pure, but contains
iron in all instances. Antimony and tin, in equal parts, form a
moderately-hard, brittle, but very brilliant alloy, not soon tarnished,
and frequently employed for small speculums in telescopes. Of all the metals, antimony combines
most readily with potassium and sodium. These alloys are obtained by smelting the carbonaceous
compounds of these metals or their oxides mixed with carbon. The presence of other metals, such as
copper and silver, does not diminish the affinity of these metals for antimony. The alloy thus formed
of the alkaline metals is not easily evaporated by a strong heat. 80 parts of lead and 20 of anti-
mony form type-metal ; to this, commonly, 5 or 6 parts of bismuth are added. Tin 80 parts, antimony
20, is music-metal; it is also composed of 62.8 tin, 8 antimony, 26 copper, and 3.2 iron. Plate-pew


ALLOYS. 59

ter also contains from 5 to 7 per cent. of antimony; 89 tin, 7 antimony, 2 copper, 2 iron, is one of
these compositions. Britannia-metal contains frequently an equal amount of antimony. Queen’s-
metal is 75 tin, 8 antimony, 8 bismuth, and 9 lead. Crude antimony is employed for purifying gold.
Aluminum Alloys.--' ‘he only aluminum alloys which have acquired importance in the arts are the
so~callcd aluminum bronzes. According to M. Morin, very homogeneous alloys are obtained with
copper, and 5, '71}, and 10 per cent. of aluminum. The alloys with 5 and 10 per cent. of aluminum
are both of a golden color, while that with 71} per cent. has a greenish tint. Even so small an addi-
tion as 1 per cent. of aluminum to copper considerably increases its ductility and fusibility, and im-
parts to it the property of completely filling the mould, making a dense casting free from all air-
bubblcs. At the same time the copper becomes more resistant of chemical reagents, increases in
hardness without losing in malleability, and unites in itself the most valuable qualities of bronze and
brass. A copper alloy with 2 per cent. of aluminum is said to be used in the studio of Christofle, in
Paris, for works of art. It works well under the chisel and graver.
The true aluminum bronzes are alloys containing 90 to 95 per cent. of copper with 10 to 5 per cent.
of aluminum. The direct mixture, by first fusion, of 10 parts of aluminum and 90 of copper, gives
a brittle alloy, which, however, increases in strength and tenacity by several successive fusions ef-
fected in crucibles. The aluminum bronze is homogeneous, and possesses sufficient expansion to fill
the remotest parts of the mould. It affords sharp castings that can be worked more readily than
steel. Aluminum bronze may be forged at a dull-red heat, and hammered until cooled off without
presenting any flaws or cracks. Like copper, it is rendered milder and more ductile by being plunged
into cold water when hot. The bronze polishes beautifully and possesses great strength—according
to Anderson’s experiments, an average of 75,618% lbs. per square inch. The resistance to compres-
sion is feeble. From the experiments of Colonel Strange on the relative rigidity of brass, ordinary,
and aluminum bronze, it appears that the last named is 40 times as rigid as brass, and 3 times as
rigid as ordinary bronze.
Other experiments have shown that aluminum bronze does not expand or contract as much as
ordinary bronze, or brass; that under the tool it produces long and resisting chips, does not clog the
file, engravcs nicely, etc., and it is easily rolled into sheets; that in the melted state it expands very
much, and is fit for the sharpest castings; but that, as it cools off rapidly, it is subject to shrinkage,
and hence to cracks when the articles are bulky, thus requiring numerous runners and a heavy feed-
ing head; and lastly, that, although not entirely unoxidizable, it is not so readily tarnished by con-
tact with the air as polished brass, iron, steel, etc. Dr. Bicdermann speaks very highly of this metal:
“ In the construction of physical, geodic, and astronomical instruments,” he says, “it is far prefer-
able to all other metals. In jewelry, and articles of art and luxury, it is employed in large quantities.
Many kinds of house-utensils are made of it, and it is also adapted to journal and axle boxes. Gun
and pistol barrels, as well as rifled cannon, have been made of it, and have done excellent service.”
It has been highly recommended for type-inctal—type made of it lasting, it is affirmed, fully 50 times
as long as those from common metal type. It has been employed for the bed of perforating machines
for perforating postage-stamps, and for the main~springs of watches (90 copper and 5 aluminum),
being very hard and elastic, not magnetic, and less liable to rust than steel. Its price, however,
ranging, according to its percentage of aluminum, is probably the greatest impediment to its com-
men use.
Aluminum alloys with many other metals have been made, but none of them have acquired a
permanent value in the arts. They may be passed over with the brief remark that aluminum contain-
ing 4 per cent. of silver is employed for the beams of fine balances, for which it is peculiarly fitted
from its comparative lightness and stability; and that the addition of a small percentage of aluminum
to steel is claimed to impart special virtues to the latter—a claim which, however, has not yet been
well established.
Arsmlz'c Alloy/a—Arsenic promotes the union of these metals which without its assistance do not
unite. It has this effect on zinc and lead, iron and lead, and iron and aluminum. Like antimony, it
has a remarkable tendency to cause metals to crystallize, but its alloys are not so brittle as those of
antimony. In producing a high degree of fluidity, it admits of the melting of metals at a low heat,
and enables them to contract in small compass. All metals combine easily with arsenic, and the
alloys, with the exception of silver, are readily decomposed by continued heat. It requires caution in
operating upon the arsenic alloys of alkaline metals, as they decompose rapidly in damp air, and
evolve arseniureted hydrogen, a virulent poison. Alloys of copper and arsenic are commonly known
as white copper or tombac. Arsenic is added to lead in the proportion of two or three thousandths
in the manufacture of shot, the effect being to help the solidification, and to cause the metal to pour
more readily. The alloys of arsenic are generally known as arsenidcs, and are rather “unions” than
true alloys of metals.
Bismuth Alloys.-—Bismuth is scarcely used alone, but it is employed for imparting fusibility to
alloys, thus:
8 bismuth, 5 lead, 3 tin, constitute Newton’s fusible alloy, which melts at 212° F.
2 bismuth, 1 lead, 1 tin, Rose’s fusible alloy, which melts at 201° F.
5 bismuth, 3 lead, 2 tin, when combined, melt at 199°.
8 bismuth, 5 lead, 4 tin, 1 type-metal, constitute the fusible alloy used on the Continent for pro-
ducing the beautiful casts of the French medals, by the cl'iché process. The metals should be re-
peatedly melted, and poured into drops until they are well mixed. Mr. Charles V. Walker substituted
antimony for the type-metal, and strongly recommends this latter in preference to the first-named
fusible alloy. Sec “ Electrotype Manipulation,” part ii., pp. 9~11, where the cliclzé process is described.
1 bismuth and 2 tin make the alloy Mr. Cowper found to be the most suitable for rose-engine and
eccentric-turned patterns, to be printed from after the manner of letter-press. He recommends the
thin plates to be cast upon a cold surface of metal or stone, upon which a piece of smooth paper is
60 ALLOYS.

placed, and then a metal ring; the alloy should neither burr nor crumble; if proper, it turns soft
and silky; when too crystalline, more tin should be added.
2 bismuth, 4 lead, 3 tin,
1 bismuth, 1 lead, 2 tin,
All these alloys must be cooled quickly, to avoid the separation of the bismuth ; they are rendered
more fusible by a small addition of mercury.
Cadmium Alloys are little used in the arts. The ready volatilization of the metal has been the
chief drawback to their formation and study. '7 8 parts of cadmium to 22 parts mercury is sometimes
used for filling teeth. 750 parts gold, 166 silver, and 84 cadmium, is an alloy for jewelers’
use. Cadmium 2, tin 2, lead 1, and bismuth 3, melts at 150° F., and is known as Wood’s fusible
allov. -
Chromium Alloys—These are usually combinations of the metal with iron or steel. Iron 68.60 and
chromium 31.40 is fibrous, silvery, and very brittle. Alloys of steel and chromium can be polished
and damascened. The addition of from 1 to 2 per cent. of chromium tends to harden and slightly
increase the tenacity and ductility of cast-steel. Chromeisen, however, has been used to replace
Spiegeleisen in steel-making, and the result has been a very soft steel. This is remarkable, owing
to the known hardness of chromium. The alloy, on being analyzed, yielded metallic iron 96.40 per
cent; metallic chromium, 2.30 per cent; lime, silica, 1.30, and carbon traces. Chromium alloys
have been made with tin and copper, but have no utilizations.
Cobalt Alloys.—Cobalt with antimony forms an iron-gray alloy; with iron, a very hard alloy; with
gold, it is yellow and fragile; with platinum, fusible. Cobalt amalgam resembles silver. Alloys of
this metal have been made with lead and tin, but have no especial interest.
Copper Alloys.—Copper unites easily with most other metals, and forms the basis of a large num-
ber of important alloys. Of these the principal are those made of copper and zinc, or the brasses,
and those of copper and tin, known as bronze, gun and bell metal.
Copper, when alloyed with nearly half its weight of lead, forms an inferior alloy, resembling gun-
metal in color, but very much softer and cheaper, lead being only about one-fourth the value of tin,
and used in much larger proportion. This inferior alloy is called pot-metal, and also cock-metal,
because it is used for large vessels and measures, for the large taps or cocks for brewers, dyers, and
distillers, and those of smaller kinds [or household use. ’
Generally the copper is only alloyed with one of the metals—zinc, tin, or lead; occasionally with
two, and sometimes with the three in various proportions. In many cases the new metals are care-
fully weighed, according to the qualities desired in the alloy, but random mixtures more frequently
occur, from the ordinary practice of filling the crucible in great part with various pieces of old metal,
of unknown proportions, and adding a certain quantity of new metal to bring it up to the color and
hardness required. This is not done solely from motives of economy, but also from an impression
which appears to be very generally entertained, that such mixtures are more homogeneous than those
composed entirely of new metals, fused together for the first time.
The remarks we have to offer on these copper alloys will be arranged in the tabular form, in four
groups; and, to make them as practical as possible, they will be stated in the terms commonly used
in the brass-foundery. Thus, when the founder is asked the usual proportions of yellow brass, he will
say, 6 to 8 oz. of zinc (to every pound of copper being implied). In speaking of gun-metal, he would
not say it had one-ninth, or 11 per cent., of tin, but simply that it was 11}, 2, or 21} oz. (of tin), as the
case might be ; so that the quantity and kind of the alloy, or the addition to the pound of copper, is
usually alone named.
Alloys of Copper and Zinc only—The marginal numbers denote the ounces of zinc added to every
pound of copper.
% to 1}- oz. Castings are seldom made of pure copper, as, under ordinary circumstances, it does not
cast soundly; about half an ounce of zinc is usually added, frequently in the shape of 4 oz. of
brass to every pound of copper; and by others, 4 oz. of brass are added to every 2 or 3 lbs.
of co )per.
1 to 1% oz. lGrilding-metal, for common jewelry. It is made by mixing 4 parts of copper with 1 of
calamine brass; or sometimes 1 lb. of copper with 6 oz. of brass. The sheet gilding-metal
will be found to match pretty well in color with the cast gun-metal, which latter does not
admit of being rolled; they may be therefore used together when required.
3 oz. Red sheet-brass, made at Hegermiihl, or 51} parts copper, 1 zinc. (Urea)
3 to 4 oz. Bath-metal, pinehbeck, Mannheim gold, similor, and alloys bearing various names, and re-
sembling inferior jeweler’s gold greatly alloyed with copper, are of about this proportion;
some of them contain a little tin; now, however, they are scarcely used.
6 oz. Brass, that bears soldering well.
6 oz. Bristol brass is said to be of this proportion.
8 oz. Ordinary brass, the general proportion ; less fit for soldering than 6 oz., it being more fusible.
8 oz. Emerson’s patent brass was of this proportion, and so is, generally, the ingot brass, made by
simple fusion of the two metals.
9 oz. This proportion is the one extreme of Muntz’s patent sheathing. See 10%.
10.} oz. Muntz’s metal, or 40 zinc and 60 copper. “Any proportions,” says the patentee, “between
the extremes 50 zinc and 50 copper, and 37 zinc, 63 copper, will roll and work at the red-
heat; ” but the first-named proportion, or 40 zinc to 60 copper, is preferred.
The metal is cast into ingots, heated to a red heat, and rolled and worked at that heat into
ships’ bolts and other fastenings and sheathing.
12 oz. Spelter-solder for copper and iron is sometimes made in this proportion; for brass-work the
metals are generally mixed in equal parts. See 16 oz.
12 oz. Pale-yellow metal, fit for dipping in acids, is often made in this proportion.
% constitute pewterer’s soft-solders.
ALLOYS. 61

16 oz. Soft spelter-solder, suitable for ordinary brass-work, is made of equal parts of copper and
zinc. About 14 lbs. of each are melted together and poured into an ingot-mould with cross-
ribs, which indents it into little squares of about 2 lbs. weight; much of the zinc is lost.
These lumps are afterward heated nearly to redness upon a charcoal fire, and are broken up,
one at a time, with great rapidity, on an anvil or in an iron pestle and mortar. The heat is
a critical point; if too great, the solder is beaten into a cake or coarse lumps, and becomes
\ tarnished; when the heat is proper, it is nicely granulated, and remains of a bright-yellow
color; it is afterward passed through a sieve. Of course, the ultimate proportion is less
than 16 oz. of zinc.
16 oz. Equal parts is the one extreme of Muntz’s patent sheathing. See 105.
161} oz. Hamilton and Parker’s patent mosaic gold, which is dark-colored when first cast, but on
dipping assumes a beautiful golden tint. “ When cooled and broken,” say the patentees, “all
yellowness must cease, and the tinge vary from reddish-fawn or salmon color to a light purple
or lilac, and from that to whiteness.” The proportions are stated as from 52 to 58 zinc to
50 of copper, or 161- to 17 oz. to the pound.
32 oz., or 2 zinc to 1 copper. A bluish-white brittle alloy, very brilliant, and so crystalline that it
may be pounded cold in a pestle and mortar.
128 oz., or 2 oz. of copper to every pound of zinc. A hard crystalline metal, differing but little from
zinc, but more tenacious ; it has been used for laps or polishing-disks.
Remarks on {he Alloys of Copper and Zine—These metals seem to mix in all proportions.
The addition of zinc continually increases the fusibility, but, from the extremely volatile nature of
zinc, these alloys cannot he arrived at with very strict regard to proportion.
The red color of copper slides into that of yellow brass at about 4 to 5 oz. to the pound, and
remains little altered unto about 8 or 10 oz.; after this it becomes whiter, and when 32 oz. of zinc
are added to 16 of copper, the mixture has the brilliant silvery color of speculum metal, but with
a bluish tint.
These alloys, from about 8 to 16 oz. to the pound of copper, are extensively used for dipping,
as in an enormous variety of furniture-work ; in all cases the metal is annealed before the application
of the scouring or cleaning processes, and of the acids, bronzes, and lacquers subsequently used.
The alloys with zinc retain their malleability and ductility well, unto about 8 or ten oz. to the
pound ; after this the crystalline character slowly begins to prevail. The alloy of 2 zinc and l cop-
per, before named, may be crumbled in a mortar when cold.
The ordinary range of good yellow brass, that files and turns well, is from about 4;} to 9 oz. to
the pound. With additional zinc, it is harder and more crystalline ; with less, more tenacious, and it
hangs to the file like copper; the range is wide, and small differences are not perceived.
Alloys of Copper and Tim only—The marginal numbers denote the ounces of tin added to every
pound of copper.
Ancient Copper and Tin Alloys.
% oz. Ancient bronze nails, flexible, or 20 copper, 1 tin. (Ure.) .
According to Pliny, as quoted by Wilkinson.
9 32' ioefsiggngféizreg Ct: to 1 Ancient weapons and tools, by various analyses, or 8 to 15 per
2% 02' Hard bronze 0!] 7 to 1 ' cent. tin; medals from 8 to 12 per cent. tin, with 2 parts
' ’ ' zinc added to each 100, for improving the bronze color. ( U re.)
6 to 8 oz. Ancient mirrors.
Alodern Copper and Tin Alloys.
1 oz. Soft gun-metal, that bears drifting, or stretching from a perforation.
1?} oz. A little harder alloy, fit for mathematical instruments; or 12 copper and 1 very pure grain
tin.
1% oz. Still harder, fit for wheels to be cut with teeth.
1% to 2 oz. Brass ordnance, or 8 to 12 per cent. tin; but the general proportion is one-ninth part
of tin.
2 oz. Hard bearings for machinery.
22L oz.- Very hard bearings for machinery. By Muschenbroek’s tables it appears that the proportion
1 tin and 6 copper is the most tenacious alloy ; it is too brittle for general use, and contains
2;} oz. to the pound of copper.
3 oz. Soft musical bells.
3% oz. Chinese gongs and cymbals, or 20 per cent. tin.
4 oz. House-bells.
41} oz. Large bells.
5 oz. Largest bells.
7} to 8;} oz. Speculum metal. Sometimes 1 oz. of brass is added to every pound, as the means
of introducing a trifling quantity of zinc; at other times small proportions of silver are added;
the employment of arsenic was strongly advocated by the Rev. John Edwards. Lord Oxman-
town, now the Earl of Rosse, says: “ Tin and copper, the materials employed by Newton in the
first reflecting telescope, are preferable to any other with which I am acquainted; the best
proportions being 4 atoms of copper to 1 of tin (Turner’s numbers) ; in fact, 126.4 parts of
copper to 58.9 of tin.”
32 oz. of tin to 1 lb. of copper make the alloy called by the pewterers “ temper,” which is added in
small quantities to tin for some kinds of pewter, called “tin and temper,” in which the copper is fre-
quently much less than 1 per cent.
Remarks on the Alloys of Copper and Tin only—These metals seem to mix in all proportions.
62 ' ALLOYS.

The addition of tin continually increases the fusibility, although, when it is added cold, it is apt to
make the copper pasty, or even to set it in a solid lump in the crucible.
The red color of the copper is not greatly impaired in those proportions used by the engineer,
namely, up to about 21,; oz. to the pound ; it becomes grayish-white at 6, the limit suitable for bells,
and quite white at about 8, the speculum metal; after this the alloy becomes of a bluish cast.
The tin alloy is scarcely malleable at 2 oz., and soon becomes very hard, brittle, and sonorous; and
when it has ceased to serve for producing sound, it is employed for reflecting light.
The tough, tenacious character of copper under the tools rapidly gives way ; alloys of 1% out easily,
2% assume about the maximum hardness without. being crystalline; after this they yield to the file by
crumbling in fragments rather than by ordinary abrasion in shreds, until the tin very greatly predomi-
nates, as in the pewters. When the alloys become the more flexible, soft, malleable, and ductile, the
less copper they contain.
Alloys of Copper and Lead only—The marginal numbers denote the ounces of lead added to every
pound of copper.
2 oz. A red-colored and ductile alloy.
4 oz. Less red and ductile; neither of these is so much used as the following, as the object is to em-
ploy as much lead as possible.
6 oz. Ordinary pot-metal, called dry pot-metal, as this quantity of lead will be taken up without sep-
arating on cooling; this is brittle when warmed.
'7 oz. This alloy is rather short, or disposed to break.
8 oz. Inferior pot-metal, called wet pot-metal, as the lead partly oozes out in cooling, especially when
the new metals are mixed; it is therefore always usual to fill the crucible in part with old
metal, and to add new for the remainder. This alloy is very brittle when slightly warmed.
More lead can scarcely be used, as it separates on cooling. '
Remarks on the Alloys of Copper and Lead only—These metals mix in all proportions until the lead
amounts to nearly half ; after this they separate in cooling.
The addition of lead greatly increases the fusibility.
The red color of the copper is soon deadened by the lead; at about 4' oz. to the pound the work
has a bluish leaden hue when first turned, but changes in an hour or so to that of a dull gun-metal
character.
When the lead does not exceed about 4 oz. the mixture is tolerably malleable, but with more lead ‘
it soon becomes very brittle and rotten; the alloy is greatly inferior to gun-metal, and is principally
used on account of the cheapness of the mixture, and the facility with which it is turned and filed.
Alloys of Copper, Zinc, Tin, and Lead, eta—This group refers principally to gun-metal alloys, to which
more or less zinc is added by many engineers; the quantity of tin in every pound of the alloy, which
is expressed by the marginal numbers, principally determines the hardness.
Keller’s statues at Versailles are found, as the mean of four analyses, to consist of
Copper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.40, or about 1413L oz.
Zinc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5.53 “ 1 “
Tin . . . . . . . . . . . . . . 1.70 “ a“
Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.37 “ 1]; “
In 100 parts or the 16 oz.
11} to 21; oz. tin to 1 lb. copper used for bronze medals, or 8 to 15 per cent. tin, with the addition of
2 parts in each 100 of zinc, to improve the color.
The modern so-called bronze medals of our mint are of pure copper, and are afterward
bronzed superficially;
1.1; oz. tin, 1} oz. zinc, to 16 oz. copper. Pumps and works requiring great tenacity.
14; oz. tin, 2 oz. brass, 16
1g (4 2 H
2 “ 1% " 16 For turning-work.
2,1» “ 1.1; “ 16 “ For nuts of coarse threads, and bearings.
The engineer who uses these five alloys recommends melting the copper alone; the small
quantity of brass is then melted in another crucible, and the tin in a ladle ; the two latter are
added to the copper when it has been removed from the furnace; the whole are stirred together
and poured into the moulds without being run into ingots. The real quantity of tin to every
pound of copper is about one-eighth ounce less than the numbers stated, owing to the addition
of the brass, which increases the proportion of copper.
1% oz. tin, 1% oz. zine, to 1 lb. of copper. This alloy, which is a tough, yellow, brassy gun-metal, is
used for general purposes by a celebrated engineer; it is made by mixing 1% lb. tin, 11} lb.
zinc, and 10 lbs. of copper. The alloy is first run into ingots.
2?} oz. tin, 1} oz. zine, to 1 lb. of copper, used for bearings to sustain great weights.
2% oz. tin, 24; oz. zinc, to 1 lb. of copper, were mixed by the late Sir F. Chantry, and a razor was made
from the alloy ; it proved nearly as hard as tempered steel, and exceedingly destructive to new
files, and none others would touch it. '
1 oz. tin, 2 oz. zinc, 16 oz. brass. Best hard white metal for buttons.
15 oz. tin, 11}; oz. zinc, 16 oz. brass. Common ditto. (Plrlllips’s Dictionary.)
10 lbs. tin, 6 lbs. copper, 4 lbs. brass, constitute white solder. The copper and brass are first melted
together, the tin is added, and the whole stirred and poured through birch twigs into water to
granulate it; it is afterward dried and pulverized cold in an iron pestle and mortar. This
white solder was introduced as a substitute for silver solder in making gilt buttons. Another
button-solder consists of 10 parts copper, 8 of brass, and 12 of spelter or zinc.
s For wheels to be cut into teeth.
ran
“Ah
ALLOYS. 63

v w_>~_---..
Remarks on Alloy/s of Copper, Zine, Tin, Lea/1, eta—Ordinary Yellow Brass (copper and zinc) is ren
dered very sensibly harder, so as not to require to be hammered, by a small addition of tin, say one
quarter or one-half oz. to the pound. On the other hand, by the addition of one-quarter to one-half
oz. of lead, it becomes more malleable and casts more sharply. Brass becomes a little whiter for the
tin, and redder for the lead. The addition of nickel to copper and zinc constitutes the so-callcd Ger
man silver.
Gun-Metal (copper and tin) very commonly receives a small addition of zinc; this makes the alloy
mix better, and to lean to the character of brass by increasing the malleability without materially re-
ducing the hardness. The standard measures for the Exchequer were made of a tough alloy of this
kind. The zinc, which is sometimes added in the form of brass, also improves the color of the alloy.
both in the recent and bronzed states. Lead, in small quantity, improves the ductility of gun-metal.
but at the expense of its hardness and color; it is seldom added. Nickel has been proposed as an
addition to gun-metal by Mr. Donkin, and antimony by Dr. Ure.
Some important experiments in regard to the strength of gun-metal, as affected by heat and as
compared with the strength of some other metals under like conditions, have been made by the Brit-
ish Admiralty (see “Engineering,” vol. xxiv., No. 614). Five rods 1 inch in diameter were made re-
spectivcly of the following compositions: No. l—copper, 87.75; tin, 9.75; zinc, 2.5. No. 2—-coppcr,
91 ; tin, 7; zinc, 2. N0. 3—coppcr, 85 ; tin, 5 ; zinc, 10. No. 4—coppcr, 83; tin, 2; zinc, 15. N0. 5
—copper, 92.5; tin, 5; zinc, 2.5. These were gradually heated in an oil-bath up to 500° Fahr. It
appears that all the varieties of gun-metal suifer a gradual but not serious loss of strength and due-
tility up to a certain temperature, at which, within a few degrees, a great change takes place; the
strength falls to about one-half the original, and the ductility is wholly gone. At temperatures above
this point, up to 500°, there is little, if any, further loss of strength. The precise temperature at
which this great change and loss of strength takes place, although uniform in the specimens cast from
the same pot, varies about 100° in the same composition cast at different temperatures, or with some
varying conditions in the foundery process. The precise temperature at which the change took place
in N o. 1 series was ascertained to be about 370°, while in another bar of similar composition the change
occurred at a little over 250°. The possibility of such a change taking place at a temperature so low
in the best gun-metal, used for the more important parts of machinery and boiler-mountings, is serious.
Phosphor-bronze, the only metal in the series which, from its strength and hardness, could be used
as a substitute, was less afiected by temperature, and at 500° retains more than two-thirds of its
strength and one-third its ductility.
Rolled Muntz metal and copper are satisfactory up to 500°, and may be used as securing bolts
with safety.
Pot-.Metal (copper and lead) is improved by the addition of tin, and the three metals will mix in
almost any proportions. When the tin predominates, the alloy so much the more nearly approaches
the condition of gun-metal. Zinc may be added to pot-metal in very small quantity, but when the
zinc becomes a considerable amount, the copper takes up the zinc, forming a kind of brass, and
leaves the lead at liberty, and which, in great measure, separates in cooling Zinc and lead are
also very indisposed to mix alone, although a little arsenic assists their union by “killing” the
lead, as in shot-metal. , Antimony also facilitates the combination of pot-metal; 7 lead, 1 anti-
mony, and 16 copper, mixed perfectly well the first fusion, and the alloy was decidedly harder than
4 lead and 16 copper, and apparently a better metal. “ Lead and antimony, though in small quan-
tity, have a remarkable effect in diminishing the elasticity and sonorousness of the copper alloys.”
Prof. R. H. Thurston has conducted a very extended series of investigations into the properties
of certain copper alloys, and has deduced the following principal results:
Copper-Zinc Alloys—The experiments upon copper-zinc were begun by casting one series of 21 bars,
each 28 inches in length and 1 inch square in section, and then a second series of 20 bars of similar
size. In the first series the proportions of zinc and copper diifercd regularly for each bar, to the ex-
tent of 5 per cent., bar 1 containing 5 per cent. of zinc, bar 2, 10 per cent., and so on up to 100 per
cent. of pure zinc. In the second series the first bar contained 2% per cent. and the last 974; per cent.
of zinc, the relative differences being the same.
By examination of the color of these various alloys it appears that they may be divided into three
clearly-marked classes, viz.: the yellow alloys, which excludes all those containing less than 55 per
cent. of zinc; the silver-white and brilliant alloys, containing between 60 and 70 per cent. of zinc; and
the bluish-gray alloys, containing more than 75 per cent. of zinc. On applying tests for transverse
strength, it appears that the first class above noted may be separated into two divisions, one showing
considerably more strength than the other; in the first are included the bars containing from 17.99
to 33.50 zinc (and probably all the alloys from pure copper to the latter limit). These show a mod-
ulus of rupture (by which is meant a value proportional to the transverse strength of a bar, and which
is theoretically equivalent to 1% times the load which would break a bar of 1 unit in length, breadth,
and depth, supported at both ends, and loaded in the middle) from 21,000 to 28,000, and are charac-
terized by great ductility and an earthy fracture. The second division includes alloys from 38.65
zinc to 52.28 zinc inclusive, which show greater strength than the preceding. The point of maximum
strength is determined to be between 38.65 zinc and 44.94 zine. The second class of alloys show
great weakness and lack of ductility. The minimum strength was found in alloy of 65 per cent. zinc,
the modulus of rupture being but one-tenth of the maximum. Alloys of the third class showed much
greater strength than those of the second, but not equal to that of those of the first.
In tensile strength, alloys containing up to 50 per cent. zinc average 30,000 lbs. to the square
inch, and are classed as useful metals. 60, 65, and 70 per cent. zinc alloys are very weak, the highest
average being that of the 60 percent. alloy, which is 3,7 27 lbs. to the square inch. The remainder
0f the 21, or third class, average from 18,005 to 5,400 lbs. per square inch, pure zinc being the
weakest. The maximum strength is possessed by an alloy containing somewhat less than 44 per
64 ALLOYS.

-_
cent. of zinc, and the minimum tenacity is 1,774 lbs. per square inch in an alloy of 70 per cent.
zinc. In torsional tests the average results agreed with the foregoing. In compression the 55 per
cent. alloy showed a maximum of 121,000 lbs. to the square inch, pure zinc yielding at 22,000
lbs. Tests conducted on the second series of alloys closely confirm the results already stated, and
need not be detailed.
It is well known that, no matter how accurately alloys may be compounded, chemical analysis of
the metal after casting often reveals a notably difl'crent composition. In analyzing the copper-zinc
alloys above noted, it was found that the only general difference between the components of the
original mixtures and those determined by analysis was that in almost every case a smaller percent-
age of zinc appeared, and a larger percentage of copper. The real decrease of zinc is believed to be
due to volatilization of the metal in melting and casting. The average loss was from 1 to 2 per cent.
in a bar. In several bars a considerable amount of liquation took place, and in general the upper
end of the bar contained the highest percentage of copper.
The variation of specific gravity with change of composition follows a very definite law, decreasing
very regularly with the increase in percentage of zinc. None of the zinc-copper alloys have a greater
density than that of pure zinc, the only apparent exceptions being caused by the presence of pores
and other flaws.
Cbpper-Te'n Alloys—In the experiments on the copper-tin alloys, bars of the same size as already
noted were first cast. Two series of alloys were prepared, the first numbering 30 compositions, be-
ginning with pure copper, and then varying in percentages of tin from 1.9 up to 99.44, and ending in
pure tin. The second series consisted of 20 bars ranging from 97% per cent. copper and 2% per cent.
tin to 974; per cent. tin and 21} per cent. copper, with a regular difference of 5 per cent.
Alloys containing respectively 1.9, 3.73, 7.20, 10, 13.43, 20, and 23.68 per cent. tin were found to
have considerable strength; and all the rest of series 1 are stated to be practically useless where
strength is a requirement. The dividing-line between the strong and brittle alloys is precisely that
at which the color changes from golden-yellow to silver-white, viz., at a composition containing be-
tween 2~1 and 30 per cent. of tin. Alloys containing more than 24 per cent. of tin are comparatively
valueless. Tests by tension give results according with the foregoing. Generally it appears that the
tensile and compressive strengths of the alloys are in no way related to each other; that the torsion-
al strength is closely proportional to the tensile strength, and that the transverse strength may de-
pend in some degree upon the compressive strength; but it is much more nearly related to the ten-
sile strength, as is shown by the general correspondence of the curve of the transverse with that of
the tensile strength. The maximum crushing strength was given by the 30 per cent. tin alloy, and
the minimum by pure tin.
The results of the tests for transverse strength on the second series do not seem to corroborate the
theory given by some writers, that peculiar properties are possessed by the alloys which are com-
pounded of simple multiples of their atomic weights or chemical equivalents, and that these properties
are lost as the composition varies more or less from this definite constitution. It does appear that a
certain percentage composition gives a maximum strength, and another certain percentage a mini-
mum; but neither of these compositions is represented by simple multiples of the atomic weights.
Besides, there appears to be a perfectly regular law of decrease from the maximum to the minimum
strength, which does not seem to have any relation to the atomic proportions, but only to the percent-
age composition. 0n analyzing the copper-tin alloys, there appears to be a greater loss of tin than
of copper in the bars which contain the greater percentage of copper, and a greater loss of copper
than of tin in the bars which contain the largest percentage of tin; and that the bars which contain
about equal amounts of the two metals show a great tendency to liquation. In the alloys containing
less than 35 per cent. of tin by original mixture there is a greater loss of tin than of copper, with but
three exceptions. In the alloys containing more than 70 per cent. of tin there is a greater loss of
copper than of tin, with only one exception. In all of the alloys of these two classes the extreme
variation of a single mixture is 3.6 per cent., and generally it is less than 1 per cent. It further ap-
pears that the actual specific gravitics of all the alloys containing less than 25 per cent. of tin does
not greatly vary from 8.95.
Japanese and Chinese Bronzcs.--.\Iagnificent objects of art produced from these alloys attracted
great attention at the Centennial Exposition of 1876.
The J apanesc alloys are mostly used for ornamental castings, statues, musical instruments, and bells.
The name given to an alloy generally corresponds to the color produced by the treatment which the
objects have to undergo before they are finished; thus some of the alloys are named green copper.
violet copper, black copper, etc. This color depends both upon the composition of the alloy and the
chemicals used in coloring the metal. There are many different means used to produce one and the
same color, and it so happens that almost every manufacturer uses particular compositions of his
own ; generally it is only the proportions that differ, but sometimes even the constituent elements are
different, although the alloy is called by the same name.
The “green copper” (Sci-Do) is composed of copper and lead, or copper, lead, and tin; the Sen-
toku-do, of copper, lead, and spelter, and similar to the old Corinthian alloy, is said to have been
first produced by a large conflagration which took place in China during the earlier part of the
fifteenth century. The black alloy called U-do, of copper, lead, and tin; the brass, of copper and
spelter, sometimes with a slight addition of lead, as, for instance, in Yechiu, one of the chief places
of production of ornamental castings, inlaid with gold and silver; the purple alloy is composed of cop-
per and lead ; the so-called Gin-shibu-ichi is generally composed of 4 parts of copper or alloy and 6
parts of silver. Another peculiar composition is the Shakudo, copper with a small percentage (2 to
5 per cent.) of gold, which produces a beautiful dark-blue color, and is mostly used for articles formed
by hammering, or for repoussé work, generally inlaid with gold and silver, and producing designs
Somewhat similar to the so-called “ Niello ” work.
ALLOYS. 65
A very beautiful production is Mokumc, a word meaning “veins of the wood.” Pieces of this
metal are produced by overlaying and soldering together a certain number of plates of alloys of
silver, red copper, and a blue alloy. These are hammered, kneaded, resoldered, and the hollow spaces
filled up with new metal. Finally, when stretched out in a thin sheet, an exquisite mar-bled pattern
is produced. Messrs. Tiffany & Co., of New York City, have succeeded also in making this curious
combination in great beauty. M. Morin has analyzed various Japanese bronzes, and considers that
the palivfia of black bronzes forms part of the metal, and is not due to a varnish or a superficial
sulphuri'ation, but results from the use of a bronze of rather complex nature, in which are 80 per
cent. of copper, 4 of tin, 10 of lead, 2 of zinc, and 4 of iron, gold, nickel, arsenic, and sulphur.
Some of the bronzes analyzed show a proportion of lead varying from 10 to 20 per cent. added at the
expense of the copper, and a quantity of 7 per cent. of tin. Moulded in very thin plates, this bronze
readily takes any form given to it, and is easily worked, the patina appearing of itself when the fin-
ished work of art is subjected, in a mntflc~furnace, to the action of a very high temperature. Un-
fortunately, these bronzes are very brittle. Fine imitations of Japanese bronzes are made in France
by peculiar chemical treatment of metallic surfaces.
Plwsphor~Bronze.—By the addition of a small percentage of phosphorus to bronze alloy, the qualities
of the latter become more and more changed, the grain or fracture becomes finer, the color brighter,
the elasticity and resistance to strain and compression increase considerably, and when melted it
attains great fluidity. Messrs. Montefiore and Kiinzel have experimented with alloys of copper and
nickel, and with manganese—binary alloys; also with ternary—bronzes of copper, tin, and manga-
nese, with copper, tin, and nickel, as well as with iron alloyed with copper and tin. The manganese
alloys they concluded to be entirely useless, as also those of nickel and of iron. They obtained great
tensile strength and hardness with some of these compositions, but their ready oxidability at high
temperatures made the qualities of the castings uncertain and impracticable.
The action of phosphorus is twofold : 1. It eliminates the oxides, as stated above; and, 2. It makes
the tin capable of adopting a crystalline structure; and as two crystalline metals form a much more
homogeneous alloy than two metals of which one is not crystalline, phosphor-bronze must necessa-
rily be more homogeneous than ordinary bronze. Homogeneity and absence of oxygen increase the
elasticity and absolute resistance of the alloy. Another great advantage of phosphor-bronze is that
its hardness can be regulated by varying the proportion of phosphorus, which, in ordinary bronze,
is done by increasing the proportion of tin, whereby the danger of segregation in the casting is
greatly augmented. Ordinary bronze, after one or two smeltings, becomes thick-flowing and putty-
]ike, while phosphor-bronze remains perfectly liquid until the moment it sets—solidifies; if, there-
fore, it is east just before the “setting” takes place, no segregation is possible. Combinations
of phosphorus with copper, with tin, or with other metals, have long been known by chemists, but
Dr. Kiinzel was the first to employ the same for the purposes above stated. A number of phosphor-
bronze alloys are new manufactured, varying in composition to suit the objects for which they are
intended. The scope of their applications is of course very great. The harder alloys are used for
casting bells, tools for gunpowder mills, etc. ; other somewhat softer alloys are used for engineering
purposes, and the still softer for rolling, drawing, and embossing, etc.
The following tables will show the results of tests made by Mr. Kirkaldy with various phosphor-
bronze alloys:













‘" ' fl
i Pulling Stress per l_Twists in i
Diminution Red‘nsztr“:g 1:22;“ per ‘ Square Inch. 5 Inches. 3 g: ;
I c .—
CAST METAL. °'bse°"°“ nnxwx METAL. _. s .. _' 'u _E E
efore = g 3 a: E; a E .;
Rupture' Elastic. Absolute. ~i g 3 lg: g g H m
‘ “e r j 2 f5 s: 2
__.____ ___.,
P ‘ n, lb Various alloys: lb. lb. . lb. Pent
“'“n- ' - Phosphor-bronze 102.759 49.351? 6.71 ea 37.5
Pure copper . . . . . . . . . .. 8.80 4.4000 6.975 “ “ .. . . . 120.957 47.787 22.8. 52 34.1
Ordinary gun-metal, “ “ .. .. . 120.950 58.381 18.0124 42.4
containing 9 parts cop- “ “ 139.141 54.111.17.93. 53 44.9
per and 1 part tin..... 8.60 12.800 16.650 “ “ 159.515 58.853 13.8, 66 46.6
I hosphcr-bronze .... .. 8.40 2:3.s00 52.625 r *'-
151.119 64.569;15.8; to 42s
“ “ .. .. . . 1.50 24.700 46.100 Copper . . . . . . . . . . . . . . . . . 63.122 37.00286.T; 96 84.1
“ “ . . . . .. 88.40 16.100 44.448 Steel . . . . . . . . . . . . . . . . .. 120.976 74.687.22.41 79 10.9
Iron, galvanized, best I ,
{ charcoal E ......... .. 6588446160480; sr 2st 1.



A series of interesting experiments with phosphor-bronze were made in Berlin by the Royal
Academy of Industry, in order to ascertain the qualities and capacities of the metal while under
heavy strain, and its resistance to often repeated strains. The first bar of phosphor-bronze was tried
under a constant strain of 10 tons per square inch, and resisted 408,230 pulls; a bar of- ordinary
bronze broke even before the strain of 10 tons per square inch had been attained. A secend'bar
of phosphor-bronze was tried under a strain of 12% tons per square inch, and withstood 147,850
pulls; and a third bar, under 7% tons strain, broke only after 3,100,000 pulls. ()n the bending-
machine, phosphor-bronze, while under 9 tons strain per square inch, remained unbroken- after
4,000,000 bends, while ordinary bronze broke after 150,000 bends. Major Majendie tested phosphor-
bronze as to its liability to emit sparks when subject to friction, and attained very satisfactory results.
A grindstone of 9 inches diameter was made to revolve very rapidly, so that any point on the grinding-
face would describe a distance of 2,000 feet per minute; the metal was then pressed against the
revolving stone, and the results proved that the harder descriptions of phosphor~bronze emit sparks
less readily than the softer samples, and much less readily than ordinary gun-metal or copper;
5
66 ALLOYS.

For frictional purposes a special alloy is made by fusing phosphor-bronze in certain proportions,
together with another soft alloy of difierent degree of fusibility, so as to produce by cooling the
given alloys. The shell is then formed of a very tough and hard phosphor-bronze, and the interior
of aforesaid soft alloy. The bearing-surface may then be considered to consist of a large number
of small bearings of soft metal, inclosed in castings of metal almost as hard as the arbor itself.
The microscope reveals this disposition very plainly; and if one of these hearings be carefully sub-
mitted to heat, so as to cause the soft fusible metal to run off, the rest will remain in the form
of a spongy mass. Bearings, slides, eccentrics, etc., of this peculiar alloy are now very largely in
use, and the practical results show that it wears more than five times as long as gun-metal.
Phosphor-bronze is readily rolled or beaten out into sheets. In Russia it has been used as a
material for cartridge sheathing, and specimens have stood 120 trials without tearing. Sheets of
the alloy stand the action of sea-water much better than copper. In a comparative experiment
made at Blankenberg, lasting over a period of six months, between the best English copper and
phosphor-bronze, the following results were arrived at :






THICKNESS OF THE SHEETS Wei ht before Wei ht after .
= 0.236 Inches. Imgnersion. Imgersion. Loss or “Ye‘ght'
lb lb. lb. Per cent.
Sheet ofcopper . . . . . . . . . . . . . . . . . . . . . . . .. 74.4 72.2 2.2 . -
“ “ . . . . . . . . . . . . . . . . . . . . . . . .. 88.9 86.2 2.7 3.100
Sheet of phosphor-bronze . . . . . . . . . . . . . .. 69.5 68.75 0.75 1 .123
“ “ “ . . . . . . . . . . . . . . . 114.3 I 112.97 1 .33 1.195

The loss in weight, therefore, due to the oxidizing action of sea-water during the six months’
trial, averaged for the English copper 3.058 per cent., while that of the phosphor-bronze was but 1.158
per cent., or about one-third. Several Governments have experimented on the use of the alloy for
making cannons. Without any exception, the results showed a much greater resisting power than -
that possessed by ordinary bronze.*
Gold Alloy/a—Gold in the pure or fine state is not employed in bulk for many purposes in the
arts, as it is then too soft to be durable. The gold foil used by dentists for stopping decayed teeth is
perhaps as nearly pure as the metal can be obtained: it contains about 6 grains of alloy in the pennd
troy, or the one-thousandth part. Every superficial inch of this gold foil or leaf weighs three-fourths
of a grain, and is 42 times as thick as the leaf used for gilding.
The wire for gold lace, prepared by the refiners for gold-lace manufacturers, requires equally fine
gold, as, when alloyed, it does not so well retain its brilliancy. The gold, in the proportion of about
100 grains to the pound troy of silver, or of 140 grains for double-gilt wire, is beaten into sheets as
thin as paper; it is then burnished upon a stout red-hot silver bar, the surface of which has been
scraped perfectly clean. 'Whcn extended by drawing, the gold still bearing the same relation as to
quantity, namely, the 57th part of the weight, becomes of only one-third the thickness of ordinary
gold-leaf used for gilding. In water-gilding, fine gold is amalgamated with mercury and washed over
the gilding metal (copper and tin); the mercury attaches itself to the metal, and, when evaporated
by heat, it leaves the gold behind in the dead or frosted state: it is brightened with the burnisher.
By the electrotypc process, a still thinner covering of pure gold may be deposited on silver, steel, and
other metals. Mr. Dent has introduced this method of protecting the steel pendulum-springs of ma-
rine chronometers and other time-pieces from rust.
Fine gold is also used for soldering chemical vessels made of platinum.
Gold leaf, for gilding, contains from 3 to 12 grains of alloy to the ounce, but generally 6 grains.
The gold used by respectable dentists for plates is nearly pure, but necessarily contains about 6
grains of copper in the ounce troy, or one-eightieth part. Others use gold containing upward of one-
third of alloy: the copper is then very injurious.
With Copper, gold forms a ductile alloy of a deeper color, harder and more fusible than pure gold.
This alloy, in the proportion of 11 of gold to 1 of copper, constitutes standard gold; its density is
17.157, being a little below the mean, so that the metals slightly expand on combining. One troy
pound of this alloy is coined into 46% sovereigns, or 20 troy pounds into 9341; sovereigns. The
pound was formerly coined into 44% guineas. The standard gold of France consists of 9 parts of
gold and 1 of copper. (Brande, 979.)
For Gold Plate the French have three different standards: 92 parts gold, 8 copper; also 84 gold,
16 copper; and 75 gold, 25 copper.
In England, the purity of gold is expressed by the terms 22, 18, 16 carats, etc. The pound troy is
supposed to be divided into 24 parts, and the gold, if it could be obtained perfectly pure, might be
called 24.- carats fine.
The “Old Standard Gold,” or that of the present currency, is called fine, there being 22 parts of
pure gold to 2 of copper.
The “New Standard,” for watch-cases, etc., is 18 carats of fine gold and 6 of alloy. No gold of
inferior quality to 18 carats, or the “New Standard,” can receive the Hall mark; and gold of lower
quality is generally described by its commercial value. as 60 or 40 shilling gold, etc.
The alloy may be entirely silver, which will give a green color, or entirely copper for a red color;
but the copper and silver are more usually mixed in the one alloy, according to the taste and judg-
ment of the jeweler.

* Abridged from alecture delivered by Mr. A. Dick before the Society of Arts, 1877.
ALLOYS.
67


*1
a practical jeweler of considerable experience: *
First Group—Different kinds of gold that are finished by polishing,
sarily requiring to be colored.
The following alloys of gold are transcribed from the memoranda of the proportions employed by
burnishing, etc., without neces-
The gold of 22 carats fine, or the “Old Standard,” is so little used, on account of its expense and
greater softness, that it has been purposely omitted.
18 carats, or New Standard gold, of yellow tint : *‘



15 dwt. O grs. gold.
2 dwt. 18 grs. silver.
2 dwt. 6 grs. copper.
20 dwt. O grs.
18 carats, or New Standard gold, of red tint :*
15 dwt. O grs. gold.
1 dwt. 18 grs. silver.
3 dwt. 6 grs. copper.
20 dwt. O grs.

16 carats, or spring-gold. This, when drawn or
rolled very hard, makes springs little inferior
to those of steel:
1 oz. 16 dwt. gold, or 1.12
6 dwt. silver, —- .4
12 dwt. copper,— .12
_______
2 oz. 14 dwt.

—-
2.8
608. gold of yellow tint, or the fine gold of the
jewelers—16 carats nearly:
1 oz. 0 dwt. gold.
7 dwt. silver.
5 dwt. copper.
1 oz. 12 dwt.

608. gold of red tint, or 16 carats:
1 oz. 0 dwt. gold.
2 dwt. silver.
8 dwt. copper.

1 oz. 10 dwt.
408. gold, or the old-fashioned jewelers’ gold,
about 11 carats fine; no longer used:
1 oz. 0 dwt. gold.
12 dwt. silver.
12 dwt. copper.

2 oz. 4 dwt.
Second Group—Colored golds: these all require to be submitted to the process of wet-coloring,
which will be explained. They are used in much smaller quantities, and require to be very exactly
proportioned.
Full red gold:
5 dwt. gold.
5 dwt. copper.
_—
10 dwt.
Red gold:
10 dwt
1 dwt
4 dwt
. gold.
. silver.
. copper.

15 dwt.

Blue gold, scarcely used :
5 dwt. gold.
5 dwt. steel filings.

10 dwt.
Green gold:
5 dwt. O grs. gold.
21 grs. silver.
5 dwt. 21 grs.

Gray gold (platinum is also called gray gold by
jewelers) :
3 dwt. 15 grs. gold.
1 dwt. 9 grs. silver.

5 dwt. O grs.
Antique gold, of a fine greenish-yellow color:




18 dwt. 9 grs. gold, or 18. 9
21 grs. silver, — 1. 3
18 grs. copper, -- .12
20 dwt. O grs. 20. 0
Third Group—Gold solders: these are generally made from gold of the same quality and value as
they are intended for, with a small addition of silver and copper, thus :
Solder for 22-carat gold :
1 dwt. 0 grs. of 22-carat gold.
2 grs. silver
1 gr. copper.
1 dwt. 3 grs.
Solder for 18-carat gold:
1 dwt. O grs. of 18-carat gold.
2 grs. silver.
1 gr. copper.



1 dwt. 3 grs.
Solder for 60s. gold: ’1‘
1 dwt. O grs. of 608. gold.
10 grs. silver.
8 grs. copper.


1 dwt. 18 grs.

Solder for 40s. gold; but middling silver solder is
more generally used:
1 dwt. fine gold.
1 dwt. silver.
2 dwt. copper.


4 dwt.

* When it is not otherwise expressed, it will be understood all these allo
And to insure the standa
fine copper, _obtaincd direct from the refiners.
grains additional of gold are usually added to every ounce.
's are made with fine gold. fine silver. and
gold passing the test of the Hall, 3 or 4
68 ALLOYS.

‘
Dr. Hermstadt’s imitation of gold, which is stated not only to resemble gold in color, but also in
specific gravity and ductility, consists of 16 parts of platinum, 7 parts of copper, and 1 of zinc, put
in a crucible, covered with charcoal powder, and melted into a mass.
Gold alloyed with platinum is also rather elastic, but the platinum whitens the alloy more rapidly
than silver.
When 12 parts manganese and 88 parts gold are melted together, an alloy is produced having a
pale yellowish-gray color, with considerable lustre and hardness, and little ductility. Its fracture is
granular and spongy. It is less easily fusible than gold, and the manganese may be completely sep-
arated by roasting.
Iron and gold have a strong affinity for each other, and the latter may be united in all proportions
with steel or cast-iron. Gold may be used for soldering iron. An alloy with 8 per cent. of iron is of
a pale yellowish-gray color, very ductile and tenacious, and harder than gold. \Vith from 15 to 20
per cent. of iron, the alloy is gray, and will take a very beautiful polish. It is used in jewelry under
the name of gray gold. When 75 to 80 per cent. of iron is alloyed with gold, it has the color of sil-
ver, and is so hard as to be applicable to the purposes of cutting-instruments.
Ooball readily unites with gold, and forms alloys of a dull yellow color, which are brittle when the
proportion of cobalt is one-sixtieth.
Nickel and gold have a brass-yellow color, and are also brittle.
Copper has a great affinity for gold, and combines in all proportions. It heightens the color of
gold and increases its hardness, while its ductility is somewhat impaired. The maximum hardness is
attained with one-eighteenth copper. These alloys, being more fusible than gold, are used for solder-
ing this metal.
The alloy called jewelers’ gold should contain at least 74.6 of gold. In France, according to Ber-
thier, it varies from 92 to 25 per cent. In Great Britain, 18 carats, or 75 per cent., is the standard
for jewelers’ gold, although the proportion of this metal is rarely so much. In Sweden it is 76.6 per
cent., it being there, as in most parts of Europe, regulated by law. In the United States the standard
of gold is not subjected to any legal provision, except in regard to coin, which must contain 9 parts
gold to 1 alloy, of which alloy at least one-half must be silver. In Great Britain the coin consists
of 11 parts gold and 1 copper; and in France, 10 parts of gold and 1 part of copper.
In order to deepen the color of gold alloyed with silver, artists have a mode of alloying a small por-
tion of copper with the surface only, which is done in the following manner: 1 oz. of yellow wax is
melted, and there is added to it a mixture of 2 oz. calcined alum, 12 oz. red chalk, 2 oz. verdigris, and
2 oz. peroxide of copper (copper scales). The four last named must be ground to an impalpable
powder, completely mixed with the melted wax, and moulded into sticks for use. After the surface
of the gold is well rubbed over with these sticks, the article must be exposed to heat sufficient to
burn off the wax entirely. It is then burnished, and washed with a liquor composed of one pint of
water to 2 oz. ashes produced by calcining argal or crude tartar, 2 oz. common salt, and 4 oz. sulphur.
An/imony unites easily with gold, and produces alloys 9f a color more or less pale, according to the
proportions used. They are brittle, and have a dull, granular fracture. The presence of a very
minute proportion of antimony destroys the ductility of gold. It was from this faculty to render
brittle, which antimony exerts over all the other metals, that the earlier chemists gave it the title of
regulars, or le'llle king. To its sulphuret was given the name of lupus metallorum, because, in the puri-
fication of gold, its feeble affinity allowed it to yield the sulphur to the inferior metals, while itself
combined with the gold. The sulphuret is still used for thesame purpose.
Tin forms, with gold, compounds more fusible than the latter; they are ductile when cold, but
crumble at a red heat, if the proportion of tin be as much as ouc~thirty-seventh. With one-twelfth
tin the alloy is of a pale-yellow color, but slightly ductile. and has an earthy fracture.
Zine, in small proportion, renders gold brittle: even 'ts vapors sensibly produce this effect on gold
in fusion. With one-tenth zinc the alloy is very brittle, and has the color of brass. With one-half
zinc it is white, very hard, and takes a high polish. Hellat asserts that an alloy of 7 parts zinc and 1
part of gold is entirely volatilized in a furnace.
Bismuth forms, with gold, brittle alloys of a brassy color. The vapor of bismuth is also sufficient to
diminish the ductility of gold.
Lead forms alloys with gold which are brittle in every proportion. It requires but 1 part of lead
in 500,000 of gold to alter sensibly its ductility. An alloy consisting of 1 part lead and 12 parts
gold is extremely brittle, and has a dull granular fracture similar to that of porcelain.
Silver and gold may be united by rapid fusion in all proportions; but if the fused mass be very
slowly cooled, part of the silver, in combination with a small proportion of gold, separates and floats
upon the surface, leaving beneath an alloy of 5 parts gold and 1 part silver. The alloys of these
metals are more fusible than gold, and have a greenish tinge; even 5 per cent. of silver produces a
decided change of color. The proportions used for the green gold of the jewelers are 70.8 of gold
and 29.2 of silver. These alloys are vcrv ductile, and are harder, more elastic, and more sonorous
than either of the metals themselves. The maximum hardness is attained when the proportion of
silver is one-third.
Plalz'num may be united with gold in all proportions; but, to produce an alloy completely homo~
geneous, it should be exposed to a very high temperature, so as to effect a perfect fusion. These al-
loys are ductile and elastic. When they contain from 7 to 10 per cent. of platinum the color is dull
yellow, like tarnished silver. With one-fifth it exactly resembles platinum; with one-seventeenth
platinum it is in appearance not distinguishable from gold.
Platinum and silver together combine with gold in all proportions, forming double alloys which are
ductile, and possess more stiffness and elasticity than alloys of gold and silver only. Platinum is
sometimes introduced into an alloy of silver, gold, and copper, called doré, and it is not easy to detect
the fraud.
ALLOYS. . 69

r———
Palladium and gold form alloys with less ductility than that of the pure metals. They have a gran-
ular structure, and vary in color from white to gray. With equal parts it is nearly white, and a very
small proportion lessens the color of gold.
Rhodium and gold form alloys, according to Del Rio, which are brittle, unless the proportion of the
former be very small, when it hardens the gold without impairing its ductility. With one-seventh
rhodium the color is unaltered—a striking difference between its effects and those of platinum and
palladiuml upon gold.
Iridium, in being alloyed with gold, but slightly affects it color, and produces ductile alloys. D
Osmium also forms ductile alloys with gold.
Arseniurets of gold (as alloys of arsenic with gold are termed) may be formed by exposing heated
gold to the vapor of arsenic. The gold absorbs a very small proportion, but retains it with so strong
an affinity that it cannot be entirely separated even at a very high temperature. This alloy is
brittle.
Tellurium may be combined with gold artificially, by treating the latter in solution with tellureted
hydrogen gas. The native combinations of these metals found in Transylvania will be noticed among
the ores of gold.
illm'eury and gold form alloys called amalgams. They may be formed by immersing or agitating
gold in mercury, which dissolves it even at common temperatures; but the combination is hastened
by heat. An alloy saturated with gold, and compressed in chamois skin, is white, and at first soft,
but soon becomes solid. It crystallizes in four-sided prisms, and contains 2 parts of gold and 1 of
mercury. When sufficiently soft to be kneaded between the fingers, it contains 6 or 7 parts mercury
and 1 of gold. Amalgams are used in gelding.
Iridium Alloys.—-Iridium is usually mingled with platinum, the alloys of which see.
Iron Allega—[ron and Copper.—Dircct union difficult, but an apparently homogeneous alloy can
be obtained by the simultaneous reduction of the oxides of iron and copper. 0.0286 per cent. of cop-
per diminishes the tenacity of malleable iron; 0.5 per cent. of copper in wrought-iron or steel renders
it red-short; 2 per cent. makes steel brittle.
Iron and Zinc yield, when heated together, a crystalline friable alloy of no value. So-callcd gal.
vanizcd iron is iron covered with a thin alloy of iron and zinc. The iron is immersed in dilute sul-
phuric acid to clear off rust, and is passed through a bath of molten zinc covered with sal ammoniaa.
Aieh zlletal is copper 60 per cent., zinc 38 to 44, and iron 5 to 3 per cent. It is very ductile.
Sterro Metal is a similar alloy, containing copper 60, zinc 34 to 44, malleable iron 2 to 4, and tin
1 to 2.
Iron and T in, when heated together, combine in various proportions, producing alloys varying from
gray to white in color, with a granular crystalline fracture, somewhat brittle, and harder than tin.
When a clean surface of sheet-iron is immersed in a bath of molten tin, a firm adherent coating of a
highly stanniferous alloy is deposited on the surface, the plate so prepared constituting the ordinary
tin-plate.
Iron and Titanium—By the treatment of titaniferous iron ores in the blast-furnace, pig-iron has
been obtained containing upward of 1 per cent. of titanium, either alloyed or disseminated through
the iron; but the malleable iron or steel produced therefrom affords no evidence of its presence.
Iron and Manganese—The necessity of an alloy rich in manganese for the success of the Bessemer
steel process has given rise to ferro-manganese, which is obtained by reducing peroxide of manga-
nese, charcoal, and granulated scrap or cast iron in graphite crucibles. Carbonate of manganese
and oxide of iron, with excess of charcoal in the specially-prepared bed of the Siemens furnace, re-
sult in a fusible alloy of carbon, iron, and manganese. See .llanganese Alloys.
Iron and Tungsten—Tungsten may be mixed with iron by fusion in all proportions, and the larger
the quantity of tungsten, the harder and more difficult to melt is the compound. Like carbon, it ap-
pears to diminish the ductility of iron both when hot and cold, but especially when cold. It is then pos-
sible, by melting together tungsten and iron, to obtain a steel much harder than one with carbon
alone, without the danger of incurring at the same time an excessive fragility when cold, or difficulties
of working when hot. For uses which require a special degree of hardness, a steel rich in tungsten,
called “special steel,” is frequently employed. Thus a fine Sheffield steel for lathe tools, according
to an analysis made by Baron Barnckow in the laboratory of the Stockholm School of Mines, con-
tained 9.3 per cent. of tungsten and 0.7 per cent. of silicium, with only 0.6 per cent. of carbon. This
steel, which 1s used, without being tempered. for turning cylinders cast of hard iron, is of sufficient
hardness to scratch glass, and yet it is not fragile, for great difficulty is experienced in breaking a
31-inch square bar. Prof. IIccren has also found, in a special steel of Mushet’s, 8.3 per cent. of tungsten
and 1.73 per cent. of manganese; this steel seems by its properties to be analogous to that mentioned
above. In another special steel from Howell, Sheffield, 2.863 per cent. of tungsten and 1.15 per cent.
of carbon were found.
Tungsten is added for obtaining not only a steel of great hardness, but one of moderate hardness
combined with a great softness and high ductile capacity. Thus, a steel which would seem to be suit-
able for the tubes of cast-iron cannons gave, on analysis by Tamm : Carbon, 0.52 per cent. ; silicium,
0.04 per cent. ; tungsten, 0.3 per cent. ; phosphorus, 0.04 per cent. ; sulphur, 0.005 per cent. Tested
by Styffe, it showed a strength of 7 71} tons per square inch, with a ratio of the section of rupture to
the original section represented by 0.54. The mean lengthening after rupture was 13 per cent., with-
out taking into account the striction, or reduction of area due to tension, produced by the rupture, and
which extended itself over about three-fourths of an inch.
Iron and Lead—No good alloy known.
Iron and Nickel—Tho alloys of iron and nickel are whiter than iron, are magnetic, capable of rc-
cciving a high polish, and are not so easily affected by air or moisture as iron alone. A natural alloy
of iron and nickel occurs in meteoric masses.
70 ALLOYS.

Iron and Cobalt produce alloys similar to those of nickel. The eifcet of the cobalt is to render the
iron red-short.
Iron and Silver do not alloy well together. The alloy seems homogeneous when fluid, but the silver
separates after cooling. Silver tends to render malleable iron red-short.
Iron with Gold and Platinum..—These metals allay well together, small quantities of iron added to
gold increasing its hardness. With platinum and steel an alloy may be obtained that is fusible at a
temperature considerably below that required to melt steel ; and, with 1 per cent. of platinum, steel
yields a tenacious and fine-grained .product.
Lead Alloys—Lead is alloyed with antimony in the manufacture of type-metal; see Antimony
Alloys. Combined with arsenic, it is employed for shot-making; sec Arsenic Alloys. Lead in very
small proportions suffices to impair the ductility of copper both at ordinary temperatures and at a
red heat. For pewter, solders, etc., see Tin Alloys ,' also SOLDERING. Lead enters into fusible alloys,
for which see Bismuth Alloys. The alloys of lead and silver separate when slowly cooled from fusion.
Practical application of this quality is ailerded in the Patinson process for the separation or con-
centration of silver, in the treatment of argentiferous lead.
.ll/[anganese Alloys.——See Iron and Manganese, under Iron Alloys. Manganese bronze is formed by
the addition of from 1 to 2 per cent. of manganese to the proper proportions of copper and zinc, for
the making of either bronze or brass. It is very homogeneous and close-grained, even a good-sized
ing'ot broken through presenting a fracture as fine and close-grained as a piece of steel; the metal
also possesses increased strength, toughness, and hardness, which latter quality can be increased very
considerably. In color it resembles good gun-metal, but is of a rather brighter and more golden hue.
It can be forged at a red heat and rolled into rods or sheets, and drawn into wire and tubes.
It is about equal in tensile strength and elongation to wrought-iron of average good quality, while
its elastic limit is rather higher; for scarcely any wrought-iron will exceed 10 or 11 tons. A num-
ber of forged specimens which have been tested considerably exceed the very best wrought-iron both
in tensile strength and ultimate elongation, and are fully equal to mild qualities of steel.
llfm-eary Amalgama—The bodies resulting from the union of mercury with another metal are called
amalgams. They include amalgams of mercury and tin, for silvering of mirrors; of mercury with
gold and tin, employed in gilding; and with tin, gold, and silver, used in dentistry. 30 parts of mer-
cury to 1 part sodium forms a compound liquid at moderate heat, but at the ordinary temperature
yields a granular, tolerably hard solid, which may be filed into a powder; while with 1 per cent. of
sodium it is viseid, and consists of a solid and liquid portion. This amalgam is employed as a
medium for elfecting the amalgamation of iron, platinum, etc.; it is also used to facilitate the amal-
gamation of gold and silver. An amalgam of zinc with 20 per cent. mercury is used for coating the
rubbers of electrical machines.
alfolybclen'am Alloys—Berthier states that an alloy of tin 83, molybdenum 7 (or 17 ‘2), is as white,
ductile, and tenacious, as tin, and may be laminated into thin sheets. An alloy of molybdenum with
lead whitcns the color of the lead, if the proportion of molybdenum is not over one-twentieth; above
that, lead becomes harder and darker.
Platinum Alloys.-—~The alloy of platinum, iridium, and rhodium, is harder and withstands a higher
heat than pure platinum, and for that reason is better adapted for making crucibles. Alloys of
platinum and iridium have a greater density in proportion to the amount of iridium present. With
90 per cent. of platinum and 10 of iridium, the density is 21.6; it reaches 22.38 if the iridium forms
95 per cent. of the whole.
Rhodium Alloys—According to Messrs. Scott and Faraday, alloys of steel holding from 1 to 2 per
cent. of rhodium present very great tenacity united to such hardness, that the cutting-instruments made
with these alloys could bear a tempering-heat 30° Fahr. above that of the best Indian wootz, although
the tempering-point of the latter is 40° above that of the best English cast—steel. Equal parts of steel
and rhodium yield a fusible alloy well adapted for the manufacture of metallic mirrors.
Nickel Alloys.-——Nickel is principally used together with copper and zinc, in alloys that are rendered
the harder and whiter the more nickel they contain; they are known under the names of albata,
British plate, electrum, German silver, pakfong, teutanag, etc. The proportions differ much, accord-
ing to price ; thus the
Commoncst are 3 to 4 parts nickel, 20 copper, and 16 zinc.
Best are 5 to 6 parts nickel, 20 copper, and 8 to 10 zinc.
About two-thirds of this metal is used for articles resembling plated goods, and some of which are
also plated (see Silver); the remainder is employed for harness, furniture, drawing and mathematical
instruments, spectacles, the tongues for accordions, and numerous other small works.
The White Copper of the Chinese, which is the same as the German silver of the present day, is
composed, according to the analysis of Dr. Fyfe, of
31.6 parts of nickel, 40.4 of copper, 25.4 of zinc, and 2.6 of iron.
17.48 “ “ 53.39 “ 13.0 “ Frich’s Imitalive Silver.
The white copper manufactured at Sutil, in the duchy of Saxe-Ilildburghausen, is said by Kefer-
stein to consist of copper, 88.000; nickel, 8.753; sulphur, with a little antimony, 0.750; silex, clay,
and iron, 1.75. The iron is considered to be accidentally introduced into these several alloys, along
with the nickel, and a minute quantity is not prejudicial.
Iron and steel have been alloyed with nickel; the former (the same as the meteoric iron, which
always contains nickel) is little disposed to rust, whereas the alloy of steel with nickel is worse in
that respect than steel not alloyed.
Palladium Alloy/a—These are all harder than the pure metal. With silver it forms a very tough
malleable alloy, fit for the graduations of mathematical instruments, and for dental surgery, for
which it is much used by the French. With silver and copper, palladium makes a very springy alloy,
used for the points of pencil-cases, inoculating lancets, tooth-picks, or any purpose where elasticity
ALLOYS. 7 1


and the property of not tarnishing are required; thus alloyed, it takes a high polish. Pure palladium
is not fusible at ordinary temperatures, but at a high temperature it agglutinates so as to be after-
ward malleable and ductile. ,
Palladium and silver combine in almost all proportions, making alloys which have been used for
scales on philosophical instruments.
Silver Alloys.---English standard silver consists of 111,21; pure silver and i8 copper, or 11.10 silver
and 0.90 copper. A pound of troy, therefore, is composed of 11 oz. 2dwts. pure silver and 18 dwts. of
copper. Its density is 10.3; its calculated density is 10.5, so that the metals dilate a little on com-
bining. The French silver coin is constituted of 9 silver and 1 copper. (Brande) The French
billon coin is 1 silver and 4 copper. (Kelly)
“For silver plate, the French proportions are 91} parts silver, i copper; and for trinkets, 8 parts
silver, 2 copper.”
Silver solders are made in the following proportions :
Hardest silver solder: 4 parts fine silver and 1 part copper. This is difficult to fuse, but is occa-
sionally employed for figures.
Hard silver solder: 3 parts sterling silver and 1 part brass wire, which is added when the silver is
melted, to avoid wasting the zinc.
Soft silver solder, for general use: 2 parts fine silver and 1 part brass wire. By some few, three-
fourths part of arsenic is added, to render the solder more fusible and white, but it becomes less
malleable. The arsenic must be introduced at the last moment, with care to avoid its fumes.
Silver is also soldered with tin solder (2 tin, 1 lead), and with pure tin.
Silver and mercury are used in the plastic metallic stopping for teeth.
When heated in a muffle, the alloys of silver and copper are superficially oxidized, presenting various
colored films on the surface. Thus, pure silver with 50 parts of copper per 1,000 silver becomes dull
grayish-white; with 100 parts of copper per 1,000, it assumes a dull grayish-white color with black
fringes along the edges; while with 120 to 140 parts copper the alloy becomes gray, and almost black.
If the copper reaches 160 parts per 1,000, the alloy becomes entirely black. Doppler-‘s reflector-
metal has a bluish-white color, and contains 4 parts of silver to 1 of zinc.
Tin Alloy/a—Tin imparts hardness, whiteness, and fusibility to many alloys, and is the basis of
different solders, pewter-s, Britannia metal, and other important alloys, all of which have a low power
of conducting heat.
Pewter is principally tin; mostly lead is the only addition, at other times copper, but antimony,
zinc, etc., are used with the above, as will be separately adverted to. The exact proportions are un-
known even to those engaged in the manufacture of pewter, as it is found to be the better mixed
when it contains a considerable portion of old metal, to which new metal is added by trial.
Generally, however, pewter consists of lead 80 and tin 20 parts, to which other metals are often
added. Some pcwters, when cast, are black, shining, and soft; when turned, dull and bluish. Other
pewters only contain one-fifth or one-sixth of lead; these, when cast, are white, without gloss, and
hard ; such are pronounced very good metal, and are but little darker than tin. The French Legisla-
ture sanctions the employment of 18 per cent. of lead with 82 of tin, as quite harmless in vessels for
wine and vinegar.
The finest pewter, frequently called “tin and temper,” consists mostly of tin, with a very little cop-
per, which makes it hard and somewhat sonorous, but the pewter becomes brow n-colcred when the
copper is in excess. The copper is melted, and twice its weight of tin is added to it, and from about
one-half to 7 lbs. of this alley, or the “ temper,” are added to every block of tin weighing from 360 to
390 lbs.
Antimony is said to harden tin and to preserve a more silvery color, but is little used in pewter.
Zinc is employed to cleanse the metal, rather than as an ingredient. Some stir the fluid pewter with a
thin strip, half zinc and half tin; others allow a small lump of zinc to float on the surface of the
fluid metal while they are casting, to lessen the oxidation.
Coarse plumbers’ solder contains lead 2 to tin 1 part; common solder is formed of equal parts of
the two metals and fine solder has 2 parts of tin to 1 of lead.
Zinc Alloys—The principal zinc alloys have already been referred to in connection with the alloys
of copper, tin, and lead, which see. In alloys where zinc is a component part, it is best to melt the
zinc in a separate vessel, to pour the molten copper, etc., into the casting-ladle, and, after having cov-
ered the latter with a brasque, to let the zinc into the copper through an opening made in the brasquc.
When melted, zinc is quickly oxidized by air; and if' the temperature is raised above that of fusion, it
will volatilize rapidly, and its vapors will burn, producing a flaring white light and fumes.
Works for Rejertmce.-—“A Treatise on Metallurgy,” Overman, 1866; “The Practical Brass and
Iron Founder’s Guide,” Larkin, 1867 ; “ N ouveau Manuel complet des Alliages Métalliques,” llervé,
Paris, Libruirie Encyclopédique dc Roret (no date); “ Das Kupfer und seine Legirungen, mit beson-
derer Beriicksichtigung ihrer Anwendung in der Technik,” Bischoff‘, Berlin, 1865; “The Brass
Founder’s Manual,” Graham, 1868; “Guide Pratique des Alliages Metalliques,” Guettier, Paris,
1865 ; same in English, “ Metallic Alloys,” 1872; “ Useful Metals and their Alloys,” Scoifern,
Truan, and others, London, 1866; “The Physical Conditions involved in the Construction of Artil-
lery,” Robert Mallet, 1856; “A Manual of Metallurgy,” Greenwood, 187 5; article “ Alloys ” in
Knight’s “American Mechanical Dictionary,” 1874; “A Practical Treatise on Casting and Founding,”
Spretson, 1878; “ Wrinkles and Recipes,” Benjamin, 1878. See also “Report of Committee on
Metallic Alloys,” U. S. Board appointed to test iron, steel, and other metals, Washington, Govern-
ment Printing Office, 1878.
For special alloys, see as follows: “ Fusible at specified Temperatures,” Eclectic Engineering
flfagazine, 1869, p. 172; “Cu 60; Zn 40, very malleable,” M'em. Am. Academy, New Series, Vol.
viii.; “ Phosphorizcd and other Bronzcs for Artillery,” Engineer, Feb. 23, 1872, p. 127; “ Rules for
72 AMALGAMATING MACHINERY.

Making and Melting Alloys,” Jew. Applied Chem, Oct., 1873, p. 158; “Melting Points, Lead and
Tin Alloys,” Iron Age, March 27, 1873, p. 1, also ltbzgtneeo', Sept. 4, 1874 ; “White Metal for
Machinery,” Eeleetz'e Eng. 111669., June, 1873, p. 570; “Deposition of Alloys,” Iron Age, Dec., 1874;
“ Malleable Brass,” Am. Record of Science, &e., 1874, p. 510; “Alloy of Silver and Copper,” Proc.
Roy. 800., May 27, 1875, p. 433; “Alloy of Lead and Tin Foil,” Iron Age, Aug. 26, 1875, p. 3;
“ Chrome Iron,” Chemical News, Sept. 10, 1875, p. 136 ; “ Chromeisen and Others,” Eng. and
Mining Joan, Dec. 25, 1875, p. 627; “Alloy for Journal-Boxes,” Mines, Metals, and Arts, Feb. 3,
1876, p. 182; “Alloy for Bearings,” 92% Rep. Am. B. R. Master Meekam'es’ Assoe’n, 1876, p. 20;
“Alloy of Bronze and Spiegeleisen,” Sci. American Supplement, Dee. 2,1876, p.713; “Parson’s
Alloy,” Set. Amen, Dec. 9, 1876, p. 367;. “Muntz’s Metal,” Iron. Age, Dec. 14, 1876, p. 7 ; “Alloys,”
by W. G. Wertheim, Comptes Rendm, 1843, vol. xxi., p. 998; “Tin and Phosphorus in Copper,” Sci.
Amer. Sup, March 24., 1877, p. 10l7 ; “Copper Alloys,” Sci. Amer, Aug. 4, 1877, p. 65; “Nickel
Alloys,” fifetallw'g. Review, 1*‘eb., 1878, p. 602; “How to improve Alloys,” Sci. Amer. Sup, March
30, 1878, p. 1855 ; “Estimation of Manganese, Lead, Copper, Zinc, and Nickel, and their Alloys,” Sci.
Amer. Sup, Oct. 26, 1878, p. 2343; “Gallium and Aluminum Alloys,” Sci. Amer. Sup, Aug. 3,
1878, p. 2153.
AMALGAMATIN G MACHINERY. Amalgamation is the process of extracting gold and silver
from the gangues in which they occur in Nature by combining them with mercury. The ores are
crushed, and then washed through difierent machines in which mercury is placed. This seizes upon
the little particles of the metals that come in contact with it, and brings them together into one
mass, from which the earthy matters are all washed away. Any greasy substance present almost
wholly prevents this efiect, the grease adhering in a film upon the surface of the mercury, and thus
rendering impracticable the close contact necessary for their union. The amalgam is from time to
time taken out of the washing-machines, squeezed through cloth or dressed deerskin, the liquid por-
tion replaced, and the solid distilled in an apparatus suitable for saving the mercury, which is then
ready for use upon another lot of ore.
AMALGAMATION or Simian—The various processes are as follows: The patio process, the hot
process, the estufa process, the barrel process, and the pan process. In the patio process, the materials
necessary for the reduction of the silver are magistral (a soluble sulphate of copper produced from cop-
per pyrites), common salt, and mercury. The ore is ground to powder and mixed with water to a mud.
It is then placed in walled receivers called “lameros,” where it parts with a portion of its water,
and accumulates until it becomes sufficient to form a “ torta.” This is. then spread out to the thick-
ness of about a foot and tramped by animals, magistral and salt being afterward added, and finally
‘ the mercury. lepeated treading
follows, until the mercury has ab-
sorbed all the silver, when the
mass is washed by agitation in a
series of tanks in which are rap-
idly revolving stirrers. The rate
of motion of these is gradually re-
duced, and the metallic or heavier
particles sink. The earthy por-
tions in suspension are drawn
off, and the amalgam and heavier
mineral particles are separated by
subsequent washing. A portion
of the mercury is then strained
out, and the remaining amalgam
is formed into bricks and retorted.
The hot process is chiefly em-
ployed in South America on a
peculiar class of ores, containing
a large proportion of native silver
ore, in which that metal occurs in
the form of chloride, iodide, or
bromide. The ore is stamped and
washed, and the richer portion
condensed. The latter is placed
in a eazo, or copper-bottomed ves-
sel, over a furnace; water is added
to make it into a paste, and sub-
sequently the salt and mercury
are introduced. The operation
completed, the liquid matter is
removed and added to the ingre-
dients of a “torta,” while the solid
portions are stored in wooden cis-
terns, and are subsequently washed
and treated as described under the
patio process.
In the estufa process, the ground ore is amalgamated as described by patio amalgamation until
the process is about half completed. It is then removed into a chamber termed an estufa (stove),
which has under it a fireplace 6 or 8 feet in length, so connected by side-fines with small chimneys
171.


AMALGAMATING MACHINERY. 73

as to elevate the temperature of the room containing the ore. Here it is exposed to a gentle heat,
and allowed to remain two or three days, when it is again removed, and the reduction completed by
the ordinary method of patio amalgamation.
In the barrel process, the ores are dried in a kiln, dry-stamped, screened, and roasted in reverbera-
tory furnaces, salt and carbonate of soda being added. The roasted ore is then screened and placed
with iron fragments, mercury, and water in revolving barrels. The amalgam is strained through a
canvasi bag to remove a portion of the quicksilver, and is distilled in circular retorts.
The pan process dispenses with the roasting incident to the barrel process. and with the frequent
manipulations and loss of time incident to the patio process. A large number of pans and'amalga-
mators have been devised, all, however, being similar in their action. The grinding in all is effected
between two opposing plates of iron, and the chief differences between them consist in the modifica-
tion of the form of these plates and the extent of their surface. They all combine the qualities of
a mill with the capacity to hold a certain amount of ore-pulp, for it is not simply grinding that is
required; the operation of amalgamation and chemical reduction of the ores is connected with it.
Inasmuch as the constant grinding would soon cut through the thin bottoms of the pans if unpro_
' tected, and destroy the mullers, false bottoms or dies are cast for the pans, and face-plates (shoes)
of hard white iron for the mullers. These are so made as to be easily taken out, and are renewed
when worn out. In general, the pans are not intended to receive and grind coarse materials, though
in some of them ore as large as kernels of corn, or even larger, can be ground to a fine powder with-
17 2. 173.


out much injury to the pan. In practice it is the
battery-pulp and sand which are fed, and this is
generally done in charges (or “ batches”), the weight
of which depends upon the capacity of the pan. _ ~
They are first ground, and then, with the addition of quicksilver, and at a lower rate of speed,
the amalgamation is effected. The charge is then drawn off into a larger pan, fitted With stirrers,
called the separator. In this the pulp is much diluted with water, and the quicksilver and amalgam
fall to the bottom and are collected. _ _ _ _
Pans—The principal pans and amalgamators may be grouped in two chief dIVISIODSZ 1. Those
with flat bottoms; 2. Those with curved or conoidal bottoms. _
The Wheeler pan, Fig. 171, is made with a flat bottom, to which the dies are secured by dovetailed
tongues and sockets. The shoes are attached to the niuller-plate in similar way. The iiiuller is car-
ried by a vertical shaft passing up through the cone in the middle of the pan, and is raised up for
the purpose of cleaning the pan by a screw cut on the shaft. The regulation of the distance of the
shoe and die from one another in working is accomplished by a hand-wheel at the side of the pan,
which through a lever raises or lowers the steel block into which the toe of the upright shaft steps.
Bevel-gearing transmits the motion of the vertical shaft from the horizontal shaft, which has a pulley
on its outer end. . ‘
The Horn pan, Fig. 172, has, like the Wheeler, a flat bottom. The body of the. pan set direct 1y
upon the plate which serves both as foundation and as steam-bottom, and the Jomt is made with
cement. The shoes and dies are secured by dovetailed tongues and sockets. A groove runs around
the pan, outside the circumference of the muller, which is traversed by a scraper, fastened to the
muller. The gutter around the cone is also scraped in the same way. The muller is hung loose
upon the driver, which is carried by the vertical shaft, and is regulated as to height by the screw at
the top, the point of which rests upon the top of the shaft. A yoke is fastened to the bottom 01
the pan, which serves fora foot-step, and also carries the bearing for the horizontal-motion shaft.
The Patton pan, Fig. 173, is a combination of the two pans above described. The steam-bottom
is fastened beneath, as in the Wheeler pan; and the yoke, which in the Horn pan serves for a foot


'74
AMALGAMATING MACHINERY.

step, and also carries the bearing for the horizontal shaft, is here dispensed with, the foot-step and
shaft-bearing being set upon the wooden framing of the mill which carries the pans. The manner of
hanging the muller loose upon the driver, which is carried by a vertical shaft and regulated in height

by a screw at the top, is the same as in the Horn
pan; and the attachment of the dies to the bottom,
and of the shoes to the muller, by means of dove-
tailed tongues and sockets, is the same as in both
the Wheeler and the Horn pans; but in the Patton
pan the sides are of wood. The curved flanges shown



extending inward from the upper part of the side are intended to effect a circulation of the pulp.
The combination pan, Fig. 174, is the Patton pan with the Wheeler foot-step, its chief feature being
a cast-iron ring set in the pan to protect the wooden sides. This ring can be replaced when worn.


































\ a
U









NVV‘J




MAM.
The Knox pan, Fig. 175, is of cast-iron, and has
a false bottom with projecting vertical rim at the
periphery to form a hollow annular space under-
neath for the introduction of steam. There is
also a radial groove in the false bottom for the
accumulation of quicksilver and amalgam, con-
necting with the lower discharge-hole situated op-
posite the driving-shaft. The centre of the yoke
d, attached to the muller m, is keyed to a vertical
wrought-iron shaft 8, guided by a cast-iron hollow
cone in the middle of the pan. The muller m is '
a flat east-iron ring, attached to which are four ,
arms at right angles to one another, and to these
the cast-iron shoes a are bolted through slits c.
Between the muller and shoe a wooden shoe '1',
of the exact shape of the iron one, is introduced ’
to prevent the settling of the unground pulp in
the latter, the upper face of the wooden shoe
reaching above the surface of the pulp.
The Agitator.—The battery-slimes, after being
amalgamated in the pan and the amalgam col-
lected in the settler, are run to a third receptacle
resembling the pan and settler, but of larger di-
mensions and with different working apparatus.
Some kinds of amalgam, such as those containing
copper or antimony, are friable, and on account
of their fineness cannot be recovered from the pulp while it is thick. It is, therefore, run into a
circular tank or tub in which wooden stirrers revolve, a copious stream of water running constantly
AMALGAMATING MACHINERY. 7 5

7*
in at the top. Here the pulp is thoroughly beaten up and thinned, and while the lighter parts flow
off with the current, the amalgam and floured mercury fall to the bottom and collect there. Tlis
amalgam is always both poorer and less pure than that from the settler.
Fig. 176 shows one of II. J. Booth & Company’s agitators. It is formed of a round tub, the bot-
tom and sides of which are made of wood. In the centre a hollow cast-iron cone is bolted, through
which rises the shaft, driven by a cog-wheel below. A cast-iron cap or carrier rests on the top of the
shaft, and from this project iron arms, in which are fastened the wooden stirrers, hanging vertically
and reaching down nearly to the bottom of the tub.
The Smitten—The work of the settler, Fig. 177, in the system of amalgamation, is to separate the
minute particles of mercury and amalgam from the pulp through which they are distributed. It
resembles a pan in some respects,

being made up of a circular box, in 177-
which revolves a central axis carry-
ing arms, and to these arms are fixed shoes. These iron shoes, however, do ‘ ii
not come in contact with the bottom of the settler, as no grinding action is desired. They are faced with wooden rubbers, which keep the heavier parts
of the pulp thoroughly stirred up,
while the revolving arms perform a ._ _ I ,_ p similar service for the lighter portions ,1 ~ floating above. The pulp is thinned “ by a stream of water during the ope-
ration, for which reason the settler
has a larger capacity than the pan.
It is formed of a conoidal iron cast-
ing, in the hollow axis of which works
the upright to which the revolving
arms are fastened. The sides of the
settler are of wood, but sometimes
sheet-iron is used instead. Holes
stopped by plugs are pierced in the
sides at different levels, through which
the thinned pulp can be gradually
drawn off. On one side is bolted an
iron quicksilver bowl, communicating M M
with a radial gutter cast in the iron
bottom. The rotary part of the apparatus consists of the central shaft before mentioned, which
carries on its lower end a beveled cog-wheel, and at its upper end an arrangement for adjusting the
height of the Wooden rubbers, so as to lower them as they gradually wear away. This arrangement
consists in a deep collar embracing the vertical part of the conoidal iron bottom of the settler, and
178. hung upon_ the shaft by a screw furnished with a hand-wheel.
' The revolving arms are carried out from this collar.
Retorts for Amalgama—The silver retort is as well adapted
for the retorting of gold as of silver amalgam, when the quan-
tity is sufficiently large to render it desirable. The silver retort
, shown at a in Fig. 17 S is commonly made 12 inches in diame-
ter inside, with a hood at the mouth having lugs to catch the
" ' clamp which fastens the door. The whole retort is set on cast—
iron bearers in an arch, with the fire-grate under it. The neck
of the retort passes through the back wall, and connects with
the condenser. The condensed
' quicksilver filters through a bag
fastened on the end of the pipe,
and is received into a tray.
AMALGAMATION or GOLD.—
Two distinct systems of gold
amalgamation are in use in Cali-
fornia, namely, amalgamation in
the battery, and amalgamation
in special appliances after the
gold has been previously crushed. In amalgamating in the battery, the latter is often provided with
amalgamated copper plates extending the whole length of the box, one on the feed side and the other
on the discharge, and each having an inclination of from 40° to 45° toward the stampers. When
these are not employed, spaces for the accumulation of amalgam are allowed between the dies and
sides of the box, and vertical iron bars are placed inside the gratings, between which the hard amal-
gam is found to collect. The copper plates are covered with mercury, and the latter is also sprinkled
into the boxes by the feeder. One ounce of gold requires for its collection about an ounce of mercury.
When the rock is crushed without the introduction of silver into the mill, the sand and water
issuing from the latter are conducted over blankets spread on the bottoms and lining the sides of
shallow troughs and sluices inclined at an angle of from 3° to 4° with the horizon. Beyond these
blankets there are in most cases riiflcs or amalgamated copper plates, which are again followed by




















'7 6 AMALGAMATING MACHINERY.

some eontrivance for collecting the pyrites remaining in the tailings. At the further extremity of
this system of appliances there is sometimes a long tail-sluice for the purpose of arresting any auri-
ferous material which may have escaped being caught by the other arrangements.
The blanket washings are introduced into a box in front of the amalgamators, one of which, the
invention of Mr. M. A. Atwood, is represented in Fig. 179. This consists of two hollow cylindrical
179.


l





. W“‘ \
f a so



troughs t t, of wood or iron, which are filled with pure quicksilver. Over these the blanket wash-
ings are directed. The gold, being' specifically heavier than the quicksilver, will sink to the bot-
tom, with the exception of that part which is attached to the quartz or sulphuret, and is conse-
quently buoyed up. The floating skimmings are agitated by wooden cylinders a, suspended par-
allel to and over the centre lines of the trough, and provided with radial arms of iron,the ends
of which are slightly curved. These arms are set along the cylinders in 12 longitudinal rows,
containing alternately 8 and 9 arms, those of each row being set opposite the spaces in the next.
They are not allowed to dip into the quicksilver, but almost touch. These cylinders make 60 revo~
lutions per minute. " ‘
The Rubber.--The sands, after passing from the amalgamators, may be discharged into Eureka
rubbers, in which the particles of gold are intended to be further cleaned and brightened by rubbing
and detached from the sands, while they have an opportunity at the same time to be caught on the
amalgamated copper plates of the rubber. The Eureka, rubber, Fig. 180, consists of a rectangular
cast-iron box, 7 inches deep and 4 feet 8 inches square, provided with a false bottom of cast-iron
dies or plates, on which cast-iron shoes, fastened to a wooden frame, receive a rectilinear motion by
rods connected with an eccentric. The wooden- shoe-boards are covered
with amalgamated copper plate.
3 In the Forster and Firmt'n system of amalgamation the pulverized
ore containing free gold or silver is fed from the hopper, shown in
Fig. 181, with a horizontal tube A. While in the act of falling-it
is impinged upon by a stream of mercury, which escapes from the re-
180.

ll




















BET-diuum



ceptacle B through the inner pipe shown. The flow is broken up and carried forward by steam
or air pressure, after the manner of the well-known principle of the sand-blast. The horizontal
tube connects with a vertical tube 0, upon which the ore and the atomized mercury are together
forcibly projected, grain by grain, in a continuous stream, and fall by their own gravity into the
\
AMALGAMATING MACHINERY. 77

'-
washer or receiver D. It is claimed that an almost unlimited quantity of ore may be treated
by this process, as the attendants have only to feed the hoppers and remove the deposit. The
inventors state that “ with only a three-inch tube from three to five tons of ore can be treated
per hour.” In connection with this amalgamator an improved washer, shown in detail in Fig.
1.81, is used. This consists of a vessel having a conical bottom, in which rollers E, and also with
scrapers or mullers F, are placed. The feed-water is injected through the shaft or near the
bottom of the vessel, and the upward current carries off the waste ore, while the amalgam and
surplus mercury collect in the dead-water space in the conical bottom, whence they are drawn off
through the discharge cock. _ .
Use of Sodium Amalgam—The extraction of gold by amalgamation has hitherto been often at-
tended with difliculties, occasioned by the presence of compounds of sulphur, arsenic, antimony, bis-
muth, or tellurium in the ores, which by covering the gold with a thin film of tarnish prevents its
entering into combination with mercury. The use of sodium amalgam, discovered by Dr. Henry
YVurtz of New York, is said not only to facilitate amalgamation under such circumstances, but also
to prevent the “sickening” of mercury, which is apt to take place in the presence of certain chemi-
cal compounds (among others, sulphate of iron). It is also claimed that by its use the “ flouring ” of
mercury when ground with compounds containing sulphur, arsenic, tellurium, etc., may to a great extent
be avoided. See Phillips’s “ Mining and Metallurgy of Gold and Silver,” London, 1867, p. 220.
Miscellaneous Maehinea—A large number of special contrivances for separating and amalgamating
purposes have been patented, none of which have come into very extended use. Many of them will
be found fully illustrated and described in the article “Amalgamator” in Knight’s “Mechanical
Dictionary.”
AN OHOR. A heavy curved instrument, used for retaining ships in a required position. The forms
of anchors, and the materials of which they are made, are various. In many parts of the East Indies
the lower part of the anchor is formed of a cross of avery strong and heavy kind of wood, the extrem-
ities of which are made pointed. About the middle of each arm of the cross is inserted a long bar of
the same wood, the upper ends of which converge to a point, and are secured either by ropes or an iron
hoop, and the space between the bars is filled up with stones, to make the anchors sink more deeply and
readily. In Spain, and in the South Seas, anchors are sometimes formed of copper, but generally in
Europe they are made of forged iron. Anchors may be divided into two classes: mooring anchors and
ships’ anchors. Mooring anchors are those which are laid down for a permanency in docks and harbors,
and are considerably heavier than ships’ anchors, from which they differ in form, having sometimes but
one arm, and sometimes, instead of arms, having at the extremity a heavy circular mass of iron and
no stock: these latter are called mushroom-anchors. The general form of ships’ anchors is shown in
the annexed figure. There is a long bar of iron a, called the shank, from the lower extremity of which
._ branch two curved arms 6 b in opposite
182- directions, and forming an angle of 60°
‘ each with the shank. Upon each arm,
toward the end, is laid a thick triangu-
lar piece of iron 0 c, termed the fluke.
In the upper end of the shank is an eye,
through which passes a ring d, to which
the cable is attached. The stock ee is
composed of two strong beams of wood,
embracing the shank, or an iron rod
passing through the shank. The stock
stands at right angles to the plane of
the arms, and serves to guide the an-
chor in its descent, so as to cause one of the flukes to enter the ground. Ships are generally provided
with three large anchors, named the best bower, the small, and the sheet anchor; a smaller anchor,
termed the streamnnchor ; and another, still smaller, named the kedge, which latter has generally an
iron stock passing through an eye in the shank, secured thereto by a key, or forelock, which admits
of its being readily displaced : its principal use is in changing the position of a ship in harbor, and in
an operation termed kedging. From the great mass of iron in large anchors (some weighing from
3 to 4 tons), the perfect forging of them becomes a matter of much difficulty; as, from the great
heat necessary to weld such masses, the iron is liable to become “ burnt,” as it is termed. The
strength of anchors is tested by means of the hydrostatic press. The proof-strains are as follows :




Weight of Anchor in Cwt. Strain, Tons. Weight of Anchor in Cwt.‘ Strain, Tons.
l
100 GT 40 i 35
90 63 30 g 23
SO 58 .20 * ‘20
70 53 10 1 2
(i0 48 5 7
50 42 1 3




The following proportions may be used in designing anchors: Length of shank, 100; of each arm
from crown to bill, 40 ; of stock, 100; radius for describing outside curve of arms, 35; angle of face
of palm with shank, 57°. With such proportions the angle of the shank with the ground is 24°, and
that of blade 75°. In devising a new anchor, the danger of the ship’s grounding upon it is a most
important consideration. As a rule, the stocks of anchors weighing more than 60 cwt. are of wood.
The following is a table of the approximate values of the properties essential to a good anchor:
Strength, 45; holding, 30; quick holding, 15; canting, 15; facility of sweeping, 10; facility of stow-
7 8 i . ANCHOR.

ing, 10; exemption from fouling, 10; fishing, 10; facility of transportation in boats, 5; quick trip-
ping, 5: total, 160.
The largest anchor now in existence was made for the Great Eastern. It weighs 8 tons exclusive
of the stock, and the length of its shank is 20 feet 6 inches. It is somewhat different in form from
ordinary anchors, the flukes being split so that the sea-bottom may be more readily pierced. The '
weight of the largest anchors for vessels of 1,000 tens or less bears usually the proportion of about
.0025 the tonnage.
The form of anchor most commonly used in place of that represented in Fig. 182 is Trotman’s,
which is an improvement embodying some minor modifications on Porter’s anchor, shown in Fig. 183.
Hawkins’s anchor, A to E, Fig. 184, hasits shank a
forked to form two loops 6 and c, in each of which is
an eye. Between the loops is an iron block (1, having
a circular aperture to receive the arms, and a square
aperture at right angles to the former, into which is
screwed a stout bar of iron 0, termed a toggle, project-
ing equally on each side of the crown-piece; on the - ,
end of the crown-piece, opposite to that in which is
inserted the toggle, is a ring f for the buoy-rope. The
arms 9 h are formed in one piece, and, before the palms
Mare attached, one end of the arms must be passed
through the eyes in the loops of the shanks and through
the eye of the crown-piece; the palms are then to be put on, and must both lie in the same plane;
after which the arms are to be curved in the same plane with the palms. The crown-piece is firmly
keyed to the arms, and the toggle must be of such a length and form as to make it bear firmly against
the forepart of the fork in the shank, so as to prevent the crown-piece and arms from turning round
upon it, and to retain them at an angle of 50° with the shank. When the anchor is let go, one end
of the toggle will come in contact with the ground, which puts the fiukes in a position to enter; and
' when the strain is upon the cable, that end of the toggle which is upward comes in contact with the






threat of the shank, and sets the anchor in the holding. position, which is shown in perspective at C'.
The advantage of this mode of constructing anchors is, that both arms take the ground, and there-
fore the weight of metal may be diminished and yet an equal, if not a greater, effect be obtained;
also, as there is no stock, and no projecting upper fluke, there is little risk of fouling, as it is termed—
that is, of the cable entwining round the arms.
An anchor upon a similar principle, but of a somewhat different construction, was invented by Mr.
Soames, a front and a side elevation of which are given in Figs. 185 and 186 respectively. In this
anchor there is but one fluke a, which is T-shaped, and works on a pivot in a triangular frame, com-
posed of the two sides 6 and a, forged in one piece, and a stay 01, which serves 'as a stock; ff are
loops, or eyes, for the reception of the chains that unite the ring g, to which the cable is to be fast-
ened. For general purposes, this anchor is perhaps preferable to the former, it being free from the
objection we made to that one, as it admits of detaching the arm, which renders it more convenient
to stow away; also, as the shank is formed in two parts, instead of one of equal area, they are more
easily forged soundly, and consequently less liable to breakage.
The peculiarity of the anchor proposed by W. Rogers consists in its having a hollow shank, formed
ANCHOR. ' '7 9

w—
out of 6 bars of iron, of such thickness as to insure the forging of them perfectly sound for an-
. chors of the largest dimensions. In Fig. 187, A represents a side-view of the anchor, and B a plan
of the stock. The two principal pieces a a are bent so as to form a part of the arms or fiukes; the
other four are formed into a hollow tube 61) (as shown in section at 0) for a centre-piece, and p
the whole are firmly welded together at both ends of the shank. The intermediate parts are secured
by strong hoops ii, so that every piece must bear its proportion of the entire strain. In place of
the usual ring, there is a bolt and shackle c, employed alone when the anchor is to be used with


72—h—









chain cables; but when hempen cables are to be used, a ring d is connected to the shackle c by an
additional shackle and bolt e. The anchor-stock f may be formed either of a single piece, or of two
pieces hooped together, and is secured in its place as follows: The belt and shackle 0 being with-
drawn, the small end of the shank is passed through the eye of the stock f (which is defended by an
iron plate 9 on each side); the collar 71. is then put over, and the stock is keyed up against the hoop
2' by the forelock key It passing through a hole in the shank.
\Villiams’s anchor, Fig. 188, has three flukes hinged to a block at the lower end of the shank, and
so set that two of them may penetrate the ground simultaneously, while the third falls down upon
the shank to prevent the fouling of the cable. The flukes are hinged to separate blocks, and are
188.
188.4. 188 B.









120° apart. Fig. 188arepresents Morgan’s anchor, the arms of which are separately pivoted to the
shank, and are connected by a curved bar passing through the latter. When one fluke has held on
the ground, its arm rests against and is supported by the crown-piece, while the other arm falls down
upon the shank. Fouling is thus prevented, and the arms through the curved bar re'cnforce one an-
other. Marshall’s anchor, Fig. 188 B, has straight arms, moving separately on a pivot passing through
the crown. The arms are barbed, and oscillation is checked by cusps on the thick portion of the
crown, which hold the arms at a given inclination to the shank. Latham’s anchor, Fig. 189, has its
so ' ANCHOR.

shank A B in two pieces, between which plays a middle fluke attached to an arm 0,>which has two
other flukes on its ends. When the anchor is let go, the flukes make about a quarter of a revolution,
lying in the position shown when they enter the ground. The shoulder on the crown-piece comes
, against the shank, and restrains the oscillation of the arms in either direction. This anchor maybe
very compactly stowed by bringing the arms parallel with the shank. P
Two simple forms of anchor are represented in Figs. 190 and 190 A. Both are in use by fishermen
the world over. In Fig. 190A two stout pieces of wood are lashed or framed together crosswise;
from the extremities rise wooden or iron rods, which inclose a large stone; the rods meet above,
190 A.


190 C.


and an eye is added for the attachment of the cable. Fig. 190 is simply a forked piece of wood, the
long arm serving as a shank, the short one, Which is barbed and shed with iron, as a single fluke.
Sea-anchors are used by vessels when off soundings to prevent drifting, and to keep the ship’s head to
wind or sea. They are used during bad weather, and often enable vessels to ride out storms in which
their safety might otherwise be endangered. The sea-anchor represented in Fig. 1903 consists of
three spars lashed in the form of a triangle. Canvas is attached to the spars and backed by a strong


f: I
a time ".




2%. \-
rope-nettine'. A kedge suspended from the base of the triangle, keeps it in vertical position, and
three hawsers are attached to the angles and also to the ship’s cable. 'The anchor in Fig. 190 c is made
of two stout iron bars pivoted together at their middle and spread apart at right angles to each other.
A rope is carried from end to end, and canvas and netting are spread on. the frame thus formed. A
buoy is fastened to the end of one of the bars, and prevents the sinking of the eontrivance, while
showing its position. The bars of which this anchor is formed may be folded parallel, thus admit-
ting of the compact stowage of the device when not in use. -
Tyzack’s anchor is represented in Figs. 191 and 192. A is the shank made in two'parts secured
ANCHOR. , ' * , 81

to each other by the pins H a K D. The arm with its fluke B is fitted with a T head hg, which
bears on the pin H, as shown. Two pins F Fare fixed in the head, and act instead of the single
pin H. The anchor has only one arm, which is reversible, and so arranged that, whichever way the
anchor falls, it finds itself at once in a position. to bite. The other chief advantages claimed are:
that the anchor cannot foul when hold-ing, having no projection above the shank; that it is very snug
for hazi‘dling; occupies a minimum space in stowing; can be readily taken to pieces; and pos-



sesses unusual strength, being made without a single weld. This anchor has been experimented
with to test its biting and holding power, by dragging it over some rough ground by means of a
powerful steam winch, when it was found that, immediately the steam winch caused the anchor to
move, the arm at once penetrated the ground and buried itself immovably. An anchor of this type,
weighing 6 tons 3 cwt. 5 qrs. exclusive of stock, has been subjected to the following strains, viz.:
In the first instance to the Admiralty test, 9 tons 1 cwt. l qr.; then to 13, 17, 21, 25, 26; and finally
to 32 tons, at which strain—250 per cent. overproof—it was broken to destruction.
Anchor-trippers are devices for tripping or letting go an anchor, either after it is catted and fished
or while it is hanging from the cat-falls. We give illustrations of five devices for tripping the
anchor under the first-mentioned circumstances. In Holmes’s tripper, Fig. 193, a short chain is at-
tached to the ring of the anchor, and a large link on the end of said chain passes over a pin. The
latter has a spiral thread which works in a nut in the hearing, so that, when the pin is turned, it re-
cedes, and so frees the link. The shank-painter is similarly secured to a like device, and both pins
must therefore be turned simultaneously to drop the anchor. In Ileitman’s tripper, Fig. 194, the
anchor is suspended by shank-painter and ringstopper. One end of each chain is fast to the vessel,
while the rings at the other ends rest upon pivoted latch-pieces. These last are supported upon a
bar, which is rotated by a lever to give simultaneous disengagement of the latches. In Gibson’s
tripper, Fig. 195, the fluke ol' the anchor rests on a block A, which is pivoted in a notch of the
' gunwalc. A bar B attached to said
195. block is held by a shackle-bar 0, when
the latter is in its upper position.
196, By sliding the shackle in its staple
the bar is released, and the block A
~—--——-—"—":* “2 v— is thus free to turn under the weight
< of the anchor. Duncan’s device, Fig.
‘\ 196, is for dropping the anchor from

the cat-falls. The ring of the anchor-
is held in a clutch substituted for the -
usual cat-hook, which is automatical--
ly opened by the chains and levers
shown as the tackle is slackencd. In-
Stacy’s device, Fig. 197, the hook is
1 canted by a rope made fast to an eye
in its rear portion, as the fall is paid.
out. As the hook upsets, the anchor,
of course, slides off. In both Bur-
ton’s and Spenee’s inventions the prin-
ciple is the same. It consists in sup-
porting the end of what is termed the
standing part of the cat-head stopper
and shank-painter by bolts turning
upon pivots, and retained in a proper
position by a catch, which being with-
drawn, the bolt turns upon its pivot
and the stopper slips off; by which
means all risk of jamming the turns
of the stopper (as in the common method of letting go the running end) is avoided, the danger to the
men on the forecastle is done away, and the anchor can be let go at. a moment’s warning.
The arrangements in each of these inventions being the same, whether applied to cathead stoppers
0r shank-painters, we shall therefore show one invention as applied to cat-head stoppers, and the
other to shank-painters. Figs. 198 and 199 show Capt. Burton’s method of letting go a cat-head
stopper. a is the cat-head; b c a bolt, turning upon a pivot d; the end 0 forms an oblique plane,









-
\\\.\\\‘$
“
.~






6 ' .
82 ANEMOMETER.

and is held down by the clamp e turning upon a pivot f, the clamp being secured by a hasp yand
pin h. The standing end of the stopper,_having an eye formed in it, passes over the end 6 of the
' bolt b c; the other end of the stopper passes through the ring of the anchor and over the thumb-
cleat k, and is made fast round the timber-head Z. When it is required to let go the anchor, a hand-
spike is inserted between the thumb~cleat It, so as to nip the clamp e, and the hasp g is cast oil’;
then, upon withdrawing the handspike, the bolt, being no longer held by the clamp e, turn-s upon
its pivot cl by the weight of the anchor on the stopper, and the eye of the stopper slips off the end
of the bolt.
Figs. 200 and 200A represent Mr. Spence’s invention for letting go a shank-painter. Fig. 200 is an
elevation, and Fig. 200 A the plan. a is a cast-iron carriage, bolted through the ship’s side, and sup-
porting the hook d by a pin or pivot at b; d e a lever turning upon a centre f, the end d being
formed into a hook, which clasps the upper end of the bolt 6, the lever being retained in the posi-
tion shown in the plan by a pin 9; k is part of a chain forming the standing part of the shank-
painter, and supported by the bolt b. To the other end of the chain is spliced the running part of
the shank-painter, which passes round the shank of the anchor, and is made fast to'a timber-head.
When it is required to let go the shank-painter, an iron bar is inserted into the end e of the lever
dc, which is made hollow for the purpose, and, the pin 9 being ,
withdrawn, the lever is turned round its centre until the bolt is 200 B.
released from the hook cl, when it falls, and the chain-end of the
shank painter slips out. '


















19$.
,
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4 - 200.
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_—


The Dunn Steel Anchor, represented in Fig. 200 n, is made of cast steel, and has but three principal
parts: the shank, the pin, and the combined crown and fiukes.
The crown and flukes rotate on a pin joining them to the shank-head, and are so constructed that
if the pin breaks the anchor will still hold and perform its functions, while the shank cannot draw out
and the anchor be lost. The enlarged shank-head working against the round shoulders inside the
crown prevents any such accident.
When let go from a ship this anchor, on striking the bottom, “ bites” immediately after strain is
brought upon the chain, irrespective of the position in which it strikes, and owing to the shape
of its crown both flukes engage at once, thus securing a large holding surface. As constructed for
the new U. S. cruisers Newark, San Francisco, Philadelphia, Baltimore, Concord, and Bennington,
the Dunn anchor is made under the following specifications: Tensile strength of steel, 60,000 lbs. per
sq. in.; elongation, 15 per cent. in 8 in. Test-pieces 1 in. square must bend 90° over a radius of
not more than 1:} in., and the steel must not show more than 0.06 per cent of phosphorus.
ANEMOMETER. An instrument for measuring the force of the wind. The apparatus of
Whewell and Osler determine the force of the wind by the number of revolutions of a
ANIMAL STRENGTH. 83

windmill fly, the axis of which by perpetual screws and toothed wheels is connected with the register-
ing pencil. In Whewell’s instrument the windmill with its wheels and vane is on a horizontal plate,
which revolves on the top of a vertical cylinder. The pencil is attached to a little block of wood or
nut, through which passes a screw from the horizontal plate above to a circular rim below the cylin-
der, all which revolves around the cylinder as the wind changes. A straight rod also goes through
the pencil-block or nut, up and down which it slides as the screw turns. According as the wind
blows gently or strongly, this screw turns slowly or fast, and carries the pencil down the cylinder at
a proportional rate. Its point reaches the surface of the cylinder and marks upon it its position;
and as the frame turns with the change of direction of the wind, the course of the wind is registered
upon the face of the cylinder. For this purpose it is divided by vertical lines into 16,01' 32 equal
parts corresponding to the points of the compass. This instrument is deficient in not recording the
time during which each wind blows, nor the times of its changes, nor its force at any particular
moment. It merely gives the order of the changes of the wind, and the entire quantity that
blows from each point. This is known by the vertical length of the pencil-mark in each
division of the cylinders corresponding to the courses. It is defective also by the friction of its
machinery. ‘ '
Osler’s instrument, constructed on similar principles, is more complicated than Whewell’s. Its
register is divided by lines into spaces, which represent the 24 hours of the day, and in these spaces
pencils inscribe lines, one of which indicates the direction, another the pressure of the wind, and a
third, connected with a rain-gauge, the quantity of rain which has fallen at every hour. The register
moves along by clockwork under the pencils, and at the meteorological observatory at Greenwich a
new one is employed every day. In the Royal Exchange in London one of these instruments is in
use with a register made to last a week. By the lines inscribed on the register the integral or quan-
tity of the wind can be calculated that has blown to each point of the compass during the periods
of the observations; and thence the resultant, or average effect of all the winds.
The instrument now in use in'the United States office for weather reports is Robinson’s anemomc'
ter, Fig. 201, which consists of four horizontal arms
radiating from a central point, at which is a ver-
tical axis of revolution. A hollow hemispherical cup
is attached to each arm in such manner that, when
the wind is pressing upon the concave side of a cup
on one arm, the cup on the opposite arm presents its
convex side toward the wind. The wind exerts more
pressure on the concave side than on the convex, and
hence causes the arms to revolve. The rate of revo-
lution per minute gives the velocity of the wind.
Each instrument has to be tested by placing it upon
a moving body on a calm day. In this way it is
easily found what the number of revolutions is which
the instrument will give for any velocity; it is then placed upon a high building, and its axis
attached to a recording apparatus similar to that described above.
Biram’s anemometer is an instrument for measuring and registering the quantities of air which
circulate through the passages of mines. It was invented in consequence of the recommendation of
a committee appointed by the British House of Commons, that the use of such an instrument should
be adopted as a precaution against the explosions in coal-mines. It is a disk of a foot diameter,
made to revolve when placed in a current of air, and furnished with registering wheels like those
upon a gas-meter. Any want of attention on the part of those having charge of supplying the re-
quired current of fresh air is thus readily detected.
An extended treatise on this subject will be found under the same heading in Spon’s “Dictionary
of Engineering.”
ANIMAL STRENGTH. Of all the first movers of machinery, the force derived from the strength
of man or other animals was first used, and at present, in a multitude of cases, is still the most
convenient. As horses were formerly employed for the same purposes that water-wheels, wind-
mills, and steam-engines now are, it has become usual to calculate the effect of these machines
as equivalent to so many horses; and animal strength becomes thus a sort of measure of mechanical
force.
When an animal is at rest, and exerts its strength against any obstacle, then the force of the animal
is greatest; or the animal, when standing still, will support the greatest load. If the animal begins to
move, then it cannot support so great a load, because a part of its strength must be employed to efi‘ect
the motion; and the greater the speed with which the animal moves, the less will be the force exerted
on the obstacle, or the less will be the load which it is able to carry, for the greater will be the portion
of its strength directed to the movement of its own body; and there will be a speed with which the
animal can move and carry no load, but where the whole of his strength is employed in keeping up
its velocity. ' '
It is clear that, in the first and last of these cases, the useful effect of the animal is nothing, in a.
mechanical point of view. There must, however, be a certain relation between the load and speed of
the animal, in which the useful effect is a- maximum. It has been found that the mechanical effect
of any animal at work during a given time is greatest when the animal moves with one-third of the
greatest velocity with which it can move unloaded, and the load which it bears is four-ninths of that
which it can only move.
Jl/[an and Animal Power compared—The following table, from Haswcll’s “Engineers’ and Me-
chanics’ ?ockct-Book,” shows the amount of labor produced by animal power under difl'ercnt cir-
cumstances :


84 " ' ANIMAL STRENGTH.




‘ , . Weight Raised Horse-Power
Power. veisoc“, dper Foot per , for Given
MANNER or APPLICATION. 8”“ ' Minute. - Period.
Lbs. Feet. Lbs. “No.
10 House PER DAY.
Man throwing earth with shovel a height of 5 feet . . . . . . . . . . . . . 6 1} v _ 480 8.7
Man wheeling a loaded barrow up an inclined plane, height one-
twelfth of length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 182 5 4,950 90
Man raising and pitching earth with a shovel to a horizontal
distance of 18 feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 21- 810 14.7
Man pushing and drawing alternately in a vertical direction. . . 13 2} 1,950 . 85.5
Man transporting weight upon a barrow and returning unloaded. 182 1 7,920 144
Man walking upon a level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 5 42,900 780
Horse drawing a four-wheeled carriage at a walk . . . . . . . . . . . . . 154 8 27,720 504
Horse with load on back at walk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 8% 59,400 1080
Horse transporting a loaded wagon and returning unloaded at a -
' walk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,540 2 ’ 184.800 8360
Horse drawing a loaded wagon at a walk . . . . . . . . . . . . . . . . . . . . .. 1,540 8} 846,500 6800
8 Hours PER DAY. ‘
Man ascending a slight elevation unloaded . . . . . . . . . . . . . . . . . . .. 143 1} 4,290 62
Man walking and pushing or drawing in a horizontal direction. 26 2 3,120 45.2
Man turning a crank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 2‘} 2,790 89
Man upon a tread-mill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 140 1} 4,200 60 9
Man rowing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26 5 7,800 113 a
Horse upon a revolving platform at a walk . . . . . . . . . . . . . . . . . .. 100 8 18,000 260.8
Ox, same conditions . . . . ..-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 182 2 15,840 220.5
Mule, “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 3 11,880 172.2
Ass, “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2% 5,280 ' 76.5
7 Hones PER DAY.
Man walking with a load on his back . . . . . . . . . . . . . . . . . . . . . . . . . 88 _ 2} 18,200 167 .9
6 Bones PER DAY.
Man transporting a weight upon his back and returning un-
loaded. . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 13- 14,700 160.5
Man transporting a weight upon his back up a slight elevation, . '
and returning unloaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 .2 1,680 19
Man raising a weight by the hands . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 1 1,820 14.4
41} HOURS PER DAY.
Horse upon a revolving platform at a trot . . . . . . . . . . . . . . . . . .. 66 6} 26,730 218.7
Horse drawing an unloaded four-wheeled carriage at a trot.. .. 97 7:} 43,195 358.5
Horse drawing a loaded four-wheeled carriage at a trot . . . . . . . . 770 9} 884,950 2741







Hwnan Strength—The mean effect of the power of a man unaided by a'machine working to the
best practicable advantage, is the raising of 70 lbs. 1 foot high in a second, or 10 hours per day.
The maximum power of a strong man exerted for 25» minutes equals 18,000 lbs. raised 1 foot in a
minute. A man can travel without a load on level ground during 81} hours per day, at the rate of 3.7
miles per hour, or 31;}; miles per day. Trained pedestrians have, however, greatly exceeded this:
100 miles has been walked in 20 hours, 37 minutes, and 45 seconds; 1,000 miles in 1,000 consecutive
hours (this by a young woman); and 520 miles in 6 days. Among other exceptional feats of strength
which may be mentioned, are the swimming of the English Channel from Dover to Calais—distance,
23 miles in a straight line, but amounting in the accomplishment to 50 miles—by Matthew Webb, in 21
hours and 45 minutes. Agnes Beckwith, a young girl, swam 5 miles in 1 hour and 9 minutes. 13
feet '7 inches has been leaped at a standing jump. 11} miles has been skated in 3 minutes and 6 sec-
onds. A man has lifted 3,300 lbs. in harness, and 1,230 lbs. by the hands alone- A dumb~bcll
weighing 201 lbs. has been raised with one hand. One-quarter of a mile has been run in 48;} sec-
onds. Cases of this kind indicate exceptional powers of endurance, and usually abnormal develop-
ment of certain muscles. Such extreme stress on the physical powers is apt to be injurious. Dr. B.
F. Richardson, in discussing the subject, says that physical overculture produces aneurism of the
aorta, wearing out of the heart, and also an undue muscular development of that organ; and he fur-
ther asserts that “there is not a professional athlete in England of the age of 35, who has been 10
years at his calling, who is not disabled.”
An investigation has been made (1877) by Dr. Burcq, of Paris, in the .E'cole dc la Faisanderz'e, a
gymnasium where are drilled the soldiers who are destined to be the gymnastic instructors of the
French army. No better set of men could be selected for examination, for the reason that each in-
dividual is virtually intended hereafter to serve as a model for others, and therefore his physical cult-
ure is brought to the best possible state. Dr. Burcq continued his investigations with the utmost care
and minutcness for six months, during which period the progress of over a thousand men was closely
watched and criticised. As a general result, he states that gymnastic exercises—1. Increase the mus-
cular forces up to 25 and even up to 38 per cent., at the same time tending to equilibrate them in
the two halves of the body; 2. Increase the pulmonary capacity at least one-sixth; 3. Increase the
weight of men up to 15 per cent., while, on the other hand, diminishing the volume. - This augmenta-
tion exclusively benefits the muscular system, as is demonstrated by its elevated dynamometric value.
And Dr. Burcq further observes that, during the first half of the six months’ course at the school,
the increase of force was most markedly noted. ~
AQUEDUCT. 85

F?
To Dr. Bureq’s studies upon this body of trained gymnasts may be added those of M. Eugene Paz,
who for a long period has been observing the results which methodical physical exercise produces in
certain invalids, and in a large number of people of various callings, notably artists, literary and busi-
ness men, and others, whose muscles are normally less voluminous than those of the picked soldiers
at the Faisanderie School. By means of a variety of ingenious mechanical apparatus, and by a course
of investigation wholly different from that of Dr. Burcq, M. Paz reaches precisely the same results.
He notes especially the increase in weight and decrease of volume of the body, above referred to, and
also the augmentation of pulmonary capacity. Three operatic singers, who were rigorously trained for
a year, attained a maximum lung-power corresponding exactly to an increase of one-sixth. It fol-
lows, therefore, that Dr. Burcq’s results may be considered in the light of a general law.
F. E. Nipher has determined, after a series of investigations upon variation of muscular strength,
that the coefficient of muscular power per square centimetre of section of muscle is a quality which
varies greatly with different muscles, and with the same muscle at different times; or, the work which
a muscle can perform depends not only upon its size, but also upon its quality. Muscles which are
seldom called into action have not the same contracting power as those which are daily used. '
Brute Strength—The following table shows the amount of labor a horse of average strength is
capable of performing at different velocities on canals, railroads, and turnpikes:





USEFUL EFFECT FOR 1 DAY,
VELOCITY PER DURATION OF DRA“’N 1 MILE.
' noun. wonx.
On 5 Canal. On 0 Railroad. I On a Turnpike.
Miles. Hours. Tons. Tons. Tons.
. 2% 11.5 520 115 14
3 S 243 92 - 12
4 4.5 102 7‘2 .0
5 2.9 52 57 7.2
6 2 30 " 4S 6
7 1 . 5 19 41 5 . 1
8 1.125 12.8 36 4.5
10 .7 5 ' 6.6 28.8 3.6







AQUEDUCT. The new Croton Aqueduct recently constructed for the supply of New York city
has a maximum flowing capacity of 320,000,000 gallons per day from Croton Dam to a point near the
New York city boundary-line, where it is designed to construct a large distributing reservoir to
supply the annexed district; a part of the supply being there diverted, the remaining portion of the
aqueduct has a flowing capacity of 250,000,000 gallons per day. The'northern portion is 13.6 ft.
high and 13.6 ft. wide; the semicircular arch has a radius of 6.8 ft., the concave sides are on a
radius of 20.92 ft., and the invert . p
has a radius =of 18.5 ft. Where "'01 A'
necessary, the rock walls are
evened with concrete, and a ma-
sonry lining built 12 in. thick at
the side and arch, and 6 in. thick
at the. invert; but where the
character of the rock justifies it,
no masonry is needed. The other
part of the aqueduct, about 61}
miles in length, is circular in sec-
tion, 12 ft. in diameter, and lined
with masonry 12 in. thick. Owing
to the insufficient elevation of the
land, this section is depressed
about 100 feet below the other.
The Harlem River is crossed by
an inverted siphon, the depth be
low the river being about 200 ft.
From Groton Dam to Harlem
River the aqueduct is 28;} miles
long, and to Central Park reservoir 3% miles; the total length of open cuts, varying from 0 to 40 or
50 ft. between the arch and ground surface, north of the Harlem, is but about 3,000 ft. ; all the rest
of the line is through solid rock. The method of building the aqueduct was by sinking shaft-s about
one mile and a quarter apart, and working both ways from each. There were 24 shafts north of the
Harlem and 8 south of it, varying in depth from 28 to 350 feet.
Mg. 201 A represents a longitudinal section of the tunnel under the Harlem River, the length of the
here being 1,937 ft. Where the aqueduct has a diameter of 12 ft. 3 in., the cross-section of the
excavation is a circle 14 ft. 11 in. in diameter; where it is 10 ft. 6 in. in diameter, the circular see-
tlon of the excavation is 13 ft. 10 in. in diameter. _
AROHES. Arches are of various shapes, as pointed, elliptical, segmental, and circular. The outer
surface of the arch is called the extrados, or back of the arch; the inner or concave surface the intrados
or the sqzfit. The joints of all arches should be perpendicular to the surface of the soflits. The stones


se ARBOR.
"\
are called arch-stones, or voussoirs. The first course on each side are termed wingers, which rest on
the imposts or abutments. In case of' a segmental arch, the course beneath the springers are called
skew-backs. The extreme width between springers is called the span of the arch, and the versed sine
of the curve of the soffit the rise of the arch. The highest portion of the arch is called the crown,
and the centre course of voussoirs the key-course. The side portions of arches between the springing
and the crown are termed haunches, or flanks. All arches should be well sustained by backing on
A


C





















the haunches, called spandreZ-backing. The line of intersection of arches cutting across each other
transversely is called a groin. In Fig. 238, A is a semicircular arch; B, segmental arch; C, ellip-
‘ tical arch; D, three-centre arch; E, parabolic arch; F, pointed arch; G, straight arch; H, cam-
bered arch; I, groined arch; J, fluing arch; K, skew arch; L, trimmer arch; M, relieving arch;
.N, inverted arch.
ARBOR. The axle or spindle of a wheel or pinion ; also the mandrel on which a circular object is
turned on the lathe.
ARCI-HMEDEAN SCREW. This consists of a screw-blade turned around a solid axis, similar to a.
winding staircase, and inclosed in a hollow cylin-
der. When placed in an inclined position with the
lower end in the water, the latter is caught be-
tween the screw-blades, and, the cylinder being
turned in the proper direction, the water will be
raised and discharged at the upper end. This
apparatus may be usefully employed in raising
water to a limited height (10 or 15 feet or less).
By its aid one man may raise 40 gallons of water
10 feet high in a minute—a larger amount of
work than can generally be done with hand-
umps, owing to friction in the latter. Fig. 239.
ARCHITRAVE. In carpentry, borders fixed
around the opening of doorways or windows for
ornament, and also to conceal the joint between _
frame and plastering. When the base of the architrave is not of equal thickness throughout, but
stepped back in the centre, it is said to be “ double-faced.” Architraves are generally built up of
parts glued together, tongued and grooved if large. They are also made by machinery in one piece.
ARMATURE. Sec MAGNET. '


ARMING-PRESS. ' s:

'____
ARMING-PRESS. A machine used for embossing the back and sides of the cover of a book.
ARMOR. The problem for which a solution is sought in the cuirassing of ships of war, is, how
best to protect them against the effects of the shock of the enormous projectiles which, thrown with
an extraordinary energy from heavy guns of large calibre, will have to be resisted in future naval
engagements, and against the convergent and simultaneous fire of other heavy guns but of smaller
calibres. Up to 1862', experiments which involved the testing of plates ranging from a quarter of an
inch to 8 inches in thickness, supported by various backings, yielded the following conclusions: 1.
Good thugh wrought-iron of high elasticity, but not necessarily of the highest ultimate tensile strength,
is the best material for use in iron defenses; 2. Rolled iron, though not, perhaps, equal in resistance
to the best hammered iron, has such great advantages as to cost, if used in simple forms, as to justify
its use where lightness is not of extreme importance; 3. In plates or bars of ordinary dimensions, the
resistance to cannon-shot varies in a proportion approximating that of the squares of the thickness of
the bars or plates; 4. Rigid backing is immensely superior to elastic backing, so far as the endurance
of the front facing is concerned, but the elastic backing deadens the effect of a blow upon any struct-
ure behind ; 5. The larger the masses and the fewer the joints, the stronger the structure, so long as
the limits of uniform and perfect manufacture are observed; 6. Revolving iron shields are practi—
cable and safe; 7. The qualities necessary in an armor-plate are softness combined with toughness,
or better expressed by the word ductility. Apparently, the purer and better the iron is, the more this
quality is perceptible; any impurity or alloy appears to harden the metal and produce brittleness.
The presence of either sulphur or phosphorus in the fuel is specially to be guarded against, as pre-
duetive of red-shortness and cold-shortness in the iron. The presence of more than 0.2 per cent. of
carbon in the armor-plates also appears highly prejudlcial.
In 1865 a series of experiments were made by the British Government, to determine the relative
penetrating effects of two shot on an iron plate, provided they strike with the same work or energy,
notwithstanding the one may be heavy with a low velocity, and the other light with a high velocity.
From these tests the following practical conclusions were drawn when the projectiles are fired direct:
An unbacked wrought-iron plate will be perforated with equal facility by solid steel shot of similar
form of head, and having the same diameter, provided they have the same vis viva on impact; and it
is immaterial whether this m's viva be the result of a heavy shot and low velocity, or a light shot and
high velocity within the usual limits of length, and so on, which occur in practice. An unbacked iron
plate will be penetrated by solid steel shot of the same form of head but different diameters, provided
their striking vz's viva varies as the diameter, nearly, that is, as the circumference of the shot; and
the resistance of unbacked wrought-iron plates to absolute penetration by solid steel shot and equal
diameter varies as the square of their thickness nearly. These expen'ments also proved that, al-
though, in the case of cast-iron, a light projectile moving with a high velocity will indent iron plates
to a greater depth than a heavier projectile with a low velocity but equal work, it is not as necessary
that there should be a high velocity when the projectiles are of a hard material, such as steel and
chillediron; and this result is much in favor of rifled guns, by enabling them to prove effective with
comparatively moderate charges. If the plate is set at an angle, or the gun is fired obliquely at an up-
right plate, the shot has then a tendency to glance off and continue its motion in a new direction.
The force with which the shot acting obliquely will strike is to that with which it would strike if act-
ing directly as the sine of the angle of incidence is to unity. That is, the shot striking in a slanting
direction may be supposed to have opposed to it a plate of a thickness equal to the diagonal formed by
the-line of direction. From the foregoing it may be demonstrated that a. 4.5-inch unbacked plate, when
fired at direct, requires a force represented by 28 foot-tons per inch of shot’s circumference to insure
penetration. When placed at an angle of 38° with the ground, the force required is increased to
73.9 foot-tons. An experiment of this nature, where solid steel shot of 70 lbs. weight and 6.34
inches in diameter were fired against a 4.5-inch plate, set at an angle of 52° with the vertical, showed
that a force of 52.7 foot-tons per inch of shot’s circumference was not sufficient to insure perfora‘
tion, although the plates were cracked and opened at the back.
Since the determination of these results, both the calibre of guns and the thickness of armor_
plates have greatly increased, and the latest trials—those of the Milton gun built 1‘ or the Italian Gov-
ernment for use on the iron-clads Dandolo and Duilio—bring into remarkable relief the great supeii-
ority of steel as compared with iron plates, and at the same time yield results which could not be
predicated upon those obtained with guns of smaller size. -
The difficulties connected with the manufacture of iron plates of thicknesses greater than about
14 inches, and the consequent deterioration of the manufactured product, have hitherto led to a
preference being given to armor built up of two plates, the thicker of which placed outside has sulfi~
cient strength to arrest, or nearly so, the heaviest projectiles at present forming the armaments of
European navies (that is to say, calibres from 10 to 14 inches). The inner skin of the ship is thus
protected by the second and thinner armor-plate, unless the shell should burst in the packing between
the two plates, which would necessarily produce disastrous effects. The penetration of iron plates
14 inches in thickness requires an energy in the projectile of 230 foot-tons per inch of circumfer-
ence; and only the heaviest calibrcs have hitherto been able to effect this, imparting, as they do, a
striking energy of about this amount. So that, in the presence of 12-inch or 14~inch calibres, the
adoption of this form of armor has been entirely justified.
In the experiments conducted at Spezia against targets, the projectiles from the 100-ton gun de-
veloped a mean striking energy of 550 foot-tons, and those of the 18-ton and 25-ton guns an energy
Of 170 foot-tons per inch of circumference. The outer iron plate of the compound target at Spezia
was 12 inches thick, to perforate which, according to Noble’s formula, would require a somewhat less
force; and other trials with the 18-ton gun entirely confirmed this theory, the projectiles pos-
sessing only the force actually required to pierce the outer plate; this force being thus absorbed,
the shots were of course stopped without producing any further destructive effects upon the target.
as . ARMOR.

The projectiles fired with an energy of 230 foot-tons per inch of circumference, fired separately as
well as simultaneously and converging, naturally produced effects very similar to those fired against
the heavy 22-inch iron and the steel plates.
Invariably, however, totally different effects were produced by the projectiles from the IOO-ton
gun, which were fired, as has been already stated, with a velocity representing an average of 550
foot-tons per inch of circumference. The thickest iron plates forming the target should have been,
according to Noble, easily pierced by the projectile endowed with such a striking force, and they
were pierced completely. N 0 reference need be made here to the compound target, which required
only 275 foot-tons per inch to penetrate it; while the shot from the IOU-ton gun, possessing twofold
this force, had, as the experiments showed, a very large excess of power. On the other hand, the
untouched steel plate, and the second one that had been injured by previous rounds, both completely
stopped the projectiles from the IOO-ton gun, and thus preserved the inner wall of the ship. The results
of these rounds, and especially of that one fired against a fragment of the target much smaller than
the original plate, and which, moreover, was only hanging to the backing, proves undoubtedly the
superior resisting power of steel as compared with iron. Thus the same plate resisted one round
from a 9.8-inch calibre gun, with a striking force of projectile of 162 foot-tons per inch of circumfer-
ence; two simultaneous rounds from the 9.8-inch and 11-inch gun, with a striking force of about 170
foot-tons for each projectile, and one round from the lOO-ton gun. After sustaining these three
rounds, the backing was quite preserved without the skin of the ship sustaining serious injury. The
pointed end of the projectile striking the iron plate acted like a wedge, rolled the fibres of the iron
back laterally, and destroyed, by the vibration produced, the welding between the layers of iron
forming the plate—an effect very visible at the Spezia trials; the projectile thus opens a way for
itself through what can only be considered as a series of plates in close juxtaposition, but with
only imperfect adherence.
Steel plates, which are constructed of a compact metal, are homogeneous, of an equal and con-
stant resistance in all directions, and present quite a different nature of resistance to the pointed head
of the projectile, which, striking a compact mass, cannot penetrate with the same facility, and, finding
no fibre it can throw back, it is broken up, and tends to act like a wedge. In consequence of the
rupture of the point, the shot is stopped, producing an effect which, it is true, damages the plate, but,
thanks to the uniform compactness of the metal of the plate, the penetrating effects of the projectile
are destroyed. Iron plates, even of enormous thickness, must remain powerless to resist such for-
midable assaults; and it would therefore appear that steel alone is capable of opposing itself to
shocks of these tremendous magnitudes.
The targets referred to are shown in Figs. 240-243 the plates being mounted on framing repre-
senting that of the Duilio and the Dandolo. Figs. 240 and 241 are front elevations, showing the
two wrought-iron plates of Cammell and Marrel respectively. The plates were each 11 feet 6 inches






























241.
| ' F
c '7 1 l' o o i
{K j; l
r P a
o ,,?.......9.Jlk.'.°_......Q. .L......./ld'.[..... .1
e {To 6 ' 0 Y. '
L i '
< X
[1 ’1 ?
0 Q9" .- -9. 6'9..... .‘1. '_.__,. ._..10'I_’ .._.....
o'qflomyfi
_ m 11"
illlll‘ii; is
'h a; 142w-
7' ‘2‘ Ifmflm-
“M”
' 3 Wm“


243.
long by 4.- feet 7 inches deep, and 22 inches thick. In the target constructed of the steel plates'of
Messrs. Schneider, the upper plate was 11 feet 6 inches and the lower one 10 feet 9 inches long, and
each 4 feet 7 .inches deep by 22 inches thick. The backing consisted of two thicknesses of timber,
the front balks being arranged in horizontal layers and the rear vertically. The inner skin of each
target consisted of two {{dnch wrought-iron plates. Figs. 242 and 248 show sections through the cen-
‘ tre of each plate. From these the methods of bolting through will be seen. A portion of the target,
shown in the elevation at Fig. 240, consisted of one of Marrel’s 12-ineh wrought-iron plates of the
same length and depth as before. Behind this was first a wood backing arranged horizontally, then
another of Marrcl’s plates 10 inches thick, and then the vertical wood backing and skin. The lower
part of this target was made up of a face-plate of wrought-iron 8 inches thick, backed with vertical
timbers, behind which was a 14-inch chilled cast-iron plate, and to its rear the vertical timbers and
iron skin-plates. The remainder of this target had at the upper part a 12-inch wrought-iron face-
plate by Cammell, a thickness of horizontal timbering, and a 10-ineh wrought-iron plate by the same
maker, the whole being backed as before. The lower portion was made up of an S-inch wrought-iron
face-plate with a 14-inch cast-iron plate immediately behind it. The plates were backed with hori-
zontal and vertical timbers and two j-inch wrought-iron plates as before. Sections of the targets
shown in Fig. 21-1 are given in Fig. 242, and in each case it will be seen that the targets are further
)
ARMOR. 89

backed by framing representing that of the ships, the deck-beams, however, being bent downward
toward the ground, and their ends being well struttcd. Wrought-iron stringers were also introduced
in the timber backing.
It will be seen from the Spezia trials that steel may stop shot which would penetrate iron. At
the same time, steel is much more liable to be destroyed by splitting, and to snap its bolts. The state-
ment may be put in this way: The shot, may be stopped by expending its work in fracturing stccl
when itywould penetrate iron, because the steel, by transmitting the shock through its mass, absorbs
it chiefly in making cracks in various directions, while soft iron does not transmit the blow, but
receives the whole work on the immediate locality of the point of impact, and so must yield more
easily. In order to keep intact the steel protection when the plate becomes disintegrated grad-
ually under the blows of comparatively small shot, the adoption of an outside coating or hinder of
wrought-iron plates of great width and extent has been proposed, into which the bolts would hold,
with massive steel plates behind it. It is claimed that much cracking and splitting of the steel
might then take place without serious displacement of fragments. Tests of plates constructed in
view of the foregoing have been made, the general results of which show a decided advantage in
placing iron behind the steel. The “compound plates” tested by the Admiralty (Portsmouth, 1877)*-'
were of four types: 1. Cammell’s sub-carbonized plate of solid steel, containing but 13 per cent.
of carbon. This split, although the test (impact of 250-lb. Palliser shot from 12-ton 9-inch muzzle-
loading rifle-gun at 30 feet range) was well withstood. 2. A combined iron and steel plate, ccmposcd
of steel (.64 per cent. carbon) 4 inches thick, backed by 5 inches of wrought-iron, was easily pene-
' trated. 3. A sandwiched plate, composed of three-quarter inch of wrought-iron, 6!; inches of steel,
and 1%} inch of iron, likewise failed. 4. A plate of Whitworth compressed steel, in which liardcntd
steel screw-plugs were inserted, cracked under the impact, the plugs tending to produce this effect.
It may he added that the whole question of armor-plating is (1878) undergoing revolution, and that
no completely efficient system has ever yet been discovered. The problem, after all the enormous
outlay spent in attempts toward its solution, has virtually narrowed itself down to whether it were
better to adopt iron armor, which does not fissure, but allows the projectiles to penetrate; or steel
armor, which successfully resists the penetration of the shot, but is itself broken up.
The .Modem ’Jfl/pes of Armored Vessels—The Inflexiblc, A, Fig. 244. The protected portion of the
ship is confined to the citadel or battery, within whose walls are inclosed all the vital parts of the
vessel. The vessel measures 110 feet in length, 75 feet in breadth, and is armored to the depth
of 6 feet 5 inches below the water-line, and 9 feet 7 inches above it. The armored portion is
included between the two shaded vertical bands in the figure. The Sides 0f the Citadel COHSiSt Of an
outer thickness of 12-inch armor-plating, strengthened by vertical angle-iron guides 11 inches wide
and 3 feet apart, the space between them being filled in with teak backing. Behind these girders, in
the wake of the water-line, is another thickness of 12-inch armor, backed by horizontal girders 6
inches wide, and supported by a second thickness of teak backing. Inside this are two thicknessis
of 1-inch plating, to which the horizontal girders are secured; the whole of the armor-backing and
plating being supported by and bolted to transverse frames 2 feet apart, and composed of plates and
angle-irons. It will thus be seen that the total thickness of armor at the water-line shake is not less
than 24 inches. The armor-belt, however, is not of uniform strength throughout, but varies in
accordance with the importance of the protection required and the exposure to attack. Consequently,
while the armor at the water-level is 24 inches in two thicknesses of 12 inches each, above the water-
line it is 20 inches in two thicknesses of 12 inches and 8 inches, and below the water-line it is
reduced to 16 inches in two thickness of 12 inches and 4 inches. The teak backing with which it is
supported also varies inversely as the thickness of the armor, being respectively 17 inches, 21
inches, and 25 inches in thickness, and forming, with the armor with which it is associated, a uni-
form wall 41 inches thick. The depth of armor below the load water-line is 6 feet 5 inches; but as
the vessel will be sunk a foot on going into action, by letting water into its double bottom, the sides
will thus have armor protection to the depth of ’7 feet 5 inches below the fightingdine. The outside
armor is fastened by bolts 4 inches in diameter, secured with nuts and elastic washers on the inside.
The shelf-plate on which the armor rests is formed of g-inch steel plates, with angle-iron on the
outer edge 5 inches by 3% inches by nine-tenths of an inch. The armor on the fore. bulkhead of
the citadel is exactly the same in every respect as that on the sides, but- the armor of the rear bulk-
head is somewhat thinner, being of the respective gradations of 22, 18, and 14 inches, and forming,
with the teak backing, which is 16, 20, and 24 inches, a uniform thickness of SS inches. It may also
be useful to mention that before and abaft the citadel the frames are formed of 7-inch and 4-inch
angle-irons, covered with {JG-inch plates. The total weight of the armor, exclusive of deck, is 2,250
tons, and the total weight of armor, inclusive of deck, is 3,155 tons. _
The most singular feature in the design of the ship is the situation of the turrets. All turrets
are placed on the middle line—an arrangement which, though advantageous in some respects, pos-
sesses this signal disadvantage, that in double-turretcd monitors only one-half of the guns can he
brought to bear on the enemy—which rise up on either side of the ship en édzclen within the walls
of the citadel, the forward turret being on the port-side and the alter turret on the starboard
side, while the superstructures are built up along a fore-and-aft line of the deck. By these means
the whole of the four guns can be discharged simultaneously at a ship right ahead or right astern,
or on either beam, or in pairs, toward any point of the compass. The walls of the turrets, which
last have an internal diameter of 28 feet, are formed of a single thickness of 18 inches, with
backing of the same thickness, and an inner plating of 1 inch in two equal thicknesses.
The Thundcrer, B, Fig. 244. Here the height of the side-armor above and below water is shown.
The position of the armored deck is indicated by the line along the upper edge of the side-armor.

* Engineering, xxxiv., 625.

























































The Dreadnought, 0, Fig. 244. The citadel is 184 feet in length, and the height between-decks is 7
feet 6 inches. It is armored with solid plates 11 inches thick, except at the ends and abreast the
bases of the turrets, where the thickness is increased to 13 and 14 inches. The armor-belt, which is
carried entirely around the vessel, is 11 inches thick on the water-line, tapering to 8 inches at 5 feet
below water, where it stops. It also tapers above water, fore and aft of the citadel as well as toward
the ends. This armor—belt, fore and aft the fighting part of the ship, rises only 4- feet above water,
and is intended solely to protect the vital portion of the hull. The turret-deck is plated, with two
courses of 11} and 1 inch iron respectively, and the main berth-deck below is also plated with the same
thickness of metal fore and aft ofthe citadel.
The turrets rise through the citadel-deck to a height of 12 feet from the base or revolving deck-
platforin inclosed by the citadel. The diameter of each turret inside of framing is 27 feet 4 inches,

v
ll.ll..llulm l
multiliillllll"


ii
- I
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:_...j
THE ARMSTRONG HUNDRED-TON GUN.
ARMOR. 91

f
the depth of the framing being 10 inches. They are built up with two courses of plates and two
courses of teak, in the following manner: first, the shell or wall consists of two fi-inch plates, bolted
together and riveted to the framing; on the exterior of this shell is a teak backing 6 inches thick; on
this backing armor-plates 7 inches thick are secured; next, teak backing 9 inches thlck is fastened
on ; finally, armor-plates outside of all, 7 inches thick—all securely bolted together. The plates were
rolled at Sheffield, and curved to templates, drilled and prepared for their places.
The Alexandra, D, Fig. 244. The sills of the main-deck ports are 9 feet and those of the upper-deck
ports more than 17 feet above the water. The water’line is protected by a belt having a maxmmm
thickness of 12 inches, and it will be seen that the armor forward is carried down over the ram,
both to strengthen the latter, and to guard the vital parts of the ship from injury by a raking
fire from ahead, at times when waves or pitching action might expose the how. The machinery,
magazines, etc., are similarly protected against a raking fire from ahaft by an armed bulkhead 5
inches thick. The batteries are protected by armor only 8 inches thick below and 6 inches above;
the total weight of armor and backing is 2,350 tons.
The Te'mérairc, E, Fig. 244. This vessel carries her upper-deck armament in two fixed open-top tur-
rets, the forward one protected by lO-inch, the after one by S-inch armor. Like all belted ships, the
Téméraire has weak places in her water-line; but amidships, over the most vital parts, she has
ll-inch armor (against 12-inch in the Alexandra), reduced very slightly above and below. At the
bow, to guard against exposure to raking fire in pitching, the armor is carried down over the point
of the ram, and similar protection is gained for the magazines, etc., against raking fire from aft, by
an armored bulkhead across the hold (shown in the sketches); this is plated with 55-inch armor. The
deck at the level of the top of the belt outside the main-deck battery is 11} inch thick. The hull,
which has the usual double bottom, and is divided into very numerous water-tight compartments. is
built on the well-known bracket-frame system, and it is sheathed externally with wood covered with
zinc. The weight of the armor and backing is about 2,300 tens, or nearly the same as in the Alex-
andra.
The Shannon, F, Fig. 244. There are several interesting peculiarities in the construction of this
vessel. The guns which are to fight upon the broadside are on an open deck, and all without protec-
tion of armor. The armor is limited to a belt extending around the vessel at the water-line; this
belt is not tapered toward the bow, as is usual, but ends abruptly 60 feet short of it, at an armored
bulkhead 9 inches thick, which extends across the vessel at this point, and descends 5 feet under
water. Forward of this bulkhead the armor takes the form of a submerged deck 5 feet below water,
running forward and sloping to 10 feet at the stem. The plating of this deck is 3 inches thick. The
deck aft of this armor-bulkhead is of iron 11} inch thick, covered by wood; the hatches passing
through it are protected by shell-proof gratings. The armor-bulkhead already referred to—tliat across
the bow of the vessel, 60 feet from the stem—rises to a height of 20 feet above the water-level to the
top of the forecastle; and it here turns at the sides, extending aft and embracing the forecastle with
arms 26 feet long on both sides. It thus guards both decks against raking fires from ahead, and
creates an armored forecastle, open at the rear, and carrying two 18-ton bow-guns. Within this
armored forecastle are the instruments for communicating with the engine-room, the helm, and the
battery. In other respects the ship is unarmored.
The armor-belt referred to is 9 feet deep, 5 feet of which are under water and 4 f ect above \\ ater.
It is put on in 12-f00t lengths, and extends from 4 inches under the counter to 60 feet from the stem.
The thickness at the water-line is 9 inches, tapering below as well as above the water.
The N elson and Northampton, G, Fig. 244. In these vessels the protecting armor consists of a belt
on the water-line of about 181 feet in length amidships; this belt is 9 feet deep, 4 feet above water
and 5 feet under water. It is put on in two stral;es; the upper plates are 9 inches thick on a 10-inch
backing of teak, and the lower plates are tapered to 6 inches thick, supported by a teak backing 13
inches thick. Extending across the ship at each end of this armor-belt there is an armor-bulkhead;
it starts at the bottom of the armor-belt, 5 feet under water, and extends to the upper deck, having in
all a depth of 22 feet. Its thickness is 9 inches above water, tapering to 6 inches at the bottom.
Between the main and upper decks these bulkheads are shaped to form corner ports at the fore and
after ends of the battery. Between the armor~bulkheads, and at the upper level of the armor-belt,
the lower deck is formed throughout of 2-inch plates, by means of which protection is afforded to the
machinery, boilers, magazines, etc. A peculiar feature is the horizontal armor as here applied. For
about 57 feet at the fore-end there is an armor-deck. This deck is 2 inches thick, and it is 5 feet
under water at the junction with the armor-bulkhead, but inclines deeper toward the stem, and ter-
minates forward in the ram. There is likewise an horizontal armor-deck of the same thickness and
depth under water, extending from the after armored bulkhead to the stern. These submerged
armor-decks are intended to protect the lower part of the ship fore and aft of the armored bulkheads,
especially the steering-gear provided for emergencies.
The Duquesne (French), H, Fig. 244. This vessel is a cruiser of the rapid type, and is designed for
17 knots per hour at sea. The frames, bulkheads, beams, and all interior parts, also masts, are com-
posed of steel; but the outside plating of the hull is entirely of iron, and the bottom is sheathed with
2 layers of teak planks, in all 7 inches thick, and coppercd, put on in a similar manner to the svstun
of the English, except that, to insulate the iron from the copper, thick layers of marine glue. have
been placed between the iron hull and the teak planks, also between the teak and copper.
The Dandolo (Italian), I, Fig. 244. There is a central armored citadel or compartment, 107 feet in
length and 58 feet in breadth, which descends to 5 feet 11 inches below the load water-line. It pro-
tects the machinery and boilers, the magazines and shell-rooms, and a portion of the machinery for
working the turrets and guns. Forward and aft of this citadel, the decks, which are 4 feet 9 inches
under water, are defended by horizontal armor. Over this citadel is built a second central armored
compartment, which incloscs the bases of the turrets and the remaining portion of the mechanism
92 ARMOR.

employed in loading and working the guns. Lastly, above this second compartment rise the two tur-
rets. The turrets are placed at each end of the central armored citadel—not in an even line with
each other, but diagonally at opposite corners of it, with the centres at the distance of 7 feet 8 inches
from the longitudinal centre-line of the vessel, so that one turret is on the starboard side and the other
on the port side. The effect of this arrangement is to render possible the discharge of three guns
simultaneously in a direction parallel with the keel. Only the central portion of the ship and the
two turrets will be protected by vertical armor.
As regards the armor of the central portion of the vessel, the thickness at the water-line is 22
inches. The decks are protected by horizontal armor of iron and steel, the former being under the
latter. The armor of the turrets will be composed of solid plates 19 inches in thickness, resting upon
teak backing.
Admiral Pcpoif and Novgorod (Russian), Figs. 245 and 245A: Circular iron-clads or Popoifkas
245 A.





These vessels are circular only in one sense; i. e.,
their horizontal sections only are circular, or, in
other words, they have circular water-lines. The
departure from a circle is a small extension or pro-
tuberance at the stern for the purpose of facilitat-
ing the arrangement and working of the rudder
and steering-apparatus. It follows as a conse-
quence from the circular form of water-line, that
all the radial sections are alike ; the bottom of the
vessel is an extended plane surface. which is con-
nected with the edge of the deck by a quadrant of
a small circle. With this form of section great
displacement is obtained on moderate draught of
water. The deck of the circular ship is formed in
section with such curvature as to give in a ship of
100 feet in diameter a round-up of about 4 feet.
Zypes of Armor Plaling—Lamz'natcd Arman—In American iron-clads this type of armor has been
largely used. It consists of consecutive plates averaging 1 inch in thickness, but backed, as in some
of our monitors, by armor-stringers or plank-armor of small breadth and moderate thickness. Ex-
periments made by the English Admiralty proved this laminated armor to be far inferior to solid
armor in power of resistance, and that no amount of strengthening can compensate for the defects
of the system. The resistance of single armor-plates, shown by direct experiment for all thicknesses
up to 5.1; inches to vary as the square of the thickness, does not obtain for laminated armor. For
example, a 4-inch solid plate would be 16 times as strong as a 1-inch plate, but would not be four
times as strong as [our 1-inch plates riveted together, although it would be much stronger than the
laminated structure. From actual experiment, it also appears that projectiles arrested by a 4-inch
solid plate easily penetrated 6 inches of laminated plates.
Elastic-Backed Arman—It has already been noted that a rigid backing for armor is in all re-
spects preferable to an elastic one; and this conclusion is substantiated by experiments upon a large
variety of types of armor, using a number of different substances as support. Millboard in thicknesses
of 15 inches, tissues of wire ropes 14 inches thick, India-rubber and pine, India-rubber and oak (1 inch
rubber and 20 inches oak, afterward 4 inches of rubber and same thickness of wood), have all been
tried, and have failed. A similar result was obtained with a target of four 1-inch wrought-iron
plates, and four sheets of rubber 1 inch thick, backed by 20 inches of solid oak; and it was conclu-
sively settled, by comparative tests, that India-rubber serves no useful purpose in causing (as was
supposed might be the case) the shot to recoil. A large iron boiler 10 feet in diameter was packed
with wool at Shoeburyness, in 1864, and subjected to the shot of a 68-poundcr and a Ill-pounder
Armstrong gun at 100 yards range. The shot passed through 11 feet of wool, the iron caisson, and
buried themselves in 12 feet of solid earth. Five bales of hog-hair, backed by 4-inch plank, aggregating
a thickness of 3 feet 8% inches, have been easily pierced by a 38-pound rifle-shot. The advantages of
wood backing are not so much that it adds material strength or resistance to the armor-plate, but-
1. It distributes the blow. 2. It is a soft cushion, to dcaden the vibration and save the fastenings.
3. It catches the splinters. 4. It still holds the large disks, that may be broken out of a plate,
firmly enough to resist shells. A solid backing of wood of from 2 to 411- times the thickness of the
iron unquestionably adds to the resistance, and, when divided into a cellular form by iron edge-pieces
or girders, as in the Chalmers target, offers great support, and prevents the distortion of the plates
by buckling?
The Armor of American Iron-dads may be briefly summarized as follows: The original monitor
had her hull protected by 5 layers of 1-ineh plate, diminishing first to 4 inches and then to 3 inches
in thickness below the water-line. IIer turret was built of 8 layers of l-inch iron. The Passaic
class of monitors have armor of the same thickness as the first monitor, with 39 inches of wood
backing. The Canonicus class have 5 layers of l-inch plates, supported by 2 armor-stringers let
into 27 inches of wood backing. Their turrets have 11 layers of 1-inch plates. The Miantonomoh



ARMOR, SUBMARI N E. 93

and the Monadnoek, which are wood-built, are protected much like the Canonicus. The Puritan
and the Dictator have 6 layers of 1-inch plates on their sides, with 42 inches of wood backing.
Their turrets are 15 inches thick, made up of two drums, with segments of wrought-iron hoops 5
inches thick, placed between the drums, which are composed of layers of l-inch plates. In the
Kalamazoo class the total thickness of hull-armor is 6 inches, made up of 2 layers of 3~inch
plates, backed by 30 inches of oak, still further strengthened near the water-line with 3 armor-
stringers 8 inches square, let into the backing, and only a few inches apart. This is by far the
most formidable armor carried by any of our monitors; and while there are in some places 14
inches of iron, there is no part of it nearly so strong as it would be with that thickness of solid plates.
The turrets of the Kalamazoo are 15 inches thick, like those of the Dictator, but none of them have
any backing or wood about them. The rapid diminution in thickness of armor on these vessels is a
serious defect, leaving no ground for comparison with corresponding English ships. The Dictator,
for instance, 25 feet below the water-line, has but two 1-inch plates, and at 3 feet only one. Though
generally unfit for cruisers, the monitors are well adapted to coast and harbor defense.
Works for Reference—“A Treatise on Ordnance and Armor,” A. L. Holley, 1865; “Report of
Secretary of the Navy on Armored Vessels,” Washington, 1864; Capt. Noble’s “ lcport on the Pene-
tration, etc., of Armor-Plates,” 1876; “System of Naval Defenses,” Beds, 1868; “Our Iron-clad
Ships,” and “Shipbuilding in Iron and Steel,” by E. J. Reed, London, 1869; “ Reports of the Com-
mittee Appointed by the Lords Commissioners of the Admiralty to Examine the Designs upon
Ships-of-War which have recently been Constructed,” London, 187 2 ; “ La Marine cuirassée,” by M. P.
Dislere, Paris, 1873; and “ Reports of the Secretary of the Navy”—Report of Chief-Engineer J W.
King, U. S. N., on European Ships-of-War, etc., Senate Ex. Docs, No. 27, Washington, 1877 (from
which copious extracts are embodied in the foregoing).
ARMOR, SUBMARINE. See DIVING.
ARRIS. The angle formed by the meeting of two surfaces not in the same plane. A piece of square
timber sawed diagonally is said to be cut arriswise. The term is applied to tiles laid diagonally.
ARRIS—PIECES. The portions of a built mast between the hoops.
ARTESIAN WELL. See WELL-Beams.
ARTIFICIAL STONE. See Coucasrs.
ARTILLERY. See ORDNANCE.
ASBESTOS. A mineral fibre composed of silicate of magnesia, silicate of lime, and protoxide of
iron and manganese. Mineralogically, the name is given to the fibrous varieties of tremolite, actino-
lite, and other species of hornblende, excepting such as contain alumina, and also to the corresponding
mineral pyroxene. It exists in vast quantities in the United States, in various parts of Great Britain,
Hungary, Italy, Corsica, and the Tyrol. To various kinds of asbestos have been applied the names
“mountain leather,” “mountain cork,” “amianthus,” and “chrysolite,” and certain other minerals
having characteristics resembling those of asbestos are described as asbestoid, asbestiform, and as la-
mcllar-fibrous. The chief characteristics of the mineral upon which its value depends are its inde-
structibility by fire and its insolubility (except for a few varieties) in acids; secondly, its peculiar
fibrous quality. The material is obtained from the mines, in forms ranging from bundles of soft,
silky fibres to hard blocks. The blocks may be broken up and separated into fibres, which, like those
naturally obtained in that state, are extremely flexible, admit of great extension in the direction of
their length without cracking, are greasy to the touch, and very strong. The fibre obtained in New
York and Vermont varies in length from 2 to 4 inches, and resembles unbleached flax when found
near the surface, but when taken at a great depth it is pure white.
One of the first applications of this mineral was the manufacture of incombustiblc cloth, the fabric
being woven of asbestos and vegetable fibre. The latter was employed on account of the shortness
of the asbestos fibre. The vegetable substance was afterward burned out, leaving the incombustible
texture. Another early utilization was in lamp-wicks, for which purpose it is still used by the Green-
landers. Asbestos has also been woven into a fabric for shrouds. At the present time it has many
important utilizations, and as it is practically an almost undeveloped substance, others will doubt-
less eventually be discovered.
A paper is manufactured containing about one-third its weight of asbestos. It burns with a flame
leaving a white residue, which, it carefully handled, retains the shape of the sheet. Any writing in
common ink upon it remains legible even after the organic substance has been consumed. An asbes-
tos pasteboard is made in Italy which has withstood the heat ina furnace-fire indefinitely. Boxes
of this material are now made to serve as fire-proof receptacles for valuable documents.
Asbestos cloth is worn by firemen in Paris for protective purposes. Hats and coats are made of
it, and with gloves of asbestos the wearer may handle a firebrand or frozen hose without danger of
burning or freezing the fingers. Moreover, the hose may be protected from the action of frost by
Jacketing the couplings with asbestos cloth, or may itself be manufactured from that material. In
Siberia, purses and gloves are produced from the asbestos fabric. In Italy, lace has been made from
it. According to Sage, in China, sheets of paper 19.2 feet long, and entire webs of cloth, have been
prepared from the mineral. Such fabric (paradoxical as the statement appears) is washed by putting
it in fire, which burns out the foreign matters.
Besides being one of the most refractory substances, asbestos is probably one of the most perfect
non-conductors and insulating mediums known. Like all non-conductors, it takes protracted exposure
to heat to change its temperature; but, once hot, it in like manner tenaciously retains heat. This fact
prevents its being used successfully for fire-proof safes. It has been applied to the construction of
refrigerators, and a patent in the United States covers its utilization in a refrigerator-car. Asbestos
is also used as an insulating material in electrical apparatus, as a means of absorbing illuminating oil
and preventing its distribution in case of fracture of the lamp, and, combined with mercury, fats.
soapstone, plumbago, and oils, as a lubricant. It is also utilized as a means of burning petroleum oil
94 ASSAYING.

under steam-boilers, a thin layer of the mineral being placed on a suitable grate and soaked with the
oil, the vapor from which is ignited, producing an intense heat. So perfect is the non-conducting
nature of the asbestos, that a sheet of paper placed beneath the oil-soaked layer remained in the fur-
nace uninjured, despite the fierce heat above. It is also proposed to use asbestos as a lining for
blast-furnaces, particularly adapted for employment where the metals or ores contain sulphides, the
efieets of which the mineral resists.
A New York manufacturer of roofing, etc., has patented a large number of applications of asbestos.
Combined with felt and other materials, he employs it for roofing purposes, where its incombustible
nature tends to prevent the possible conflagration of the roof by sparks from chimneys or from adja-
cent burning buildings. The same manufacturer has devised an asbestos concrete, asbestos-lined
hair-felt for boilers, and an especial cement, in which layers of asbestos are inserted for the same
purpose. He also uses the ground mineral as a body for oil-paint, and incloses the fine, short fibre
in hollow tubes of webbing to adapt it for use as packing.
The employment of asbestos as steam-packing is probably its most important mechanical applica-
tion. The credit of its suggestion for this purpose is due to Mr. St. John Vincent Way, 0. E. Re-
ferring to the value of the material, in a paper read before the Institution of Engineers and Ship-
builders in Scotland, he says: “The packing used for piston and valve rods or spindles has three
prime elements of destruction to contend with, namely, an elevated temperature, friction, and moist-
ure; and one of them only—namely, friction—has any appreciable effect on asbestos packing, when
the mineral is pure and properly prepared. N o matter how high the temperature of the steam, how
rapid the stroke of the piston, or how great the steam pressure, the packing seems to be unaffected by
these conditions. In America, where the new packing was first used, some of it was taken from
the piston-rod stuffing-box of a locomotive-engine, after having been in another engine at constant
work for three months, with steam at 130 lbs. pressure per square inch, and making an average daily
run of 100 miles, including Sundays; and, as can be seen by the sample shown, the fibre, with the
exception of being discolored by oil and iron, is just as flexible and tenacious as originally. After
having been once disintegrated, it appears impossible so to pack or mat the fibres together that they
are not easily separated by the fingers.”
Asbestos packing, according to Mr. P. L. Simmons, in whose work on “Waste Products and Unde-
veloped Substances ” (London, 187 6) a valuable paper on this subject appears, has been in use on the
Anglia, of the Anchor Line of transatlantic steamships, for 16 months, during which period the
vessel steamed over 98,000 miles. The chief advantages possessed by asbestos as packing seem to
be its freedom from the slow carbonization which occurs in hemp, and its retention of elasticity, thus
always keeping tight joints.
The utilization of asbestos in boats, boxes, wagon-bodies, and in railway cars, to prevent conflagra-
tion, has been suggested. A late plan for preparing the mineral includes its treatment by fluorine or
hydrofluoric-acid gas, to dissolve and eliminate the silex and other foreign substances in the crude
material, and thus to secure a pure and fibrous condition of the asbestos. Thus freed from grit, it is
proposed to reduce it to a flock, and then compress it into a rope of octagonal, square, or flat form,
and with a dense and adhesive structure, either with or without strengthening-cords imbedded in the
surface, or, as the equivalent of such cords, a covering of canvas or muslin. Asbestos is an excellent
material for the chemist as a filter. Being a silicate, acids can be filtered through it which would
destroy ordinary filtering material. It is also used to dry air, by placing the asbestos loose in a tube-
1ike sponge, moistening it with sulphuric acid, and passing the air through in a gentle current.
An asbestos building-stone is composed of asbestos in fibre mixed with silicate of potash or soda,
and pressed in moulds. After the block is set it is saturated with chloride of calcium, and afterward
washed in water. Asbestos building-blocks have also been made of asbestos and plaster of Paris com-
bined with sawdust, coke-dust, or cinders. Asbestos mixed with earthy matter and applied to wire
gauze has been suggested for walls.
The following analysis of asbestos is given by Ghenevis : Silica, 59 ; magnesia, 25 ; lime, 9; alumi-
na, 3 ; water, iron, etc., 4: total, 100.
ASSAYIN G. This art has for its object the determination of the metals in their ores and alloys.
The methods employed may be classed under two heads: 1. The “dry way,” or assaying proper.
2. The “wet way,” or analysis. The first includes all processes where the determinations are made by
the direct action of heat, the various operations being performed in furnaces. The second head em-
braces the estimation and separation of the
elements by the action of solvents, aided or - _\
unaided by heat, the use of furnaces not be- ‘
ing essential ; and it does not, therefore, come
under consideration, save in speaking of the
methods employed for parting and refining gold
and silver used principally in the assay offices
and government mints. ~
I. TREATMENT OF Dims—The various opera- _4 _
tions which may take place in making the as- " .l y, .
say of any ore are: 1. Preliminary testing of j I ' ‘iqi:
the ore. 2. Preparation of the ore, sampling, ' "
pulverizing, etc. 3. Weighing out the ore and '
reagents. 4. Calcination and roasting. 5. Reduction and fusion. 6. Scorification and cupcllation.
7. Inquartation and parting of the silver and gold bead. 8. Weighing beads or bullion.
1. The preliminary determination of the ore is effected either by the eye or the blowpipe, or else
by making up a charge of ore, if it be gold or silver, with litharge and soda, fusing the mixture in
a hot fire, and weighing the resulting button of lead. This determines what is called the “reducing
246.





ASSAYING. ' 195
,_______ a

power ” of the ore, and enables the assayer to calculate with exactness the proper charge for the
regular assay. .
2. Preparation of the 0re.--All ores must be pulverized and sampled before they can be assayed.
For this purpose, the following toolsor apparatus will be found convenient:
Mgl







__-‘
___
1. An iron mortar and pestle, and, if much ore is to be pulverized, a grinding plate and rubber, as
shown in Fig. 246. The plate is a flat iron casting 18 x 24 inches, and 1 inch thick, the surface used









beingplaned smooth. The rubber or grinder is a piece of cast-iron, 4x 6 inches square, ii inch
thick in the middle, and seven-eighths of an inch at the ends ; thus giving a slightly convex surface,
96 - ASSAYING.
b

which should be true on the board at all points. To conduct the operation, place the left hand upon
the rubber, throwing the weight of the body upon it, grasp the handle with the right hand, and move




the iron rubber back and forth, depressing the handle when pushing for-
ward and raising it in drawing back.
2. A tin sampler, shown in Fig. 247. It consists of a series of troughs
arranged in a row and fastened together at equal distances by a tin strip
soldered on their ends. A shovelful of ore, emptied by a series of shakes
upon them, is just half caught by the troughs, the other half going through
By repeating this operation, the size of the sam-
the openings between.
ple can be reduced to any extent desired.
3. A box with a sieve fitting into it, as represented in Fig.
sieve is a tin frame with gauze of any desired mesh soldered to it, and
The advantage gained by its use is that in sift-
ing the pulverized ore there is no dust; the 'fine material, being passed
All of the sample should
The size most convenient is 8 inches in di-
ameter, the box 2 inches deep, and the rim of the sieve 1:2L inch, fitting
fits tightly in the box.
through the sieve, is kept from flying around.
be passed through the sieve.
about three-quarters of an inch into the box.
248. The
The ore is first broken into small pieces, and then cracked in the mor-
tar until it is reduced to a coarse sand, when it is transferred to the plate and rubbed down.


If the
sample is a large one, the tin sampler is used to divide it after breaking down the lumps in the mortar.
4. The balance for weighing out ore for assay, and the buttons of the base metals, is shown in Fig.





249.
the pans made of horn, and supported by threads to a brass
beam. They should carry at least 10 ounces, and turn with
one-half grain. The ore, litharge, test lead, oxidizing and re-
ducing agents, should be weighed accurately. The ordinary
fluxes may be weighed approximately; but it is better to weigh
closely, as more uniform results are obtained. The gramme
or decimal system of weights will be found most convenient
in all cases, save perhaps in the assay of gold and silver ores,
where a special sysrem of weights, called the assay ton weights,
will be found most convenient. The unit of the system is the
assay ton: 29.166 grammes. Its derivationwill be seen at
a glance. 1 lb. avoirdupois : 7,000 troy grains. 2,000 lbs. :
1 ton. 2,000 x 7,000: 14,000,000 troy grains, in 1 ton avoir-
dupois. 480 troy grains : 1 oz.
troy. 14,000,000 —:— 480 = 29,166
+ troy oz. in 2,000 lbs. avoirdu-


pois. There are 29,166 milli- 39,
grammes in one assay ton (A. T.) ; 2
hence, 2,000 lbs. is to 1 A. T. as
1 oz. troy is to 1 milligramme.
EXAMPLE.——‘Veigh an A. T. of
ore, and if on assay it yields one


milligramme of gold or silver, the result reads 1 oz. troy in 2,000 'ggglmgzt
lbs. avoirdupois, without further g
calculation. .
The ore to be weighed out is a
spread upon glazed paper and as,“ j?1,.,,,,,,,mw”m”


mixed with a bone or steel spatula,
\\
fri\\\\\‘
\ \\ \\\\ l
f'
yx\
\’
_ \\\\\\\\\\\\\\
[III/[III]! (


F\\\\\\\\\\\\\
asx\\\\\\\‘
\\\\


\
_/\\_\\\.\‘\ .




6
\‘s
\\\\\
\\
._‘\~§\\\\\\\\'§ \x
fill x \


This balance should take 10 ounces in each pan, turn with one-twentieth of a grain, and be
provided with movable pans, level, and set- screws for adjusting.
It is generally placed on a box,
with drawer for weights. For weighing reagents and .fluxcs, han
ging scales will be found useful,
!
257.


s\§1\\\\\\\\x\\\\\\\\\\h‘
\\ .-.\
\\"*" “e s. \\\ K:
.\\
\‘
PK \.'. ‘.\\;\:;“.‘I-.‘

\\
\\\\\\\\\\\\\\
§k§§m\\\
and then sampled by taking a little from each part of the pile, until a sufficient quantity has been
transferred to the scale-pan for the assay.
3. Calcination and Roasting—If the ore be dam-p, it must be calcined to dry it, and then weighed
ASSAYING. 9'7
Q
*
again; or if it be a sulphide, it must be roasted before charged in the crucible with the fluxes, etc.
In calcination the object is simply to drive ofi moisture, while in roasting the operation is conducted
in such a manner as to insure oxidation, and the elimination of sulphur, arsenic, antimony, etc. To
calcine a substance, it is not necessary that the air should have free access, or that the material
treated be stirred. For roasting, combustion must take place, and consequently the vessels employed
must be open and flat to allow the oxygen of the air to act freely. The ore must be stirred continu-
- ally, and when easily fusible be mixed with some sub-
258' stance to prevent am'lutination. Charcoal graphite or
I 0P . . ’ . ’
sand may be used for this purpose. 'lhe heat should
be low at first. Fig. 250 represents two sections of a
convenient furnace for calcining or roasting. The fire-
.. __'l ,. place is made shallow; and, as a high temperature is
5 not required, it may be made of red brick, or only lined
1 ~—---* with fire-brick, and the body of the furnace bound with
-- ' strap-iron. It should also have a cast-iron top-plate.
‘3 a The grate-bars may be in one piece or separate, and
draw out. The ash-pit should be provided with a door,
i/v-r which may be closed or opened in order to regulate the
4 draft. A hood of sheet-iron will also be found neces-
fi sary in many cases, as the fumes given off in roasting
_ “fig are often injurious. It is an excellent plan to have
.T. If: the hood of galvanized iron to prevent rusting. The
J e i J chimney may be of brick, iron, or clay.


35



_ ‘E
















I
l
\l
I
L!
\
h
I


,"
¢






LV 4. Reduction and Fusion—In this operation the
- —1 ore is heated with fluxes and reducing agents in a
| crucible or scorifier. Among the furnaces best adapt-
ed for this are those shown in Figs. 251 and 257.
Fig. 251 shows a crucible furnace for fusion with inclined cover, to facilitate the lifting in and
out of crucibles. Sometimes a crane is added for this purpose. The chimney ought to be of brick,
and the larger and higher it is, the stronger the draft. This may be regulated by a damper as well
as by the ash-pit door. The top should be of cast-iron, and the cover roll or slide easily. Fig. 252
shows a good form of tongs for lifting crucibles out of the furnace. They should be made with long
handles, and bent as shown in the illustration.
5. Scorification and Gupellation.—Both of these operations may be classed as a combination of
fusion, roasting, and sublimation, the difference being that in the latter case (cupellation) the volatile
_ compounds formed are absorbed by the cupel, while in the former they form a slag. Fig. 253 shows


J
































sections of a portable muffle furnace for scorification and cupcllation. The same furnace may be
used for both operations, but generally it will be found convenient to have a larger mufiie for scori-
ficatlon and higher heat. The muffles are made of refractory clay, and in one piece, and should be
thoroughly dried before using. Figs. 254 and 255 show the best forms of tongs for this furnace.
In the scorification tongs, Fig. 254, the spring should not be too strong, and the horse-shoe part should
Just fit the scorifier. The cupel tongs, Fig. 255, should be made of steel, and be about 2% feet long,
98 ASSAYING.

with an easy spring. Ores rich enough to be scorified do not require to be roasted, but may be
assayed directly; so that this method is preferable to the crucible assay, as it saves time. For
' details of eupellation, see section II. of this article.
6 Inqnartution and Parting—Under this head come the separation of alloys and the treatment of
the buttons from the gold and silver assay. Inquartation is the process of alloying gold with silver
to form a more soluble alloy, while parting is the separation of the metals by solvents. Fig. 256
shows the glass vessel used for parting alloys of gold on a small scale. For a description of the
apparatus used where a quantity of bullion is to be parted, see section II. The weighing of beads
and bullion must be conducted with the greatest care, and the balance adjusted both before and after
Weighing. Before weighing, the head or bullion should be well cleaned with a small brush.
II. TREATMENT or AtLors.'*——The following is the method of parting, melting, and refining em- '
ployed in the United States mints. All deposits of bars and gold-dust received at the mint are re-
melted in the crucible of a smelting furnace, shown in section at a, Fig. 257. g is the grate, f the
fuel, d the ash-pit, and e the flue. To toughen impure brittle deposits, borax is added, which com-
bines with the impurities, and on pouring appears on the surface of the bar as a slag, which is re-
moved and ground in a small Chili mill, shown in Fig. 258. a is the revolving pan; 6 b are the
rollers, 17 inches diameter by 6% inches face. The pulverized slag is pan-washed, and any metallic
result is added to the bar. From the remelted gold bars chips are taken ofi of two diagonal corners
for assaying. For silver assays a small amount of metal is granulated by pouring it in water before
and after casting, a little being left in the crucible for this purpose. After every operation performed
on the metals, as well in melting and refining as in coining, they are weighed to determine the amount
of loss by vaporization or abrasion.
The method of gold assaying at the mint is the dry or cupelling process. The cupel furnace used,
shown in Fig. 259 in different views, is made of cast-iron, lined with 2 inches of fire-brick, and measures
11 by 30 inches in the '
clear, and 30 inches 261. 264-
.above the grate-bars.
The fuel is charged at
a- a. b is the grate-bar,
c the ash-pit, d the muf-
fle (shown enlarged at
D, Fig. 260). The gold
is mixed with three
times its weight of sil-
ver and about 11 parts
of lead, and placed on
a cupel E, in the muffle
D, Fig. 260. The lead
forms with the impuri-
ties a slag which is ab-
sorbed by the bone-ash
cupel, the gold and sil-
ver alloy remaining in
the shape of a button
on cooling. The “but-
ton ” is then flattened
on an anvil, rolled into
- a strip, and finally bent
into a spiral or S shape
called a “cornet;” this
is placed in a vial (ma-
trass), and the silver dis-
solved ont by nitric acid.
The resulting pure gold
is washed, dried in a
porous crucible (shown
at A, Fig. 260), and
weighed. The weight
before and after assay-
ing gives the proportion-
ate amount of gold in
the piece. About 30
pieces from one deposit
are thus assayed at the
same time, and the mean
result taken as correct. . ‘
The humid assay is nearly always used for silver. Ten or more small pieces are placed in as many
vials, and dissolved by nitric acid ; after which the vials a a are set in the recesses cl d d of the agi-
tator shown in Fig. 261, and a standard solution of sea-salt added. The vials are then corked, and
the covers 6 b fastened down by the screws 9 g. The agitator next receives, either by hand or ma-
chinery, a rapid vertical shaking motion, whereby the chlorine of the salt decomposes the nitrate of











\\ \\\ \\ \\
liafl‘QQI'
_. _ __ - .
$3“*
el
/ // //// ////

. ,///
1.1
a .
/




* Contributed by Irving M. Scott. '
ASSAYING. 99

silver, and chloride of silver falls as a white precipitate. The quantity of the salt solution required
to precipitate all the silver from its nitrate determines the amount of silver in the vial. The precipi-
tation is considered complete when no more of a cloudy stratum can be detected over the liquid. The
weight of silver precipi-
265' tatcd, compared to the
' weight before assaying,
| gives the proportionate
, amount in the piece, the
(— i mean of which is taken
from all the assays.



I
l "—1 Refining. —-The as-
sa ed old and silver
I y s
' I, deposits are melted to-
| A L ~ gether in the proportion
l five-e of one gold and two
'—"— 11:1 "2:1:"Ml '''''' --'- ----- --~l-"".IT_'_”T.'.T. ___:ti]~"-‘ silver, then granulated,
:5



----.

|
I
l
l
I
I
| t







"" " and sent to the refinery
department, where the
------ --
—-——-~ mixture is treated with
x a , \ f nitric acid in porcelain
pets. The resulting sil-
\ ver solution is decanted
\ from the unaltered gold
‘ _ I, I , into large vats, and by
x \1.‘ | ,1, ,' ; adding a solution of. sea-
i
i









\\,
\‘
l\
g
l\
I
l
l
l\
I
I
l
l
I
I
‘\
m
l
I
l
l
l
l
l
|
l
:\
I
I
l
.. //\/
I/ \
, -, , 1 salt chloride of silver is
‘\ I ,’ formed, which is sepa-
Z/ /l/ // / /| x/fy /// >// ggtedtfrom 1,2113; liqpor by
, , ' ' "sq/.41." -/ / ////’/"’/ j- ' ' , S V ‘-
th'eldl policipitaied
the chlorine with zinc
and sulphuric acid as a
grayish-black powder, which is dried, pressed, and sent to the melting-room, where it is fused with
borax and poured into cast-iron moulds, 1*‘g. 262. The gold left in the pets is repeatedly treated
with nitric acid, to remove all traces of silver, washed, pressed, and cast into bars of the size and
shape of the moulds.
Dig/ot-Zlfelt'iny—The refined metals are melted together with 100 parts of copper in 1,000, and cast
into ingot-moulds. These moulds, Fie‘. 263, consist of four cast-iron plates, two of which, a a, have
the shape of the mould cut out, the others, I) b, acting as covers. The plates are held together by
the dog 9. Immediately after casting, the ingots solidify, and are removed from the moulds by
r unscrewing the dog, and dropped into
\ \ 266, ' cold water. Assays are made of the first
Q and last ingot of each melt, and, if found
\\ \\ ‘ to disagree sensibly with each other or
_¢


the Government standard, the whole lot
\\
must be again melted and cast. The
152,, tops of the ingots, being rough and un-
even, are cut off by the shears, a a, of
E a topping machine, Fig. 264, in which 6
g: is the crankshaft, c the connecting-rod,
*1 e the gear and pinion, d d the pulleys,
and g the fly-wheel.
a Treatment of -S:1'cqi.v.—The slags, worn-
out crucibles, and sweepings of the fines
E are sent to the sweep-room, where they
i_ are pulverized in a large Chili mill, Fig.
I? 265, in which a is the revolving pan, and
N




' b b are rollers of 36 inches diameter and
\\\v ' lflinches face. The pulp from the mill
\\. \ i\\\~m\m\\\m passes through a bolting-screen, which
separates an;r integral metallic parts, and
thence into an amalgamator, where from 500 to 1,000 ounces of amalgam are collected per month.
The auialgamator tailings are run into settling-tanks, thence shoveled into wrought-iron pans, and
dried in a sweep-furnace, Fig. 266, where an. are the pans, and bis the grate. After about three
hours’ drying the pulp is packed into barrels, then concentrated and reworked as often as it will pay.
l'Vorlrs for Refermwc.—-In the preceding pages the details of the processes for assaying many ores
and alloys have been necessarily omittcdrbu't the reader can obtain these by reference to the fol-
lowing works: “ Sulphurets, Treatment,” etc., Barstow, San Francisco, 1867 ; “ Anlcitung zur Berg-
und I-Iiittenmiinnischcn Probirkunst,” Th. Bodemaun and Bruno Kerl, Clausthal, 1857 ; “Treatise on
the Assaying of Lead, Copper, Silver, Gold, and Mercury.” Th. Bodemann and Bruno Keri (trans-
lated by W. A. Goodyear), New York, 1865; “On Gold, Silver, and Iron,” T. M. Blossom, American
Cyhcm'ist for 1870; “Practical Miners’ Guide,” J. Budge, London, 1866; “Assay of Gold and Silver'
ll ares,” A. Byland; “Metallurgisehe Probirkunst,” Bruno Kerl, Leipsie, 1866; “A Practical Treatise g ;


100 ASTYLLEN.

fl
on Metallurgy," Wilhelm Kerl (edited by William Crooks and Ernst Rohrig); “The Assayers’ Guide,"
0. M. Licher; “ Manual of Practical Assaying,” John Mitchell (edited by William Crooks), New York,
187 2; “Manual of Practical Assaying,” John Mitchell, London, 1868; “Practical Assayer,” Oliver
North, London, 1874; “Practical Mineralogy, Assaying, and Mining,” Frederick Overman, Phila-
delphia, 1863; “Notes on Assaying and Assay Schemes,” Ricketts, New York, 1878; “Hand-Book
for Miners, Metallurgists, and Assayers,” Julius Silversmith; “Chemical Technology,” F. Knapp;
“ Dictionary of Chemistry,” Henry Watt, London, 1866-’72; “The Mints and Assay Offices of
Europe,” Ricketts; Transactions of the Ameitcan Institute of Mining Engineers, vol. iv. Besides
the above, almost all works on the chemistry of the metals treat more or less of the assay of the
same. See also the annual reports of the directors of English and United States mints, which con-
tain much valuable information. P. DE P. R.
ASTYLLEN. A small dam in an adit or mine, to check the passage of water.
AUGER. See Brrs AND Aucnus.
AWL. A pointed instrument for piercing small holes, as in leather or wood. The brad-awl, A,
Fig. 267, is the smallest boring tool. Its handle is the frustum of a cone tapering
downward. The steel part is also conical, but tapering upward; and the cutting edge
is the meeting of two basils, ground equally from each side. A hole is made by
placing the edge transverse to the fibres of the wood, and pushing the brad-awl into
the material, turning it to and fro by a reciprocatory motion. The core is not brought
out as by other boring instruments, but the wood is displaced and condensed around
the hole. The wire-worker’s awl, B, 267, is less disposed to split the wood. It is (9
square and sharp on all four edges, and tapers off very gradually until near the point,
where the sides meet rather more abruptly.
AXE A cutting tool, usually of iron with a steel edge, used for hcwing and chop- 1
ping wood. The butt of the tool is made from a good quality of rolled iron, the bars
of which are first out into pieces of suitable length by heavy shears. The blanks are )
then passed through rolls, and thus made to assume the form shown at A, Fig. 268. 6
By a simple machine the ends of the blank are brought together, or rather the blank
is folded so as to assume the form shown at B, Fig. 268, the indentations on the side ~
coming together roughly to form the eye. The blank in this shape is heated in an
open furnace to a welding heat, and then, being placed under a trip-hammer, is forged
to an approximation of its final form. The separated ends are welded together, and
the eye is opened out, as shown at C. Meanwhile the steel edges or blades are being formed in the
shape represented at D. The part which is to form the keen edge is left thick, as shown at E,
while the portion to be inserted in the iron blank is made much thinner. The head or butt of the
axe being again heated, the portion to receive the steel edge is split by means of a hand-wedge.
Borax is introduced as a flux, and the edge is inserted, as shown at E. The tool is then brought
to a welding heat, and the weld of steel and iron is made under a heavy trip-hammer. The form is
finally shaped and trued by hand-hammers. In the tempering process which follows, the axes are
heated to a low cherry-red and hardened in brine, the water being fully saturated with salt. The
temper is subsequently drawn to a pigeon~blue. The remaining operations are grinding on large
stones some 4 feet in diameter, polishing on emery-wheels, painting, and affixing the handle. The
method of testing axes at the factory of the Weed 85 Becker Manufacturing Company, of Gehoes, N.
Y., is simply to place several selected at random from a given number in the hands of an experienced
axeman, and to allow him to prove their cutting power on a tough and knotty hemlock stump.
The shapes of axes depend in some degree upon the kind of timber on which the tools are to be
used; but generally woodmen in various sections of the United States and in different parts of the
world have special predilections for particular forms, the reasons for such preference being merely
fanciful. From F to K are various forms of axes used in the United States. F is the Kentucky
axe, weight from 3 to 7 lbs. ; G is the Georgia long-bit axe, same weight; 11 is the N cw Jersey axe,
267.
A
|==- s




268.
A ‘ D








AXLES. ’ . 101

268 (eont'm'ued).




weight from 3 to 5.1; lbs.; I is the Michigan or wide-bit axe, same weight; J is the Western axe,
weight from 3 to 6 lbs.; K is the Yankee heavy-head axe, same weight. L represents the heaviest
form of Spanish axe, the out being from 8 to 81} inches. all is a shingling hatchet or light hand-axe,
and N is a lath hatchet.
Pickaxes are made in the manner above described for ordinary axes, the difference in manipula-
tion being in the forging. 0 represents a mining pick, weighing from 3t to 6 lbs. P is a light
mattock; Q, a bush-hook for cutting underbrushand shruhbery; R, a cooper’s axe; S, a Dutch side-
axe; T, a broad-axe; and U, a coachmaker’s axe.
All axes should be so constructed that either the centre of percussion or centre of gravity of the
moving mass may be directly over and in the plane of the cutting edge. When the edge is required
to throw chips, the plane passing through the centre of percussion must also pass through the here],
and not through the cutting edge of the blade.
The adze is a hand-tool used by carpenters for chipping. It is formed with a thin arching blade,
and has its edge at right angles to the handle. The edge is beveled only on the inside, and the
269.


handle is easily removed when the tool is to be ground. It should be so constructed that the centre
of gyration of the moving mass is in the cutting edge. In Fig. 269, A represents the ordinary form
of carpenter’s adze; B is a small hand-adzc; and C is the coopcr’s adze.
AXLES. See RAILWAY Cans.
BABBITT METAL. See ALLOYS.
' BAG. 1. A seow or broad-beamed flat-boat, used for ferriage, usually navigated by a rope fast-
ened on each side of the stream. 2. A cistern with a perforated metallic bottom, used for straining
the hops from the beer previous to its entrance into the cooler.
BACK—LASH. The jar which arises when a part of the machinery which ought to receive motion
from another part suddenly falls back upon its driver. It is caused by wear or imperfect fitting.
BADIGEON. A cement for filling holes or covering defects in wozt. Sculptors’—Plaster and
frecstone. Joiners’—-Sawdust and glue; whiting and glue; putty. opm-s’—-Tallow and chalk.
Stone-Masons’—Wood-dust and lime slaked together, with stone-powder or sienna for color, and
mixed with alum-water to the consistence of paint.
BALANCE. An instrument intended to measure different amounts or masses of matter by the
determination of their weight, using as standards of comparison certain fixed units, as the gramme,
the pound, the ten, etc. The instrument is founded on the law that gravitation acts in a direct ratio
to the mass, and on the mechanical principle that when a solid body is suspended on one point, the
centre of gravity will place itself always perpendicularly under that point. If therefore a beam,
1'02 BALANCE.

a b, Fig. 270, is supported in the middle at c, and movable around this point, its centre of gravitv, s,
will place itself under the point e ; and if disturbed from that position, this centre will oscillate like a
pendulum, and the beam will finally come to rest only with the centre of gravity in the perpendicular
passing through the point of " support. It is evident that when the distances from a to c and from b
to c are equal, the two sides of the beam equal, and the whole made of homogeneous material, the
horizontal position will he arrived at, and also when at a and 6 equal weights 1) p are suspended.
The gravity of such scales and weights must be considered concentrated in the points of suspension
at and b, and their common centre of gravity will be either in, under, or above the point of support,
according as the line a b uniting them passes through, under, or above the support 0. But suppose
we place an additional weight r in one of the scales, then the common centre of gravity of the
weights in the scales will be shifted toward the side of that additional weight. Suppose it to be in
d, then the centre of gravity of the whole balance will be in the line at s, uniting the centre of grav-
ity d of the weights with that of the balance .9 ,' if then it is somewhere at m, it is evident that the
balance can no longer maintain the horizontal position, but will only come to rest when m is under
0, or the line a m has attained a perpendicular position. It is evident that the angle which the beam
in this case makes with a horizontal line is equal to the angle 8 c m. If the centre of gravity is in
the point of support, the balance is indifferent; that is, it will, when charged with equal weights,
remain at rest in any position. And if the centre of gravity is above the point of support, we have
a case of so-called unstable equilibrium; the balance will with equalease tip over to the right or
left, and the beam can never be brought into the horizontal position. In either case the balance is
useless, and it follows from this that the centre of ~ ‘
gravity must be under the point of support, and
the sensitiveness of the instrument depends to a
great extent on the distance between these two
points. This derived degree of sensitiveness varies
with the purposes for which balances are to be
used.
The most delicate balances are those used for
physical and chemical investigation; and in order
to secure the greatest possible degree of sensitive-
ness the ,conditions are as follows: 1. The centre of
gravity of the beam must lie as near as possible
under the point of suspension; it is evident that
when this centre of gravity s is raised, the point
m will be raised also, and the angle 8 c m will be-
come larger, which results in a greater deflection of
the beam in case there is no proper equilibrium.
Fine balances are provided with an upright rod
above their point of suspension, on which a small
weight may be screwed up or down, in order to
raise or lower the centre of gravity, and so to in-
crease or diminish the delicacy of the instrument.
In Fig. 270 this red is represented below, which
is only admissible when no great degree of sensi-
tiveness is required, as in this case the centre of
gravity is lowered too much. 2. The beam should
be as long as compatible with strength. As the
distance 0 cl becomes greater in proportion to
' the length of the arms, any difference in the two
weights with which the balance is charged will be
the more perceptible the longer the arms are. 3.
The beam should also be as light as compatible
with strength; the smaller the weight of the bal-
ance itself, the greater the influence of minute dif- .
ferences in the load will be to shift the position of the point (Z from the centre. Therefore the
beams of chemical balances are made like an elongated frame, with large openings between, on the
same principle as the walking-beams of steam-engines are constructed. 4. The points of suspension
of the two scales must be such that the line uniting them passes exactly through the point of sup-
port; if this line passes under that point, the sensitiveness of the balance will diminish too much
when the load is increased. This takes place in any case to a small degree, as no beam is so per-
fectly inelastic that a slight flexion will not take place under the maximum load. 5. The distances
of the points of suspension of the scales at and b from the centre a should be perfectly equal; this
is best verified by changing the weights in the two scales, when, if the equilibrium remains un-
changed, their distances are equal. Some balances have screw arrangements to correct small differ-
ences in this respect.
In Fig. 271 a chemical balance is represented as used, in a glass case, which serves to protect it
not only from dust, but also against air-currents, which might prevent a truly sensitive balance from
ever coming to rest, and thus make correct weighings impossible. The turning-point of the beam, in
order to reduce the friction to the least amount, is a knife-edge or triangular prism of hardened steel
passing at right angles through the beam, and resting when in use upon polished plates of agate (one
each side of the beam), which are set exactly upon the same horizontal plane. This knife-edge is
polished, and brought to an angle of 30°. The points of suspension are also knife-edges, one set
across each extremity of the beam. Great care is required that the line connecting them shall be













BALANCE. 103

precisely at right angles With the line passing through the centres of motion and of gravity. The
index or pointer is sometimes a long needle, its line passing through the centre, and extending either '
above or below the beam, or it is a needle extended from each extremity of the beam. In either
case it vibrates with the motion of the beam over a graduated are, and rests upon the zero point
when the beam is horizontal. The degrees upon each side of the zero of the scale indicate, as the
needle oscillates past them, the intermediate point at which this will stop, thus rendering it unneces~
sary to wait its coming to rest. In order to save the knife-edges from wear, the beam is made, in
delicate balances, to rest when not in use upon a forked arm, and the pans upon the floor of the case
in which the instrument stands. The agate surfaces, being lifted by means of a cam or lever, raise
the beam elf its supports and put it in action; or the supports, by a similar eontrivance, are let down
from the beam, leaving it to rest upon the agate; the pans in the latter case must always remain
suspended. ~
However perfectly a balance may be made, there is always great care to be exercised in its use.
Errors areeasily made in the estimation of the nice quantities it is used to determine. The sources
of some are avoided by a simple and ingenious method of weighing suggested by Borda. The body
to be weighed is exactly counterpoised, and then taken out of the pan and replaced by known
weights, added till they produce the same effect. A false balance must by this method produce cor-
rect results. ~ The weights employed for delicate balances are either troy grains, one of each of the
units, one of each of the tens, and the same of the hundreds and thousands, as also of the tenths,
hundredths, and thousandths of a grain; or they are the French gramme weights, with their decimal
parts. The latter are' the most commonly used in chemical assays and analyses. The larger weights
are of brass, the smaller of platinum, and these are always handled by means of a pair of forceps.
The beam of the balance is, according to the method introduced by Berzelius, frequently marked by
divisional lines into tenths, and one of the small weights, as a tenth or hundredth of a grain, or a
milligramme, is bent into the form of a hook, so that it may be moved along the beam to any one of
these lines to bring the balance to exact equilibrium. By this arrangement the picking up and trying
one weight after another is avoided, and the proportional part of the weight used is that indicated by
the decimal number upon the beam at which it rests to produce equilibrium. The best materials for
a balance are those which combine strength with lightness, and are least liable to be affected by the
atmosphere and acid vapors. Brass, platinum, or steel is used for the beam; but probably aluminum
will prove to be better adapted for this purpose than either. The pans are commonly of platinum,
made very thin, and suspended by fine platinum wires. The support is a brass pillar secured to the
floor of the glass case in which the instrument is kept. Doors are provided in front and at the sides,
by which access is bad to the instrument; but these are commonly kept closed, and are always shut
in delicate weighing, that the beam shall not be disturbed by currents of air. So delicate are the
best balances, that when lightly loaded and left to vibrate, they may be affected by the approach of
a person to one side of the glass case, the warmth radiated from the body causing the nearest arm of
the beam to be slightly expanded and elongated, so as to sensibly preponderate. The degree of
sensibility is estimated by the smallest weight in proportion to the load that will cause the beam to
be deflected from a horizontal line. It is said that a balance is in possession of Bowdoin College,
Maine, which, with a charge of 10 kilogrammes in each scale, is sensitive to one-tenth of a milli-
gramme. Becker dz Sons of New York made the balance; and they make ordinary chemical bal'
ances which with one kilogranime in each scale are sensitive to one-tenth of a milligramme; their
small balances now in use in the Assay Office, New York, show a difference in load of less than
one-hundredth part of a milligramme. ‘
- The torsion balance, invented by Coulomb to measure minute electrical forces, is still more delicate
than the best beam balance. It consists of a brass wire,
hung by one end and stretched by a light weight, carry-
ing at its lower end a~horizontal needle. Any force ap-
plied to one end of this needle, tending to rotate it hori-
zontally, will be measured by the angle through which
it causes the needle to move; that is, by the torsion of
the wire.
The steelyard, the Roman siaz'cra, is one of the forms
of the balance, the two arms being of unequal length,
the body to be weighed being suspended in a pan or
otherwise from the short arm, and the counter-poise,
which is a constant weight, being slid along the longer
arm until equilibrium is established. As this occurs
when the weight on one side multiplied by its distance
from the fulcrum is equal to the weight on the other mul-
tiplied by its distance from the fulcrum, and as on one
side the weight is constant, and on the other the distance
from the centre of motion is variable, the unknown weight
must be determined by the distance of the constant
. weight from the centre. The Danish balance differs
from the common steelyard in having the counterpoise fixed at one end, and the fulcrum being
slid along the graduated beam. The graduation commences at a point near the counterpoise, at
which the beam with the pan suspended at the other end is in equilibrium, and the numbers increase
toward the pan. A balance called the bent lever is employed to some extent for purposes not re-
quiring extreme accuracy. The pan is attached to one end of the beam, and the other carries a con-
stant weight. From the bent form of the lever this weight is raised to a height varying with the
weight placed in the scale pan. A pointer attached to the constant weight and moving along a grad-
271 A.



104 , .BALANCEeRYND.‘

\
uated are indicates by the number at which it stops the weight of the body in the settle-pan. Its
indications are the least to be depended open when the constant weight approaches to the horizontal
or vertical line passing through the centre of motion. The scales generally used in the United States
for weighing loaded wagons and canal-boats are modifications of the steelyard, wherein the weight
of these ponderous bodies is divided by means of levers, and a known fraction of it sustained by one
end of a beam, the other end of which is graduated for a moving weight. Modern modifications of
the steelyard contain a pan hung at the end of the arm to receive larger weights, while the sliding
weight is used only to balance the fractional parts.
The principle of platform scales, or weighing machines, is nearly if not quite the same in all scales
and balances. But the same principle is carried out in different forms. The old style of balance
was only an even beam. The new style is a multiplying beam, or in most cases a set of multiplying
beams or levers. It will be seen from Fig. 271 A that when the lever K is suspended by the red C,
the weight and lever resting on knife-edges D and F, by applying a certain weight to E, as shown at
A, it will pull down a certain amount at F, according to the difference between E and D- and E and
F. The weight being reduced at 17’, it is transferred to the second lever L at G. L being suspended
at H by the bolt J, the weight is again transmitted and reduced to I. In this way it may be re_
duced to almost any given amount; for instance, A may weigh 500 lbs., and just balance B, which
only weighs 25 lbs. ; Or it may be reduced, as is the common practice in platform scales, so that 100
lbs. at E will just balance 1 lb. at I ,' or in larger scales, such as are used for weighing wagons, it
is reduced to 1 lb. to 500, or 1 lb. at B when 500 lbs. are applied at A. This system of multiplying
levers is used in all platform scales, the principal difference being in the pattern, material, and work-
manship. Pipe and knee or right-angle levers are sometimes used in order to make the article
cheaper; but they are also only multiplying levers.
Spring balances are popular instruments, and consist of a helix of wire inclosed in a cylinder. The
body to be weighed is suspended to a wire passing up through the centre of the helix and fastened
to the upper coil, which carries a pointer down a narrow slit in the cylinder, thus indicating the
weight on the graduated sides of the cylinder. -
See Lnvnn, under STATICS. For assaying-balances, see Assavme. For balance-wheels, etc., in
watches, see Warren AND CLoeK MAKING. See also “Science of Weighing, Measuring, and Stands
ards,” Chisholm, 1877; “ Chemical Manipulations,” Faraday, for construction and management of
delicate balances used in quantitative analyses. Illustrations of nearly all modern forms of balances
and scales are contained in a pamphlet issued by Messrs. Fairbanks & Co. of New York.
BALAN CE-RYN D. In mills, the iron bar stretching across the eye of the runner, and by which it
is poised on the top of the spindle. .
BALEIN E. Figs. 2’7 2 and 27 3. A movable scaffold employed in France to facilitate the tipping of
the wagons in railroad‘embankments. It consists of two trussed beams, which are laid with rails along 4
272.






,'/'.~ '1' I; / /.4//_1 // . /' ,//I - / 1/1- // I" /
the top, one end resting on the ground at the battery-head of an embankment in course of formation;
the other end of the baleine rests on a wheeled carriage or railway, the rails of which are taken up at






\ 273. m
‘ w” ‘ ~ - —- —-l _l_ .'
~ “a ~ war-i ~ Flam“ —-s-T-r---_ \ .
\\ \\ ’ ‘ — l h i I p1 _\~ .
N " Elma!" -' ' "Gall-“trip- L-
.
“Ex c
w‘ .\‘\ I
\\_\\‘
\\ . . I; -
‘ig. _ . ‘
_\
\\_ \ _
\ "“s a;
wig“ ~ - ._.. _
<;\‘\ ghgc) ._ flaw“, \ w“ ?-"2~"¢='<-
one end as the other progresses. When a car is tipped at the battery-head, its contents are discharged
between the rails, and it is pushed to the other end of the baleine.
BALIZE. A frame of timber for a beacon or landmark.
BALLOON. See AIR-SHIP.
BAND-SAW. See Saws.
BANKER. 1. In bricklaying, a bench used in dressing bricks to peculiar shapes. On one end of
it is a grit-stone called a rubbing-stone, and on other portions is room for operating upon the bricks
with the tin saw, by which kery’s are made in the bricks to the depth to which they are to be hewn. 2.
In sculpture, a modeler’s bench, supporting a platform which can be rotated to expose any side of the
work. a . .
BAROMETER. ' 105

,-_—
BAPTATERIUM. A bark-mill, or fulling-mill.
BARI. The portion of a roofing-slate showing the gauge, and on which the water falls.
BAROMETER. An instrument used for observing the pressure and elasticity, or variations in den-
sity, of the atmosphere. It is commonly employed for the purpose of determining approaching varia-
tions in the weather, and more scientifically for measuring altitudes. There are various modifications
of the barometer, as the diagonal, horizontal, marine, pendent, reduced, and wheel barometer; in all
of which the principle of construction is the same, the only difference being in its application.
The essential part of a barometer is a well-formed glass tube, closed at one end, perfectly clear and
. free from flaws, 33 or 34 inches long, of equal bore, filled with pure mercury, and inverted, the open
end being inserted in a cup partly filled with the same metal, so that the mercury in the tube may be
supported by atmospheric pressure.
The vacant space between the top of the mercury and the top of the tube is called the Torricellian
vacuum, in honor of the inventor of the instrument.
On pouring mercury into the barometer-tube and inverting it, the air thus confined between the
mercury and the inner surface of the tube will escape into the Torricellian vacuum. In order to get
rid of this air, as well as moisture, the tube is first gently warmed, so as to dry it thoroughly. A
quantity of pure mercury is then poured in, so as to occupy 2 or 3 inches of the sealed end of the tube,
which is held over the fire until the mercury boils, taking care to turn the tube round upon its axis,
so that the heat may be equally applied. After boiling for a minute or two, the open end is closed
by a cork to prevent the introduction of moist air, and the tube is then allowed to cool, in order that
the cooled mercury which is next to be poured in may not crack the tube. \Vhen a second portion of
mercury, about equal to the first, has been poured in, the part of the tube containing this new portion
is held over the fire until it boils. It is again removed from the fire and corked up as before. A
third portion of mercury is then introduced, and the heat again applied to that part of the tube con-
taining the last addition of metal; and in this way the tube is at length filled, with the exception of
a small portion from which the mercury has been expelled by the heat. This is filled up with mer-
cury, and the finger is now placed over the opened end so as carefully to exclude any air; the tube is
then reversed into a cup of pure mercury ; as the column sinks, it expels the last portion of mercury
which had not been boiled ; and as there is neither air nor aqueous vapor above the mercurial column,
its length exactly measures the atmospheric pressure. A film of air is always retained on the outside
of the tube, and also at its under edges, which film creeps by small portions at a time into the interior,
and rises up in innumerable bubbles into the vacuum,the film being constantly renewed by the descent
of more air between the outside of the tube and the mercury in the cup, and thus the outer air slowly
insinuates itself into the barometer. In this way the most carefully-constructed barometers have
become deteriorated in the course of years.
This irregular and uncertain deterioration of barometers was remedied by Prof. Daniell, by uniting
a ring of platinum with the open end of the barometer-tube, so as to bring it into contact with the
mercury, thus effectually preventing the ingress of air into the tube.
The same philosopher also invented a new mode of filling barometer-tubes, by pouring the mercury
into the tube while both are under the exhausted receiver of a good air-pump. The mercury is poured
through a long slender funnel extending to the bottom of the tube, and dipping into a small portion
of mercury previously introduced, and boiled. By this means all agitation is confined to the tube of
the funnel, and the tube left perfectly free of air. The mercury was afterward boiled in came.
The excellence of the barometer chiefly depends on the absence of all matter except mercury from
the tube, and its value may be tested by three indications: 1. By the brightness of the mercurial
column, and the absence of any flaw, speck, or dullness of surface; 2. By the barometric light, as it
is called, or flashes of electric light in the Torricellian vacuum, produced by the friction of the mer-
cury against the glass, when the column is made to oscillate through an inch or two in the dark; 3.
By a peculiar clicking sound, produced when the mercury is made to strike the top of the tube. If air
bepresent in the tube, it will form a cushion at the top, and prevent or greatly modify this click.
The sectional area of- the tube is of no consequence; as the atmosphere presses with the same in-
tensity upon the surface of the mercury in the cup, the column suspended in the tube will be of the
same height, whatever its internal diameter.
The height of the mercurial column must be measured from the surface of the mercury in the cis-
tern. When the atmospheric pressure increases and the mercury in the tube rises, a portion of the
metal is drawn out of the cistern into, the tube, and the level of the mercury in the cistern is de-
pressed; so, on the contrary, when the atmospheric pressure diminishes, a quantity of mercury is
forced out of the tube into the cistern, and the level of the metal in the latter rises.
In some instruments the scale, accurately divided into inches and parts of inches, is made mov-
able, and terminates in an ivory point, which is brought down to the surface of the mercury. When
this point and its reflection appear to be in contact, the height indicated by the scale is correct. In
other forms of the barometer the mercury in the cistern is always maintained at the same level, for
which purpose the cistern is formed partly of leather, so that, by means of a screw at the bottom, the
surface of the mercury may always be adjusted to the neutral point before taking an observation. The
divisions of the scale usually begin at the 27th inch, and are continued to the 31st. But in instru-
ments intended to measure the height of mountains, or for accompanying balloons, the scale begins at
the 12th or 15th inch. Each inch is divided into 10 parts, and these are subdivided into 100ths by
' means of a small sliding scale, called a oerm'er or nonz'us.
The barometer ought to be fixed in a truly vertical position, and, if possible, with a northern
aspect, in order that it be subject to as few changes of temperature as possible. It is usual, for the
sake of comparison, to reduce the observations to 32°, for which purpose tables for correction for
temperature are given in scientific works devoted to the subject of the barometer. The height of the
cistern of the barometer above the level of the sea, and, if possible, the difference of the height of the
106 BAROMETER.

mercury with some standard, should be ascertained, in order that the observations made with it should
be comparative with others made in different parts of the country. Before taking an observation, the
instrument should be gently tapped, to prevent any adhesion of the mercury to the tube; the gauge
should be adjusted to the surface-line of the cistern, and the index of the vernier brought level with
the top of the mercury. .
Various contrivanees have been made for increasing the length of the scale, or for making it more
convenient for use. The most popular form is the common wheel-barometer, as it is called. In this
instrument the tube, instead of terminating at the bottom in a cistern, is recurved, so as to form an
inverted siphon. As a rise of the mercury in the longer or closed limb is equivalent to a fall in the
shorter limb, and vice versa, a float is placed on the surface of the mercury in the shorter limb, and is
connected with a string passing over a pulley, and very nearly balanced by another weight on the
other side of the pulley. An index-hand attached to the pulley moves over the surface of a dial~
plate, graduated so as to indicate the oscillations of the mercurial column. With an increase of
atmospheric pressure the mercury in the longer tube rises, and that in the short tube is depressed,
together with the float, and this gives a small motion of revolution to the pulley, and also to the
attached index-hand. A fall in the longer column causes the mercury, with its float in the short limb,
t0.rise, and consequently moves the index-hand in the contrary direction.
The measurement of heights was the first useful purpose to which the barometer was proposed to
be applied.
Although the atmosphere may extend to the height of 45 miles, yet its lower half is so compressed
as to occupy only 3% miles, so greatly do the upper portions expand when relieved from pressure.
Hence, at the height of 39; miles, the elasticity of the atmosphere is one-half ; at 7 miles, one-fourth;
at 10%; miles, one-eighth; at 14 miles, one-sixteenth, etc.
Halley was induced, by certain mathematical considerations, to fix upon the number 62,170 as
a constant multiplier, and the rule for the measurement of heights may be stated as follows:
Observe the height of the barometer at the earth’s surface, and then at the top of the moun-
tain, or other elevated station; take the logarithms of these numbers, and subtract the smaller
from the greater; multiply the difference by 62,170, and the result is the height in English feet.
This process gives a very near approximation, especially in temperate climates.
But the progress of science soon rendered it evident that a correction for temperature was neces-
sary in barometrical measurements, and a formula has been contrived to meet most of the difficulties
of the question. The following rule will be found of easy application: Multiply the difference of
the logarithms of the two heights by the barometer by 63,946 ; the result is the elevation in English
feet. Then, in order to correct for temperature, take the mean of the temperature at the two eleva-
tions. If that be 89.68° Fahr., no correction is necessary; if above that quantity, add 1&1; to the
whole height found for each degree above 69.68° ; if below, subtract the same quantity. For exam-
ple, Humboldt found that at the level of the sea, near the foot of Chimborazo, the barometer stood
at exactly 30 inches, while at the summit of the mountain it was only 14.85. The logarithm of 30 is
1.4771213, and the logarithm of 14.85 is 1.1717237 ; then subtracting
1.4771213 214-
11717237 ‘
0.3053976


multiply this by 63,946, which produces 19,539 for the elevation in feet.
'If the mean temperature of the two stations be 69.68°, no correction is
necessary for temperature. This is a tolerably close approximation. The
most careful calculation has given 19,332 for the real height, and this was
' probably estimated for a. lower temperature.
A method has been given by Leslie for measuring heights without the
use of logarithms. His rule is as follows: N otc the exact barometric press-
ure at the base and the summit of the elevation, and then make the follow-
ing proportion: As the sum of the two pressures is to their difference, so is
the constant number 52,000 feet to the answer required in feet. Suppose,
for example, the two pressures were 29.48 and 26.36 ; then
As 29.48 + 26.36 : 29.48 - 26.36:: 52,000 feet : 2,905.4 feet, the answer
required.
This rule has been found applicable to the mean temperature of England
for all heights under 5,000 feet.
Another method of obtaining approximate differences of altitude is by
a comparison of the iempm'alw-cs of boiling water (which vary with the
pressure of the atmosphere). The apparatus is exceedingly simple, and the
instrument not so liable to injury as the mercurial barometer, being much
more portable, and easily replaced. Fig. 274 : A, common tin pot, 9 inches
high by 2 in diameter. B, a sliding tube of tin, moved up and down in the
pot; the head of the tube is closed, but has a slit in it, 0, to admit of a
thermometer passing through a collar of cork, which shuts up the slit when
the thermometer is placed. D, thermometer, with so much of the scale as may be desirable. 11",
holes for the escape of steam.
The boiling-point for the level of the sea should be correctly marked by a number of careful
observations, and the difference, if any, must be noted as an index error.
These thermometers are very useful in ascertaining heights where strict accuracy is not required,
and they have the advantage over mercurial barometers in being portable. In moderate elevations,
'llillllll'






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c
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5.0“,
c b ‘
. . M
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O .
I.
BAROMETER. 107


the difference of one degree in the temperature at which water boils indicates a change of level of
about 500 ha, corresponding to a difference of 0.6 of an. inch in a mercurial barometer.
Aneroz' Barometer.--The action of the aneroid depends on the pressure of the atmosphere on a
circular metallic box hermetically sealed, and having a slightly elastic top, the vacuum serving the
purpose of the column of mercury in the ordinary barometer. The construction of the aneroid is
illustrated in Figs. 275, 276, and 277. The vacuum-chamber is represented at A ,- its top and bottom
275.






are formed of disks of thin circularly corrugated copper, held together by a circumferential strip of
plain metal, as shown in the detail, Fig. 277, which is a vertical section of the chamber detached.
A strong brass stud B is attached to the upper diaphragm of the chamber, having a slot on its end,
through which a small projecting pin 0 formed on the leveeplate A projects, the attachment being
effected by a pin passed transversely through the slotted portion of the stud, immediately over the
pin 0. The plate D, which acts as a lever in communicating the movements of the diaphragm, rests
upon two pillars E, carried by the supporting base-plate of the vacuum-chamber as fulcra. The
projecting lever-portion F conveys the movement by a joint at G, which is linked to a rocking.
spindle carrying the lever H, connected to the arbor of the index-needle by a fine chain which winds
upon it, like the mainspring chain of a watch upon the spring-box. In the interior of the vacuum-
chamber a single helix is fixed upon the base-plate, so as to abut against the lower surface of
the lever at I, and thus preserve the two diaphragms of the chambér from actual contact.
To set the instrument to indicate the same scale as the mercurial barometer, the arrangement given
full-size in Fig. 278 is adopted, to form the connection between the main lever and the index-arbor.
The link from the end of the main lever is joined to an eye at A, on a stud formed upon the end of a
metal bow-piece B, the contrary end of which is attached to the lever H, before described. The whole
of these parts are carried by a nicely-adjusted rocking-spindle C, working on centres in the frame L.
The office of this eontrivance is to afford a means of adjustment for the index-movement by the two
screws ll! N, one of which elevates or depresses the eye A, while the other sets it in or out from the
centre of the rocking-spindle, to give more or less leverage, as may be required to suit the barometri-
cal scale. The connection between the index-arbor and the lever-apparatus being by a flexible chain,
its movement can act only in one direction in bringing round the index, and a fine hair-spring is at-
tached to give the return~movement.
The tube by which the exhaustion is effected is at O. The process of exhausting, as specified by the
inventor in connection with the original plan, is as follows : A little solder is placed round the aper-
ture for the exhaust, in which a flat-headed pin is set, so open as to admit the air to pass. The dia-
phragm is compressed to its proper position by means of a board, and is then soldered to its box.
The whole is afterward placed under an air-pump receiver having an air-tight stuffing-box, through
which a rod carrying the heated soldering-iron is passed. When the vacuum is obtained, the solder-
ing-iron is pressed down, to melt the solder round the peg and close the opening.
A simple mode of adjusting the instrument by a standard barome-
ter is obtained by a screw-stud projecting through the back of the
instrument, in connection with the reacting-spring at I, the tension
' of which may thus be varied to the extent required. By a simple
arrangement, the vacuum-case is itself made to afford its own
temperature-correction, without the addition of a particle of mechan-
ism. Previous to the exhaustion of the vacuum-ehamber, the top
and bottom diaphragms are both perfectly horizontal ; but when ex-
hausted, they each take the curve shown in the section, Fig. 27 7, and
the dotted lines represented as running nearly even with the corru-
gated surfaces indicate the position they will assume when a portion
- of gas is introduced to play the important part of a compensator for
the disturbance to which the index would be liable from changes of temperature. The expansion of
the contained gas, arising from the disturbing cause itself, counteracts the loss of elastic force pro-
duced by the same cause in the diaphragms and other parts of the machinery. The external atmos-
phere is continually endeavoring to press down the diaphragm, while the helix beneath the lever is



108 BAROMETER.

as continually acting to keep it up. An increase in temperature expands the contained gas, which
thus diminishes the efiect of the external atmospheric pressure, and corrects the disturbance arising
from the expansion of the various levers and connections, which would otherwise indicate upon the
dial a greater amount of movement than is actually due to the atmospheric change.
The following convenient rule for measuring altitudes by the aid of the aneroid barometer is from
the “Hand-Book to South Africa:” Read the aneroid at A, say 30.15; take it to B, read it there,
say 29.08; take it back to A, read it again, say 30.19. Then take the mean of the readings at A,
and find the difierence between that and the reading at B; multiply the difference in hundredths by
9, and the result will be the difference of altitude in feet—thus: -
30.15 + 30.19
2
Fig. 279 represents a registering barometer made by M. Redier, of Paris, which is censtructed as
follows: In one branch of the ordinary siphon barometer is an ivory float F, on which is fastened a
very light steel pointer, on the apex of which is an horizontal needle A. One end of the latter is made
in. a small hook, or catch. Affixed to the supporting-frame of the instrument is clock-mechanism.
One train is terminated by a chronometer-escapement, and the other train by a light flywheel, which
turns with great rapidity. The two trains are calculated so that the velocity of the fly-wheel may
be double that of the escapement. A satellite gear unites these two movements, and on the axis of
the satellite is carried a wheel, which engages with a pinion on which is mounted the large four-
armed wheel shown. A chain from the latter moves the registering-pencil If in one or the other
direction, according as the wheel turns to the right or left. The axis of the large wheel has a pinion
which engages in a rack not shown, whereby the plate which carries the barometer is moved ; so that,
when the pencil is caused to travel, the barometer is also moved in a vertical direction. The needle
A touches one of the wings of the fly-wheel with its hook-end. The escapement of the chronometer
train works constantly, and so tends to carry the large wheel from right to left, and.to raise the
barometer upward. As the barometer is thus moved, however, the needle is disengaged from the
fly-wheel. The latter is then free to turn, and, as its velocity equals 2, that of the escapement being 1,
it draws the large wheel from left to right, and causes the barometer to descend. The needle then
once more catches the fly-wheel.
When atmospheric pressure does not change, the pencil describes a right line; should it augment,
however, the mercury sinks in the barometer, the needle is carried down, and the hook engages still
further on the fiy-wheel. It will then take longer for the escapement to cause the disengagement
of the fly-wheel. Consequently the large pulley turns in the same direction for a period proportional
to the change of pressure, and the mark left on the paper indicates this movement. If, on the other
hand, the pressure diminishes, the fly-wheel is freed, and the separation between wheel and needle
will be greater in degree proportional to the diminution of pressure. A movement of the pencil to '
the right, therefore, indicates a rise in the mercury; to the left, a fall.
The paper on which the indications are received is divided into spaces horizontally to represent
= 30.17; 30.17 — 29.08 = 1.09; then 109 x 9 = 981, height'in feet.


hours, and vertically to represent varying degrees of pressure. It is wrapped around a cylinder,
which is rotated by clock-work R ever given distances, to correspond with the ruling of the paper.
The length of the latter may comprise indications for several days, on which the marking for a week
BAROMETER. ‘ 109

is exhibited. The little hammer O is caused to strike gentle blows on the barometer-support, so as
to keep the mercury-column always free and lightly shaken. .
A barometer in common use is provided with an index which turns round upon a dial, and points
to figures which indicate the height of the mercury, as also to words descriptive of the state of the
weather, as “Cloudy,” “Fair,” etc. The index is made
to move by means of a string, which passes around its
axle, and has at each end a weight attached, the larger
one resting upon the surface of the mercury in the shorter
limb of a siphon barometer. Fig. 280.
The simplest form of barometer is that called the cis-
tern barometer. A straight Torricellian tube terminates
at its foot in a cistern of mercury. By the rising and
falling of the liquid in the tube the level of that in the
cistern must change. The absolute height of the mercury
is found by making the scale fixed, and bringing the mer-
cury to its zero-pOint by means of a scale which is made
to press against a flexible bag that forms the lower part
of the cylinder, as represented in Fig. 281. ,
A Magneto-registering Barometer has been devised and
has given good results. As shown in Fig. 281 A, the
mercury is contained in a siphon-tube and carries a float,
f, which acts on a lever, R The axis of this lever is a
fine steel wire supported in two small glass rings, which
are attached to the horseshoe magnet, A. This magnet
supports the greater part of the weight of the lever, and
in consequence reduces the friction of the axis on the
hearing. A fine wire carried by the free end of the
lever, F, bears against a blackened cylinder, 0 Y, which
is rotated by clock-work. A curve of pressures is thus
traced.
The Thermo - Barograph registers both barometric
heights and thermometric degrees. Its diiferent parts
are so arranged that the variations in the air thermome-
ter, due to changes of atmospheric pressure, are compen-
sated for automatically. Its characteristic feature consists in suspending from the scale-beam that
carries the manometer a barometer tube; the atmospheric changes of pressure that cause changes
in the manometer are compensated for by corresponding variations in the barometer. Again, the
scale-beams are so arranged that they maintain almost exactly their horizontal position; thus the
barometer and other balanced parts hang from points constant and fixed.
Referring to Fig. 282, which gives a general view of the essential parts, it will be understood that
the fixed cylindrical glass tube, 1", whose upper end connects by a leaden tube with the nitrogen
281 A.


























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reservoir of the gas thermometer, is carried by a stationary frame not shown in the drawing. The
lower open end of this tube dips into a mercury cistern of iron, being immersed in the mercury con
tamed therein. This cistern hangs upon a knife~edge on the upper scale-beam. Thus, when the tem-
perature rises, the gas in the thermometer (nitrogen) expands, the mercury sinks in the tube, rises in
the cistern, and makes it heavier. By the mechanism yet to be described, the rider-wheel, u’, runs
110 BAROMETER.

back exactly far enough to compensate for this increase of weight, and its new position, being regis-
tered by well-known means on a graduated sheet of paper, gives the registry of temperature. On
the same scale-beam a barometer tube is suspended. If the atmospheric pressure diminishes, this
increases the weight of mercury in the cistern of the tube, P’, but such diminishing of atmospheric
pressure also diminishes the weight of mercury in the barometer tube. Hence, by properly locating
the points of suspension of the cistern and barometer tube, the latter may be made to automati-
cally correct the errors due to change in barometric altitude. The barometer cistern hangs from
the lower scale-beam. By precisely similar means the rider-wheel, on its scale-beam, is made to
keep this cistern counterpoised. As the weight of mercury in the cistern varies with the changes
in the barometric column, the movements of the wheel, as registered, give a record of barometric
changes.
The exact counterpoising by the movements of the wheels is thus secured. Under each scale-beam
a cylinder is rotated by clock-work. Its surface contains a spiral groove. A projecting piece of the
wheel-carriage enters this groove. Thus, if the cylinder is turned in one direction, the wheel moves
outward from the fulcrum of the beam. Calling this positive rotation, the opposite or negative rota-
tion will move the wheel toward the fulcrum. From the clock shown near the base of the apparatus
a vertical rod rises, that carries two horizontal fixed gear-wheels. Each axis of the helix cylinders
carries two vertical wheels. The horizontal clock-wheels gear with one or the other of these wheels,
'as the vertical axis is moved to the right or left. The movements toward the left are given it by
electro-magnets. \Vhen released it springs back to the right, engaging with the left-hand or right-
hand horizontal wheel, according to its own position. At the end of the scale-beams will be seen
contact-points. .
When the weight of the mercury hanging on one of the scale-beams preponderates, that scale-beam
makes a contact, and the positive rotation _of its cylinder is secured by the horizontal wheel being
drawn to the left, so as to engage with the left-hand vertical wheel. This carries the rider-wheel
outward until it overbalances, when the contact is broken, and the reverse or negative rotation
begins, the right-hand horizontal wheel engaging with the vertical wheel, and this action on an infini-
tesimal scale may be supposed for each scale-beam to be indefinitely repeated.
Thus the beams are kept horizontal, and the movements of the compensating pulleys being regis-
tered by known means, the barometer and thermometer readings are continuously recorded.
Glycerz'ne Barometer—One of the largest barometers which have been constructed is the glycerine
barometer which has been built by Mr. Zophar Mills, Jr., in New York city. It consists of a glass
tube about 29 feet in length and of 1 inch internal diameter, which extends through several floors of
the building in which it is situated. ,Its lower extremity communicates with a copper vessel. The
upper end is constricted and provided with a cork and cap. The tube and cistern are filled with
glycerine, over which a layer of kerosene is poured for protection.
The readings vary from 26 feet 3 inches upward. A range of 911550— inches corresponds to an inch
of mercury. Thus a thousandth of an inch on the mercurial column becomes a tangible quantity of
nearly the Til—5 of an inch; so that this barometer can be read by the unaided eye as closely as the
ordinary mercurial barometer can be read by the aid of sliding tangent pieces.
llforelancl’s Registering Barometer—The principle on which the Moreland barometer depends is in
brief the following: The apparatus shown in outline in the cut, Fig. 288, consists of a mercurial ba-
rometer tube, B, which at a, near its base, is provided with
an air-trap. This is suspended at b to the three-armed scale-
beam, 6 c d e, and its lower end dips into the mercury cis-
tern, F Below a the tube carries the plate 1), which pro-
tects the mercury in F from dust. Every change in the
height of the barometric column changes the weight of the
barometric tube and contents, and causes a change in posi-
tion of the scale-beam and of the light-index, f, attached
thereto. .
In order that this movement of the scale-beam and index
may take place on a large enough scale, the barometer tube
at its upper end is enlarged, so as to have an internal diame~
ter of about 30 mm. The amplification of the movement of
the index, f, can be regulated by the position of the weights _,
P and g on the arms, 0 cl and c e. The nearer these are
brought to the point of suspension, 0, of the beam, the greater
will be the amplitude of the movements of the index, f.
Commonly the amplitude of the movement of the index is so
adjusted that a change of 1 mm. in the barometric column
moves the index about 2 mm. The points of the arms on
which the weights P and q should be placed are shown by
a line out in the metal. To the lower end of the index, f,
is attached either a metallic stylus or a small wheel supplied
with printer’s ink.
The registration is effected by the aid of a clock, which
carries four arms on its minute arbor. Each of these arms
raises once in a revolution of the minute-hand the lever-
arm r, and this, by the rod 9, also raises the pivoted piece It.
On the completion of each quarter of an hour the lever 1'
drops from one of the arms 0, and causes the piece It to fall, and thus drives the stylus or wheel on
the index f against the paper A. If it is a wheel that is attached to the index f, a small piece of











BARREL-MAKIN G MACHINERY. 111

leather smeared with printer’s ink lies under it, over which the wheel, at each lifting of the piece It,
is drawn by means of a hook attached thereto, and thus is newly inked for each impression On h
also is found a metallic stylus m, which, as the paper A is drawn under it, regulated by the toothed
bar n, and the wheel a, driven by the clock, marks the zero-line.
BARREL-MAKING MACHINERY. The machines which are used in the manufacture of barrels
may be divided into. three classes, namely: those employed for cutting and dressing staves; those
used for making the heads; and those adapted for finishing the barrel after portions of its parts
have been assembled. All of this machinery may also be grouped in two classes, according as the
work to be produced is a tight barrel or cask, such as is employed for containing liquids, or a slack
barrel for holding flour, sugar, cement, or other dry substances. The devices for making kegs and
small casks may’also be separately classified, as in many respects their construction differs in mat-
ters of detail from that of barrel-machinery.
1. Stave-Machinery.-—The principal manipulations of the stave are jointing, dressing, equalizing,
and sawing. In the jointing machine, the stave is tightly held in clamps, and by pressure on a foot-
trcadle moved up to a disk, on the face of which are radially disposed knives which bevel off the
edges of the stave to the proper degree for fitting it into the cylindrical barrel. With this machine
a fan-blower is combined, so that all dust and shavings are rapidly removed as fast as produced.
When the stave is jointed, the relaxation of pressure on the treadle causes its release. Arrange-
ments are provided for tightly holding the work, and also for giving to the edge any desired bilge or
bevel. The machines employed for dressing sawed staves consist of a rotary cutting-head and a
carrying or revolving bed, with feed-rollers which compel a strong forward motion. The stave is
placed upon the bed and carried under the rollers, which are straight or convex to fit the shape of
the work. The rotary head and cutters are so made and ground that the stave is smoothly finished
and a uniform thickness given. For dressing rived and sawed staves of all thicknesses, a special
machine has been devised, which dresses both sides of the stave at the same time without cutting
the wood across the grain; that is, it leaves the staves winding and crooked as they were rived from






the block. This is accomplished by allowing the frame which supports the cutters to oscillate and
rock in all directions, so that the cutters adapt themselves to all the crooks and winds of the stave.
For sawing staves, the cylinder-saw machine represented in Fig. 298 is employed. This machine
cuts the stave, which is suitably clamped and fed. forward, in circular form. The construction is
obvious from the engraving. -
In order to saw the staves to uniform length, the stave-equalizer is employed. The staves are
placed upon a conveyer consisting of two endless ropes, by which they are brought upon the periphe-
l‘lCS of two wheels on the same shaft, so that each stave rests across projections on the rim‘of the
wheels. As the wheels rotate, the ends of the stave are brought in contact with two circular saws,
which are adjusted at a distance apart equal to the desired length of the stave. The feed being con-
tinuous and the operation of the machine automatic, it is only necessary to place the staves on the
conveyer, when they are rapidly conducted to the saws.
_ 2. Head-making .Mzehénea—For ordinary casks the heads are usually made. of several portions
jointed and doweled together. To make the joints and prepare the pieces of heading which have
previously been sawn to the proper length for the dowels, is the object of the machine represented
1n Fig. 299. This consists of a large rotating metal disk, in the face of which are fixed three cutters,
relatively equidistant. In front of the disk is a standard and rest. Upon the latter a piece of rough
heading is laid, and its edges are pressed against the disk by hand, so that theyr are thus rendered
' perfectly smooth and straight. The work is then removed and laid upon another rest on top of
the machine, where it encounters two swiftly-revolving bits, which are forced against the edge by the
foot-treadle, and which speedily bore holes for the dowels. The disk acts as a fan, blowing awav
clups and shavings through the shoot shown at the right of the engraving. The heads of “a large
number of barrels can thus be prepared in a day by a single man, and the joint-knives are so
arranged that either a hollow or straight joint can be made, as desired. The dowels are next in-
112 BARREL-MAKING MACHINERY.

serted by hand, and the separate
pieces put together, forming rough
squares, ready for the next process.
This consists in leveling, facing, and
dressing the material on one side;
and it is accomplished by a special
machine shown in Fig. 300. The
head is placed in front of a planer-
cylinder on which are several blades,
and which is swiftly rotated. The
revolution of the corrugated feed-
rolls carries the head over the planer-
knives, which rapidly smooth off the
under side at the rate of from 15 to
25 heads per minute. '
The next operation is turning the
heads in circular form, and at the
same time beveling the edge with two
bevels, the upper bevel being less
than the lower one. The machine
employed is represented in Fig. 301.
The head is placed between two disks,
one of which, that on the right in the
engraving, is provided with a num-
ber of spring pins near its periphery,
which press the work against the op-
posite disk. The pin-disk is not con-
nected with the driving machinery.
Its spindle enters the cylindrical stand-
ard on the right, in which is placed
apparatus by means of which the disk
is thrown forward and locked in that
position, firmly holding the work.
Through the rotation of the oppo-
site disk, the pin-disk is also carried
round, but for only one revolution,
at the end of which stop mechanism
299.






in rear of the standard is actuated to unlock the clamp, so that the pin-disk springs back and allows
the work to fall out. The saw is mounted on a separate carriage, and has its own belt. On one
side of the blade are secured two pc-
culiarly arranged knives, by which,
when the cutting mechanism is moved
up against the edge of the head by
the foot-treadlc, both sides are cut at
once, and at the same time through
its rotating the work is turned in cir-
cular form. The machine is so con-
structed that all kinds and sizes of
heads can be made with one and the
same concave saw. An attachment
is provided for giving the heads. an
oval form- to compensate for shrink-
age of material.
3. Barrelfiuish'ing .Machines.~—B0-
fore being placed in these devices,
barrels are “set up.” The setting-
up form is composed of two heavy
circles of iron secured together and
bolted to the floor; from these rise
short standards which support a hoop.
The staves are set in between the
iron circles, and fitted carefully to-
gether. The iron truss-hooks, which
are previously placed in proper posi—
tion, are lifted up by hand so as to
embrace the lower portions of the
staves and hold them in place, when
the whole is lifted out of the frame.
One half of the barrel is now tightly
held together, but the remainder is
still open and daring. To secure this


in similar manner, a rope is passed around the flaring ends and taken to a hand windlass, by which
the staves are brought together. The truss-hoops are slipped over the extremities, and the barrel is
BARREL-MAKIN G MACHINE RY. 1 13
w”

ready to be heated in order to cause its staves to assume the curved form. The heaters are simple
iron cylindrical stoves, over which the barrel is set, the top of the latter being closed with a sheet-‘
iron cover.
The barrel is next leveled. To this end it is placed between two disks, one of which by suitable
mechanism is moved forward, powerfully compressing the cask endwise and thus leveling the staves.
It then goes to the trussing machine, which is represented in Fig. 302. Here the barrel is placed on
end, and is surrounded by sev-
801. eral hooked bars A, which usu-
' ‘ ally protrude up through » the
\. floor of the shop. The longer
arms catch above the upper
truss-hoops, and sliding collars
on these arms similarly catch
on the second bands. The low-
er hoops are pressed against
notched standards B, which
also stand up above the floor,
but do not pass through the
same. The arms are pulled
down by steam power, forcing
the heavy rings over the bulg-
ing portion of the cask, and
thus wedging them tightly in
place. The same effect is pro-
duced by the stationary short
lower standards, by their resist-
ance to the lower hoops mov-
ing them as the barrel is forced
down.
In Fig. 303 is represented a
machine specially designed for
both leveling and trussing slack
barrels, or, in other words, per-
forming both of the operations
just described. In this the arms
. A, which hook upon the rings,
are all connected with the lev-
eling disks B, and, by means
of handles C on each of the
latter, are all opened at once.
The barrel with the truss-hoops
on is then inserted, and a pressure of the foot-treadle closes all simultaneously. By means of
the clutch~1ever D the machine is then thrown into action. The pulley-shaft actuates (through
gearing) a screw-shaft, which forces the movable disk toward the stationary one, thus, through the
drivers, pushing. the truss-hoops to their proper places on the barrel, and at the same time leveling
the ends of the staves. ., -
Before the heads are put in, each barrel at each end must be erozea' and ckamfered; that is, a
groove must be out around the inside, a short distance below the edge, while the latter must be bev-
eled oif. The ends of all the staves must be cut off perfectly true, and in heavy casks it is necessary
to cut a bowel or wide semicircular indentation around
just below the croze. Fig. 304 represents a machine
which chamfers, bowels, levels, and crozes casks of im-
perfect periphery, finishing both ends at once. The
barrel, being previously placed on supporting skids,
passes directly between the chuck-rings, and its ends
fit into the peripheries of the cog-wheels which work
within the former. The wheel A, through suitable gear-
ing, governs the backward and forward motion of the.
right-hand ring B. The other chuck-ring is stationary.
As the barrel rolls into place, the operator moves up
the ring B, thus confining it; and by suitable mechan-
ism the barrel is caused to revolve. The cutters C,
which are all fastened on two circular heads (the shafts,
of which are mounted on vibrating carriages and re-
volved by thesmaller belts represented), are then moved
up against the inner edge of the barrel. A single revo-
lution sutiices to perform all the operations above named,
when the ring is drawn back and the barrel is removed. Each cutter-head is controlled by a rest
upon the outside, thus compelling a uniform thickness and depth of chime, while the same is leveled
With accuracy. The heads are usually inserted and the hoops placed in position by hand. The
final smoothing of the barrel before all the hoops are in place is also done by machinery. The bar-
rel 18 caused to revolve under a plane which serves as a smoothing tool, and the latter held so as to
be easily guided by8the attendant.





1] 4 BASKET—MAKIN G.

fi
Among other machines specially used in barrel manufacture are apparatus for punching, flaring,
and riveting iron hoops. This is done by rolls, which may beadjusted to give the flare as 'the hoop is
303.
U







passed between them ; and on the same frame which supports these rolls is a lever carrying punches
and a riveting press. There is also a distinct line of smaller machines designed for keg-making, the
804.





“if/f
principles of the construction of which are essentially the same as those of the larger machines.
All the apparatus above described is the invention and manufacture of Messrs. E. & B. Holmes, of
Buffalo, N. Y.
The machinery used for barrel-making in Europe varies in many respects from that employed in
this country. A complete description of it will be found in Engineering, xxi., 454. For further
details of the American machines, see Scientific American, xxx., 191, and xxxii., 79.
BASKET—MAKING. In making baskets, the twigs or rods of split hickory, oak, black ash, or
osicr, being assorted according to their size and use, and being left considerably longer than the
work to be woven, are arranged on the floor in pairs parallel to each other and at small intervals
apart, and in the direction of the longer diameter of the basket. Then two large rods are laid across
the parallel ones, with their thick ends toward the workman, who is to put his foot on them, thereby
holding them firm, and weave them one at a time alternately over and under those first laid down,
confining them in their places. This forms the foundation of the basket, and is technically called
the “slat” or “slate.” Then the long end of one of these two rods is woven over and under the
pairs of short ends, all around the bottom, till the whole is woven in. The same is done with the-
other red, and then additional long ones are woven in, till the bottom of the basket is of sufficient
BASKET—MAKING. 115

Ff
size. The sides are formed by sharpening the large ends of enough stout rods to form the ribs, and
plaiting or forcing the sharpened ends into the bottom of the basket, from the circumference toward
the centre; then raising the rods in the direction the sides of the basket are to have, and weaving
other rods between them till the basket is of the required depth. The brim is formed by bending
down and fastening the perpendicular sides of the ribs, whereby the whole is firmly and compactly
united. A handle is fitted to the basket by forcing two or three sharpened rods of the right length
‘ down the weaving of the sides, close to each other, and pinning them fast about two inches below
the brim, so that the handle may retain its position when completed. The ends of the rods are then
bound or plaited in any way the workman chooses. This is a basket of the rudest kind. Others
will vary according to the artist’s purpose, skill, and materials. When whole rods or twigs are not
adapted to the kind of work required, they are divided into splits and skeins. Splits are made by
305.





cleaving the rod lengthwise into four parts, by means of an implement consisting of two blades,
crossing each other at right angles, the intersection of which passes down the pith of the rod. These
splits are next drawn through an implement resembling a common spoke-shave, keeping the pith
presented to the edge of the iron, and the back of the split against the wood of the implement.
The split is then passed through another implement, called an “upright,” to bring it to a more
uniform shape. This consists of a flat piece of steel, each end of which has a cutting edge, like that
of an ordinary chisel; this piece is bent round, and the edges are made to approach each other as
near as desired by means of screws, the whole being fixed into a handle. By passing the splits
between these two edges, they are reduced to any required thickness. The implements required in
basket-making are few and simple, consisting, besides those just mentioned, of knives, bodkins, and
806.






























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drills for boring, leads fer steadying the work while in progress, and when it is of small dimensions,
and a piece of iron called a “ beater.”
_ The splints of various kinds of wood, particularly certain species of ash, elm, and birch, are exten-
swely employed in basket-work. These splints are obtained by beating logs of the wood with a
maul, thus loosening and separating the different layers or rings into narrow strips. This is the
Simple and primitive process, and is necessarily slow, and restricted to woods of a free texture.
Several machines have been invented and are now employed for the manufacture of splints, by
which different kinds of wood, prepared by steaming or otherwise, are cut or rived into the required
form. “Basketwillow” and “ osier” are terms commonly applied to the species of saliva most used
in basket-work.
Eigs. 305 and 806 represent a basket-making machine. A circular wooden bottom-piece with
radially projecting basket-strips is attached to the end of a rotating shaft, and during the rotation
0f the bottom and radial strips a filling-carrying device having a vibratory motion passes over and
1 1 6 BATHOMETER.

under the radial strips, and leaves the filling carried by it. This filling is laid in compactly by reed-
like pieces. In the machine represented, the skeleton of a top or bottom is clamped to the shaft by
set-screws. The end of the filling is fed through the apron. Motion is applied to
the driving-shaft which rotates the skeleton. The pad of the apron is vibrated
by the action of the eccentric-wheel that rests upon the ring, causing the rods to
vibrate alternately above and below the filling between them (Fig. 305).
BATIIOMETER. An instrument for measuring the depth of the sea without
the use of a sounding-line. The principle upon which the action of the bathome-
ter invented by Dr. G. William Siemens depends is the diminution of the influence
of gravitation upon a weighty body produced by a decrease in the density of the
strata immediately below it; thus, the density of sea-water being about 1.026,
and that of the solid constituents which form the earth about 2.75, it follows
that an intervening depth of sea-water must exercise a sensible influence upon the
total gravitation if measured on the surface of the sea.
The instrument, which is represented in Fig. 307, consists essentially of a ver-
tical column of mercury contained in a steel tube having cup-like extensions.
The lower portion is closed by means of a corrugated steel-plate diaphragm, simi-
lar in construction to those employed in aneroid barometers (see BAROMETER);
and the weight of the mercury is balanced at the centre of the diaphragm by the
elastic force of carefully-tempered steel springs, the length of which is the same
as that of the mercury column. Both ends of the column are open to the atmos-
phere, so that its variations of pressure do not affect the readings of the instru-
ment. The ratio between the areas of the cups and that of the tube is governed
by the diminution of the density of mercury due to dilatation on increase of
temperature, and the diminution of elasticity of the springs, due also to rise of
temperature. The reading of the instrument is effected by means of electric eon-
taet between the centre of the diaphragm and the end of a micrometer screw, the
divisions on the rim and the pitch of the screw being so proportioned that each
division represents one fathom of depth.
Sir William Thomson’s Sounding-Mackina—The most satisfactory apparatus for sounding at sea
that has been introduced for the use of navigators in recent years is that shown in Fig. 307 A, which
was devised by Sir \Villiam Thomson (now Lord Kelvin).
The machine is shown with the frame carrying the wire drum lifted out of the box and resting on
supports in the position for taking a cast. Fine piano-wire is coiled on a V-shaped ring A, which
- can revolve independently of the spin—
307 A' 30713- dlc. Half a turn, or at most one turn,
of the handle in the direction for paying
out is sufficient to release the wire drum
and allow the wire to run out with the
weight of the sinker hanging on the
wire. As soon as the sinker touches
the bottom, the handle is turned so as
to prevent any more wire running out;
when the brake has been put on and
the egress of the wire stopped, the catch
.D is turned to release the arm 0, and
the wire is wound in. It will be ob-
served that the arm 0 is held in the
fixed position during the whole time,
except when the wire is being wound in.
While the wire. is coming in, the arm 0
is allowed to turn round with the drum
and spindle. The depth-recorder is
shown at Fig. 307 n. It is attached to
the cover of the sinker, by means of a
chain 2 ft. long, from the ring at the
top. When a cast is to be taken the
recorder is put inside the sinker and is
supported by the pressure of the side
springs against the inside of the sinker;
the slack chain is put in on the top of
the recorder. The object of the side
springs is to prevent the shock, which
the sinker experiences when it strikes
the bottom, from aifecting the reading
of the depth-recorder. When the sinker strikes the bottom, the depth-recorder slips down the inside
of the sinker and is thus relieved of the sudden shock.
As the sinker descends, the increased pressure forces the piston D up into the tube, while the
spiral spring pulls the piston back. The amount that the piston is forced up against the action of the
spiral springs depends on the depth. To record the depth the marker 0' is used. As the recorder
goes down, the marker is pushed along the piston. When the recorder is brought up to the surface
of the water the piston comes back to its original position, but the marker remains at the place on the
scale to which it was pushed, and shows the depth to which the recorder has been.









BEAMS. 117

r——
The Submarine Smtry (Fig. 307 c) is described as follows: Upon the drum of a winch are coiled a
number of fathoms of single piano-wire of the best quality. To the wire is attached at its extremity
an atmospheric deep-sea sounder. The sentry itself consists of two pieces of fi-in. board, screwed
together at right angles, about 36 in. long, and pointed at one end. An inch or two from the square
end, on the ridge formed by the meeting boards, is a ring. 807
A strong spring 0, ending in a hook, occupies a groove cut ‘3'
into the ridge at the pointed end. Over the spring, but not
connected with it, is a second ring secured to the wooden
sides by iron ribs, and in this ring is twined another ring,
which is at the end of an iron pin B, long enough to project
about half an inch beyond the pointed end of the wood.
When the sentry is in action the outside of the angle formed
by the deal boards is uppermost. At the pointed end is the
striker A, an iron rod working upon a hinge fixed at the
pointed end of the wood, having at the top a hole capable
of receiving the point of the pin before mentioned, and at
the bottom a hollow, receiving tallow or other adhesive sub-
stance. To prepare the sentry for action, it is necessary to ~
affix it to the extremity of the wire on the winch by two
wires. Of these, the first is secured to the ring near the
square ends; then the! hook at the end of the spring is
placed around the striker; then the second of the two wires
named, which has a ring on its end, is threaded upon the pin
which enters the hole at the top. The machine is dragged
forward, almost immediately underneath the vessel.
The towing-line is regulated to the precise depth of water shown in the locality in which it is pro-
posed to have the registering take place. When this place is reached the sentry will touch the bot-
tom, the pressure that has been exercised upon the spring will be released, which will set a bell
ringing intermittently or will make a whistle sound, and will so give warning. 308
The sentry being no longer maintained in an upright position, will then go traiL '
ing astern on or near the surface of the water.
BEAMS. See STRENGTH or MATERIALS.
BEAR, PUNCHING. A machine for punching metals by hand-power. The
usual form is represented in Fig. 308. The punch is contained in the end of the
screw, which is operated by means of a bar or lever passed through the hole at
the head. The utmost capacity of this tool in practice is to punch a hole three-
quarters of an inch in diameter through an iron plate fiveeighths of an inch thick.
BEARINGS. By the term “bearings” is meant the surfaces of contact between
the moving piece and its support. For motion of straight translation, the surfaces
of the bearings must have a circular, square, triangular, or other straight-lined
cross-section, and be perfectly straight in the direction of motion. Such bearings
are called slides, examples of which may be seen in lathes, shaping machines, and
many steam-engines. For rotary or turning motion, the surfaces of bearings must he surfaces of revo~
lution accurately turned, as cylinders, spheres, cones, etc. The surface of the moving piece is called a
journal or neck, and the fixed or supporting piece is also called a journal, gudgcon, pedestal, plwnbc'r
or pillow block, bush, step, or pivot. These bearings provide also for rocking. F or helical or screw
motion the bearing must be an exact screw. The supporting piece is called a and. These provide
for rotation about a fixed axis, and for translation along it. The construction of one form of the
phonograph necessitates this hearing, and other examples will be seen in the screw-cutting lathe,
in various feed-motions of machine tools, etc. All bearings must so fit that the intensity of the
pressure will not force out the material employed in lubrication.
For lubrication and friction of bearings, see Fnrcrron AND LUBRICATION. See also JOURNALS, PIL-
LOW-BLOCKS, BUSH, Srnrs, HANGERS, and SHAFTING. _
BELLS. The alloy of which bells are made consists of copper and tin. 75 parts copper to 25
tin is a usual proportion, but the constituents vary from 50 copper, 33 zinc, and 17 tin, to 80 copper,
10 tin, 6 zinc, and 4 lead. Sometimes the proportions 72 copper, 26.5 tin. and 1.5 iron, have been
employed. The various parts of a bell are the clapper or tongue, the clapper-bolt, the yoke, canon
or car, mouth, sound-bow, shoulder, and barrel.
When a bell is to be constructed, the weight or key-note is given, and the diameter and sound-
bow are calculated. By the following rules all the various data may be determined."6
1. The weight of a bell is found by multiplying together the square of the diameter at the mouth
in inches by the thickness of the soundbow in inches and by .25. Example .- Required the weight
of a bell 60 inches in diameter, sound-bow 4.8 inches thick. .25 x 602 x 4.8 : 4,320 lbs. weight.
2. The diameter of a bell may be determined by dividing 4 times the weight in avoirdupois pounds
by a coefficient expressing the relative thickness of the sound-bow to the diameter of the bell, which
varies from .07 to .08, and extracting the cube-root. In peals of bells the sound-bow is generally put
.08 times the diameter at month in inches for the treble, and .07 times for the tenor; for the inter-
mediate bells in the peel, proportions lying between these for the respective sound-bows. Example :
A bell of 2,636.4 lbs. is to be constructed with a sharp note, putting for the sound-bow .075. 'What
is the diameter? V :: 52 inches.
* From Spon‘s “ Dictionary of Engineering.“









1 1 8 BELLS.

3. To find the key-note, the diameter and thickness at sound-bow being given, multiply the sound-
bow thickness by 58,000 and divide by the square of the diameter. The answer is in vibrations per
second. Example : The key-note of a bell, with diameter 44 inches and sound-bow 8.52 inches thick:
58,000 X 502,15;- = 105.45 vibrations per second, which corresponds nearly to the note A in the first
octave below zero in the bars. The second octave below this would be 53.8 vibrations, and the third
- 26.90 vibrations.
4. The key~note and weight given, to find diameter divide the weight by the number of vibrations
per second corresponding to the note, extract fourth root and multiply by 21.947. Etample .' Weight
4 6,561 lbs., key-note C in first octave below zero (64 vibrations). Then 21,947 X V9165? = 69.84- inches.
5. Given the diameter and number of vibrations, to find the thickness of sound-bow multiply the '
square of the diameter by the vibration number and divide by 58,000. Example : Taking the figures
. . ' 9 _, .
of last example, r: 0.38 inches.
After calculation by the above formulas is concluded, the diameter of the bell at the mouth is di-
vided into 10 square parts, called strokes, which then is the scale and measurement for the construc-
tion. Shrinkage is allowed at three-sixteenths of an inch to the foot._ The section of the-bell is
usually laid out on a piece of board, which is then cut out and used for turning up the mould of the
bell. Bells can be made almost in any form without seriously aifecting the quality of tone; but the
thickness of metal should always be in proportion to the square of the diameter taken at the centre
of the metal. Several methods are employed for tracing bells. The one mostly used in France gives
15 thicknesses of the bow to the diameter, '74; to the diameter of the crown, 12 to the line forming
the lower ridge of the bell and the base of the crown, and, finally, 32 to the great radius serving to
trace the profile of the bell proper. The weight of the clapper should be from one-fortieth to one-
fiftieth the weight of the bell.
Casting Bella—The method of casting bells employed by Messrs. Mcnecly & 00., of Troy, N. Y.,
is shown in Fig. 309. In the upper case is made the outside mould of the bell, and upon the lower
the inside mould. The material of the mould is a porous clay loam, put on from one to three inches
in thickness, according to the size of the bell. The proper shape and
finish is given to it by means of sweep-boards, cut respectively to the
shape of the outer and inner vertical sections of the proposed bell, and
which are made to revolve upon a centre representing that of the bell,
fixed in the centre of the cases. Before the clay is put on the inner
mould case it is wrapped with straw-rope, which, becoming charred with
the heat when the bell is poured, permits it to shrink in cooling without -
straining. The perforations in the cases serve to make the clay more
firmly adhere to them, and also to vent the mould. In the old method
of casting, the moulds, being made entirely of clay, were necessarily
packed about with sand in order to withstand the pressure of the metal,
and the confined air within not entirely escaping would cause a porous
casting, or, being converted into an inflammable gas, would take fire and
explode. In using these cases, the bell is poured above-ground, and
whatever gas may be generated in the mould permeates through the clay
and burns off at each hole in a pale jet of flame, thus being entirely re-
moved.
Hkmging Bella—Bells are suspended in yokcs, journaled in frames,
and are swung by means of a wheel secured to the yoke, the bell-rope
leading from the wheel-rim (Fig. 310). The manner of attaching the
rope is shown in the accompanying cut, it being fastened to the wheel
at A, and, if the bell is of medium weight, it passes down directly
under the centre of the wheel through the sheaves at I). With this
arrangement the bell may be thrown over, as it will be more or less,
and the connection of the rope with the wheel will not be deranged.
If the weight of the bell is such that with the bend in the rope at D
the labor of ringing is too great, then it should be run down in a
straight line through the floor, in which case no sheaves are neces-
sary. In order to prevent the bell being thrown over, it is well to
provide a stop on the wheel. The rope should not be larger than is
necessary, as its inflexibility and weight encumber the free spring of
the bell. As it is impracticable, however, to ring a bell of consider-
able weight by a small rope on account of the difficulty of grasping
it firmly in the hand, we here give the sizes of ropes suitable for bells
of different weights:
For bells of less than 500 lbs., 1‘; inch diameter.
“ from 500 to 800 “ 5 “
“ from 900 to 1,500 “
. “ above 1,500 “ . ,,
Chimes are numbers of bells attuned to each other in diatonic succession. A peal consists of three or more bells in harmonic suc-
ccssion, which may be rung successively or simultaneously, but will is:
not admit of a tune being played upon them. Thus, a set embracing
the eight notes of the gamut will constitute a chime, while one upon the first, third, fifth, and eighth


1
H


D—l'F-F-i
H

BELLS. ' ‘ 119

P—_
of the scale would be a peal. The usual number of bells in a chime is nine, embracing the seven
notes of the scale the octave and a flat seventh. Bells are caused to sound either by swinging them,
and so causing the clappers to strike them, or by the aid of hammers of various weights, according
to the size of the bell, caused to rise and suffered to fall on the bell. Peals are rung by hand, the
bells being swung; clocks always strike the hell with a hammer, the bell being at rest. The ham-
mer is raised by a wire, which pulls down the hammer-tail, the wire being worked by a lever, the
end of which is'caught by a cam on a revolving barrel in the clock below. It is obvious that, if a
number of bells are all fitted with hammers, and the number of cams is sufficiently great, and the
cams are properly arranged, a tune can be played by a mere multiplication of the device by which
a clock is made to strike the hours on a single bell.
The Carillon Machine embodies this arrangement—only, instead of earns, a number of short pins
are set in a revolving barrel, and these pins catch the toes of levers connected by wires with the
hammer-tails in the bell-chamber above. The pins are set or pricked in precisely the same way as
the little points in the barrel of a musical box. The hammer, after it has fallen, can only be lifted
by the rotation of the barrel; and, as the time of dropping the hammer depends entirely on the rota-
tion of the barrel, it is obvious that the barrel can only revolve at a slow speed, and much time is lost
in lifting the hammer. The result is that a rapid musical passage cannot possibly be performed.
Another result is that, when the small bells, the high notes, come to be played, the barrel meets with
less resistance, and revolves faster than when it has to deal with the deep notes and large bells. It
follows that the air is played out of time.
. These difficulties are overcome by the invention illustrated in Fig. 311. It is intended to show the
gear for working one hammer. It must be multiplied in proportion to the number of hammers, but
the parts are all repetitions of each other. It will be understood that this engraving does not show
details, but simply illustrates a principle.
The musical barrel B is set with pins in the usual way. A is a cam-wheel of very peculiar con-
struction, operating a lever C’ by what is, to all intents and purposes, a new mechanical motion, the
peculiarity of which is that, how-
311- ever fast the cam-wheel revolves,
' the tripping of the lever is avoided.
In all cases the outer end must be
lifted to its full height before the
swinging place D quits the cam.
The little spring-roller E directs
the tail D of the lever into the
cam-space, and, when there, it is
prevented from coming out again
by a very simple and elegant little
device, by which certainty of action
is secured. At the other end of
the lever O is a trip-leverF. This
lever is pulled toward 0 by a spring,
and whenever C is thrown up by
the cam-wheel, F seizes it and holds
it up; but the wire to the bell-ham-
mer in the tower above it is secured to the eye G, so that, when D is lifted, the eye G being pulled
down, the hammer is lifted. The pins in the musical barrel B come against a step in F ; and as
they pass by they push F outward and release 0, which immediately drops, and with it the hammer, so
that the instant a pin passes the step F a note is sounded. But the moment D drops, it engages with
A, which last revolves at a very high speed, and D is incontinently flung up again, and the hammer
raised, and raised it remains until the next pin B passes the step on F, and again a note is struck.
It will be seen, therefore, that, if we may use the phrase, B has nothing to do but let off traps set
continually by A ,' and, so long as A sets the traps fast enough, B will let them off in correct time.
But A revolves so fast and acts so powerfully that it makes nothing of even a 3-cwt. hammer, much
less the little ones; and thus is obtained a facility of- execution heretofore unknown in carillon ma-
chinery. The machine illustrated has been put up in the parish church at Shoreditch, London, by
Messrs. Gillett 8t Bland. It plays 14 tunes on 12 bells—one of the finest peals in London, the tenor
weighing no less than 34 cwt. Two barrels are used, which can be changed by hand. The peal ranges
from CC to G. There are 24 levers, two to each bell, to insure facility in playing rapid passages
without driving the cam-barrel too
fast. The motive power is supplied 812‘
by a weight of 9 cwt., allowed to
fall 7 2 feet, and wound up every 24
hours.
BELTS—In the ordinary accept-
ance of the term, belts are endless
strips of leather, rubber, or other
flexible material, stretched over pul-
leys for the purpose of transmit-
ting power from one pulley, called
the driver, to the other, or driven, pulley. Ropes and chains are also used in a similar manner,
forming rope, or chain, belting. When chains are employed, the pulleys over which they pass com-
monly have depressions or projections on the rims, which engage with the links of the chains and
prevent slipping. This arrangement forms a positive gearing, and it is to be distinguished from ordi'








120 ‘ BELTS.

nary belting, in which power is transmitted by reason of the friction between the belt and the face
of the pulley. A convenient form of chain-belt, made by the Ewart Manufacturing Company, is rep-
resented iu Fig. 312. It is composed of detachable links, so that its length can readily be changed.
Fig. 313 is a sketch of the ordinary belt-connection, A being the driving pulley, rcvolvingain the
direction of the arrow, and connected to the driven pulley B by the endless band D OE . The
portion of the belt, E F, running away from the driven pulley, is the driving part of the belt, and the
portion, D 0, running toward the driven pulley, is the slack part of the belt. These are the names
ordinarily given to the two parts of the belt, for reasons that are easily explained. Suppose the belt is
stretched over the pulleys with a certain tension—for example, 40 lbs. for each inch of width. When
the pulleys are at rest, all parts of the belt will have this tension
of 40 lbs. per inch, but if motion ensues and power is trans- 313-
mitted, it is obvious that one part of the belt must have its
tension increased. For example: Suppose that the belt, when
strained as described above, requires a force of 26 lbs. per
inch of width to slip it on the driven pulley, then the tension of
the driving part, EF, will evidently be 40 + 26 = 66, and the
tension of the slack part, D C, 40 — 26 = 16, lbs. per inch of
width, if the belt is driving up to its full capacity. As the dif- D
ferent portions of the belt become alternately tight and slack,
in passing from one side of the driven pulley to the other, and
the belt is elastic, it is evident that, even if there is no slip such
as occurs when a belt is overtaxed, there will be, under all cir-
cumstances, a creep, due to the elasticity, which will, of course,
vary with different belts and different tensions. As explained
by Prof. Osborne Reynolds: “The strap comes on to A tight
and stretched, and leaves it unstrctchcd. It has, therefore, con-
tracted while on the pulley. This contraction takes place grad-
ually from the point at which it comes on to that at which it
leaves, and the result is that the strap is continually slipping
over the pulley to the point at which it first comes on. In the
same way with B: the strap comes on unstretchcd and leaves
it stretched, and has expanded while on the wheel, which ex-
pansion takes place gradually from the point at which the strap ~


comes on until it leaves.” * Ilence, the velocity-ratio of two E
pulleys connected by a belt will not be constant under all cir- I
cumstances, as the belt does not form a positive connection.
In ordinary practice, the loss caused by the creep is very slight, C
but with highly elastic belts, tightly stretched, it may be con- [fill
siderable; and in any case where absolute uniformity of velo-
city-ratio is required, belts cannot be used. For driving most
kinds of machinery, however, the facts that the belt is elastic and yielding, and that it will slip if
overstraincd, render it one of the best appliances for transmitting power without producing injurious
shocks.
The ordinary materials used for belts are leather and rubber. Experiment shows that a rubber
belt will usually transmit at least 25 per cent. more power before slipping than one of leather under
the same circumstances—and in many cases the rubber belt has other decided advantages. For in-
stance, it is difficult to make a very wide leather belt of the same quality throughout its entire width,
because the hides of which it is composed are usually thicker and of firmer texture in the centre than
on the sides. By making a careful selection of hides, and using only selected portions of them, it is
possible to construct a wide leather belt of practically uniform quality throughout; but generally,
in the case of a very wide belt, one of rubber will run more truly and wear more satisfactorily than a
leather one. It may be further remarked, that in damp and exposed situations, in which leather belts
would soon become worthless, rubber ones can frequently be used with success. The rubber belt is,
however, of more limited application than the other. The weak points of a rubber belt are its edges,
which should not come in contact with anything; so that, when crossed or shifting belts are used, it
is not well to make them of rubber. .
The principles upon which the transmission of power by belts depends, have been carefully investi-
gated, both by analysis and experiment, and many valuable experimental data have been compiled.
Experiments on the amount of power that can be transmitted by a belt of given size show many
discrepancies, which seem to be due to the fact that belts of different quality were experimented
upon, and it is pretty well settled that, while rules can be constructed that will show what power a
good belt may transmit under given conditions, they cannot be implicitly relied upon to show how
much power a particular belt does transmit. A question of this kind can only be answered by experi-
ment, although the rules may frequently enable an experienced person to predict the result with
considerable accuracy. Rules giving results that agree with good practice will be found in another
part of this article, but before explaining their use it may be well to devote a little space to the con-
sideration of some other points connected with the subject.
It is proved, by both analysis and experiment, that the friction between a belt and a pulley varies
with the tension, is independent of the area of the surface of contact, and increases as the angle or
are of contact increases. To illustrate, suppose, in Fig. 814, that a belt is in contact with a pulley
for the distance A D 0, making the angle of contact (or angle between radii drawn to extremities of

* The Engineer, xxxvlii., 396.
BELTS. 121
J. ,, -.,
_'-.___
arc of contact) A B 0, then, if the tension of the belt is unchanged, the friction is the same whether
the pulley is 2 feet or 10 feet in diameter, and if the speed of the belt remains the same, the amount
of power transmitted will be the same for either case. This may seem contrary to the experience of
- many—for it is not an uncommon thing to replace pulleys by larger ones, having the same relative
~ dimensions, the change result-
314. - ing in a great increase of power,
D and as the angle of contact is
not altered by the changes, while
the area of contact is increased,
it seems at first sight to be a fair
conclusion that the gain in pow-
er is caused by the increased
area. So obvious, indeed, does
this appear to many, that nu-
merous rules have been pub-
lished, in which the transmitting
power is made to depend upon
the area of contact, and is en-
tirely independent of the are. A
little reflection will show, how-
ever, that the increasc of power,
in a change such as described
above, is caused by something
very different from an increase
in area of contact. The power
transmitted by a belt depends,
first, upon the difference of tension of the two parts of the belt, or force that it can transmit; and,
second, upon the velocity with which this force is transmitted. Now, in changing from one pair of
pulleys to another, in which the diameters are doubled, the same force may be transmitted in either,
but if the revolutions per minute are unchanged, the velocity with which the force is transmitted will
be'twice as great in the second case as in the first, so that the power will be doubled. Both theory
and experiment fully confirm the statement that the power transmitted, other things being equal, is
entirely independent of the area of contact of the belt with the pulley. The only limitation is in the
case of very small pulleys and stiff belts, where a considerable proportion of the power is expended
(in bending the belts; but, ordinarily, the angle of contact determines the power that a belt will
transmit at a given tension and velocity. A belt that will not do the work required of it, however
tightly it may be stretched, on account of the small angle of contact with the driven pulley, can
sometimes be rendered sufficiently powerful when less tightly strained, by the use of a hinder or
tightener, close to the driven pulley, which bends the belt through a larger angle of contact. Fre-
quently, however, in the case of a belt passing over two pulleys of greatly disproportionate size, very
close together, the use of a tightener occasions loss of power by the abrupt bends which it induces
in the belt, and the requisite tension may be better obtained by crossing the belt, since in the case
of a crossed belt the angle of contact is the same for each pulley, whatever their relative sizes.
If a pulley has a high side, as it is called, or a greater diameter in one part than another, the belt
tends to run toward the high part, and advantage is taken of this fact, in practice, to keep the belt
running straight by making the pulley with a curved face, having the greatest diameter in the centre.
Very frequently this crowning of the pulley-face is overdone, the result being that the belt does not
touch the pulley over the whole of its width. Where a belt has been running for a little time, an
examination will show whether it touches all over, and, if it does not, the high part of the pulley
should be reduced. Flat-faced pulleys can be successfully run if first-class belts are used, and the
shafts are kept in line—crowning a pulley being simply a device to counteract the bad effects arising
from the use of a crooked belt or imperfectly adjusted driving-gear. The tendency of a belt to run
'to one side or the other if a slight side-pressure is brought to bear, finds its application in the ease
of shifting belts, which at times are employed to drive machinery, and are occasionally shifted to
loose pulleys, it only being necessary to apply the side-pressure near the pulley where the shift is to
be made, and on the part of the belt that is approaching the pulley.
Experiments show that a leather belt will transmit more power, and wear more satisfactorily, if it
is run with the finished side next the pulleys, the reason, apparently, being that the belt has greater
friction on account of the more perfect contact. There are various special preparations that are
recommended for application to leather belts, to render them pliable and preserve them, but the
weight of testimony seems to favor the occasional application of either neat’s-foot or castor oil.
Belts are connected by hooks or lacing, and occasionally they are riveted together at the ends. The
latter plan is generally the best, if the belt is first run a sufficient time to stretch it thoroughly.
When motion is produced by means of a belt-connection, the velocity-ratio of the pulleys depends
on their relative diameters and the thickness of the belt. The effective diameter of a pulley is its
diameter increased by the thickness of the belt, and this should be used in calculations for velocity-
ratio. .
To {ind the diameter of a pulley for a required speed, the diameter and speed .of the other pulley
being 'nown. Divide the given speed by the required speed, and multiply the quotient by the given
‘ diameter.
Example: One pulley has a diameter of 5 feet, and makes 100 revolutions a minute. What should
be the diameter of the other pulley to make 130 revolutions a minute? x 5 = 3.84 + feet.


122 BELTS.

In transmitting motion by a belt, it is sometimes required that the two pulleys shall revolve in
different planes. It is only necessary that a belt, to maintain its position, should have its advancing
side in the plane of rotation of that section of the pulley on which it is required to remain, without
regard to the retiring side. On this principle, motion may be conveyed by belts to shafts oblique to
each other. Let A and B (Fig. 315) be two shafts
at right angles to each other, A vertical, B horizon- 315-
tal, so that the line run perpendicular to the direc-
tion of one axis is also perpendicular to the other, . B
and let it be required to connect them by pulleys and q 7,,

a belt, that their direction of motion may be as
shown by the arrows: their velocities will be as 3 of
A to 2 of B. On A describe the circumference of
the pulley proposed on that shaft; to this circum- Q' - v ference draw a tangent a 6 parallel to m n : this line
will be the projection of the edge of the belt as it
leaves A, and the centre of the belt as it approaches B; consequently, lay off the pulley b on each
side of this line, and of a diameter proportional to the velocity required. To fix the position of the
pulley on A, let Fig. 316 be another view taken at right angles to Fig. 315, and let the axis B have
316.
>
0
*%~









the direction of motion indicated by the arrow; then the circle of the pulley being described, and a
tangent a b drawn to it perpendicular to the axis B as before determined, the position of the pulley
on the shaft A is established.
The positions of the two pulleys are thus fixed in such a way that the belt is always delivered by
the pulley it is receding from into the plane of rotation of the pulley toward which it is approaching.
If the motion be reversed, the belt will run off; thus (Fig. 317) if the motion of the shaft A is
reversed, the pulley B must be placed in the position shown by the dotted lines. In order to obviate
this, round belts running in grooved pulleys are frequently employed in such cases where the power
transmitted is small, and a peculiar form of angular belting working in pulleys having V-shaped
faces is very often used for the transmission of considerable amounts of power. This belting is
318 illustrated in Fig. 318, A show-
' ing the method of construction
and connectidn of the ends, and
B and O the application to pul-
leys.
It is not an essential condi-
tion that the shafts should be at
0 right angles to each other to
have motion transferred by a






\\








of the two pulleys O and D, at
right angles to the shafts, they
will intersect in a line A B.
Assume any points, A and B, in
this line, and in the plane of
the pulley O draw the tangents
B E, A F, and in the plane of the pulley D the tangents A H, B G. These tangents represent the
path of the belt in passing from pulley (J to pulley 1), and to keep it in- this path it will only be
necessaEryBtogintroduce two guide-pulleys, one at A, in the plane H A F, and the other at B, in the
lane .
p In Fig. 320 is shown a “binder frame,” as constructed by William Sellers 8t 00., in which the
guide-pulleys can easily be adjusted so as to revolve in the required planes.
j,_‘\\"§ belt. They may be placed at
any angle to each other provid-
ii'\ ed the shafts lie in parallel
ߤ4| planes, so that the perpendicu-
lar drawn to one axis is perpen-
dicular to the other. If other-
_ ‘ wise, recourse must be had to
———*—-~§g==:93'5' guide-pulleys, as illustrated in
"::;${' Fig. 319. which shows the man-
“9% ner of finding the ositions of
lI/\' _ ‘o P
the gulde-pulleys. If planes
gjaéfsN are passed through the centres




...
";;T-'ft-_'-.l'.\".
|l||-] I'-
:-_E: g
-_.__
_____.———-


BELTS. 123







_ ....
—
—-.__r~ __.-___.v-._ .
'f‘ll
.
I
ll


l I
lll'n:
Problems relating to the length of belts and amount of power transmitted are of frequent occur-
rence. Explanations of the manner of solving the most important examples are appended. The
operations will in general be greatly facilitated by using the following table:
Table for dctm'mz'm'ng Length of Belts and Power transmitted.






Factors for Length of Belt, to be 1 Hompower that can
multiplied by distance between me or manner or BELT wrrn PULLEY. ' b; transmitted bv a
54' centres of Pulleys“ single Leather Belt,
? . one inch wide, at
Both Pulleys, Crossed Belt, and :1 Velocity of 1,090
3 Open Belt. Large Pulley, Open Belt. small Puuey’ Open Belt' Feet per Minute.
g Crossed ;
Belt. For Fraction . Length for Fraction Length for For Great- For Small-
Difi'erence f; of Circum- Deg-ea m a Radius of Circum- Degrees in a Radius 3 er Arc of er Arc of
of Radii. ' ferenee. rc‘ of 1. ferenw. R“ of 1. Contact. Contact.
1 2 s 4 5 6 7 s 9 10 11 , 12
0 2.000 2 000 0. 500 180 3.142 .500 180. 3.142 1 .485 1.485
01 2 032 2 001 .031 503 181 2 3.160 .497 178.8 3.123 1.490 1.480
02 2 064 2 001 .063 507 182 3 3.186 .493 177.7 3.098 1.494 1.476
03 2 095 2 001 .094 .510 183 5 3.204 .490 176.5 3.07 1.499 1.471
04 2 127 2 001 .126 .513 184 6 3.223 .487 175.4 3.060 1.503 1.467
0) 2 159 2 002 .157 .516 185 8 3.242 .484 174.2 3.041 1.508 1.462
06 2 191 2.103 .188 .519 186 8 3.261 .481 173.2 3.022 1.512 1 457
07 2 235 2.005 .220 .522 188. 3.280 478 172 . 3 .003 1 .516 1 .452
08 2 258 2.007 .251 .525 189.2 3.299 .475 170.8 2.985 1 .520 1.447
09 2 291 2.008 .283 .529 190.3 3.324 471 169.7 2.959 1.524 1.443
10 2 324 2.010 .314 .532 191.5 3.343 .468 168.5 2.941 1.528 1.438
11 2 358 2.012 .346 535 192.6 3.362 .465 167.4 2.922 1.532 1 .433
12 2 392 2.015 .377 538 103.8 3 380 .462 166 2 2.903 1.? 7 1 .428
13 2 425 2.017 .408 542 195. 3.405 .458 165 2.878 1 .541 1 .423
14 2 459 2.019 .440 545 196.1 3.424 .455 163 9 2.859 1.545 1.418
15 2 493 2.022 .471 548 197.3 3.443 .452 162 7 2.840 1.550 1.413
16 2 528 2.026 .502 551 198.4 3.462 .449 161 6 2.821 1.554 1.408
17 2 563 2.029 .534 554 199.6 3.481 .446 160 4 2.802 1.558 1.402
18 2 598 2.032 .566 558 200.8 3.506 .442 159 2 2.777 1.561 1.396
19 2 634 2.037 .597 561 202.. 3.525 .439 158 2 758 1.565 1.391
20 2 669 2.041 .628 564 203.1 3.544 .436 156 9 2.739 1.568 1.386
.21. 2 705 2.045 .660 567 204.2 3.563 .433 155 8 2.721 1.572 1.381
22 2 740 2.049 691 571 205.4 3.588 .429 154 6 2.695 1 .575 1 .375
23 2 775 2.053 .722 574 206.6 3.607 426 153.4 2.677 1 .579 1.368
24 2 812 2 058 ..754 577 207.7 3.625 423 152.3 2.658 1.583 1.862













124
BELTS.

Table for determining Length of Belts and Power transmitted-{Continued}


















' Factors for Length of Belt, to be _ _
multiplied by distance between ARC or counter or BELT wrrn PULLEY. 110;? 52,13,331 b3“;
[-1 “mm or pulleys' single Leather Belt,
é one inch wide, at
. Both Pulle'a, Crossed Belt, and _ a Veloclty of 1,000
5 Open Belt. Large Iguuey, open Belt. Small Pulley, Open Bolt. Feet per Minum‘
Ed: Crossed
Belt. For Fraction Length for Mction Length for For Great- For Small-
Dlfl‘erence f; of Circum- Degrees in a Radius of Circum- Dogs: in a Radius er Arc of or Arc of
of Railii. ' ference. m“ of 1. ference. ' of 1. Contact. Contact.
1 2 3 4 5 6 7 8 9 10 11 12
.25 2.849 2.063 .786 .580 208.9 3.644 .420 151.1 2.639 1.588 1.356
.26 2.885 2.068 .817 .583 210.1 3.663 .417 149 .9 2.620 1 .592 1.351
.27 2.922 2.074 .848 .587 211.3 3.6'n .413 148.7 2.595 1.596 1.345
.28 2.959 2.079 .880 .590 212.5 3.707 .410 147.5 2.576 1 .600 1 .340
.29 2.996 2.085 .911 .594 213 7 3.732 .406 146.3 2.551 1.603 1.334
.30 3.034 2.091 .943 .597 214.9 3.751 .403 145.1 2.532 1.607 1.328
.31 3.071 2.097 .974 .600 216.1 3.770 ,400 143.9 2.513 1.610 1.322
.32 3.109 2.104 1.005 .604 217.3 3.795 .396 142.7 2.488 1.614 1.316
.33 3.147 2.110 1.037 .607 218.5 3.814 .393 141.5 2.469 1.618 1.309
.34 3.185 2.117 1 .668 .610 219.7 3.833 .390 140.3 2.450 1.621 1 .303
.35 3.224 2 . 125 1 .099 . 614 220 .9 3.858 .386 139.1 2 .425 1 . 625 1 .296
.36 3.262 2.181 1.131 .617 222.2 3.877 .383 137.8 2,406 1.628 1 .289
.37 3.301 2.138 1.163 .621 223.4 3.902 .379 136.6 2.381 1.632 1.282
.38 3.340 2.146 1.194 .624 224.6 3.921 .376 135.4 2.362 1.635 1 .276
.39 3.380 2.155 1.225 .627 225.8 3.940 .373 134.2 2.344 1.638 1 .270
.40 2.419 2.162 1.257 .631 227.1 3.905 .969 182.9 2.818 1.642 1.263
.41 3.459 2.170 1.289 .685 228.4 3.990 .365 131.6 2.293 1 .646 1.256
.42 3.499 2.179 1.320 .638 229.7 4.009 .362 130.3 2.275 1.649 1.248
.46 3.540 2.189 1.351 .642 231. 4.034 .358 129. 2.249 1 .653 1.240
.44 3.580 2.197 1 .383 .645 282.2 4.053 .355 127.8 2.231 1.656 1.233
.45 3.620 2.206 1.414 .649 233.5 4.078 .351 126.5 2.205 1.660 1 .226
.46 3.661 2.216 1.445 .652 234.8 4.097 .348 125.2 2.187 1.663 1.218
.47 3.702 2.225 1.477 .656 236.1 4.122 .344 123.9 2.161 1.667 1.210
.48 3.7 3 2.235 1.508 .660 237.4 4.147 .340 122.6 2.136 1.670 1.203
.49 3.785 2.245 1.540 .663 238.7 4.166 .337 221.3 2.117 1.674 1.195
.50 3.827 2.256 1 .571 .667 240. 4.191 .333 120. 2.092 1.677 1.187
.51 3.868 2.266 1.602 .670 241.3 4.210 .330 118.7 2.073 1.680 1.179
.52 3.911 2.277 1.634 .674 242.6 4.235 .326 117.4 2.048 1.683 1.171
.53 3.954 2.289 1.665 .678 244. 4.260 .322 116. 2 .028 1 . 687 - 1 .162
.54 3.996 2.299 1.697 .682 245.4 4.285 .318 114.6 1.998 1.690 1 .153
.55 4.039 2.311 1.728 .685 246.7 4.304 .315 113,3 1 .979 1.693 1.145
.56 4.082 2.323 1.759 .689 248.1 4.329 .311 111.9 1.954 1.696 1.136
.57 4.126 2.335 1.791 .693 249.5 4.354 .307 110.5 1.929 1.700 1.126
.58 4.169 2.347 1.822 .697 250.9 4.379 .303 109.1 1.904 1.703 1.117
.59 4.213 2.360 1.853 .701 252.3 4.405 .299 107.7 1.879 1.707 1.108
.60 4.257 2.372 1.885 .705 253.8 4.430 .295 106.2 1.854 1.710 1.098
.61 4.303 2.386 1.917 .709 255.2 4.455 .291 104.8 1.828 1.713 1.089
.62 4.347 2.399 1 .948 .713 256.7 4.480 .287 103.3 1.803 1.717 1 .078
.63 4.392 2.412 1.980 .717 258.1 4.505 .283 101.9 1.778 1.720 1.068
.64 4.437 2.426 2.011 .721 259.6 4.530 .279 100.4 1.753 1.723 1.058
.65 4.482 2 .440 2.042 .725 261.1 4.555 .275 98.9 1.728 1 .726 1 .047
.66 4.529 2.455 2.074 .729 262.6 4.580 .271 97.4 1 .703 1 .730 1.036
. 67 4.57 2.469 2.105 .733 264.1 4.606 .267 95.9 1 .678 1 .733 1.025
.68 4.621 2.484 2.137 .738 265.7 4.637 .262 94.3 1 .646 1.736 1.013
.69 4.667 2.499 2.168 .742 267.2 4.662 .258 92.8 1.621 1 .739 1.002
.70 4.714 2.515 2.199 .747 268.8 4.694 .253 91.2 1.590 1.743 .990
.71 4.762 2.531 2.231 .751 270.4 4.719 .249 89.6 1 .565 1 .746 .978
.72 4.808 2.546 2.262 .756 272.1 4.750 .244 87.9 1.533 1 .749 .965
.73 4.856 2.562 2.294 .760 273.7 4.775 .240 86.3 1.508 1.752 .952
.74 4.903 2.578 2.325 .765 275.4 4.807 .235 84.6 1 .477 1.756 .939
.75 4.951 2.595 2.356 .770 277.2 4.838 .230 82.8 1 .445 1.759 .924
.76 5.000 2.612 2.888 .775 279. 4.869 .225 81. 1 .414 1 .763. .909
.77 5.049 2.630 2.419 .780 280.8 4.901 .220 79.3 1 .382 1.766 .895
.78 5.100 2.649 2.451 .785 282.6 4.932 .215 77.4 1 .351 1.770 .879
.79 5.148 2.666 2.482 .790 284.4 4.964 .210 75.6 1.319 1 .773 .863
.80 5.193 2.684 2.514 .795 286.2 4.995 .205 73.8 1.288 1.776 .848
.81 5.247 2.702 2.545 .800 288.1 5.027 .200 71.9 1.257 1.779 .832
.82 5.298 2.722 2.576 .806 290.1 5.064 .194 69.9 1.219 1.782 .814
.83 5.349 2.741. 2.608 .811 292.1 5.096 .189 67.9 1.188 1.786 .796
.84 5.400 2.761 2.639 .817 294.2 5.133 .183 65.8 1.150 1.790 .7 7
.85 5.452 2.781 2.671 .823 296.4 5.171 .177 63.6 1.112 1.794 .757
.86 5.504 2.802 2.702 .829 298.6 5.209 .171 61.4 1.074 1.797 .786
.87 5.556 2.822 2.734 .836 300.9 5.253 .164 59.1 1.030 1.801 .714
.88 5.609 2 .844 2.765 .842 303,2 5.290 .158 56.8 .993 1 .805 .692
.89 5.662 2.866 2.796 .849 305.6 5.334 .151 54.4 ' .949 1.809 .668
.90 5.716 2.888 2.828 .856 308.2 5.378 .144 51.8 .905 1.812 .642
.91 5.769 2.910 2.859 .864 311. 5.429 .136 49. .855 1.816 .613
.92 5.824 2.. 33 2.891 .872 313.9 5.479 .128 46.1 .804 1.821 .582
.93 5.879 2.957 2.922 .880 316.9 5.529 .120 43.1 .754 1.826 .550
.94 5.935 2.981 2.95.4 .889 320. 5.586 .111 40. .697 1.830 .516
.95 5.992 3.007 2.985 .899 323.6 5.649 .101 36.4 .635 1.885 .475
.96 6.047 3.031 3.016 .910 327 .6 5.718 .090 32.4 .565 1 .840 .429
.97 6.105 3.057 3.048 .922 331 .9 5.793 .078 28.1 .490 1 .846 .374
.98 6.165 3.086 3.079 .937 337.2 5.887 .063 22.8 .396 1.858 .312
.99 6.223 3.112 8.111 .955 343.8 6.000 .045 16.2 .288 1.861 .228
1. 6.284 3.142 3.142 1. 360. 6.283 0. 0. 0. 1.879 0.



BELTS. 125

ILLUSTRATION or run Use or run henna—I. To find the length of a crossed belt passing over two
pulley/s, knowing the radii and the distance between the centres. Divide the sum of the radii by the
distance between the centres, and, with the quotient as argument, seek the corresponding number
in column 2 of the table, and multiply it by the distance between centres.
Example: What is the length of a crossed belt passing over two pulleys whose diameters are 5
and 3 feet respectively, the distance between centres being 10 feet, and thickness of belt one-quarter
of an inch?

Effective radii . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30.125
18.125
Divide by distance between centres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l20)48.250
.40
Corresponding number in column 2, 3.419. 3.419X 10 = 34.2 feet length of belt.
N ore—The effective radius (radius + % thickness of belt) or effective diameter (diameter + thick-
ness of belt) of pulley should generally be used in calculations involving these elements. In dividing
sum or difference of radii by distance between centres, both terms must be expressed in the same
unit (feet, inches, or the like), such unit being taken as is most convenient. In multiplying the
resulting constant by the distance between centres, this latter term may be expressed in any denomi-
nation, and the answer will be in the same denomination. Thus, in the above example, the sum
of the radii was taken in inches, and hence the sum was divided by the distance between centres
expressed in inches, but the resulting constant was multiplied by the distance between centres in
feet, giving the length of the belt in feet.
II. To find the length of an open belt passing over two pulleys. 1. Divide the diiference of the
radii by the (fistance between centres, and, using the quotient as argument, find the corresponding
constant in column 3. 2. Divide the sum of the radii by the distance between centres, and find the
corresponding constant in column 4. 3. Multiply the sum of these constants by the distance between
centres. .
Example: Find the length of an open belt passing over two pulleys whose effective radii are 20
and 10 inches respectively, the distance between centres being 12 feet.
Diiference of radii
Distance between centres
Sum of radii “ “
, ==.2l . . . . . . . . . . . . . . . . . . . . .. :2 .660
Distance between centres

=.07 . . . . . . . . . . . . . . . . . . . . . . Corresponding constant : 2.005

Length of belt = 32 feet = 12 X 2.665
III. To design a pair of cone pulleys for a crossed belt—<1. Continuous cones (Fig. 321,11). In
this case it is only necessary to use two similar conical drums, with their large and small ends turned
821.




opposite ways. 6. Stopped cones, equal and opposite (Fig. .321, B). Divide a pair of equal and
opposite conoids into any number of equal parts by lines at right angles to the axes. The points
in which these lines cut the faces of the conoids determine the several steps. 0. Ang two szkppecl
cones. Assume values for the several radii of one of the cones, and give such values to the corre-
sponding radii of the second cone thatthe sum of each pair shall be the same.
Example: Suppose the several radii of one cone pulley are 12, 10, 8, 6, and 4 inches, and that the
smallest radius of the other stepped cone is 3 inches. This fixes the sum of each pair of radii at
15 inches, so that the remaining radii will be 5, 7, 9, and 11 inches.
IV. To design a pair'of cone pulleys for an open belt—a. Continuous cones (Fig. 322, A). Equal
and similar conoids must be used. Assume extreme radii, and, knowing distance between centres,
126 BELTS. v

calculate the length of belt required. To find the middle radius, subtract twice the distance between
centres from the length of the belt, and divide the difference by 6.2832. Draw arcs of circles
through extreme and middle ' 2
points, thus determining the 32 '
sections of the conoids. A
Example: Given largest
radius of conoid 24 inches,
I
II
I
smallest radius 6 inches dis- i
tance between centres 3,feet. } - What should be the middle ' l
radius? By means of the ' table and preceding rule, the ,
length of belt is found to be _ 14.6 feet.
ms-o
6.2832
16% inches, middle radius.
6. Step ed cones, equal and
opposite 322, B). Form
two continuous conoids in the
manner explained above, and
divide them into the required
number of steps. 0. Any two
stqoped cones. Assume one
pair of radii, and calculate
the length of the belt for the given distance between centres. Assume at pleasure the difierence
between a second pair of radii, divide this assumed value by the distance between centres, find the
number corresponding to this quotient in column 3 of the table, multiply it by the distance between ,
centres, and subtract the product from the length of the belt. Divide the remainder by the distance
between centres, and find the argument corresponding to this quotient in column 4. Multiplying
this argument by the distance between centres gives the sum of the second pair of radii. The larger
radius can be found by adding the half difference to the half sum, and the smaller radius by sub-
tracting the half difference from the half sum. The application of thisv rule is very simple, as the
following example will show: .
First pair of radii, 12 and 4 inches; distance between cent-res, 3 feet. Find another pair of radii
that will give the same length of belt, their difference being 1% inch. Calculating the length of
belt, it is found to be 10.3 feet. 1.5 -:— 36 z .04. Corresponding number in column 3, 2.001. 10.3
--2.001 x 3 = 4.3; 4.3 -—:- 3 : 1.433. Corresponding argument = .46; .46 x 36 :: 16.56 = sum of
required radii.
I
t
I
l
l
|
I
I
I
l
I
l
I
l
I
l
a
.
=1.37 feet, about








. .5 1.
Larger radius = 16 62+-__5 = 9. + inches.
Smaller radius : 16562—245 = 7.5 + inches.
Another rule, requiring only one radius and the distance between centres to be given, in order to
determine the other radius, will be found among the formulas that follow these illustrations.
V. To find the arc of contact between a belt and a pulley.
FIRST Mn'rnon—Measure the length of the portion of the circumference of the pulley that is in
contact with the belt, and the diameter of the pulley. Divide the first measurement by the radius of
the pulley, and in the same horizontal line with the quotient in column '7 or 10 will be found in col-
umns 5, 6, or 8, 9, the fraction of circumference in contact with the belt, and the angle of contact.
Example: The length of the arc of contact of a belt with a pulley is 15.3 feet, and the diameter
of the pulley is 10 feet. 15.3 -:- 5 = 3.06, and by reference to column 10 it will be seen that the arc
of contact is .487 of the circumference, corresponding to an angle of 17 54°. '
SECOND Msrnon.—-a. Crossed belt. Divide the sum of the radii by the distance between the cen-
tres of the pulleys, and with the quotient as argument in column 1 find the required data in columns
5, 6, and 7.
Example: A crossed belt passes over two pulleys whose radii are 4 and 3 feet respectively, and
the distance between their centres is 12 feet. (4 + 3) ~:— 12 = .58; hence the arc of contact is .697
of the circumference, the angle of contact is 250.9°, the length of are on larger pulley is 4.379 x 4
: 17.516 feet, and the length of are on small pulley is 4.379 x 3 :: 13.137 feet.
6. Open belt. Divide the difference of the radii of the two pulleys by the distance between their
centres, and, with the quotient as argument in column 1, find the arc of contact for the large pulley, _
in columns 5, 6, and 7, and the arc of contact for the small pulley, in columns 8, 9, and 10.
Example: An open belt passes over two pulleys whose diameters are 6 and 4 feet, and the dis-
tance between whose centres is 9 feet. (3 -- 2) ~:— 9 :: .11 ; so that the arc of contact for the large .
pulley is .535 of the circumference, the angle is 192.6°, and the length 3.362 x 3 = 10.086 feet;
and for the small pulley, .465 of the circumference, the angle is 167.4°, and the length 2.922 x 2
:: 5.844 feet. ‘
Nora—In the rules given in the second method, it is assumed that the belt is drawn perfectly
tight between the pulleys. Where there is much deviation from this in practice, it is better to
BELTS. 127

Fw—
employ the first method. It frequently happens that the are of contact, when the belt is at rest,
is materially changed when motion ensues. At very fast speeds, the centrifugal force often reduces
the arc of contact considerably; and as the power that a belt can transmit varies with this are, its
value should be estimated under the conditions that occur when the belt is running.
VI. To find the speed of a belt, in feet per minute. Multiply the diameter of either pulley, in
feet, by 3.1416 times the number of revolutions that it makes per minute.
Example: A belt passes over a pulley that is 16 feet in diameter, and makes 60 revolutions per
minute. Speed of belt = 16 x 3.1416 x 60 = 3,016 feet per minute.
VII. To find the power that can be transmitted by a single leather belt of given width passing
over smooth iron pulleys. Find, in column 11 or 12, the power corresponding to arc of contact of
the belt with the small pulley; multiply this by the speed of belt in feet per minute, and the width
of belt in inches, and point off three figures of the product to the right. The result will be the
horse-power transmitted.
Example: A 10-inch belt, moving at the rate of 4,000 feet a minute, makes an angle of contact
with the small pulley of 120°. 1.187 x 4.000 x 10 = 47.48 horse-power.
VIII. To find the width of belt required to transmit a given amount of power. Find the power
transmitted by a belt 1 inch wide, under the given conditions, and divide the amount of power
-that is to be transmitted, by the quantity so found.
Example: A belt is to have a speed of 1,500 feet a minute, and to make an arc of contact of 210°
with the small pulley. How wide will it require to be to transmit 15 horse-power?
Power transmitted by a belt 1 inch wide = 1.592 x 1.500 = 2.388 horse-power. Width of belt
required = 15 -:— 2.388 = 6.3 inches.
N orn—In these rules the coefficient of friction between the belt and the pulley is taken at .423,
and it is assumed that a safe working strain for a single leather belt, with the ends secured by
lace-leather, is 66 3‘ lbs. per inch of width. In speaking of the width of a belt, the effective width
is meant, or that portion of the width in contact with the pulley; so that, for example, if the belt
only bears for two-thirds of its width, and is 9 inches wide, the width to be used in the calculations
will be 6 inches. If, instead of leather, rubber belts are used, the above rules may be employed,
observing that, under the same circumstances, a rubber belt will transmit one-fourth more power
than a leather one. Pulleys are sometimes covered with leather or rubber, in order to increase the
friction. Mr. J. W. Sutton has made numerous experiments in order to determine the best form of
covering, and has patented a composition which is secured to the face of the pulley, and which he
claims will increase the transmitting power of a belt fully 100 per cent.
The analytical expressions on which the table and rules depend are appended, together with
formulas for finding the radius of a pulley when the other radius and the distance between centres
are given. It may be well to illustrate the use of the latter.
Suppose a pulley has a radius of 4 feet, and the distance between its centre and the other pulley
is 12 feet. What should be the radius of the other pulley, if the length of an open belt passing
over the two pulleys is 56 feet?
First find whether the given radius is the large or small one. 4 x 3.1416 + 1‘) = 24.6; and
as this is less than 56 —:— 2 : 28, the given radius is the smaller of the two. Then, according
to the formula, the other radius =
__ 9
4 + 12 x (M04674 + W - 1.5708) = 6.07 feet.
a-l

JVotation.
R: radius of larger pulley. r = radius of smaller pulley. S: distance between centres of
pulleys. L :length of belt. F: force in lbs. transmitted by a single leather belt, 1 inch wide.
W: width of belt, in inches. P: horse-power transmitted by belt. V: velocity of belt, in feet
per minute. N: revolutions of pulley per minute. a=arc of contact of belt with pulley, in
degrees. a = fraction of circumference of pulley in contact with belt. A = length of are of con.
tact, for a radius of 1.
Crossed Belt.
/ _ _ R + r
L: 2V S2 — (R + r)‘ + (R + r) x (3.1416 + 2 are. SlIlO S

For stepped cones, the only condition is R + r: a constant.

a = 180° + 2 angle. sine R;- 7'.
Open Belt.
/ “_———“_ _ R —- 'r
L = 2 V 89 - (.R--r)9 + 3.1416 x (R + r) + (R — r) x 2 are. sme
. . . . L - 28'
For continuous cone of pulleys, mlddle radius of conord = m-
. 0
If (assumed radius x 3.1416 + S) > g, the assumed radius is R.
If (assumed radius x 3.1416 + S) < g, the assumed radius is r.
128 BESSEMER PROCESS.


If R is assumed, r : R — S x (1.5708 - g/OAGH + L —6.2832 x R
S
_ o ‘ 9 ‘ R—r
If r is assumed, R = r+ Sx (M0.4674+1l§M-1-5708)- “=180°“2 angle- Bine S -


General Formulas, Crossed or Open Belt.
V: 6.2832 X R X N: 6.2832 X r X N, a: £50, A = a X 6.2832,
, 0.008206 X a _ F X W X V __ 33,000 P
In the United States, transmission of power by large belts is more common than in Europe, and
probably the largest belts in the world are to be found in this country. Mr. J. H. Cooper, in a letter
published in “Engineering,” gives several instances of large belts, from which the following are
selected:
The driving-belt of the New Jersey Zinc Works is of leather, 4 thicknesses, 48 inches wide and
102 feet long.
An elevator in Chicago has a rubber belt, 6 ply, 48 inches wide and 320 feet long.
These belts have been in use for a number of years, with very satisfactory results.
Messrs. J. B. Hoyt & Co. exhibited at the Centennial Exposition a leather belt 5 feet wide and
186%; feet in length, made for a paper-mill in Wilmington, Delaware.
Hemp ropes, running in grooved pulleys, have been used instead of flat bolts for transmitting
power. The grooves in the pulleys are V-shapcd, the sides of the V making an angle of 40° with each
other. A pulley usually has several grooves, so that the strain is distributed between two or more
ropes. Mr. James Durie, in a paper read before the Institution of Mechanical Engineers at Manches-
ter, gives some examples of the use of rope-belting, and thinks its general adoption is very desir-
able, becausc it is much cheaper than leather or rubber, and transmits power in a very satisfactmy
manner. The ropes used are from 5} to 61} inches in circumference, and are connected at the ends
by long splices of 9 or 10 feet. They can be run at a speed of 6,000 feet a minute, if used over
pulleys having a diameter not less than thirty times that of the ropes. Mr. Durie gives examples of
the application of rope-belting, working with tension varying from 256 to 349 lbs. for each rope.
In one case 18 driving ropes were used, each transmitting about 23 horse-power at a speed of 2,967
feet per minute. In another example, about 1,000 horse-power was transmitted by 25 ropes, at a
speed of 3,784 feet a minute, or at the rate of 40 horse-power for each rope. The ropes, in both
cases, were 6% inches in circumference. Taking the average value of the working tension for such
ropes at 300 lbs., the horse-power transmitted would be (300 x speed in feet per minute) —:- 33,000
for each rope, and the number of ropes required for any case would be the quotient of the wholc
power divided by the power of a single rope.
Suppose, for instance, it is required to transmit 350 horse-power by ropes 61} inches in eircumfcr
once, at a speed of 4,000 feet a minute. Each rope would transmit 300 x 4,000 —:- 33,000 = 36.45
horse-power, and the number of ropes required would be 350 + 36.45 = 10.
For the transmission of power over great distances, wire cables running in V-shaped pulleys, or
telodynamic cables, are frequently employed. This mode of transmission is very much cheaper than
either belts or shafting, where the distance is considerable. The plan is the invention of the Broth-
ers Ilirn, of Switzerland. It is found that the cables can be safely run at a speed of about a mile
a minute, and that the average life of an uncovered cable is about three years. For distances exceed-
ing 300 or 400 feet, intermediate carrying sheaves are used to support the cable, or intermediate
stations may be employed at these intervals apart. The best filling for the pulleys, in the case of an
uncovered cable, seems to be leather, forced in radially in wedge-shaped pieces. Cables, with a cov-
ering of cotton yarn, are also made, which, although quite expensive, are said to be very durable, and
can be run on pulleys that have no filling. Cables are made both with hemp and wire centres, but
the former are preferable, on account of their greater flexibility. The lightness of the mechanism
and the high velocity employed render telodynamic transmission very efficient. Mr. Albert W.
Stahl, who has written a very useful treatise on wire-rope transmission,f estimates the power trans-
mitted to be 97.5 per cent. of the power applied, if there are no carrying sheaves, with a deduction
of 110',- per cent. of the applied power for each carrying sheave that is added. He also states that
the average cost of telodynamic cables, with the necessary gearing, is about one-fifth that of bolts,
and one-twenty-fifth that of shafting. R. II. B.
BESSEMER PROCESS. See STEEL.
BETON. See CONCRETES AND CEMENTS.
DICK IRON, or BEAK IRON. A small anvil having a tang, which is inserted in a hole in the
work-bench.
BINARY ENGINE. See ENGINES, AERO-STEAM and BINARY VAPOR.
BINDER, GRAIN. Sec AGRICULTURAL MACHINERY.
BIN K. In cotton manufacture, a stack of cotton laid in successive layers from different bales;
the object being to mix the cotton.
BIN OT. A species of double mould-board plough. ,
BITS AND AUGERS. The term bit is applied to all exchangeable boring-tools. Most of these

* Vol. xvii. p. 408. t Fhzgineee'ing, 10:11., 894.
I “Transmission of Power by Wire Ropes." By Albert W. Stahl, M. E. New York, 1877.
BITS AND AUGERS. 129


implements in carpentry are fluted like reeds split in tWO parts, to give room for the shavings; and
they are sharpened in various ways, as shown in Figs. 323 to 3271* Fig. 323 is known as the shellbit,
and also as the gouge-bit, or quill-bit ; it is sharpened at the end like a gouge, and when revolved it
shears the fibres around the margin of the hole, and removes the wood almost as a solid core. The
shell-bits are in very general use; and when made very small, they are used for boring the holes in
some brushes.
Fig. 324, the spoon-bit, is generally bent up at the end to make a taper point, terminating on thé
diametrical line; it acts something after the manner of a common pointed drill, except that it pos-
sesses the keen edge suitable for wood. The spoon_bit is in very common use; the coopers’ dowel-bit,
and the table-bit, for making the holes for the wooden joints of tables, are 'of this kind. Occasion-
ally, the end is bent in a semicircular form; such are called duck-nose-bits, from their resemblance,
and also brush-bits, from their use. The diameter of the hole continues undiminished for a greater
depth than with the pointed spoon-bit.
The nose-bit, Fig. 325, called also the slit-nose-bit and auger-bit, is slit up a small distance near
the centre, and the larger piece of the end is then bent up nearly at right angles to the shaft, so as
to act like a. paring-chisel; and the corner of the reed, near the nose, also cuts slightly. The form
of the nose-bit, which is very nearly a diminutive of the shell-auger, Fig. 326, is better seen in the
latter instrument, in which the transverse cutter lies still more nearly at right angles, and is dis
tinctly curved on the edge instead of radial. The angers are sometimes made 3 inches diameter and
upward, and with long removable shanks, for the purpose of boring wooden pump-barrels; they are
then called pump-bits.
There is some little uncertainty of the nose-bit entering exactly at any required spot, unless a
small commencement is previously made with another instrument, as a spoon-bit, a gouge, a brad-aw],
a centre-punch, or some other tool; with angers a preparatory hole is frequently made, either with a
gouge, or with a centre-bit exactly of the size of the auger. When the nose-bits are used for making
the holes in sash bars, for the wooden pins or dowels, the bit is made exactly parallel, and it has a
square brass socket which fits the bit; so that, the work and socket being fixed in their respective
328.
327. 328.


















situations, the guide-principle is perfectly applied. A “guide-tube” built up as a tripod, which the
workman steadies with his foot, has been applied for boring the anger-holes in railway sleepers ex-
actly perpendicular.
The gimlet, Fig. 327, is also a fluted tool, but it terminates in a sharp worm or screw, beginning as
a point and extending to‘the full diameter of the tool, which is drawn by the screw into the wood.
The principal part of the cutting is done by the angular corner intermediate between the worm and
shell, which acts much like the auger. The gimlet is worked until the shell is full of wood, when it
is unwound and withdrawn to empty it.
The centre-bit, A, Fig. 328, shown in three views, is a very beautiful instrument. It consists of three
parts: a centre-point or pin, filed triangularly, which. serves as a guide for position; a thin shearing
point or nicker, that cuts through the fibres like the point of a knife; and a broad chisel-edge or
cutter, placed obliquely to pare up the wood within the circle marked out by the point. The cutter
should have both a little less radius and less length than the nicker, upon the keen edge of which
last the correct action of the tool principally depends.
Many variations are made from the ordinary centre-bit, A, Fig. 328. Sometimes the centre-point is
enlarged into a stout cylindrical plug, so that it may exactly fill a hole previously made, and cut out a
cylindrical countersink around the same, as for the head of a screw-bolt. This tool, known as the
plug centre-bit, is much used in making frames and furniture, held together by screw-bolts. Similar
tools, but with loose cutters inserted in a diametrical mortise, in a stout shaft. are also used in ship-
building for inlaying the heads of bolts and washers in the timbers and planking.
The wine-cooper’s centre-bit is very short, and is enlarged behind into a cone, so that immediately a
full cask has been bored, the cone plugs up the hole until the tap is inserted. The centre-bit de-
prived of its chisel-edge, or possessing only the pin and nicker, is called a button-fool ,- it is used for
boring and cutting out, at one process, the little leather disks or buttons which serve as nuts for the
screwed wires in the mechanism connected with the keys of the organ and pianoforte.
. The expanding centre-bit, shown on a much smaller scale in Fig. 329, is a very useful instrument ;
It has a central stem with a conical point, and across the end of the stem is fitted a transverse bar

9 * Holtzapfiel‘s "Turning and Mechanical Manipulation.“
130 . BITS AND AUGERS.

adjustable for radius. When the latter carries only a lamest-shaped cutter, it is used for making the
margins of circular recesses, and also for cutting out disks of wood and thin materials generally.
A modification of this device serves for making grooves for inlaying rings of metal or wood in
cabinet-work, and other purposes. Another form of expanding bit has a cutting-blade which passes
through a mortise in the head of the tool and is secured by a key. This may be adjusted radially
to bore holes of different sizes.
The above tools being generally used for woods of the softer kinds, and the plankway of the grain,
the shearing-point and oblique chisel of the centre-bit are constantly retained; but the corresponding
tools used for the hard woods assume the characters of the hard-wood tools generally. For instance,
a, Fig. 328 (B), has a square point, also two cutting edges, which are nearly diametrical, and sharp-
ened with a single chamfcr at about 60°; this is the ordinary drill used for boring the finger-holes in
flutes and clarionets, which are afterward chamfered on the inner side with a stout knife, the angle
of the edge of which measures about 50°. The key-holes are first scored with the cup-key tool, b, and
then drilled, the tools a and I) being represented of corresponding sizes, and forming between them
the annular ridge which indents the leather of the valve or key. When a is made exactly parallel
and sharpened up the sides, it cuts hard mahogany very cleanly in all directions of the grain, and is
used for drilling the various holes in the small machinery of pianofortes; this drill (and also the
last two) is put in motion in the lathe; and in the lathe-drill for hard woods, C, Fig. 328, called by
the French langue (le cm'pe, the centre-point and the two sides melt into an easy curve, which is
sharpened all the way round and a little beyond its largest part. Various tools for boring wood are
made with spiral stems, in order that the shavings ma y be enabled to ascend the hollow worm, and
thereby save the trouble of so frequently withdrawing the bit. For example, the shaft of Fig. 330,
the single-lip auger, is forged as a half-round bar, nearly as in the section shown; it is then coiled
into an open spiral, with the flat side outward, to constitute the cylindrical surface, and the end is
formed almost the same as that of the shell-auger, Fig. 326. The twisted gimlet, Fig. 331, is made
with a conical shaft, around which is filed a half-round groove, the one edge of which becomes
thereby sharpened, so as gradually to enlarge the hole after the first penetration of the worm, which,
from being smaller than in the common gimlet, acts with less risk of splitting. The ordinary screw-
auger, Fig. 332, is forged as a parallel blade of steel (seen in Fig. 333, which also refers to 332 and
334); it is twisted red-hot. The end terminates in a worm by which the anger is gradually drawn
into the work, as in the gimlet, and the two angles or lips are sharpened to cut at the extreme ends,
and a little up the sides also. Angers are also cast in two-part flasks, swaged between dies, or
twisted by successive motions of the parts of sectional dies. The same kind of shaft is sometimes
made as in Fig. 333, with a plain conical point, with two scoring-cutters and two chisel-edges,
which receive their obliquity from the slope of the worm; it is as it were a double centre-bit, or
one with two lips grafted on a spiral shaft. The same shaft has been also made, as in Fig. 334,
with a common drill-point, for metal.
Another screw-auger, which is sometimes used instead of the double-lippcd screw-auger, Fig.
332, is known as the American screw-auger, and is shown in Fig. 335, A and B. This has a cylin-
drical shaft, around which is brazed a single fin or rib; the end is filed into a worm as usual, and
immediately behind the worm a small diametrical mortise is formed for the reception of a detached
cutter, which exactly resembles the nicking-point and chisel-edge 0f the centre-bit; it may be called
a centre-bit for deep holes. The parts are shown detached at B. The loose cutter is kept central
330 331. 832. 333. 834. 335.
I
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n
. , .
l/v
,
'11“
54'
I
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I
I
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If
. .
.
a?
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by its square notch, embracing the central shaft of the auger; it is fixed by a wedge driven in
behind, and the chisel-edge rests against the spiral worm.
Taper augers are used for reaming out bung-holes, making butter-prints, etc. The centre-bit
bores a hole, and is succeeded by the taper reamer, which has a throat for the chips cut through
from the edge of the bit on one side to the opposite side of the stock.
An auger applicable to producing square holes, and those of other forms, is also an American
invention. The tool consists of a steel tube, of the width of the hole ; the end of the tube is sharp-
ened from within, with the corners in advance, or with four hollowed edges. In the centre of the
square tube works a screw-auger, the thread of which projects a little beyond the end of the tube,
BLAST FURNACE. 131

so as first to penetrate the wood, and then to drag after it the sheath, and thus complete the hole at
one process; the removed shavings making their escape up the worm and through the tube.
Hollow angers are used for forming tenons on spokes, chair-legs, etc. In one form the cutting
tool is so attached as to project within the opening, and the size of the tcnon is regulated by the
adjustment of the angular rest.
Annular angers cut an annular groove, leaving wood on the inside and outside of its channel.
The slotting auger cuts laterally, the work being fed against its sides. A number of chisel-shaped
lips are formed on the edges of the twist. "
The most usual of the modes of giving motion to the various kinds of boring bits is by the or-
dinary carpenter’s brace with a crank-formed shaft. The instrument is made in wood or metal, and
at the one extremity has a metal socket called the pad, with a taper square hole, and a spring catch
used for retaining the drills in the brace when they are ,
withdrawn from the work; and at the other it has a
swiveled head or shield, which is pressed forward hori-


zontally by the chest of the workman, or, when used 52%;;
vertically, by the left hand, which is then commonly
placed against the forehead. S
The ordinary carpenter’s brace is too familiarly known S


to require further description, but it sometimes hap-
pens that in corners and other places there is not room
to swing round the handle. The angle-brace, Fig. 337,
is then convenient. It is made entirely of metal, with
a pair of bevel-pinions, and a winch-handle that is
placed on the axis of one of these, at various distances
from the centre, according to the power or velocity
required. Sometimes the bevel-wheel attached to the
winch-handle is three or four times the diameter of
the pinion on the drill; this gives greater speed, but
less power.
The angers, which from their increased size require
more power, are moved by transverse handles; some
angers are made with shanks, and are riveted into the
handles just like the gimlet; occasionally the handle
has a socket or pad, for receiving several angers, but
the most common mode is to form the end of the shaft
into a ring or eye, through which the transverse han-
dle is tightly driven. The brad-awls, and occasionally
the other tools requiring but slight force, are fitted in
straight handles; many of the smaller tools-are attached
to the lathe-mandrel by means of chucks, and the work
is pressed against them. either by the hand, or by a
screw, a slide, or other eontrivance.
Among the recent improvements in hand-boring ap-
pliances is the flexible auger illustrated in Fig. 338, which is manufactured by Messrs. Stow and
Burnham, of Philadelphia. It consists simply of a flexible tube lined with a spiral wire, and through
Which is passed a closely-coiled spiral, having at each end suitable connections for a small sheave
and for the auger respectively. These details are clearly shown in the drawing. A link passes
around the sheave and has a hook attached to it, for the purpose of holding a tension-rope when
the anger is in use. The sheave is driven by a cord from a countershaft direct, or through a system
of pulleys when the work to be done is removed to any distance. The largest-sized anger yet made
is one inch, which is worked by a one inch cable; and the smaller sizes range from three-eighths of
an inch upward, increasing by eighths of an inch; the longest cable hitherto employed is 15 feet.
This device may also be adapted for metaLdrilling.
B For metal-boring implements, see DRILLS, an'l DRILL‘ING AND BORING-MACHINES. See also WELL-
came. '
BLAST FURNACE. See FURNACES, Bnasr.
BLASTING. The process of breaking rocks with explosive compounds. In ordinary blasting
operations, simple drill-holes are usually tired, and may be so placed and combined in groups as to
effect the displacement of great masses of rock; but in large operations mines are excavated for the
introduction of the explosive.
The blowing up of rock by gunpowder is a simple process. The hole is bored in the rock, and in
such direction as to expose the weakest part to the action of the powder; this hole is charged with a
certain portion of gunpowder, and is then filled with clay, or, more usually, with a soft kind of rock,
which is rammed into it, leaving a small orifice, through which the fuse is afterward introduced for
setting fire to it. At the present day, a variety of tubular fuse is used in the coal-regions of Penn-
sylvania, where a long iron tube is used, and the firing done with a straw or a Daddow squib. A
narrow ribbon of copper is used as covering material for the squib, and is folded spirally around the
core, through which passes a string coated with mealed powder or any other combustible material,
and intended to insure quick and certain ignition. These squibs are found cheap and reliable.
Bickford’s fuse is used in cases where it is not desired to fire several charges at once. When used
with gun-cotton and nitro-glycerine or any compounds of the latter, all of which have to be detonated
by a cap of fulminating powder, the fuse is slightly rasped at the end and inserted into the cap.
Electrical firing is generally used for simultaneous blasting; by it, ignition of the charge is effected
- '; I/III "II/III}.
up
I ~___-_-\\\
' - ' [III/III


iu_\


IIIIIII)‘ if: ‘I _— \‘\\\r
' n I,




'a
1 32 BLASTIN G.

in two ways. One is by interposing an exceedingly fine platinum wire (iron or alloyed metal-will also
answer) in the path of a current of electricity from a powerful voltaic battery, the resistance offered
by the diminished conducting power of the fine wire to the passage of the electric current heating
the wire to redness, and thereby exploding the charge. Another system of electrical blasting de-
pends upon a sudden discharge of static electricity between the terminals of two wires imbedded in a
suitable priming composition, which is thereby fired. For this, various appliances have been used,
viz: (a.) A frictional electric machine and Leyden jar; (b.) A voltaic battery induction coil; (0.)
An electro-dynamic machine, such as Siemens’s, Ladd’s, Farn'ier’s, Gramme’s, etc.; An electro-
dynamic machine, as Wheatstone’s, Breguet’s, Saxton’s, Clarke’s, etc.
Fig. 338 A shows the electrical fuse so called, made by the Lafiin 81. Band company, which belongs
to the second system above noted, and which it is claimed will cause the detonation of common blast-
. ing powder. All of these caps or exploders are practically con-
SSSB. structed on the same principle, and they are chiefly used in deto-
nating charges of gun-cotton, intro-glycerine, dynamite, and the
other nitro-glyeerine compounds.
Among the direct advantages of electric firing may be sum-
marized: (a) Simultaneous firing of different charges; (6.) Pre-
mature escape of any of the gas developed absolutely avoided
by close tamping; (0.) N o smoke or gas from fuses; ((1.) Great-
est safety; (e.) llapidity of work.
Tampz'ng.—With black powder, clay is perhaps best, but soft
rock, sand, etc., are often substituted. With pure nitro-glycerine,
no tamping is needed but water; therefore intro-glycerine, hav-
ing greater specific gravity than water and no aflinity for it, is
an especially suitable agent for subaqueous blasting, where it can
simply be poured down into the holes through a tube and funnel.
Fig. 338 B shows a charge of nitro-glycerine with water-tamping
and tape-fuse and exploder. Where the rock is split or seamy,
nitro-glycerine must be encased in some substance, say tin cases,
338 A.
~ ’2 ‘ ’ 3'
* s ‘ 23-? -.'.,”/’ '/ .- :t
. . “':' a- " " , T g ‘ .“ V
l . _-,-, . , ,. '1 ,1, . . _ P}
.a,‘ , ~,_. ~._ ~ - ___.. N: 1_ ~‘_'~__- _\ -
Water


1
I



I.' § \ a a o I o n _\ \ i u ‘
,% 3,5,2), , 5.3 and this, 1t is said, lessens its explosive 101cc by p1 eventing close
\~~ . t s; contact. Where the rock 1s firm, it can be poured d1reetly into
' 16 a - -
“ \.\ b,» the hole. In this respect, dynamite has a great advantage over
a nitro-glycerine, in that it can be charged in roof-holes and in
Q a, seamy rock, there being no danger of running out, leakage, etc.
In charging No. '1 dynamite, it was formerly thought that no
tamping would be required, but the general experience of blasters
has led to the practice of tamping the holes solidly to the lip with clay. _
T/ze Paanciples of Blasting—The effect of a shot may be influenced, among other considerations,
by: (m) The shape in which the rock is presented, the size and number of the open faces, the shape
of the piece it is desired to take out, if that be an object, and, of course, primarily, the size of the
cross-section. of the face, if it be heading work. (6.) The texture of the rock, whether it be hard or
easy, firm or loose, whether it be brittle or tough; thus experience gained in blasting close-grained,
hard granite, trap, gneiss, etc., would not apply to limestone, sandstone, slate, etc., etc. (0.) The
structure of the rock. as to whether it be laminated, stratified, or fissured; upon its cleavage, etc.,
and upon whether it be massive or broken, etc. (d.) The elasticity of the rock. (a) The explosive
used. (f.) Whether the hole is to act alone or simultaneously with or following others ; in the case
of simultaneous firing, the question arises of how the waves of oscillation will best act in concert.
(9.) The character of the fuse and tamping.
1. The hole should not be located in the line of least resistance, otherwise the tamping would
simply be blown out. (Be it remembered this discussion is as to black powder, not nitro-glycerine.)
2. Experience has established the average ratio between the depth of hole and the length of the line
of least resistance to be as 4 to 3, or the length of the line of least resistance will be three-quarters
of the depth of the hole; and experience has further shown that the charge of black powder should
be, on the average, about one-third of the depth of the hole, the varying limits being 0.29 to 0.45.
3. Holes ought in general to be bored at or under an angle of 45°; a larger angle, increasing to
as much as 90°, is advisable when open faces occur, and a smaller angle is advisable when the tex-
ture and structure of the rock necessitate assuming the line of least resistance as less than three-
quarters of the depth of the hole. Further, as the mass thrown breaks in the general direction of
the line of least resistance, and as, in fact, this line lies in the mass ejected, or, in the extreme case
of an angle of 90°, bounds the ejected mass, we must carefully observe,
4. The external shape of the rock, in order to reach a maximum effect,
5. Clefts and fissures and lines of stratification in the rock must be carefully used to advantage.
In general, we may say, as to blasting in regularly stratified rock, that,
6. In regular seams, the shots should be set perpendicular to the face of the seam.
7. The portion of the hole holding the powder should be located within the whole rock. This
rule, of course, only holds in rock where the strata are thicker than the depth of the powder-charge.
in the hole. If the charge intersect a stratification-bed, there will, in general, be a waste of force.
Therefore, a short-fissured rock (i. e., one naturally broken by short clefts, etc.), or one much lami-
nated, though it gives more faces for the p0wder to act on again, is ultimately less favorable material,
in many cases, than more solid material; therefore,
8. Short-fissured, lammated, or slaty rock should not be drilled, if possible, in the direction of the
laminae, but, according to circumstances, in an oblique or normal direction to them. N 0t only should
9. Each shot be set so as to clear a bearing for following shots, but also
_ BLASTING. - 133

10. The proper volume should be blasted away. a
11. Short-fissured or very tough rock requires shallow holes; coarse-fissured, moderately tough
rock takes holes of average depth ; and brittle and solid rock works well with deep holes. 1n tough
rock wide holes, and in brittle rock narrow holes, are the more economical.
It should here be noted that firm, brittle rock may be distinguished by the rebound of the hammer;
it drills hard, but breaks easily. Examples are: Trap, granite, gneiss, syenite, etc. Firm, tough
rock does not cause the hammer to rebound so violently, leaves a white streak when scratched with
steel, drills easy, but breaks hard. Examples are: Limestone, porphyry, quartzose lodes, etc.
12. In driving a heading, particular care should be taken that unnecessary cost in flushing the
clear profile does not arise. Large protuberances and cavities must be avoided, and particular care
in this respect should be paid in tunneling in taking out the bottom 'or bench, that there be not a
large amount of trimming left to be subsequently done inv clearing the normal profile, for such work
is not only very tedious, delaying the work, but is costly. For this reason, holes located near the
sides or roof should receive especial care.
Blossom Roch—The removal of Blossom Rock, in the harbor of San Francisco, is an example of
the process of removing submarine rocks by conducting the excavation from within. Full particulars
of this work are given in the official reports of 001. R. S. \Villiamson and Lieut. W. H. Heiier, U. S.
A. The top of the rock was about 5 feet below the surface of the water at mean low tide. A hori-
zontal section at'the depth of 24 feet measured 195 by 105 feet. The quantity of rock contained
within these boundaries was about 5,000 cubic yards, and consisted of a metamorphic sandstone of
irregular stratification. The great mass of it was so soft as not to require blasting. The plan pro-
posed by A. W. Von Schmidt involved the sinking of an iron cylinder 6 feet in diameter, carry-ing an
India-rubber flap at its lower end. The water was pumped out, the rock bored into, and another
cylinder was slid inside the first and down into the excavation, and secured by cement. (Fig. 338 c.)
It was, however, found difficult to place the iron cylinder in position without first resorting to the
338 c. 338 D.


, flex-5531s? '


_______—


~
~.\.\
\ ~ ;\\
\







llijllllllllll I ‘ w ‘~ :2 \‘U 1'-
13:- ®yafaw i _ i I t
\\ \‘ ~\\- \ ~\ \ \
~ \‘s‘xs. \‘\\‘»‘\ -\\J\‘
ordinary eribwork coffer-dam. The sinking of the shaft was commenced December 7, 1869. Only
one man could work at a time, but in the space of 4 weeks a depth of 30 feet below low water was
reached. Drifts were then run into the longer and shorter axes of the rock, and steam was used in
hoisting. . The rubbish was dumped upon one side of the rock, from which most of it was washed by
the tide. During the month of January, 1870, 8 men found room to work. Most of the rock was
removed by picks and sledges, only 10 lbs. of explosive (giant powder) being used in the whole opera-
tion. In February 16 men found space to work, and by the 20th of April the dimensions of the
cavity were 140 by 60 feet, with a maximum height of 12 feet. Columns of rock were at first left
for support, but they were from time to time replaced with upright timbers from 8 to 10 inches in
diameter, with the exception of 4, which were left standing near the shaft. Preparations were now
made to blow up the shell. Fig. 338 D, copied from the official report, will explain the method of
conducting the explosion. Powder was used as the explosive, nitrate of soda taking the place of
nitrate of potash in its composition. The quantity used was 43,000 lbs. The vessels for containing
it were 38 ale-casks of 60 gallons each, and 7 old tanks made of boiler iron, holding about 300
lbs. of powder each. The explosion was effected by a galvanic battery stationed in a heat about 800
feet from the rock. A column of water about 200 feet in diameter was thrown into the air to a
height of 200 to 300 feet, and pieces of rock and timber were thrown high above the water column.
The rock was found to be effectually demolished.
The East River Improvement Worka—The object of the works for the improvement of the East
River was the removal of a mass of rocks that impeded the navigation from the Atlantic to New
York by way of Long Island Sound, and were situated in the immediate vicinity of Hallett’s Point, a
promontory of Long Island. These obstructions consist of a number of sunken reefs and rocks
well known as “Hell-Gate,” which caused a. rush of water through the pass, and which, taken in
connection with the dangerous currents and surface agitation, have been a lively source of danger
to navigation ever since ships came up the river.
In 1852 an appropriation of $20,000 was made, and work was commenced under the charge
of Major Fraser, of the United States‘Corps of Engineers, upon one of the obstructions, known as Pot
Rock. By means of sinking blasting charges on to the top of the rock, and firing them by batteries on
the surface, the depth of water at this point was increased from 18.3 feet to 20.6 feet; the expense
attending this operation having been $18,000.
The work stopped here for about 15 years, when some action was again taken in the matter. and
General Newton, of the United States Engineers, reported on the obstructions in January, 1867.
Upon this report appropriations were made, and operations were commenced at Hell-Gate. A scow
was built specially adapted for drilling, Fig. 338 E, and towed over the rock in which it was desired
134 BLA STING.

to form the holes. In the centre isan octagonal well 32 feet in diameter, in which is suspended a
wrought-iron dome for protecting the divers. At the top of the dome is a telescope 12 feet in diame-
ter, with a rise and fall of 6 feet, to adapt its height to the various stages of the tide. When the
dome is in working position, it stands clear of the scow, resting on self-adjusting legs, which adapt
388 E.


themselves to the inequalities of the reef. The drilling engines, 9 in number, are supported by mov-
able bridges, thrown back when the dome is up. The drill-bars work within stout iron tubes, pass-
ing through the dome, one at the centre, the others ranged in a circle about 20 feet in diameter.
This machine was set to work in 1869, and considerable improvements were effected by it on two of
the most formidable reefs.
In August, 1869, the first works were commenced for attacking the main body of obstructions at
Haliett’s Point, and a coifer-dam was formed upon the reef, where the rocks were bare at low water.
It was built of heavy timbers bolted down to the rock. The coffer-dam was completed and pumped
out the following October, and a shaft ft. below low water was sunk. This part of the work
was continued till June, 1870, when it was suspended for want of funds. At that time 484 yards of
rock had been removed at a cost of $5.7 5 a yard. In July, however, operations were resumed with
vigor, the shaft was sunk to its full
333F- depth, the ten main radiating galleries
were driven for lengths varying from 51
feet to 126 feet, and two of the cross-
galleries were commenced. During 1870
no less than 8,306 cubic yards of rock
were removed, the drilling having all
been done by hand.
In 1871 machine-drilling supplemented
the slower and more costly handwork;
1,653 feet of main tunnel and 654 feet
of connecting galleries were made, and
8,293 cubic yards of rock were taken out.
The same year a careful survey of the
reef was made to ascertain the exact con—
tour of the rock, in order to regulate the
operations beneath ; more than 16,000
observations were recorded in connection
with this part of the work. Fig. 3381‘
shows the general arrangement of the
work. The form of the reef on the 2"-
foot water-line is indicated in dotted lines, and it will be seen that the main tunnels radiate
from the sides of the shaft inclosed by the coffer-dams to the 25-foet water-line. Between
these main tunnels 13 intermediate ones of greater or less extent were driven, and the whole
series were connected by means of concentric galleries, approximating to the contour of the reef,
which was, it will be seen, completely honey/combed, a roof being left of a thickness ranging from 6
feet to 16 feet, and supported on 17 2 columns. In order to prepare for the immense blast which
was instantaneously to break up the shell of rock left, and open the passage to navigation, over 4,000
holes were drilled in the columns and roof to receive the charges, which were all connected together
and brought to the discharging battery on shore. The holes were from 2 to 3 inches in diameter,
about 10 feet apart, and the average depth was 9 feet; the proportions, however, varied with the
nature of the rock and other circumStances. It should be mentioned that some difficulty was caused
in drilling these holes by the increased amount of leakage produced by tapping seams; the maximum
quantity of water pumped, however, did not exceed 500 gallons per minute. The following is a sum-
mary of the leading particulars of matém'el used for the explosion:







Peimds.
Dynamite in tin cartridges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24,812
:: paper “ . . . . . . . . . . . . . . . . . . . . .» . . . . . . . . . . . . . . . . . . 1,164
prnners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _2,9___Z_l_5
Total weight of dynamite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28,901
“Rendrock” in cartridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,0611}
“Vulcan” powder in cartridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,244
Total charge . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52,2061}
BLASTING. , 135




Pounds.
Total number of cartridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13,596
“ “ brass primers . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . 3,680
“ “ holes with primers. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,645
Number of iron pipes with primers . . . . . . . . . . . . . . . . . . . . . . . . . 35
Number of holes not charged . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 782
Total number of holes and pipes . . . . . . . . . . . . . . . . . . . . . . . 4,462
- Feet.
Length of connecting wire . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . 100,000
“ leading wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120,000
Number of cells in firing battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 960
There were employed 12 firing batteries of 40 cells each, 4 of 43 cells, and 7 of 44 cells. The
distance of the firing-point from the shaft was 650 yards.
The holes having been all charged and the connection with the batteries made, the workings were
flooded by means of a 12-inch siphon on September 11, 1876; and on the 24th, with scarcely any
perceptible tremor, and with a comparatively insignificant lifting of the water, the 50,000 lbs. of
dynamite were exploded, and the work which had been so many years in progress was thus com-
pleted in a moment. The result was a depth of 12 feet at 180 feet from the shore, 16 feet from
180 to 300 feet, and 20 feet beyond 300 feet from shore, leaving about 30,000 cubic yards of rocL ~
to be dredged in order to complete the works. The estimate for completing the entire work of im-
proving Hell-Gate and the East River was $5,139,120.
Blasting at Flood Rock—The methods pursued at Flood Rock were substantially those that had
been tested on a smaller scale at Hallett’s Point. Flood Rock was exploded October 10, 1885 ; 21,-
669 ft. of tunnels were driven, 80,232 cub. yds. of rock excavated, and about 480,000 lbs. of
high explosives consumed. Experience at Hallett’s Point proved the impracticability of the first plans
for the excavation of rock at Hell Gate. It was intended in the first place to excavate a cavity suffi-
ciently large to receive the débrz's from the roof and leave a depth of 26 ft. at mean low water imme-
diately after the final blast. This result was not attained. Instead of a depreciation after the blast,
there was an upheaval of broken rock; hence the Flood Rock plans were to simply excavate a series
of tunnels and galleries for the insertion of explosives. and to dredge the broken material after the
blast. The average charge of explosive per hole was 22.5 lbs., which permitted the reduction in the
amount of drilling required from 0.93 of a foot per cub. yd., broken at Hallett’s Point, to 0.42 of a
foot. This was because of holes of large diameter were used, such holes having been drilled with a
special bit designed by Lieutenant Derby. '
In this bit the cutting surfaces are so distributed as to utilize the power applied with a greater
economy. As used at Flood Rock, the drillingbar was hollow, having a cutting-tool on its end also
hollow. The cutting-tool has six cutting points, and in its operation a little core was formed, which
disappeared, however, under a slight blow from the end of the drill-rod. The debris was washed out
by, a stream of water through the bit as fast as made, and consequently little force was spent in pul-
verizing the rock after it was broken off. The result of this was the drilling of 7 3,984—11090- ft. of
holes for the final blast, 59.5 per cent. faster than with the X-bit, and making the holes of at least 25
per cent. greater area at the bottom. This permitted the use of cartridges 241! in. diameter, and in
many of the holes even 2% in. could have been used, although the bit at the start was only 3% in. in
diameter. The experiment to determine these comparative results continued through months, and an
average is made on 39,119 ft. drilled with the X-bit, and 39,200.75 ft. with the tubular bit. The total
number of feet drilled for the final blast was 113,10111096 ft. Very much of this work was done in
the roof, which in most places was too high to be reached except by placing the column on the top
of a temporary staging erected for the purpose. As but few holes could be reached in one setting
of the staging (generally two), much time of the eight-hour shift was occupied in moving.
The total cost of the final blast at Hallett’s Point was about $81,092.24 At Flood Rock it was
about $105,000, though the blast was 5.6 times as large.
That appliances for submarine rock-work have advanced beyond the methods pursued at Hell Gate,
is shown in no clearer way than by the fact that the contract price for removing the broken rock, let
on proposals duly advertised, is $3.19 per ten, or about $6 per cub. yd. This is in addition to the
enormous cost of tunnelling and blasting.
Submarine Drilling Plants—At the present time two distinct kinds of submarine drilling plants
are in use: 1. A fixed drill platform elevated above the level of the tide and supplied with power
from a barge moored in the vicinity. 2. A barge combining all the apparatus mounted, the drills
working from the edge of the barge.
The elevated platform idea was a development from the form of plant used by Mr. L. Y. Schermer-
horn at Ahnepee Harbor, Wis. This plant consisted of two parts: 1. The drilling-platform; 2. The
scow containing boiler, pump, hoisting apparatus, blacksmith-shop, etc. The drilling-platform
gas a framework of timbers suspended by chains which bear upon tripods resting upon the rock
ottom.
A modified form of this Schermerhorn tripod was used at Eagle Harbor, Mich. Instead of a plat-
form mounted on several tripods, one tripod only was used, the top projecting to such a height above
the evel of the water as to admit of a rock-drill working upon a platform suspended within the
tripod. The drill and tripod together were easily and quickly moved from point to point by the der-
rick of the hoisting-scow. This arrangement occupied but little space, and could be placed with
1 36 BLASTING.

certainty over the points where drilling was required. It was found useful in drilling isolated
bowlders, or to do drilling work where a series of continuous holes was not required.
Blasting at Ahnepee Harbon—At the Ahnepee (Wis) work the. following system was pursued : A
deposit of sand, mud, gravel, and sawdust covered the limestone rock to a depth of from 1 to 6
ft.; this was excluded from the drill-hole by inserting, after the withdrawal of the first steel, a
piece of light wrought-iron pipe of 3 in. internal diameter, and long enough to reach from above the
surface of the detritus down into the rock about 1% ft., or the distance penetrated by the first steel.
These pipes were withdrawn after the holes were loaded. The immediately successive drill-steels,
with bits reduced to 2% in. diameter, passed through the pipe.
About 10 ft. below water surface a horizontal stratum was found, consisting of loose angular frag-
ments of rock, and having a thickness of from 9 to 18 in.; the exclusion of these rock fragments
from the drill-hole was necessary, and was accomplished as follows: As soon as the drill-steel—drill'
ing a hole 22- in. in diameter—had passed slightly below the bed of this seam it was withdrawn, and
a piece of gas-pipe 2 ft. long and 2a in. internal diameter was dropped into the hole and driven to the
bottom, thereby scaling off the loose rock. The successive drill-steels, with bits reduced to 2 in.
diameter, passed through this pipe, which was left in the hole and destroyed in the blast. This
operation was not without its difficulties, and the delay connected with the successful passage of this
scam added largely to the cost of drilling.
The drill-holes were carried to a depth of 17 ft. below the plane of low water, or 5 ft. below the
bottom of intended excavation. At first the drill-holes were placed about 75 ft. apart each way;
this distance was increased to 91} ft. ; a greater increase seemed to result in breaking the rock into
masses too large to be economically handled by the dredge. Giant powder of Nos. 1 and 2 were chiefly
used as the explosive. The drill-holes were usually charged with the following proportions and ar-
rangement of Nos. 1 and 2, viz. : 1 lb. of the former to 4 lbs. of the latter; one half of the No. 1 was
placed in the bottom of the hole, the No. 2 was then superposed, upon the top of which was
placed the remaining N o. 1, the last cartridge of which contained the exploding cap and wires; gen-
erally the holes were loaded to within less than 2 ft. of the surface of the rock, and averaging one
fourth of a pound of N o. 1 and 1 lb. of N o. 2 per linear feet of drill-hole. Experiments were
made in which the proportion of N 0. 1 was in excess of the above, the results of which cannot yet
be determined. The dynamites or high explosives have a value as disruptive agents directly proportional
to their inherent nitro-glycerine, and black powder, salts of potassa or soda, or anything else added to
or constituting the absorbent for the nitro-glycerine, have no value as assistant disruptive agents, but
are only useful as absorbents or diluents. But to have alone employed the nitric-glycerine contained
in the charges used would have reduced their volume about one half, thereby placing the top of the
charge about 8 ft. below the surface of the rock, concentrating the disruptive efiort near the bottom
of the hole, and breaking the lower part of the rock into unnecessarily small fragments, leaving the
upper part in large masses. The use of Nos. 1 and 2 dynamite permits of the distribution of the
disruptive energy of the minimum amount of nitro-glycerine along the entire section of fracture, pro-
ducing a nearly uniform breakage. In shallow 11018.2,01' where the necessity of breaking the rock
into small masses does not exist, undiluted nitro-glycerine would be more economical, but the danger
accompanying it prohibits its use. .
In placing the cartridges in the drill-holes they should not be subjected to more ramming than just
sufficient to bring them into close contact; experience indicating that the breaking up of the cartridges
and their admixture with water resulted in a loss of disruptive energy. Twelve hundred lbs. of
Hercules powder was used; in this, carbonate of magnesia seems to largely constitute the absorbent.
Generally force had to be expended on the cartridges in getting them into the drill-holes, and as the
Hercules powder was very soft and plastic, the cartridges were easily pushed to pieces, allowing the
water to exert its solvent effect on the absorbent, and resulting in a separation of the nitro-glycerine
from the mass.
When a number of symmetrically arranged and equally charged holes were simultaneously fired,
a piling up of the broken rock around the central area of the blast resulted; and this tendency
seemed to obtain both where the rock had been broken by previous blasts on two sides of a new
group of holes and where the rock on all sides of the group was solid. It was found that this central
upheaval could be prevented by making the charges in the outside holes of a group in excess over the
' charges for central holes, and about in the proportion of 4 to 3. The effect of explosions on adjacent
buildings is of interest. The largest blast fired contained 25 holes, charged with an amount of dyna-
mite carrying 330 lbs. of nitro-glycerine. Not the slightest injury resulted to buildings but 50 ft.
from the blast. At another time the explosion in the open air of a small amount of dynamite, carry-
ing less than 10 lbs. of nitro-glycerine, broke the glass in windows, and the supposition was that a
very heavy blast had been fired. This seems to indicate that, as long as the energy of the nitro-
glycerine is usefully applied toward overcoming the resistances ofrthe rock, the residual effect will
be too small to produce destructive detonation even in close proximity to the blast. Many of the
blasts were covered with less than 4 ft. of water. From these very large quantities of rock frag-
ments were thrown into the air, while with a covering depth of 10 ft. no rock appeared above the
water surface.
The vertical elevation was carefully measured to which the water was thrown from a blast of 20
holes charged with about 275 lbs. of nitro-glycerine, and covering an area of 33 by 50 ft. Over the
entire area the water attained an elevation of 40ft. ; from this mass ascended a column whose base
covered about one half the area of the blast, to an additional height of 155 ft. ; while from the centre
of this column was thrown a spire-like jet to a farther height of 20 ft., or a total of 215 ft.
The cost of the work was 89-135 cts. per linear ft. of drilLhole blasted, or 44-11;; cts. per cub. yd. of
rock broken; making the aggregate cost of drilling and blasting 82-120- cts. per cub. yd., meas-
ured in place, or, exclusive of superintendence, 75,50- cts. per cub. yd. -
BLASTING. 137


In the foregoingr statements of costs the expenditure for machinery and tools was charged as though
these items were no longer available, whereas a large part of such expenditure was applicable toward
continuing the work during the followmg season. In the removal of rock on the James River, Vir-
ginia, under Colonel Craighill, a modified form of plant was used, the difl’crcnce being that the rock-
drill was mounted upon a spud, the point of which rested upon the bottom. This spud was bound to
the. floatingr barge which contained boiler and other apparatus, and which rose or fell with the wind and
tide without affecting the spud.
illodcrn Drill-Baizqe.*-The Ahnepee 3380.
Harbor plant and that used on the
James River were limited in their use-
fulness, and have been superseded by
the more simple, compact, and durable
platform shown in Fig. G.
This plant consists in the main of
a barge containing boiler, blacksniith’s
shop, diving apparatus, and pump, float-
able platform or drill-stage, provided
with spuds by which it is elevated above
the surface of the water; two or more
steam-drills, mounted upon an “ A ”
frame or platform to facilitate moving
them about the deck; and cylindrical
conically tapering tubes, with an eject-
or device attached; these tubes being
let down to the rock through the trunk-
way in the deck of the platform, and the process of drilling and the charging being carried on through
the tubes. The barge may be of any ordinary design, and is moored in position by four anchors, one at
each corner. The drill-stage is made of very strong timbers, bound together underneath. The spuds
are free to slide through trunk-ways fixed to the platform. Heavy pulley-blocks are at each spud-top, to
serve to raise the platform above the surface of the water. There are three gallows-frames, one at each
end and one in the middle of the platform ; these serve to hold a pipe which is free to roll about in a
horizontal position over the top of the frames. To this pipe were hung blocks and tackle, which com-
mand any position over the deck, and serve to lift the drill-steels, etc. The drill-stage is made floatable
by means of empty barrels or water-tight tanks placed underneath. The barge is moored to within 15
ft. of one end of the drill-stage, and the two are connected by a gang-plank, steam hose, etc. The
ejector-tubes are made telescoping, so that they may be adjusted to various elevations of the rock.
These tubes consist in the main of two telescoping cylindrical sections, made of No 8 boiler-plate. On
the lower end of one of these sections is attached a casting tapering conically to a 4-in. opening, into
which is inserted a piece of 4-in. tubing; this tubing forms the lower end of the apparatus or that
nearer the rock. Where there is an accumulation of material over the rock a common ejector is at-
tached to the side of the conical casting, and is connected directly with the interior of the tube. By
forcing a stream of water through this ejector the overlying material is pumped from underneath the
tube, allowing it to readily sink until it rests on the surface of the rock. The steam-drill being
placed over the mouth of the tube, a drill-steel is here inserted, and a hole drilled to the required
depth. The lower end of the conical attachment serves to guide the steel in starting a hole, and pre-
vents “stepping.” When the drill has been driven the length of the feed of the machine, on exten-
sion piece is inserted over the shank of the steel ; the machine is wound up again to the top of the
screw-feed, when, the chuck being clamped on the top of the extension piece, the drill is driven
farther on till the required depth is attained; the drill is then removed from the tube and a
graduated plunger or ramrod inserted to ascertain the exact depth of the hole. Dynamite inclosed
in tin cans is then suspended into the tube, and pressed down to the bottom of the tube by means of
the plunger. The connecting wires are then attached to a piece of cork and thrown down into the drill-
tube, which is next lifted on deck, and the floating cork with wires picked up, led to the battery, and
fired. The progress of drilling is very materially facilitated by feeding down into the hole and through
the drill-tube a length of j-in. pipe, at the upper end of which is attached a hose which connects
it with a pump; then a stream of water is fed upon the drilling-bit, preventing the accumulation of
cuttings under the bit or in the shape of a collar just above it. This small pipe follows alongside the
drill-steel, but is not injured by it, except it be allowed to get underneath the bit.
The drill-stage, being elevated above the surface of the water, is not affected by winds or tides, nor
is it necessary to remove it before blasting. A severe blast will only break a spud, which can readily
be replaced. In submarine blasting pieces of rock are seldom thrown above the surface of the water.
The upheaval of the water has no injurious effect upon the drill-stage, but with a barge the effect
would be disastrous in springing leaks in her timbers and injuring the machinery. With such a
plant as this in connection with the ejector-tubes, all the diiiiculties encountered in submarine drilling
may be overcome. Holes can be drilled, charged, and blasted through as much as six feet of over.
lay of material. Swift currents will not affect the platform, and, as no divers are employed, it is only
necessary to secure the tubes in position, when the static water inclosed within will admit of free
charging of the holes. The tides rise and fall underneath the stage without affecting the position of
the drills. High winds and rough weather within certain limits are not antagonistic to the opera-
tions. In the event of a collision with any passing vessel, the spuds of the stage act like spring-piles
in a ferry-slip, and the most serious result would be to break all the spuds, which might. be replaced
at but slight expense.
The submarine ejector-tubes, designed and patented by Mr. W. L. Saunders, M. 15., and used in New


138 BLASTIN G.

York Harbor, Erie, Pa, etc., are shown in Fig. 338 H. Surrounding the drill A is an inclosing case
B, which consists of two or more cylinders, b and 6‘, one of which is constructed to slide into the
other, like the sections of a telescope, and of a conically tapering terminal section 69 secured to the
lower extremity of 6‘, and provided with a lower extension 12", con-
sisting of a straight metallic pipe or tube.
The sections b and I)1 serve to support the remaining portions of
the apparatus, and, together with the extension 6, to protect it, as
well as to control the direction of the drill. The section b'2 is prefer
ably of cast-iron, and serves to unite the cylindrical portion of the
inclosing case with the tubular extension 6". The tube 63 follows the
point of the drill through the comparatively soft earth or other ma-
terial which may cover the rock to be operated upon, as shown at F,
the width of the bit being preferably nearly equal to the interior
diameter of the tube. The tube b3 thus forms an interior wall for
the drill-hole, and prevents the surrounding earth F from pressing
against the steel an1 after the bit has penetrated it. Upon reaching
the surface of the rock G, further descent to the tube 63 is prevented,
for the reason that the hole formed therein by the bit of the drill
will not be of sufficient size to receive the tube. The latter will, in
consequence, rest upon the upper surface of the rock, and while in
that position serves to steady the motion of the drill, causing its
successive strokes to fall upon the same point until it has entered
the rock. In this manner a clear passage is always maintained from
the surface of the water to the bottom of the hole, whereby the
drills may be removed and replaced with great facility, and through
which the blasting-cartridge may afterward be inserted.
For the purpose of clearing the pulverized rock and clippings from
the hole as rapidly as they are formed by the drill, and thereby pre-
venting the formation of a collar about the steel above the bit, a tube
0 is used for conveying a stream of water to the bottom of the hole,
thereby occasioning a continuous agitation and outflow of water and
débris. To the upper extremity of the tube 0 a hose 0 is attached, constructed of rubber Or other
suitable material for convenience in handling. The hose 0 extends through a pipe 01 secured to the
interior of the section b, which section serves to retain the hose away from the steel of the drill and
to prevent it from being bruised. Suitable means are provided for allowing the pipe 0 to descend
into the hole at the same rate as the drill, and for maintaining its lower extremity a short distance
above the bit of the drill. ‘
To facilitate the discharge of the water and powdered rock, or other accumulations, from the tube
63, a discharge-opening D is provided for, which consists of a short branch-tube d secured to the side
of the conical section 69, with the interior of which it communicates. A jet-pipe E
extends downward from the upper extremity of the inclosing case B, preferably out- 335J-
side and parallel with it, to the tapering section 62, into the interior of which it extends,
terminating in a nozzle e, concentric with the discharge-opening D. The discharge- @i—lfi‘
tube D and the nozzle e preferably extend in an upward direction from the section ()9,
and they together form an ejector for discharging the muddy water from the tube b2,
suitable means being provided for forcing a stream of water or jet of steam through
the pipe E.
During the operation of the drill, streams of water or steam are constantly forced
through the two tubes 0 and E, which keep the hole free from débris ,' and in this man-
ner a hole may be drilled to a great depth in a submerged rock without necessitating the frequent removal of the drill and pumping out the hole, as has heretofore been
customary. Whenever it is desired to remove the drill, it is Simply withdrawn from
the inclosing case B, which is allowed to remain in position in order to facilitate the
insertion of the charge of explosive material for blasting. This is effected by intro-
ducing a suitable cartridge provided with a fuse, and having electric conductors
attached thereto, within the tube B, and thus lowering it into the hole drilled in the
rock. A graduated plunger is then employed for ascertaining whether the cartridge
has descended to the bottom of the hole; and this may be readily determined by
comparing the distance to which the drill has been sunk with that registered by the
plunger when resting upon the cartridge. The tamping of sand or other suitable mate-
rial is also introduced through the tube B, after which the latter is withdrawn or
removed, the upper extremities of the electric conductors having been previously
attached to floats for more readily securing them after the tube B has been drawn
from over them. . ' -
In excavating the opening to the rock through the overlying bed of sand, mud, or
gravel, it is in some instances unnecessary to employ the drill for loosening, as the
stream of water forced through the jet-tube will be sufficient for the purpose. The
cle'bm's will be discharged through the lateral opening in the same manner, and the tube
will gradually descend to the rock. It is often desirable, in drilling holes, to give
them a lift—that is, to drill them at an angle—and in this way it is simply necessary to raise the ejector-
pipe a short distance above the surface of the rock, to let it swing entirely out of the range of the blast.
A modified form of ejector-pipe is shown in Fig 338 J. This is a plain tube made of boiler-iron
attached at the bottom to common 4-in. pipe through a cross-fitting. The simplicity of this tube





ll Q .1\







BLASTING. - 139

commends it, and unless the conditions are very severe it serves the purpose admirably. The tube is
made to accOmmodate various depths by lengthening or shortening the pipe at the bottom. The cut-
tings from the drill-hole and the débris removed from over the rock are discharged through the open-
ings of the pipe-cross. The tube is made about 11 in. in diameter, in order to accommodate the chuck
of the drill, and where an extension-piece is used.
The extension~piece (Fig. 338 K) is designed and used in submarine work
where it is possible to drill a hole deeper than the feed of the machine with-
out changing the bit. By means of this extension-piece the starter used with
the drill is extended and continued until the hole is completed, otherwise it
would be necessary to lift the bit out of the hole, and every time the hole
is drilled a depth about equal to the length of the feed-screw of the rock-
drill. This extension-piece consists of a simple shaft of steel containing a
chuck at each end. These chucks are exact duplicates of the regular chuck
attached to the piston of the rock-drill. The length of the extension-piece
is a little less than the length of feed of the drill. After the extension-
piece has been used for one length of drilling, a piece of steel with a double
shank is used to continue the drilling without change of bit, or without
detaching the extension-piece.
Fig. 338 L illustrates an “ A ” frame used for mounting the drill in subma-
rine rock. This frame is made of oak timbers
securely bolted together, and serves as a false
platform for the tripod of the drill. By means
of iron lugs and projections the frame carrying
the drill is moved about the deck of the platform
of the scow by using a crowbar. When it is in
position it is held by dogs driven into the deck
of the platform and attached at one end to the
“A ” frame.
Rock-Drilling at Black Tom Reef, N. Y.—-The
following is a report of the removal of rock on Black Tom Reef, N. Y.
Harbor. In this work the several devices shown in Figs. 2, 3, 4, 5,
and 6 were used. Date of beginning of operations, May 2, 1881 ;
actual working days, 344; days lost in equipment of Barge No. 4, 26;
days lost through winter and storms, 35 ; lineal feet of hole drilled,
17,658; lineal feet of effective drilling, 16,567; number of holes drilled, 1,736; number of holes
charged, 1,629; number of holes blasted, 1,542; average depth of hole, 10.17 ft.; average distance
between holes, 4 ft.; area drilled over, 32,100 sq. ft.; rock removed, 5,136 cu. yds.; explosive used
(dynamite), 20,461-‘2- lbs.; number of exploders used, 1,844; number of drilling-machines used, 3 ; num-
ber of steels (ecta on 11} in. diameter), 18; longest steel used, 28 ft. ; shortest steel used, 16 ft. ; largest
diameter of bit, 3;, in. ; smallest diameter of bit, 2% in. ; greatest depth drilled without change of the
steels, 12 ft. ; average depth drilled to each dressing of steel, 9 ft. ; average loss of gauge per l-in. ft.
drilled, 0.03 in.; total loss of steel by abrasion and dressing 59%— ft., 394.48 lbs. ; greatest number of
lineal feet drilled in one day, November 14, 1881, 169 ft. ; expenditure for coal, 200.19 tons, $828.03 ;
expenditure for water, $500.55; expenditure for hose, $491.18; connecting wire used, 7 714- lbs., $52.08 ;
rubber tape for covering connections, 7 rolls, $12.25; expenditure of steel to each lineal foot drilled,
0.36 of an oz., 13036 ct.; explosive used in each lineal foot drilled, 1.16 lbs., 53 cts.; rock removed,
to each lineal foot drilled, 0.29 cu. yds. ; cost in labor to each lineal foot drilled, 52 cts. ; cost in coal
and water to each lineal foot drilled, 07:} cts.; cost in repairs to plant to each lineal foot drilled,
9 cts.; cost in repairs to drills to each lineal foot drilled, 150% ct.; cost in repairs to ejector-pipes
to each lineal foot drilled, 1% ct.; cost in hose to each lineal foot drilled, 2%,,- cts.; cost in wire and
tape to each lineal foot drilled, 131,- ct. ; average cost per lineal foot of hole drilled, $126-$056; expend-
iture of steel to each hole charged, 0.24 lbs., 333% cts. ; average explosive used to each hole charged,
12.56 lbs., $5.80; average rock removed to each hole charged, 3.15 cu. yds.; average exploders to each .
hole, $1.13 ; average cost of labor to each hole charged, $5.65; average coal and water to each hole
charged, 81 cts.; average repairs to plant (charged), 96775 cts.; average repairs to Ingersoll drills,
5,"o cts. ; average repairs to ejector-pipes, 16130- cts.; average repairs to hose to each charged, 30-,»16
cts.; average repairs to wire and tape, 3195 cts.; average cost per hole charges, 5513.82156; average
depth drilled to each hole, 3.44 lin. ft.; cubic yards of rock removed, efl'ective, 3.22 linear ft.;
average explosive to each cubic yard of rock removed, 3.98 lbs., $1.84; expenditure of steel per
cubic yard of rock removed, 1.22 oz., 1,5,, ct. ; cost in labor cubic yard of rock removed, $1.7 9; coal
and water, 25 cts.; repairs to plant, 301% cts.; repairs to drills, 11%; cts.; repairs to ejector-pipes,
51%; cts.; repairs to hose, cubic yard, 9,50- cts.; wire and tape, cubic yard, 113,—, ct.; cost per cubic
yard, $4.3713if’q.
Cost of plant, including alterations, additions, etc.: Barge No. 4, hull and equipment; $6,640; drill-
float N o. 1, $4,095.70; drill-float N o. 2, $4,987.40 ; store-room account, including repairs, alterations,
coal and water, cost of machinery, etc., $5,663.49 ; total, $21,386.50; expenditure in labor, $9,203.88 ;
expenditure in explosive, $9,461; total expenditure, $18,664.88; total cost, $40,051.47 ; cost per
cubic yard on total expenditure, 557.7 9.
Operating expenses: Labor, $9,203.88; explosives, $9,461; actual repairs to plant (breaks, loss,
etc), $1,575.57 ; repairs to Ingersoll drills, $93.31 ; steam and water hose, $91.18 ; repairs to ejector-
pipes, $267.54; wire and tape used, $64.33; coal and water, $1,323.53; operating expenses, $522,-
430.39; cost per cubic yard, $4.37 ; pay-roll per day, $26.76; coal, .058 tons, $2.39; water, $1.45 ;
explosive, 59.481bs., $27.50; actual repairs to plant per day, $4.58; repairs to drills per day, 27
338 x.


140 BLASTIN G.

cts.; loss of steel per day, 1.15 lbs., 16 cts.; repairs to ejector-pipes per day, 78 cts.; losses in
hose per day, $51.43; losses in wire per day, 15 cts. ; losses in tape per day, 3 cts.; average cost per
day, $65.50; average cubic yards rock per day, $14.93 ; average cost per cubic yards, $433.
The contract price for removing this rock by dredging was $1.95 per cubic yard. Many items in
this report, notably the cost of plant, are very much higher than they need be. The prices given in-
clude all the experimental work done prior to the introduction of the improved methods of operation.
This rock was situated in New York Bay, near Bedloc’s Island. It was of granite formation, varying
in texture from a soft, muddy pyrites to a hard mixture of hornblende and quartz. The surface was
covered by a deposit of mud, sand, and gravel, which at first interfered with the progress of the work
to such an extent that little headway was effected. After the use of the ejector-pipes no further
difficulty from that source was experienced.
‘ The In,(/e2~soll-Scrgeant Submarine Drilling-Scoun—Fig. 338 M illustrates the Ingersoll-Sergeant sub-
marine drilling-scow used on Hay Lake Channel, Mich., Detroit River, etc. A modified form of this
scow was used by the Gilbert Blasting and Dredging Company on the Gaulos Rapids, Canada, also by
Hingston 8t Woods, Buffalo, .1. Y., and the general design has been adopted and is now used for the
removal of the Iron Gates of the Danube, Austria.
While the elevated platform previously described is preferable for work in the surf, or where the
water is subject to violent disturbances, yet the self-contained scow and drilling-boat has given the
most economical results when used in comparatively smooth water, and where extensive drilling is
required. The Ingersoll-Sergeant drilling-boat as built and used by Messrs. Dunbar is 80 ft. long
and 27 ft. wide. It is specially constructed for this work, having a convex bottom of double plank-
ing, so as to stand the jar of blasting. The depth of hull is 6 ft., and the distance from the deck to
the bottom at the side is 5 ft. A house is built upon the barge 11 ft. high, in which are placed
the boilers, pumps, blacksmith’s shop, hoisting machinery, etc. Four spuds are attached through the
trunk-ways at each corner. These spuds not only serve to anchor the boat, but by means of hoist-
ing machinery a part of the boat is lifted and made to bear on the spuds; thus a condition of things
is produced very much like that of the platform, in that the boat is not subject to the action of the
tide or waves, but rests upon fixed legs upon the bottom.
Three or more frames are built upon the side of the scow. These frames are for the purpose of
carrying the drills and other appurtenances connected therewith. The frames move sidewise by
means of chains on deck pulled by hydraulic rams inside the house. The frames move in a rack
running longitudinally along the scow, and are guided above by a trestle attached to the roof of the
scow. This trestle simply serves as a guide, and prevents the frame getting out of position. The
frames have telescoping tops by means of which they are lengthened. A rock~drill of the largest size
made, 5-in. diameter of cylinder, is mounted upon a cross-pipe attached to the top part of each frame.
The drill has an adjustment equal to the width of the frame in one direction, and by loosening the
back bolt it may be swung around the pipe mounting to any point desired. The sliding top of the
frame carrying the rock-drill is raised or lowered by hydraulic rams worked by a man on the main
deck. This rain is little more than an upright tube having a piston-rod attached to the top of the
frame. Force-pumps maintain a pressure in the tube, so that the operator by simply moving a valve
may control the position of the drill. Steam is supplied to the drill by means of upright telescop-
ing pipes. No hose is used. At the bottom of each frame is a platform and guide for the drill-
rod. The drill-runner stands on a little platform fixed to the top of the frame-piece, so that the drill,
runner, and frame-piece move up and down by the hydraulic lifts.
Such a plant as this admits not only of rapid drilling, but of deep drilling without changing bits.
A depth of hole is made of 16 ft. without change; 3% ft. of this is made by feeding the cylinder of
the rock-drill or turning the feed-screw, and 12.) ft. by the lift of the frame. The frames cannot
run off, because of guard-chains on top to limit the lift. These chains may be adjusted so that the
limit may be fixed at any point in accordance with the depth of drilling. A hole is begun by insert-
ing in the top of the drill an iron tube 2 in. in diameter with a 25-in. octagon steel point. The bit
is usually a + or X-shape, and about 3k in. in diameter. It is obvious that this long bar reciprocat-
ing rapidly would “step” widely at the bottom and start a hole with difficulty, but for the guide at
the bottom of the frame. By means of this guide and the short stroke of the drill a hole is rapidly
started, and the entire frame with drills, etc., is lowered as the cutting progresses. Little or no div-
ing is done, as the holes are charged from the surface in a similar manner to that hereinbefore de-
scribed. A water-jet is used while drilling the hole—this jet being made of a pipe of small diameter
following the bit into the hole and thus discharging the cuttings as they are produced. Each hole.
as it is completed is charged before progressing with another hole. In some cases plugs are put in
the holes in the shape of iron tubes tapering at the bottom ; but owing to the liability to wash gravel
and other material into the hole, and the danger of losing the plug, it is best to insert the cartridge
as soon as the hole has been drilled. The depth of the hole is measured by the charger, which is a
long, graduated rod. If the hole should fill up with gravel or other foreign matter at the bottom, the
water-jet should be lowered until it is cleaned out thoroughly. The cartridge should be carefully
protected by having the dynamite inclosed in tin cases with corked and sealed top. The cartridges
are lowered into the holes by guide-rods or through tubes. A bucket of sand or gravel thrown into
the hole after charging will serve to keep the cartridge in position, and the wires can be secured to
the side of the bucket until ready for blasting.
At the Sioux Ste. Marie work, Mr. H. T. Dunbar averaged with this plant 540 holes a week, of 138
working hours, using 3 drills. Average depth of hole, 12 ft. The mere drilling of the hole does not
in this work take over 15 minutes, the loss of time being principally in moving the scow, bad holes,
etc. Sometimes the blasting is done without moving the scow, and owing to its special and substan-
tial construction no damage results; but in large blasts the scow is drawn away a few hundred feet by
means of anchors, and the blast is discharged by the battery worked from the boat.
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142 BLOCKS.

Submarine Excavations in Sand—Excavations have recently been made in Dutch waters for the
recovery of the treasure carried by the ship-of-war Lutine, which in 1799 foundered upon a sand-
bank, and soon sank, carrying down with her a large amount of gold and silver coin and bullion. A
novel system devised by Mr. W. H. Ter Meulen has been put in practice, which is based on the dis-
integration of the sand by injected waterjets. A new feature of the appa-
ratus is that it permits the diver to walk without danger in sandy soil down
to a very great depth. The so-called “sand extractor,” Fig. 338 N, consists
of a very strong hose 7 in. in diameter, from the lower extremity of which
is suspended a heavy cast-iron tube 5 ft. in length, with a copper rose,
through which the water, injected into the hose with a strong pressure, radi-
ates against the bed of sand. As soon as the extractor touches the bottom,
the sand is disintegrated and converted into ooze. A well is then formed
which becomes deeper in measure as the apparatus is lowered. The slower
the operation, the wider the well becomes. The apparatus having reached
the bottom, and the diver having revolved it several times, the lower part of
’ the well widens so as to form an excavation of from 10 to 12 ft. in diame~
ter. Although the diver works in entire darkness in this chamber, he is not
subjected to deception. Not only can he touch the bottom, but he can sound
it by means of a second and narrower hose connected with the other. Pro-
vided with this, he can inject water into the interstices of the vessel’s re-
mains, and open a passage therein. The figure represents the extractor at
the moment when the well has just been finished. The excavation is still
small, but it rapidly increases, and will soon become larger yet through the
disintegration of the upper walls of the vault Experience has demonstrated
that the blocks of sand that may detach themselves from these walls are
immediately disintegrated and converted into moving, liquid sand. The
arrows shown in the engraving, in the sand around the well, indicate that
the sand is not at rest. Under the pressure of the ascending water it con-
stantly sinks, and tends to compress the sides of the well that the water tends to enlarge. There is
thus set up a rotary motion, owing to which the layers at the bottom are brought to the surface,
and conversely. The trials made with this apparatus at Ymuiden have shown that the sides of sand,
under the injection of the water, behave like walls, and appear very hard to the touch.
Sarface-Blasting.—-The simplest kind of submarine rock excavation is that known as sur-
face-blasting. In the early history of the Hell Gate operations in New York harbor, surface-
blasting was resorted to with much success in knocking off the prominent and isolated projcc~
tions of rock. Surface-blasting has little or no effect upon large ledges of rock, and the method
is to be discouraged, because of the violence of the shock to surrounding objects. It is best, even
in breaking up boulders, to either get the explosive underneath the rock, or to confine it in a
drill-hole.
Since 1832 submarine rock excavation has been carried on at Hell Gate, New York harbor. It is
natural to suppose that during all this time improvements have been made in methods of submarine
rock-work It is a fact, however, that few, if any, improvements have been made on the Hell Gate
work. Major Frazer, of the United States Engineer Corps, began operations on Hell Gate according
to the methods suggested by Maillefort, and expended the first appropriation of $18,000 in knocking
off the jagged points of the rock by surface-blasts. When the smoother top of the ledge was reached
surface-blasts had no effect, and in order to make further progress it was necessary to drill the
rock for the insertion of explosives. The problem admitted of two methods of solution: First, drill
ing through the water into the rock; second, going under the rock-surface with a network of mines
and galleries, and breaking up the roof and its supports by a simultaneous explosion of the whole
mass. The first-named system was considered impracticable at that time, and it doubtless was. The
steam-drill had not been adapted to submarine work. The chain-drill involved the assistance of
divers, who could not work in the swift current of Hell Gate. Under favorable circumstances progress
with these clumsy appliances was slow, and the fleet of barges which must be employed over the rock
was in constant danger of collision with passing vessels. These were the main reasons which induced
General Newton to adopt the system of submarine mining. It is doubtful, in view of the improved
appliances which have been successfully introduced subsequent to the beginning of operations on
Hell Gate, if the undermining system will ever again be resorted to. We look upon the stupendous
operations of Hell Gate with wonder and admiration, but we can learn nothing, so far as the general
system is concerned, that will guide us in the future. The process employed at Hell Gate differs in
no important feature from all the general systems of mining and trenching employed throughout the
United States.
It is scarcely necessary to add, that mining at best is far more expensive than open-cut work, and
is only resorted to where open work, or the bench process, is impracticable.
The Diamond Drill has been employed for submarine work. In the removal of the ledge
known as Rockctt’s Reef, James River, Virginia, it was used to bore circular holes 2.} in. in
diameter at a distance of 25 ft. from the rock, at right angles to the current and in some instances
at an angle of 60 degrees to the perpendicular. The average progress of the bit was from 3 to 5
ft. per hour.
A full description of the various forms of rock-drills will be found under that heading, both in
vol. ii. and in vol. iii. (“Modern Mechanism ”) of this work. See also the articles on Quannvme
Macmmcs and EXPLOSIVES.
BLOCKS. A block consists of one or more pulleys, called sheaves, which are generally formed of
lignum-vitae or some hard wood, inserted between cheek-pieces forming what is called the shell
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BLOCKS. * > 143

of the block, and turning upon a pin passing through the shell and the centres of the sheaves. Blocks
are suspended by straps, either of rope or iron ; the latter are called iron-strapped blocks, and have
frequently a swivel-hook. A combination of two blocks, one of which is attached to the load to be
raised, is called a tackle, and the power is to be estimated by the space through which the fall (which
is that part of the rope to which the power is applied) passes, compared with the space through
which the load is raised, deducting for friction, which is great, owing to the rigidity of the ropes and
the small diameter of the sheaves; these, for nautical purposes, are necessarily limited by considera-
tions as to weight and space. The grooves in the body of the block are called scores. The hole in
the shell for the sheave pin or pintle is lined with bronze or gun-metal called a bushing. When the
shell is made of one piece it is called a mortise-block . when more than one are employed it is termed
a made block. The sides of the shell are checks. The groove in the sheave is termed the gorge.
It has a bushing called a coak around the pintle hole. The space between the sheave and its block
through which the rope runs is called the swallow, or channel. For strapping a block with rope in
the common way, the rope is cut 11} time the circumference of the block. In many cases blocks are
strapped with eyes or thimbles on the ends, or, instead of the loop, have a tail, as is the case with
Jigger-Bloclcs—or, as they are commonly termed, Tail-Blocks. Blocks receive names from peculiari-
ties of structure, from their materials, uses, mode of connection, etc. A block having a fixed position
is called a Standing-Block, while one which is attached to the weight and hoisted with it is called a
running-block. A Snatch-Block consists of a single sheave, with a. notch cut through one side of the
shell to allow the rope to be lifted in or out without inserting it end first. Fig. 339, A B, is a form
of block in common use for shipping in this country. Its construction is easily understood from
the figure. The block is double, Or with two sheaves, and the shell consists of three large pieces
with four pieces inserted between them at the top and bottom of the block. The whole is firmly
bound with an iron strap. Figs. 340, 341, represent the construction of sheaves, with iron bushings,
A
839.







the collars and rivets being counter-sunk. Fig. 342 is an elevation of a sheave showing an arrange-
ment of friction-pulleys or rolls, to admit of an easier motion.
Bee-Blocks are pieces of hard wood bolted to the sides of the bowsprit-head for reeving the fore-
top-mast stays through.
There is a species of blocks termed “ Dead-Eyes,” which are used for tightening or setting up, as
it is called, the standing rigging of ships. It consists merely of a circular block of wood, with a
groove on its circumference, round which the lower end of the shroud, or an iron strap, is fastened ;
three holes passing through the face (ranged in a triangle), to receive the laniard, or smaller rope,
which forms a species of tackle for tightening the shrouds. There are no sheaves in the dead-eye,
but the edges of the holes are rounded off to prevent cutting the laniard; but this very imperfect-
ly answers the purpose; as from the roughness of the grain of the wood, which is usually elm, and
from the stiffness of the rope, the laniard renders wit-h dilficulty; and from the great strain to
wlnch it isg subjected, it is frequently broken. A very simple and effectual improvement has been
made in this respect, by inserting a half-sheave of lignum-vitze into each of the holes, which causes
the laniard to render with greater facility, and the shroud to be set up in half the usual time.
A Double-Block has two sheaves, which are usually placed on the same pin, but rotate on separate
mortises inthe shell. A Euphroc is a long slat of wood perforated for the passage of the awning-
cprds, which suspend the edge of an awning. A Fiddle-Block has two sheaves in shells of difierent
sizes placed end to end.
Differential Pulley-Block—The upper block of the tackle has two sheaves, one a little smaller than
14.4 BLOWERS.

the other, fastened together; they are, in fact, one piece. The grooves are furnished with ridges,
which prevent the chain from slipping round them. The lower pulley consists of one sheave, which
is also furnished with a groove. To this pulley the
load is attached. The endless chain passes up from the
hand over the large part of the sheave in the upper
pulley, then down and under the lower pulley, then up
over the small part of the sheave, and thence forms a
bight to the hand. When the hand pulls the chain
downward the two grooves of the upper pulley begin to
turn together, so that the large portion winds up the
chain while the smaller portion is lowering. By pull-
'ing on the chain, proceeding from the smaller part of
the upper sheave, the chain is lowered by the large
groove faster than it is raised by the small one, and
the lower pulley descends. With the arrangement as .
shown in Fig. 34-3, a man is enabled to raise a weight
about six times greater than he could raise without
such assistance. With the Epicycloidal pulleyblock
two chains are used: one a slight, endless chain, to
which the power is applied; the other, a short chain,
which has a hook at each end, from either of which
the load may be suspended. Each of these chains
passes over a sheave in the block; these sheaves are
connected by mechanism so contrived that, when the
power causes the sheave over which the slight chain
passes to revolve, the sheave which carries the large
chain is also made to revolve, but very slowly. While the Differential
pulley-block has a mechanical efficiency of 6, the Epicycloidal block has
only a mechanical efficiency of 5.
A self-stopping pulley-block is illustrated in Fig. 344. The rope, after
being fastened to the bottom of the top pulley, is so passed round the
pulley that the end to which the power is applied passes immediately under
a brake-piece. To allow of the load being lowered, a cord is fastened to
the brake, the load is slightly lifted, the cord is pulled, thus relieving the
pulley-rope from the brake, when the load will descend of its own weight, care being taken not to
let go the pulley-rope.
BLOWERS. Machines especially adapted to the creation of an air-blast. They are also employed
for the converse purpose of exhausting air. Their application was at first mainly restricted to the
supplying of blasts for furnaces for working metals and for steam-boilers. At the present time, the
principal uses of the blower may be summarized as follows : To generate blasts for forges, and for
all kinds of furnaces for the smelting, melting, heating, and converting metals and ores, or for like
apparatus employed in the metal-working industries; to force the hot volatile products of combus-
tion into kilns for drying fertilizers, brick, etc. ; for blowing air heated by live or exhaust steam, or
other means, under beds of wet wool and cotton, into machines for drying wet cloth and hosiery,
or into receptacles for drying lumber or manufactured products, such as tubs, pails, etc., or tobacco,
grain, vegetables, gunpowder, glue, chemicals, or leather in tanneries; to remove shavings, sawdust,
etc., from wood-working machines; steam and vapor arising from paper-machines, and all drying
cylinders and dry rooms; sweat from milletones; offensive odors from fat-rendering and dyeing
establishments; dust from rag and cotton-pickers, flax and rope machinery ; light impurities aiising
from the cleansing of grain; dust from grinding-rooms. Blowers are also used as exhausters in
gas-works; to ventilate close, fetid places, as mines, wells, cisterns, holds of ships, etc.; to furnish
a current of warmed, cooled, moistened, 0r medicated air, to public buildings and apartments liable
to be closely occupied; to assist in evaporating fluids by removing the steam from the vicinity of
the boiling sirup, or other solutions; to raise fluids on the principle of the Giffard injector, as in
some of the ejectors used in oil-wells; to assist in the dispersion of liquids, as in atomizers; and
to afford a current of air to be cooled by passing over ice, or artificially-cooled surfaces, as in meat-
preserving chambers and in ice-machines; to furnish the suction or blast necessary to impel the
carriages or boxes in pneumatic railroads or dispatch-pipes.
The three chief types of apparatus for generating air-blasts are: 1. The blowing-engine, wherein
the blast is generated by pistons working in cylinders ; 2. The rotary-force blast-blower, which op-
erates also by the regular displacement of the air, measuring and forcing forward a definite quantity
at each revolution ; and 3. Fan-blowers wherein the current is produced by vanes revolving in a case
or box. For blowing-engines, see AIR-COMPRESSORS.
Rotary-Force Blcwt-Blowm's.—Root’s blower, a section of which is given in Fig. 345-, contains two
rotating pistons, the ’curved edges of which mutually enter suitably-formed indentations in the sides.
When the air enters the case at the induction opening, it is closed in by the pistons (or rather the
wings) of the same, and is thus absolutely confined and forced forward as the pistons rotate, until
brought to the eduction-pipe, where it is discharged. The system of construction and packing is
such that there can be no backward escape of the air after it enters the case, the pistons being at
all times in contact. Besides producing a positive force-blast, this machine operates effectively
at a speed of 100 to 200 revolutions per minute. At the Cincinnati Industrial Exposition of 1871,
the following tests were made of the Root blower, with the results noted: Diameter of pulley on
line-shaft, 36 inches; width of belt, 51}, inches; circumference of pulley, 9.425 feet; number of




BLOWERS.
145
1845..
f I
\w‘lz .._..///_
\- \‘1
x in A
\ \
a






square feet of belt traveling over main pulley by each revolution, 4.32. The tension of the belt
was regulated by cutting out one inch for every 10 feet of length, so that the belt had to stretch
1-120 of its length, after being laid over pulleys.






TRIAL DATA. First 'rea'. Second Test. Third Test. Fourth Test.
Number of revolutions of line shafl: per minute . . . . . . . . . . . . . . . . . . . . . . 200 200 152 9 100
Number of revolutions of blower per minute . . . . . . . . . . . . . . . . . . . . . . . . . 200 200 152 100
Diameter of nozzle in inches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5%,- 4 3,1,, 2
Area of nozzle in square inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 .63 12.566 . 7 .37 8.14
Pressure of air above atmosphere in pounds per square inch . . . . . . . . . . . {- 5- 1% 1%
Volume of air delivered per minute in cubic feet (reduced to atmos-
pheric pressure) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,155. 1,112. 8.84 465.
Volume of air delivered per revolution of blower in cubic feet (reduced
to atmospheric pressure) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.77 5 5.56 5.81 9 4. 65
Volume 'of air delivered per 100 square feet of belt traveling over
main pulley . . . . . . . . . . . . . . . . . . . . . . . . ._ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183. 129 . - ? 108.



The belt slipped when the opening was closed. The volume is calculated from the following formula:
A
VzOx—xfiOxM2Gx1,782P.
- 144
V, volume delivered per minute in cubic feet.
G, acceleration of gravity : 32.166.
0', coefficient
of contraction of nozzle used =O.8. A, area of nozzle in square inches. P, pressure in lbs. per
square inch.
1,782 : height of column of air of 1 square inch section weighing 1 lb.
The following table furnishes some interesting particulars as to the dimensions, work, dimension
of discharge-pipes, and other details respecting Root’s blowers :
Particulars of Root’s Rotary Blowers.







MELTING mon. §
m' g l“
E '1 g 'g a g 2: ,
3 g s i a a
a g g f .. a s 2 =3 ,1:
‘3 E! s E" 5 s» 2 l5 8. _ '5: 5?
n: ‘ '5 3 O 2 E a "3 3 °
h] s .. g s :3 'g ‘5 3; s a
m 3. Q Q ° I I: o I:
2 3 ° 2: 5. ° ° é a
D 'n a a. Q. 8 '5 - m
Z 5 o ,8 q {E Q
2 i" 4 >
In. In. In.
No. 2 A. 330 2} 24 to 30 2 1.650 14 5
No 2 400 3 24 “ 30 2 2,000 12 I 4
No.3 350 4*} 80 “ 36 4 3,000 14 . 5
No.4 825 8 86 “ 4S 6 4,550 16 6
N0. 5 320 12 48 “ 60 8 6,400 18 7
No. 6 810 16 . . . . . . . . 11 8,680 20 9











GENERAL DIMENSIONS.
.1. i
<5 '50
i? E
E EXTERNAL DmENSIONS. 3
E a
a - ,5
“a 3 5
g c:-
e 91
g - <:
5 Length. Breadth. Height.
Q
In. Ft. In. FL 111. Ft. In. Cwts..
8 3 10 3 0 2 6 Si-
3 4 S 3 0 2 6 9k.
10 5 S 3 0 2 S 12
12 6 S 4 0 3 4 18
14 7 10 4 0 3 6 23
18 8 0 5 0 4 0 3,0





Blowers should be set on good solid stone“ foundations, to which they should be held by proper.
Iron piping for the air-conducting
pipes should be provided, and these, with the shut-off valves and connections, should be perfectly tight. .
An escape-valve may be fixed upon the air-pipes, to relieve the blower from too great an increase of
pressure of air, caused by the closing of the shut-01f valves while thc'maehine is in operation.
bolts, and care should be taken to set them level lengthwise.
A section of Disston’s rotary blower-is given in
Fig. 346. Within the case are two. revolving bodies,.
~ 10
146 BLOWERS.
'—

working together as shown, and geared by a pair of equal wheels at one end of their shafts, to insure
conformity of motion. One of these bodies is a drum, turned on its outer circumference and at its
ends to fit its part of the casing snugly, and having the hypocycloidal cavities opposite each other.
The other revolving body, of a considerably larger diameter, is also of cast-iron, its central cylindri-
cal part fitting against the outside of the drum ; alternately, one of its blades works into the hypo-
cycloidal cavities of the drum, while the other works against its side of the casting. This body
might properly be called the piston, as it performs nearly all the work ; only a small part of the air
taken in by the cavities of the drum is forced into the delivery-passage when the blade of the piston
enters the cavity. The blades of the piston are cored out, as seen in the section, and these cores
have openings to the outside. When a blade begins to enter one of the cavities in the drum, its
core is filled with compressed air, which afterward, when connection with the supply space is cut off,
flows into the cavity of the drum, where the air, in consequence of the piston-blade passing out, is
expanded. Before the piston-blade leaves the cavity of the drum entirely, its core comes opposite
to openings in the heads of the casing, which allows either atmospheric air to enter, or any surplus
air to escape, thus putting all these spaces in equilibrium.
The Baker rotary blower is represented in Fig. 347. The external case of the blower is made of
cast-iron and bored out truly. The heads of the machine are also made of cast-iron and faced off,
and firmly secured by bolts to a cast-iron bed-plate. The case is bolted and doweled between the
two heads, which retains it in proper position. The drum
concentric with the case, as well as the two lower drums,
are each one solid casting, and are all turned and bal-
anced as true as possible. The two lower drums only act
as abutinents alternately; the opening in their sides is to
allow free passage of the vanes of the central drum.
The gearing on the exterior of the blower is for the pur-
pose only of retaining each drum in its proper position.
The semi-annular space above the central drum is the
chamber, from which the air is expelled by the vanes of
the central drum in its revolutions. This space, as may
be seen by the cut, is a section of a ring at all points of
equal radius and area; ,and, as the vanes of the central
drum continue to revolve at the same velocity, the air
expelled must be in a continuous stream. One advantage
in the internal movements of this blower is that each
part is in a true circle; therefore, if the gears should
wear, it will not affect the efficiency of the machine. At a test made of this machine by a com-
mittee of the Franklin Institute of Philadelphia, in 1875, the following results were obtained. Ex-
periments conducted as to forcing capacity and tightness by applying pressure-gauges to a machine
,of the capacity of 12 cubic feet per revolution and by indicator-diagrams from a Rider engine: 1.
Blower run for 5 hours at 150 revolutions per minute, equal to a displacement of 1,800 cubic feet per
minute. A diagram taken at the
beginning and end of the run, and
air-pressure observed at like times.
Found not to have varied. 2. Out-
lot of blowercontracted to 9 square
'inches, and a pressure of 2 lbs. was
shown in the manometer, with an
indicated horse-power of 12.88.
A repetition of this experiment
five minutes later showed H,- lb. on
manometer, with indicated horse-
power of 13.95. A third experi-
ment showed 11m?- lb. on manome-
ter, with indicated horse-power of
14. The discharge-orifice was then
closed, and the engine came to rest,
after showing 3 lbs. on the ma-
nometer and indicating horse-pow-
er of 17.45. A further test was
made by applying a sensitive press-


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.
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ure-gauge, and noting the fluctua- t/L'g'g/é
tion of pressure at different points J? /"
in the revolution of the machine.-
Its variations were found to be
greatest at low velocities, being
from 15 to 18 per cent. of the
pressure of the column of air dis- 5‘.‘
charged, the resistance on the driv- \\
in g-belt appearing to be nearly uni- \
form throughout the rotation of the
blower.
3. Fans—Sturtevant’s blower, Figs. 348, 349, has spoked wheels with conical annular disks mounted
on an axis driven by two belts to prevent tendency to wabbling. The air enters between the spokes

BLOWERS. 147

¢
.~.-
round the axis, and is driven forcibly by the curved floats which span the space between the disks,
being discharged into the peripheral chamber, whence it reaches the horizontal eduction-pipe, shown
in the lower part of the figure. An oil-collector in each pulley gathers superfluous oil, and conducts
the same to oil-chambers at the extremity of the shaft. Two machines of this description, used as
exhaust-fans, and capable of removing 1,800,000 cubic feet of foul air per hour, are used for ven-
tilating the Senate chamber and House of Representatives in Washington.







In the Mackenzie blower, Fig. 350, the fans are supported by a shaft, and caused to revolve by
the revolutions of a cylinder contained in the shell. The fans are three in number, as will be seen
by reference to the cross-section, loosely jointed to the shaft, and so arranged as to adapt themselves
to a continuous alteration of the angle as they pass through the cylinder. The cylinder is hollow,
and contains within it the fan-shaft. When the cylinder is in motion, the fans are caused gradually
to project and gradually to recede beyond and beneath the line of its circumference, so as to con-
form accurately to the contour of the receptacle between the cylinder and the outer shell. The air
is drawn in at the upper extremity in the direction of the arrow in the cut, and ejaculated from the
lower extremity, as indicated by the outward-shooting arrow.
The following conclusions were reached after experiment by Mr. W. Buckle: “Having given the
velocity of the air and the diameter of the fan, to ascertain the centrifugal force:
“ Rule—Divide the velocity by 4.01, and again divide the square of the quotient by the diameter
of the fan’. This last quotient multiplied by the weight of a cubic foot of air, at 60° Fahr., is equal
to the force in ounces per square feet, which, divided by 144, is equal to the density of air per square
inch.
“Or, substituting the following formula, we have 1) z: N x .000034. Where D is the density of
the air in ounces per square inch, and N the number of revolutions of fan per minute, and I" the
velocity of the tips of the fan in feet per second.
“Having given the density in inches of mercury (1 inch of which is equal to 8 oz. pressure), to
find the velocity which a body would acquire in falling the height of a column of air equivalent to
that density: .
“Rulc.--.\Iultiply the density in inches of mercury by 930.3, and this product by 64. The square
root of the last product will be the velocity in feet per second. Or, more simply—-
“Multiply the square root of the density in inches of mercury by 244, and the product will be the
velocity.
“It will be seen by the table that the velocity of the tins of the fan is practically somewhat less
than this theoretical velocity, and from the experiments it further appears that the velocity of the
tips of the fan is equal to nine-tenths of the velocity a body would acquire in falling the height of a
homogeneous column of air equivalent to the density.
“Experiments were made as to the proper size of the inlet openings, and on the proper proportions
to be given to the vane. The inlet openings in the sides of the fan-chest were contracted from 171},
the original diameter, to 12 and 6 inches diameter, when the following results were obtained :
“First, that the power expended with the opening contracted to 12 inches diameter was as 21} to 1
compared with the opening of 171} inches diameter; the velocity of the fan being nearly the same, as
also the quantity and density of air delivered.
“ Second, that the power expended with the opening contracted to 6 inches diameter was as 2% to 1
compared with the opening of 171;~ inches diameter; the velocity of the fan being nearly the same,
and also the area of the etiiux pipe, but the density of the air decreased one-fourth.
“ These experiments show that the inlet openings must be made of sufficient size, that the air may
have a free and uninterrupted action in its passage to the blades of the fan, for if we impede this
action we do so at the expense of power.
“ With a vane 14 inches long, the tips of which revolve at the rate of 236.8 feet per second, air is
condensed to 9.4 ounces per square inch above the pressure of the atmosphere, with a power of 9.6
14s ' BLOWERS.
r—
horses; but a vane 8 inches long, the diameter at the tips being the same, and having, therefore, the
same velocity, condenses air to 6 ounces per square inch only, and takes 12 horse-power.
“Thus, the density of the latter is little better than six-tenths of the former, while the power ab-
sorbed is nearly 1.25 to 1. Although the velocity of the tips of the vanes is the same in each case,
the velocities of the heels of the respective blades are very different; for, while the tips of the blades
in each case move at the rate of 236.8 feet per second, the heels of the l4-inch blades move at the
rate of 90.8 feet per second; and the heels of the 8_inch move at the rate of 151.7 5 feet per second;
or, the velocity, of the heels of the 14-inch moves in the ratio of 1 to 1.67, compared with the heel of
the 8-inch blade. The longer blade, approaching nearer the centre, strikes the air with less velocity,
and allows it to enter on the blade with greater freedom, and with considerable less force than the
shorter one. The inference is, that the short blade must take more power at the same time that it
accumulates a less quantity of the air.
“These experiments lead me to conclude that the length of the vane demands as great a considera-
tion as the proper diameter of the inlet opening. If there were no other object in view, it would be
useless to make the vanes of the fan of a greater width than the inlet opening can freely supply.
0n the proportion of the length and width of the vane, and the diameter of the inlet opening, rest
the three most important points, viz., quantity, and density of air, and expenditure of power.
“In the 14-inch blade the tip has a velocity 2.6 times greater than the heel ; or, by the laws of cen-
trifugal force, the'air will have a density 2.6 times greater at the tip of the blade than that at the
heel. The air cannot enter on the heel with a density higher than that of the atmosphere; but in its
passage along the vanes, it becomes compressed in proportion to its centrifugal force. The greater
the length of vane, the greater will be the difference of the centrifugal force between the heel and
the tip of the blade; consequently, the greater the density of the air. ‘
“Reasoning, then, from these experiments, I recommend, for easy reference, the following propor-
tions for the construction of the fan:
“Let the width of the vanes be one-fourth of the diameter.
-“ Let the diameter of the inlet openings in the sides of the fan-chest be one-half the diameter of
the fan.
“ And let the length of the vanes be one-fourth of the diameter of the fan. '
“In adopting this mode of construction, the area of the inlet openings in the sides of the fan-chest
will be the same as the circumference of the heel of the blade, multiplied by its width; or the same
area as the space described by the heel of the blade.
“ The following table gives the sizes of fans varying from 3 to 6 feet diameter:
TABLE OF BEST PROPORTIONS OF FANS.
Diameter of Fan. Width of Vane Length of Vane. Diameter of inlet opening.
1‘! in. it in ft. in ft. in
3 U ................ .. O 9 ................ .. 0 9 ...................... .. 1 6
3 6 ................ .. 0 101; ................ .. O 1011; ...................... .. 1 9
4 0 ................ .. 1 . . . . . . . . . . . . . . . .. 1 (l ...................... .. 2 O
4 6 ................ .. l 1% ................ .. 1 1% . . . . . . . . . . . . . . . . . . . . . .. 2 3
5 O ................ .. 1 3 ................ .. 1 3 ...................... .. 2 6
b O ................ .. 1 6 ................ .. l 6 .................... .. 3 O
“I recommend the proportions in the above table for density ranging from 3 to 6 oz. per square
inch; and for higher densities, viz., from 6 to 9, or more oz., the sizes given in the following table:
Diameter of Fan. Width of Vane. Length of Vane. Diameter of inlet opening.
ft in. it. in. it. in. ft. in.
3 (l ................ .. 0 7 ................ .. 1 0 ...................... .. 1 0
3 6 ................ .. 0 8+ ................ .. 1 11} ...................... .. 1 3
4 O ................ .. O 9 ................ .. 1 31} ...................... .. 1 6
4 6 ................ .. 0 104; ................ .. 1 41} ...................... .. 1 9
5 O ................ .. l 0 ................ .. 1 6 ......... .......... .. 2 O
6 0 ................ .. 1 2 ................ .. 1 10 . . . . . . . . .......... .. 2 4
“The dimensions of the above tables are not laid down as prescribed limits, but as approximations
obtained from the best results in practice.
“ Experimentswere also made with reference to the admission of air into the transit or outlet pipe.
By a slide the width of the opening into this pipe was varied from 12 to 4' inches. The object of
this was to proportion the opening to the quantity of air required, and thereby to lessen the power
necessary to drive the fan. It was found that the less this opening is made, provided we produce
sufficient blast, the less noise will proceed from the fan; and by making the tops of this opening
level with the tips of the vane, the column of air has little or no reaction on the vanes. '
“As to the pressure of the blast commonly required in smithies, the range is from 4 to 5 oz. per
square inch. And an ordinary eecentrically placed fan, 4 feet diameter—the blades 10 inches wide
and 14 inches long, and making 870 revolutions per minute—will supply air at a density of 4 oz. per
square inch to 40 tuyeres, each being 151-inch diameter, without any falling off in density.”
The following table" gives particulars of some experiments made with a large fan used to blow the
cupolas, etc., at the London Works, Birmingham, England. Although in the early experiments only
36 to 50 per cent. of useful effect was reached, eventually as much as 75.16 was obtained. No

3" From “A Practical Treatise on Casting and Founding,” by E. Spretson (London, 1818).
BLOWERS. 149

allowance was made for obstruction in the fire, but the area of the tuyeres was taken, having taper
pipes leading to them, and the velocity of the air, multiplied by the pressure, was taken to represent
useful effect in horse-power.
Results of Experiments with Common Fans.











' I . 5 .I I . o ‘ . I In." ' c ""
1527?. 3. 3-58 7.".853 33 5* 15 . ‘2 £2 a
s1 2:15 sists 63‘ . t» a is >36 3
NO.ANDSIZEOF 52 g; 3351 40.: 2;; 55 a: £2 5; goé E53; 3,;
BLADES- '22 2% a"- 1852 use: es. s as g 3'55 21;?“ is
2% 11° 25% 2255.2 52 3 3 a 25 13°52 é
é?!) a > H'Blfq m Q5511 <2 g a; $3 a:
61318668, with (3011- 25 7125 12312 1135s 84 5 6 128 128 64.31 267 37.6 13.6 36.1
treplate,16x8 .. . . . . . . . . ..é 453 6} .. 19 824 24.5 é,.éé figs 22.; 2%."
20 514.28 we 177 4 5 51 2 14 1. 1 ' . . .
4Blm°811°xmd 221572.57 99212 5 .. 48.4 25.66 22.78 9.63 42.26
431m,“ ,6 8 25 712.5 12812 9678 6 5 6 128 354 03.5 22.7 34.8 23.37 67.1
' X .. . . . . . . . . . .. 10938 8} .. 123 51.6 22.9 12.23 56.4
.. .... .. 11192 10235 -7 5 0 219 220 51.2 26 25.26 17.22 68.0
4Blades,18}x12.% .. .... .. . 1092s 8 157 47.5 27.5 1500;701
.. .... .. was 64 354 55.3 221 32.53 24.7284
.. .... .. 10500 71 5 0 1825182 51. 276 . 15.2 .0
4BM°sJsixwd .. .... .. 9474 6 854 28.2 150.7 21.99 85.6
.. .... .. 10235 7 192 194 1.2 27.23 4. 15.18 .5
4B‘ad6‘3116x12-‘i .. .... .. 9377 54 . 354 561 28.7; ggm 74.}$8
1 .. .... .. 10235 7 204 204 51. 277 23.2 .97 as.
4Blad°8117X12~i .. .... .. 9474 6 194 57. 29.1 age 3.3
1 .. .... .. 10140 6§ 176 180 50. 28.34 24.5 1. .7 '. ,
4Bladesilfixn'a .. .... .. 9173 at 354 54.7 26 41 19.97 75.16,









A considerable difference in the amount of useful effect was sometimes produced by the same
power; but this arose either from a difference in the area of opening or in the pressure. When the
pressure was great, the result was generally affected, it being easier to get a moderate pressure with
a fan than a high one. A 7-inch column of water is considered ample for cupolas. In all cases
indicator figures were taken in order to arrive at the power employed, and figures were also taken
separately without the fan, in order to get at the friction of the engine and shafting. The fan-case
was an arithmetical spiral, so that the blades delivered the air regularly. The following rules were
deduced from the experiments :
That the fan-case should be an arithmetical spiral to the extent of the depth of the blade at least.
The diameter of the tips of the blades should be about double the diameter of the hole in the
centre; the width to be about two-thirds of the radius of the tips of the blades. The velocity of the
tips of the blades should be rather more than the velocity due to the air at the pressure required, say
one-eighth more velocity.
In some cases, two fans mounted on one shaft would be more useful than one wide one, as in
such an arrangement twice the area of inlet opening is obtained as compared with a single wide fan.
Such an arrangement may be adopted where occasionally half the full quantity of air is required, as
one of them may be put out of gear, thus saving power.
Fans are less expensive in first cost and repairs, for a given duty, than blowing-engines; but when
high pressures are required, they take somewhat more power to drive them. In other words, the
fan is not an economical machine, in the sense of useful effect for a certain power; and its useful
effect or “duty ” decreases rapidly as the speed is increased for the purpose of increasing the pres-
sure of blast. The power for driving a fan or fans is generally best given by a small high-pressure
engine, communicated by a belt.
The engine should run at a quick speed, and be provided with a tolerably heavy fly-wheel, to pre-
vent its running away in case of any accident to the driving-belt or fun. In order to get an increase
of speed from the engine, the flywheel may be driven by a sun-and-planet motion instead of a crank;
this will give two revolutions of the fly-wheel shaft for each double stroke of the piston, and then,
with a large pulley on the fly-wheel shaft, and a small one on the fan-axle, a high speed can be ob-
tained. But for many reasons it is unadvisable to use the sun-and-planet motion, if it can possibly
be avoided. If a'large volume of blast is required at a moderate speed, this can best be obtained
by employing a fan of large diameter, driven at a moderate speed; but where a high pressure or
great velocity of blast is desired, it is necessary to drive the fan rapidly. '
It is not advisable to construct a fan larger than 8 feet in diameter, and for most ordinary pur-
poses one of about 5 feet diameter across the vanes is to be preferred.
A silent fan can only be obtained by having vanes which do not fill the casing, having the vanes
pla‘ced eccentrically in the casing, and forming the casing in a true spiral.
Provide ample apertures for the entrance and exit of the air, avoid sharp turns or projections in
the casings, and, in designing and fitting up the fan, all the moving parts must be securely fixed in
position, so that they will be able to withstand the great centrifugal force brought on them when
driven at a high speed, as, if any part becomes detached during working, great damage and probable
loss of life would ensue.
Fans, especially when large and driven at a high speed, should be walled in all round, and every
precaution adopted to avoid loss of life, in case of any accident occurring to the fan while it is in
motion. The castings for fans should be made massive, as tending to reduce the vibration felt when
fans are worked at a high speed.
In fan-machinery, simple as it is, it_has been found that monthly and even weekly repairs have
been incurred, in consequence of the want of exact balance among the parts of the fan upon its
150 _ BLOWERS.

_____._.
axle. With careful management in the first construction, this source of annoyance may be entirely
removed. Another great fault consists of injudicious methods of “ bringing up the speed ” with too
great rapidity, with a view to which it was certainly necessary to make use of as few intermediate
shafts as possible, which of course requires that large pulleys shall drive proportionally smaller
pulleys than if the rate of the reduction of speed were more moderate. On the other hand, the
experience of many founders proves that by moderately attaining the speed by the use of a greater
number of intermediate belt-pulleys, repairs of any importance are not incurred for months and
even years. . The. great evil of too rapidly raising the speed is the liability of the belt to slip upon
the drums; for when slipping occurs, especially among the slower parts of the motion, the belt is
subjected to sudden and violent strains, caused by its unequal hold upon the rim of the drum. The
usual remedy for this state of things is to apply resin and pitch to the acting surface of the belt to
give it a hold. But the best plan is to employ spur-gear in the slower parts of the motion, and
broad belts and pulleys of conveniently large diameters for the rest.
The following notes on the construction of fans will be found of practical utility:
Good Proportions—Inlet : 1 diameter of fan. Blades : ,1» diameter of fan each way. ‘ Outlet :
area of blades Dd
density of blast, oz. per sq. in.l 8'

area of blades. The area of tuyeres is best when about:
it should not exceed twice this area.
The velocity of the circumference for difierent densities of blast is as follows, in feet per second
and ounces per inch: 170, 3; 180, 4; 195, 5; 205, 6; 215, 7. A proper speed for cupolas is 250
to 300 feet per second.
To find the Horse-power required for a Fan—D = density of blast in ounces per inch. A': area
of discharge at tuyeres in square inches. V : velocity of circumference in feet per second.
2
><D><A

1000
963
To find the Density to be obtained with a given Fan—d : diameter of fan in feet.
V 2
(1)
—--—-— = density of blast in ounces per inch.
120 X (l '
: horse-power required.
Table showing Density of Blast.



Velocity Density of
of Circumference. Area of Nozzles. Blast.
Feet per Second. Oz. per Inch.
150 Twice area of blades 1
is (In 56 2
‘6 % 3
170 ;l “ 4
200 i; “ 4
$5 Tlf \6 6
220 4 6




Table showing the quantity of Air, of a given Density, delivered by a Fan. Total area nozzles in
square feet x velocity in feet per minute, corresponding to density (see table) : air delivered in cubic
feet per minute.












Density Velocity Denaity' Velocity. Demity' Velocity Densuy' Velocity
Oz. er . ' Oz. er . Lbs. per .° Lbs. per . '
Squarelincb. Feet per Minute. Squurepmch Feet per Minute. Square Inch. Feet per Minute. Square Inch. Feet per Minute.
1 5,000 7 13,200 1 20,000 6 49,000
2 7,000 8 14,150 11} 24,500 8 56,600
8 8.600 9 1'3 000 2 28,300 10 68 2’10
4 10,000 10 15.800 21 81,600 . 12 69,280
5 11,000 11 16,500 3 34,640 15 7 8.000
6 12,250 1 2 17,300 4 40,000 20 59,400


Competitive T eats—The pressure-blower has an advantage over the fan in its delivery of a posi-
tive or force blast measuring accurately the amount of air delivered per revolution. The blast does
not depend, as in the fan, upon centrifugal action, nor upon the specific gravity of the air, to give
a definite displacement. When the proper amount of air is supplied the combustion in a cupola fur-
nace is perfect, and the highest rate of melting attained ; but as the carbon converts the oxygen of
the air into carbonic acid on its entrance at the tuyeres, so this compound is rapidly reconverted
into carbonic oxide as it ascends through the charge. In order to secure the highest temperature
and efficiency, enough of this oxygen must be continuously injected to prevent the formation of car-
bonic oxide, and this can only be done by a machine which delivers positively under all conditions of
the furnace a fixed quantity. In conducting competitive tests between pressure-blowers and fans, the
following formula: and arrangements have been employed: Both blowers were placed so that they
could be driven from one and the same shaft, to which the dynamometer was applied. The number
of revolutions of the dynamometer-shaft was counted by an apparatus expressly built for the pur-
pose. Each blower was provided with dovetail guides, to which four different slides were fitted, air-
BLOWERs. ' 151‘

~ tight. These slides, containing the discharge-openings of 6, 41}, 31}, and 2% inches diameter, respec-
tively, were made of 1-inch thickness, and fitted to each blower. The pressure of the air was meas-
ured by a water-column, attached in such a manner and at such a place as to be affected properly by
the pressure. The motive power was supplied by an oversbot water-wheel, the gate of which could
' be moved at a place in the experimenting-room, where the pressure-gauge could be observed.
The manner in which the tests were made was the following: After the slide with the discharge- '
opening was attached, the speed was regulated so that the water-gauge indicated the pressure re-
quired. While the water-column was carefully kept at the same height, the indications of the dyna-
mometer were read ofl.’ and noted. Experiments of this kind were made with each blower, and
conducted with openings ranging from 6 to 24; inches, and correspondingpressures from 4 to 16
ounces. It is evident that, through the same opening and at the same pressure, an equal volume of
air would be discharged by either the blower or the fan. It is also evident that the horse-power
indicated by the dynamometer, under the above conditions, would demonstrate the relative power
required by each blower to produce a given result, and show the comparative efficiency of each machine.
The volume of air discharged per minute was calculated from the formula:
A A - _
V: c. —601/ 2972. V: c. -— 60 64.32 x 1,7821). V: 140 c. A. Mp.
144 ' 144
In which V, the volume of air discharged per minute in cubic feet, reduced to atmospheric press-
ure 29.9 barometer, and a temperature near freezing-point. A, the area of discharge-opening in
squareinches. g, acceleration of gravity : 32.16. h, height of column of air of one square inch in
section, and of a temperature near freezing-point, weighing p—pounds—in feet. 1), pressure of air
in pounds per square inch. 0, coefficient of efHux, depending on the shape of the discharge-opening,
and due to contraction and friction. This coefficient was estimated by interpolation of the values
given by Prof. F. \Vcisbach. c. : 0.6.
The useful effect, or the work done, was assumed to consist in giving the velocity 1/ 2 g h to the
air discharged, and was calculated from the formulae, viz. :

1 144 1
Useful effect in horse-power: H: c. p. A—M 2 g 12 : p V : p V.
550 33,000 229%,-
Example : Test No. 1 : Pressure of air in pounds : 11,; : 5,- : p. V? = 1f; = t3. Area of dis-
charge-opening in square inches : 28.274 : A. c. : 0.6. Volume of air discharged per minute
in CUblG feet : V: 140 c. A V? : 140 x .6 x 28.274 x 1; : 1,186 cubic feet. Useful effect in
23 : ilhlifi : 1 2
229% ""229g
VARIOUS Foams or BLowERs.--Fig. 351 represents a steam-blower devised by E. Korting. It con-
sists, its principal parts, of an air-accumulator formed of a cast-iron tube opening below into a reser-


horse-power: H:
352.
Q.
Ma
1





_ .._.__~.__~_.._.--
;



\
A ’/ 'f
\






C : _ I". " ' M . :_____—__.___..__.—--_- _‘_'H
W, .\\\\ \\\ '
E
voir, which (serves at the same time as a base-plate. At its upper extremity the accumulator sup_
ports a dome, into which is fitted the blast-pipe b, the nozzle of which is adapted to the opening into




152 , BOILERS, STEAM.

the smithy fire. Immediately below this dome the steam-pipe traverses the accumulator with an exit
at the opposite end, as shown. At this end is the aspirator, forme of three cones, which admit air
in their interspaces, while the steam-jet is driven through the centre. The steam-loaded air passes
through a conical eduction-pipe into the reservoir, which serves as a base-plate, where the water of
condensation is parted with, and the heated current of air passes into the accumulator under a
tension corresponding'to the dimensions of the aspirator multiplied by the pressure of steam. From
the accumulator the blast passes through the nose-pipe at b to the smithy fire. In this manner a
blast is obtained, easily kept at any pressure, within certain limits, and at a temperature which very
nearly reaches that of the steam used. In the engraving, a is the steam inlet; 6, the blast-pipe
opening from the accumulator; e and d, outlets for water of condensation.
For other blowing-apparatus, see AIR-COMPRESSORS.
A simple form of blower is the Trompe, or Water-Blast, of which Fig. 352 shows the principle.
In this, a vertical tube of wood or iron, cylindrical or prismatic, of length and diameter suited to
the fall and quantity of water intended to be used, connects with a cistern below, made air-tight
except for the opening 25, to connect with the tuyere: Through this tube a stream of water is allowed
to fall, drawing in the air as it descends through openings that are indicated by broken lines in the
sides of the column, and breaking upon an altar below. The air thus carried into the cistern has no
means of escape except the tuyere t, and its quantity and pressure delivered through that depends
upon the absolute size of the column of water, and the proportions of the various parts. Venturi
has already satisfactorily investigated the relations of this machine, whichwill not be dwelt on in
that aspect further here than to say that, although very cheap and convenient in its construction, it
uses more water for, a given effect than a water-wheel would do, and that its? efieetiveness is quite
limited. . Karsten refuses to admit that the dampness of the blast it affords injures the quality of
the iron; although it is probable that most metallurgists would conclude, in the face of general
theory and experience, that the good quality of iion made by this method exists in spite of it.
The Oscillating Cylinders of D’Aubuisson are cheap to construct, and worked with little power
and at small “expense. Although not giving a blast of sufficient amount
of density for the smallest high-furnace, except with the most fusible
materials, they answer very well for chafery and finery fires. Fig. 353,
which is a section of one of the cylinders, will afford an illustration of
their action. A diaphragm, central, through the entire length and nearly
the whole diameter, is shown at ed; as are two valves, alternately as-
piring and expiring. In its normal position c cl is vertical; the barrel is
filled half full of water, through a bung, and is then set in oscillation,
through an arc of 90 or 100 degrees, by a connecting-rod and crank
geared on near 0. It is manifest that in different angular positions of
the diaphragm the content of water in the two semi-cylinders will come
to be unequal, as shown by the shaded lines; and the air will be respec-
tively rarefied and condensed accordingly.
BOILERS, STEAM. The steam-boiler is a close vessel used for the generation of steam from water.
It has a furnace for the combustion of fuel—either inclosed within the boiler, as, for instance, in
locomotive and the majority of marine boilers ; external, as in the case of land-boilers set in brick-
work ; or detached, the latter form of furnace being often used for the combustion of tan-bark, saw-
dust, and similar substances. Boilers are constructed of cast and wrought iron, steel, and copper.
\Vhere wrought-iron, steel, or copper sheets are used in the construction, they are ordinarily fastened
together with rivets, and the joints are made tight by calking; but in some instances the sheets ale
welded together, this last mode of construction having been recently introduced. Boilers may be
either plain cyiinders, or they may contain flues or tubes, so as to bring the water into more intimate
connection with the flames and heated gases issuing from the furnace. Until a recent period, nearly
all boilers, whatever their internal arrangement, contained inclosing-shells, as an essential part of
their construction. Of late years, however, what are known as sectional or water-tube boilers have
been introduced to a considerable extent. In this class of boiler, there are a number of connected
sections, each of which is quite small, and the inclosing-shell is not used. Hence the several parts
can be made light as well as strong; and it is claimed by some that an explosion of a single section
of such a boiler would be less disastrous than the explosion of a shell-boiler.
It is not possible, in the limits of the present article, to give a complete treatise on this important
subject, but the reader will find numerous references that will be of assistance in a more extended
research.
Combustion and Fuel—Combustion, in the popular acceptation, is the union of carbon or hydro-
gen with oxygen, accompanied by light and heat. Though this definition is far from being scien-
tifically exact, the word can be used in this sense without impropriety, in treating of the combustion of
fuel. Some forms of fuel, it is true, contain sulphur, which also unites with oxygen during combus-
tion, but the proportion of this latter element is usually quite small, and its heating effect can be
neglected without serious error. The sulphur in coal is, however, occasionally injurious to the fire-
box of a boiler. The chief constituents of fuel are carbon, hydrogen, oxygen, compounds of these
elements, and earthy matter. The principal varieties of fuel are wood, peat, coal (which may be
divided into lignite, bituminous, and anthracite), mineral oil, natural gas, sawdust, spent tan, straw,
and other refuse. There is generally some special arrangement of the furnace and proportions of
boiler that are best adapted for each form of fuel, as is explained more fully in another partof this
article.
The reader who desires to thoroughly investigate the qualities of the chief varieties of fuel will
find a valuable collection of data in Dr. Percy’s “Treatise on Metallurgy.” The remarks in the
present article must necessarily be confined principally to coal, the fuel in common use.


BOILERS, STEAM. 153

Mineral oil, when burned under proper conditions, is one of the most efficient forms of fuel, in
some cases about nine-tenths of its 'full calorific effect being utilized. An ordinary furnace can be
readily adapted to its use. An improved process for burning liquid fuel is described in the Engineer-
ing and Mining Journal, August 7, 1875.
In localities where natural gas is obtained, this is frequently burned in the furnaces of boilers.
Feats—Peat is used in this country as fuel to a very limited extent. In Europe its applications
have been numerous, and a large amount of capital is invested in plant for its preparation, which
consists, generally, in drying and compressing it. Considerable information in regard to the prepa-
ration and qualities of this form of fuel is to be found in “ Peat and its Uses,” by S. W. Johnson;
“Report on the Utilization of Peat and Peat Lands,” by F. A. Paget (in the “‘ British Reports on the
Vienna Exhibition,” and The Engineer, xxxix., xl.) ; in the “Proceedings of the Institution of Civil
Engineers,” xxxviii.; in the “ Proceedings of the Institution of Mechanical Engineers,” August, 1865,
and the “ Transactions of the Society of Engineers,” 1864.
Ooal.-The fuel most commonly employed in this country is coal, and some little space will be
devoted to a consideration of the phenomena of its combustion. If a mass of coal is brought to a
sufficiently high temperature (probably 1,000° Fahr.), the combustible materials enter into combina-
tion. First, the water is expelled; then the hydrogen in the volatile combustible matter unites with
oxygen, forming water; and the carbon set free unites with oxygen, forming carbonic acid if the
temperature is sufficiently high and enough oxygen is present, or, under less favorable circumstances,
forming carbonic oxide, or passing off unconsumed, as the coloring matter of black smoke, and being
deposited as soot. The combustion of the fixed carbon next begins, and usually takes place as follows:
The first combination of the carbon with oxygen produces carbonic acid, which, in passing through the
bed of coal in the furnace, frequently takes up more carbon, and is converted into carbonic oxide.
If it is allowed to pass away in this state, there is a considerable loss of heat, as carbonic oxide is a
combustible gas. By furnishing additional oxygen, however, this carbonic oxide will be burned, or
converted into carbonic acid, in the furnace, and thus the full effect of the combustion will be real-
ized. In order to effect this, it is necessary to admit more air into the furnace than is theoretically
necessary for combustion, and, generally, admission of air above the fire through holes in the furnace
door is found to be beneficial, and a combustion-chamber beyond the furnace is frequently added. In
the practical working of boiler-furnaces, only a small portion of the carbon passes oi‘f unconsumcd. Very
complete experimental investigations on the combustion of coal have been made by Messrs. Scheurer-
Kestner and Meunicr-Dollfus, and the results were published in the “ Bulletin de la Société Industrielle
de Mulhouse,” 1868, 1869. Many of the following statements are taken from their reports. The heat—
ing power of fuel is ordinarily measured by the number of thermal units given out by its combustion,
or the number of units of evaporation. A thermal unit is the amount of heat required to raise the
temperature of a pound of water from 39° to 40° F ahr., and a unit of evaporation is 966.6 thermal
units, being the amount of heat required to change a pound of water at 212° into steam of atmos-
pheric pressure. A unit of evaporation is commonly called the equivalent evaporation from and at
212°, and is expressed in pounds. The advantage of having a unit of this kind will be obvious from
the following consideration: In experiments with different kinds of fuel and forms of boiler, the
pressure under which evaporation takes place, and the temperature of the fuel, likewise vary; and,
in order to compare the various experiments, it is necessary to change the results to equivalent re-
sults for the same temperature and pressure. There is no universal standard of temperature and
pressure adopted for purposes of comparison, but the equivalent evaporation from and at 212° is
most generally accepted by engineers. The table on page 157 is designed to facilitate the reduction
to this standard.
A table of this kind may be constructed by finding (either by calculation or from a steam table)
the total amount of heat required to evaporate a pound of water at various pressures, and from
various temperatures of feed, the amount for any particular case being:
i heat required to raise the temperature of the feed-water from 32°
‘ to the given temperature.
And then dividing the quantities so obtained by the latent heat of a pound of steam at the tempera-
ture of boiling water, and at atmospheric pressure, as given in the article Exrxxsrox or STEAM.
To illustrate the use of this table, suppose it is determined, by experiment, that the evaporation
of a certain boiler is 8.25 lbs. of water per pound of coal; the absolute pressure of evaporation being
65 lbs. per square inch, and the temperature of the feed 90°, what is the equivalent evaporation
from and at 212° ? To solve this example, it is only necessary to multiply the actual evaporation,
8.25, by the proper factor, 1.154, obtained from the table, so that the equivalent evaporation per
pound of coal is 8.25 x 1.154 : 9.52 lbs.
In experiments with difierent fuels, the amount of ashes frequently varies so much that it is ad-
visable, for purposes of comparison, to use the results obtained after deducting the ashes, or those
due to the combustible.
Calm-{fie Eyed—W hen coal is burned in the furnace of a boiler, its total heating eficct may gen-
erally be classified as follows :
l. The useful effect, or the heat utilized in the evaporation of water in the boiler.
2. Heat required to raise the temperature of the products of combustion to the chimney tempera-
ture.
3. Heat not given out on account of the presence of combustible gas in the products of combustion.
4. Heat required to vaporize the water in the coal and that formed in combustion.
5. Heat not given out, on account of the presence of carbon in the smoke.
6. Heat in the refuse, when drawn from the furnace, and that lost by the presence of carbon in
the refuse. -
7. Heat lost by radiation from surfaces other than those of the boiler.
Heat of evaporation above 32°—
154
BOILERS, STEAM. '






















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'HONII ZHVIIIJS HEIJ SCIXQOd NI ‘NVQLLS JO HHHSSI’IHJ HSLII'IOSHV 'V'HHJWEII




'uopgvwdmg f0 sawgond f0 3190‘;

BOILERS, STEAM. 155

___— 4'
The experiments of Messrs. Kestner and Meunier with different varieties of fuel, in an elephant-
boiler with heaters, give the following average values of the distribution of heat:
Summary of dimers. Kestner and Mmmz'er’s Experiments on Distribution of Heat in an Elephant-Boilm'.






““ M“ '“ 1
PER erm'r. or 'rne 1111111: sxrsnnzn. i
i
now EXPENDED. ,
Per pound: or com' Per Pound of Coal. l
bumble.
Useful effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 . 6 60 .5
Products of combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .l 5.5 5.5
Combustible as. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 5.
Steam in smo e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..1 2.8 2.5
Carbon in smoke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. I .5 .5
Refuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..1 1.5 l
1 Radiation from masonry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.3 24.5
§ 100.0 100.0




These experiments were made with care and were of sufficient duration to secure average con-
ditions, so that the results are entitled to great confidence.
It will be observed that the per cent. of useful eifeet is much smaller than is given by most ex-
perimenters, and this is due to the use of a higher number to express the calorific effect of the fuel.
The ordinary method of determining the calorific efiect is by a calculation from the elementary analy-
sis of the coal, using the following formula:
C I proportion of carbon. H 2 proportion of hydrogen. 0 : proportion of oxygen.
0
Calorific efit‘ect per pound of coal in thermal units : 14,500 x g C + 4.28 ( H —
Thus, the calorific effect of a coal containing '76 per cent. 0, 4 per cent. H, and 4 per cent. 0, would
be, by calculation, 14,500 x (0.76 + 4.28 x 0.035) : 13,192.
The experiments of Messrs. Kestner and Meunier, made with the same instrument that was used
for determining the calorific effect of carbon and hydrogen, show conclusively that this formula is
very unreliable, and that the calorific effect of a given coal is almost invariably higher than the num-
ber obtained by the calculation from its analysis. Their conclusion seems to be indisputable, and is
accepted by the best authorities, although no very satisfactory explanation of the fact has yet been
given. It seems probable that the heating efi'ect depends upon the state in which the carbon exists
in the coal; and that while the effect of the combustion of carbon in the form of charcoal has been
accurately determined, it may be much higher in the ease of carbon that is not so much condensed.
Dr. Percy, one of the few English writers who have referred to these results, thinks that more ex-
tended experiments are necessary, before the matter can be satisfactorily explained. The reader
will find a very interesting discussion of these experiments, by M. L. Gruner, in the Enyiwwering
and Mining Journal, xviii. '
The accompanying tables contain a good summary of the experiments referred to:
Summary of Analyses and Calorimeha'c Trials of Fuel, by Messrs. Scheurer-Kestner and
fifeum'er-Dollfus.

















noxcnxxr. sxxnanfrcx.
ARGUMENT' l Duttwei Alien ‘F ‘ ' I a
f o , - — . . r-ednchs- Louisen- 1
No. 1. 1\o. -. No.3. } No.4. ler wald. Heimtz. i thal. M. i
l i 1
Carbon . . . . . . . . . . . . . . . . .. 76.45 68.65 76.28 73.1 71.25 69.8 70.33 67.81 64.69;
Element“ Bydrogen . . . . . . . . . . . . . .. 4.89 8.97 4.06 3.75 4.1 4.26 4.3 l 4.19 3.94
m, ,S.s (3;. Solid refuse . . . . . . . . . . . .. 15.02 20.8 12.8 16.19 18.25 18.5 11.57 ' 12.7 12.38
90211-1 1 Nitrogen .............. .. 1.09 1.00 1. 1. 0.0 0.5 0.5 l 0.5 0.5
c - Oxygen ............... .. 3.00 4.1‘ 5.91 4.87 9.15 9.9 11.51 , 13.8 15.02
‘ Water . . . . . . . . . . . . . . . . . . . . . . .. 0.7 . . . . .. 1.09 1.75 2.54 1.79 1. 8.57
Uncombined carbon..... 72.57 74.74 71.441 71.58 62.84 63.15 61.57 ’ 58.44 56.15
Combustible Carbon in hydrocarbons. 17.39 12.75 15.991 16.8 20.98 19.59 18.92 l 20.53 20.72
and volatile Hydrogen . . . . . . . . . . . . . .. 5.09 5.1 4.561 4.42 4.6 4.78 4.71 4.67 4.68
constituents. Nltrogen . . . . . . . . . . . . . . .. 1.28 1.85 1.14 1.2 0.71 006 0.68 0.59 0.6
Oxygen . . . . . . . . . . . . 8.67 6.06 6.87l 6. 10.87 11.85 14.12 15.77 17.85
Heat of combustion per ggfiir-ligglopl‘iggs 16,498 16,401 16,846 16,108 15,708 15,539 10,277 15,228 14,787
pound of combusti- ter from and l ‘
15‘” “Ferment- a 212° .... .. 11.00 10.9s 10.91 10.00 10.25 10.0s 15.8 15.70 15.3
Excess of ex erimentul value above that l '
calculated om analysis: thermal units 547 1,186 1,244 1,018 1,319 1,195 1,861 1,548 1,379
Difference between experimental and cal- \
culated values, in per cent of experi- ‘
mental value . . . . . . . . . . . . . . . . . . . . . . . . .. 3.821 7.08 7.611 6.29 8.4 7.69 8.91 10.17 9.32





The following table contains analyses and experimental heat of combustion of other coals, by the
same experimenters, the data being taken from the “ Bulletin de la Société Industrielle de Mulhouse ”
for 1868, 1869, and 1871; “Annales de Chimie,” Fourth Series, xxx; Fifth Series, ii., xxi.; and
Sixth Series, ii.; and “ Comptes Rendus de l’Académie,” 1869, Second Series:
156 BOILERS, STEAM.

Summary of Experiments by filessi's. Kestner and .Mcunier on Heat of Combustion of Various Goals.



1 HEAT OF COMBUSTION
oomsus'rmma AND VOLATILE Pun POUND or
eons'rrrunx'rs. COMBUSTIBLE, BY
EXPERIMENT.
NAME. Pounds of
Nitrogen Wat er
Carbon. Hydrogen. and T325513“ evaporated,
Oxygen. ' from and
at 212'.
Saarbriick, Sulzbach ............................. sans 4.90 12. 15,400 10 02
“ Von der Heydt . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 81.56 4.98 18.46 15,282 15 76
Creusot, caking (Chaptal Shaft) . . . . . . . . . . . . . . . . . . . . . . . . .. 88.48 4.41 7.11 17,820 17 92
“ anthracite (St. Pierre Shaft) . . . . . . . . . . . . . . . . . . .. 92.86 8.66 8.98 17,021 17 61
:: semi-bituminous (St. Paul) . . . . . . . . . . . . . . . . . . . .. 90.07 4&4 2-(13 12,2135 17 55
131......12232250153639111'1:1::1:::::::::::::::::::: #3153 3:23 16:13 .4398 it “ anthracite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 87 .02 4.72 8.26 16,400 16 97
Anzin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 84.45 4.21 11.82 16,668 17 24
Denain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.94 4.43 11.68 16,290 16 85
English, Bwlf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 91.08 8.88 5.09 15,804 16 ‘35
“ Powell Dufi‘ryn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 92.49 4.04 8.47 16,108 16 66
Russian, IC/wlrouellgpfskki anthracite . . . . . . . . . . . . . . . . . . . . . . . .. 86.66
“ ions ea *in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l .45 . v v, d - -
“ Goloubofski figming . . . . . . . . . . . . . . . . . . . . . . .. 82.67 5.07 12.26 14.488 14.94
Lignite, blue from Rocher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 72.98 4.04 33.98 13,369 12.07
6‘ ' . '- I" ' i
“ tiff f‘im Mali9sq‘le'.'.'.'.'.'.'f.'.'1 :1: :32: :::t:::: 13:57 233% 28:23. - 121532 13 :19
“ caking from Bohemia . . . . . . . . . . . . . . . . . . . . . . . . . . . 76.58 8.27 15.15 14,263 14.76
“ changing to fossil-wood . . . . . . . . . . . . . . . . . . . . . . . .. 66.51 4.72 28.77 11,444 11.84
Fossil-wood changing to lignite. . . . . . . . . . . . . . . . . . . . . . . . . . 67. 60 4.55 27.85 11,360 11.75
Russian lignite, from Toula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78.72 6.09 20.19 13,887 14.31










It will be observed that some of the coals upon which experiments were made have a similar com-
position to those of the United States, whence it is reasonable to conclude that the calorific effect of
the latter has been greatly underestimated. Experimental investigation of this subject is very de-
sirable. The most complete information on American coals is to be found in Prof. Walter F. John-
son’s “ Report to the Navy Department on American Goals.” Prof. Johnson’s experiments included
elementary analyses and descriptions of the coals, with practical trials by burning them in the fur-
nace of a boiler, and making analyses of the products of combustion. These latter analyses have
usually been considered as authority in the determination of the amount of air required for combus
tion, which is assumed, in general, to be twice as much as is theoretically necessary. The number of
pounds required for chemical combustion is
0
12 C+36 (ii-Hg),
in which formula, as before,
0 = per cent. of carbon.
H: “ “ hydrogen
0 : “ “ oxygen.
Thus, for the coal whose composition is given in the last example, the number of pounds of air theo-
retically necessary per pound of coal would be 12 x 0.76 + 36 .x 0.035 : 10.38. In Prof. John-
son’s analyses of the products of combustion he did not collect samples that represented means for
considerable periods, and the individual experiments in the case of a particular coal were so few
that it is doubtful whether the accurate mean results were obtained.
All the coals analyzed by Messrs. Kestner and Meunier were afterward tried in the furnace of a
boiler, and the products of combustion were drawn 06 in such a manner as to secure samples that
represented the averages of a day’s run. The results obtained in this manner showed that a less
amount of air in excess was necessary than is commonly supposed, and special experiments with va-
rious amounts of air indicated that, under the conditions of these experiments, an excess of air of
33 per cent. above that theoretically necessary gave the best results. Whether this is true in gen-
eral can only be settled by further experiments.
Summaries of the results obtained by Prof. Johnson and Messrs. Kestner and Meunier are given
in the tables on pages 160 and 161. In comparing the results of such experiments, it is to be re-
membcred, as pointed out by Dr. Percy, that they do not certainly determine the relative economic
effect of the different coals, since they are made under approximately the same condition as to boiler,
furnace etc., which conditions may be much more favorable to some kinds of fuel than to others.
LAND Beltane—The boilers illustrated in Figs. 354 to 396 inclusive, selected from the great
variety of examples that have been and are still in use, will give a fair idea of past and present
practice.
Boilers may be classed generally as flue and tubular, with some special exceptions, in the case of
sectional boilers. Both fine and tubular boilers may have external or internal furnaces; and tubular
boilers may be still further divided into fire-tube and water-tube boilers, the former, as the name im-
plies, having the water around the tubes, and the latter having it within them. Marine boilers com-
monly have internal furnaces, while those used for stationary purposes may be either internally or
externally fired. -
'wvnazs ‘snn'noa
LQI
Summary of Prof. Johnson’s Ea'perimmts on 000718.




























a: ‘5 "WEIGHT 117 UN Pounds of , _ z ‘
[‘72 2 PER 01,315,900? AXALYSIS, PARTS m 100. Per Cent. water Pgggggl: 0:13;: You“: of a5
1 a f Refuse evaporated 117 100 A“ sup- n: E
g m DESIGNATION or COAL. Volatile ° m . d frog: find at ' plied per g} n:
2 E or 801“ Ofelizlken Moisture. Sulphur. Combns- Fixed 80nd 021 $131; 1135;358:311- Carbonic Pound of E a
:z: a I Coal. . time. Carbon. Refuse. ' ml Bone“ Add. Oxygen. CML ; 5
CLASS I.——ANTHRAC1TE—NATURAL COKE—ARTIFICIAL COKE—MIXTURES. .
1 Beaver Meadow, Slope No. 3 . . . . . . . . . . . . . . . . . . . . . Pennsylvania. 100.65 54.98 1.5 .01 2.88 88.94 7.11 9.7 10.11 10.19 10.99 20.4 1
2 " “ “ No. 5 . . . . . . . . . . . . . . . . . . . . . . .. " 96.93 56.19 .89 .06 2.66 91.47 5.15 6.8 10.84 7.84 16.31 28.5 2
8 Forest Improvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 92.81 58.66 1.79 .02 3.07 90.75 4.41 7. 11.02 9.77 10.89 21.7 ~ 3
4 Peach Mountain . . . . . . . . . . . . . . . . . . ;' . . . . . . . . ..‘. . . . . . . “ 91.51 53.79 1.9 .01 2.96 89.02 6.13 7. 11.05 10.89 11.1 18.4 4
5 Lehigh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 99.39 55.32 5.28 89.15 5.56 7.6 9.75 4.57 16.7 47.9 5
6 Lackawanna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 88.84 48.89 2.12 .12 8.91 87.74 6.35 9.1 10.93 10.6 10.84 19.4 6
7 Lykens Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 86.82 48.56 .11 .09 6.88 83.84 9.25 12.2 10.97 7
8 Beaver Meadow (in new yard) . . . . . . . . . . . . . . . . . . . . .. “ . . . . . 55.08 .. .. .. . . . . . . . . . .. 8.1 8.1 10.18 . . . . . . . . . . .. . . 8
9 Natural coke of Virginia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Virginia. 82.7 44.64 1.12 .47 12.44 75.08 11.83 18.7 10.63 9.22 12.12 19.7 9
10 Coke of Midlothian coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ . . .. 32.7 2.81 . . . . . . . . . . . . 16.55 16.6 10.52 13.36 7.94 14.5 10
11 “ Neil‘s (Cumberland) coal . . . . . . . . . . . . . . . . . . . . . . . .Maryland. . . . .. 81.57 . . .. . . . . . 18.34 18.5 10.54 . . . . . . . . . . . . . 11
12 Mixture 01’ 1; Cumberland, ; Beaver Meadow . . . . . . . . . . . . . “ . . . . . 54.29 . . . . . . . . .. 8.88 9. 9.84 . . . . . . . . .. . 12
18 “ “ “ “ “ “ . . . . . . . . . . . .. “ 54.51 . . . . . . . . .. 8.18 8.2 10.13 . . 13.
CLASS II.-Fnnn-Bunmno BITUMINOUS COALS or MARYLAND AND PENNQYLVANIA-
14 New York 6: Maryland Mining Company . . . . . . . . . . . . . . .Maryland. 89.44 58.7 1.79 12.81 78.5 12.4 18.2 11.45 11.39 9.59 15.7 14
15 Nefi“s Cumberland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 83.28 54.29 2.46 12.67 74.58 10.34 11.1 10.81 9.98 10.78 20.1 15
16 Easby‘s “ Coal-in-Store" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 81.69 53.47 .67 14.98 76.26 8.08 8.8 11.17 8.59 10.8 23.6 16
17 Atkinson & Templeman’s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 82.09 52.92 .45 . . . 15.58 76.69 7.83 ' 8.2 11.87 10.43 11.26 18.8 17
18 Easbydz Smith‘s . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 83.26 51.16 .89 15.52 74.29 9.8 10.1 11.29 16.02 8.4 18.1 1
19 Dauphin and 8usquehanna . . . . . . . . . . . . . . . . . . . . . . . . . . Pennsylvania. 90.19 50.54 .45 .27 13.82 74.24 11.29 16.5 11.4 10.24 9.7 18.8 19
20 Blossburg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. " 82.78 58.05 1.34 .85 14.78 78.11 10.77 11.5 11.17 9.77 11 . 20.2 20
21 Lycoming Creek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 86.74 55.88 .67 .08 18.84 71.53 18.96 18.1 7.84 9.65 11.29 20.1 21
22 Quin‘s Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ .22 50.84 .84 .1 17.97 72.79 8.41 9.3 11.82 10.34 10.21 20.6 22
28 Karthaus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 80.22 52.54 1.28 1.58 19.53 78.77 7. 8. 9.93 . . . . . . . . .. 23
24 Cambria County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 87.94 53.46 2.46 1.5 20.52 69.87 9.15 9.5 10.89 24
CLASS III.--Brrunmous Coxme Conns FROM 'rmc EASTERN Com. Fnm) or Vinomu I»: run Nnmnnonnoon or RICHMOND.
25 Barr's Deep Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Vlrginin. 86.41 53.17 1.79 .. . . 19.78 67.96 10.47 11.5 10.81 7.89 18.21 26. 25
26 Crouch 85 Snead‘s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. " 90.71 53.59 1.79 .48 24.88 59.98 14.28 15.2 10. .. . 26
27 Midlothinn (900-feet shaft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 87.5 50.52 1.17 .. .. 27.28 61 .08 10.47 11.1 9.71 11.21 9.94 17.9 27
28 Creek Company’s coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 82.48 46.5 1.45 2.89 82.47 60.8 8.57 9.2 9.88 10.05 12.11 28.9 28
29 Clover Hill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 80.36 45.49 1.84 .51 82.21 56.83 10.18 11.6 8.8 . 29
30 Chesterfield Mining Company . . . . . . . . . . . . . . . . . . ... . . . . . .. “ 80.57 45.55 1.9 1.96 82.68 58.79 8.68 9.7 10.12 6.72 18.19 29.5 ‘ 30
31 Midlothinn (average) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 80.9 54.04 2.46 .06 29.86 53.01 14.7 15.5 9.98 31
32 Tippecanoe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 84.14 45.1 1.84 .38 84.54 54.62 9.37 9.1 8.57 11.14 7.78 17.8 32
33 Midlothian (new Shaft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 82.82 47.9 .67 2.29 85.7 56.4 9.44 10.7 9.95 9.6 10.73 22.6 83
34 " (screened) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 80.21 45.72 1.79 .2 34.7 54.06 9.66 11.1 10.18 10.46 8.95 19.9 84
CLASS IV.——FOREIGN Brrmumons GOALS AND Tnosn or SIMILAR Consrrrnrxon Wear or run Annnennnr Monnmms—Pmn Woon.
35 Pictou (from New York) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Novn Scotia. 82.35 53.55 2.57 .77 27.83 56.98 18.89 13.1 9.94 10.74 9.08 17.8 85
36 Sidney . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 83.66 47.44 3.18 ... . 23.81 67.57 5.49 6.4 8.66 10.36 9.54 19.5 36
37 Pictou (Cunard‘s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 82.88 49.25 .78 25.97“ 60.74 12.51 12.5 9.86 37
38 Liverpool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .England. 78.89 47.88 .89 .38 39.96 54.9 4.62 5.8 8.48 11.2 9.24 19.2 88
89 Newcastle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ 78.54 50.82 2.01 .23 85.88 57. 5.4 6.8 9.39 . . . . . . . . . . .... 39
40 Scotch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..8cotland. 74.95 51.09 8.01 .36 89.19 48.81 9.34 10 .8 7.87 11.22 11.58 18. 40
41 Pittsburgh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Pennsylvania. 78.87 46.81 1.4 .16 36.76 54.98 7.07 9 .5 8.71 . . . . . . . . . . . . . . 41
42 Cannellton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 79.54 47.65 2.6 . . . 33.99 58.44 4.97 5.6 7.88 18.21 5 51 15.9 49
43 Dry pine wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.01 8.67 . . . . . . . . .. .81 .4 4.78 9.21 10.21 21.6 48 \


158 BOILERS, STEAM.

Summary of Erperz'ments on Fuel, by Messrs. Schew'er-Kestaer and fifeunier-Dollfus.



















‘ USEFUL EFFECT,
in ’ ANALYSIS OF ASHES, PER POUND OF
E rams m 100. Heat of COMBUSTIBLE, ON
a, Combustion, Tm A1“
(2 8 Per Cent. Per Cent. in Thermal _
Z . of Solid of Ashes Units, per
g g DESIGNAT‘ON 0“ FUEL' Refuse by obtained Pound of F3“?_
E 51 Analysis. on Trial. Solid Combustible, Th , o v a?
5 Water. Carbon. Incombus- by Experl- U223“ magp‘zom
Z tible. ment. ‘
and at
212°. '
1 Ronehamp, 1 . . . . . . . . . . . . . . . . . 12.74 17.5 3.58 14.54 81.88 16,846 10,057 10.4
2 “ 11 . . . . . . . . . . . . . . . .. 16.19 13.4 .5 12.9 86.6 16,411 10,438 10.8
3 Friedrichsthal . . - . . . . . . . . . . . . 12 . 7 18. 4 4.05 14.15 81 .8 15.223 8,928 9 .24
4 Duttweiler . . . . . . . . . . . . . . . . . . .4 . 13.25 17 .7 2.22 11 .46 86.32 15,703 9,484 9 .81
5 Luisenthal . . . . . . . . . . . . . . . . . . . . 12.28 16.9 1 .25 12.48 86.27 14.787 8,348 8. 64
6 Altenwald . . . . . . . . . . . . . . . . . . . 13 .5 16 .1 2 .5 16 .7 80 .8 15,539 9.421 9 .75
7 Heinitz . . . . . . . . . . . . . . . . . . . . . .. 11.57 12. .3 12.2 87.5 15,277 8,941 9.25
8 Sulzbach . . . . . . . . . . . . . . . . . . . 10 .46 14.9 .25 6.72 93.03 15,212 8,847 9.15
9 Von der Heydt . . . . . . . . . . . . . . . 10.46 16.3 7.33 11.61 81.06 15.232 8.789 9.09
10 Blanzy, Moutceau . . . . . . . . . . .. 10.28 16.7 12.03 8.82 79.15 14.985 8,446 8.74
11 “ anthracite . . . . . . . . . . . 20.95 22 .9 9 .9 10.79 79.31 16,380 9,920 10 .26
12 Crcusot . . . . . . . . . . . . . . . . . . . . . . 3.63 10.7 1 .15 39.4 59 .45 16,942 10,472 10.83
13 Two-thirds Creusot, one-third
Ronchamp, I . . . . . . . . . . . . . . . 7.95 14.9 4. 25.3 70.7 16,758 11,268 11.66
14 Two-thirds Creusot, one—third
Ronchamp, 11 . . . . . . . . . . . . .. 11.85 17.4 13.5 18.5 ‘ 68. 16.758 11.131 11.52
15 Wood charcoal . . . . . . . . . . . . . . . . . . . .. .5 .. . . . ' .... . .... . 14,544 8,698 .
7:1 PRODUCTS OF COMBUSTION, DISTRIBUTION OF HEAT, ON TRIAL, PER POUND OF COMBUSTIBLE,
a: rams IN 100. rams IN 100.
g If]; Pounds of
11— :4 Air supplied Heat in _
ES Excess of Garb, nic itregenand per Pound _ Heating Pro- Combustible 5:30;" Heat in Haggai)?
m lad Air Acid , Combustible of Coal. Useful Efl‘ect. ducts of Gas in in Black Steam in from Brick_
E ' ' Gas. Combustion. Products of Smoke. ' ,
:3 , Combustion. Smoke. “ark, etc.
2. I
1 24.7 13.8 61.5 12.6 61.52 4.35 7.48 .77 3.02 22.86
2 29.1 12.9 58. 12.8 63.61 5.16 4.91 38 2.91 23.03
3 32.3 12.2 55.5 12.6 58.65 4.4 7.04 75 3.33 25.83
4 32.8 12.1 55.1 13.4 60.4 5.08 5.92 38 3.3 25.82
5 29.5 12.8 57.7 11.5 56.46 3.83 9.76 7 3.59 25.62
6 32.2 12. 54.8 12.8 60.63 5.57 3.16 39 3.51 26.74
7 27.1 13.3 59.6 . 11.8 58.53 5.22 7.12 58 3.16 25.39
8 32.4 12.1 55.5 13.5 58.16 5.75 5.32 39 3.58 26.8
9 30. 12.7 57.3 12.6 57.71 5.4 7.37 58 3.79 25.15
10 23.9 14. 62.1 10.6 56.36 5.72 6.01 75 3.9 27.26
11 30.5 12.6 57 9 12.5 60.56 7.71 4.91 39 3.16 23.27
12 47.6 8.9 43.5 20.5 61.82 7.34 2.46 37 2.38 25.63
13 36.2 11.4 52.4 17.1 67.24 6.04 2.41 38 2.5 21.43
14 34.2 11.8 54. 16.1 66.42 6.65 2.45 39 2.64 21.45
15 42.5 10.1 47.4 23.4 59.8 10.55 2.08 .. 27.57















FYue Boilcrs.—-I*'lue boilers are of various forms; the simplest are cylindrical boilers with single
or double return flues passing through them. In some the fire is made beneath the boiler at one
end, the flame passing beneath the boiler and returning through flues in the boiler to the front end,
where the chimney is placed; or, making one return through one flue or set of fines, it is again re-
turned by another set to the rear to the chimney. In another the boiler is 'made cylindrical, with
the lower half cut away at one end for the reception of the grate, and the flame passes directly
through the fines, and returns by one side of the boiler and back by the other, or makes but one re-
turn, and that beneath the boiler, the chimney being placed at the front end;
Fig. 354. These flues may be either large and few, or more numerous and smaller; the latter
class, when tubes are used, are called '
locomotive boilers, although used for 354-
stationary purposes. The advantage
of this form is, that the hottest part
of the flame is brought in contact with
the top of the water; desirable when-
ever the top of the fireplace and fines
can be kept covered with water with
certainty. The top of the fire-box
bemg a flat or concave surface’ It _IS Selina—l-QOth inch = 1 foot. Scans—140th inch = 1 foot.
tltml'ecflom weak unless very Strongly Longitudinal Section. Transverse Section.
s ave .
The Cornish boiler, similar to Fig. 354, is a cylindrical boiler, with an internal fine or fiues passing
through the boiler, and thence being returned on one side and back on the other; or, making the first
return at the sides, is brought back beneath the bottom of the boiler. The diameter of the Cornish
boilers is usually about one-sixth of their length; a common proportion is from 36 to 40 feet in
length, and from 6 to 7 feet in diameter. The pressure per square inch is from 15 to 35 lbs.


BOILER-S, STEAM. 159

C. D. Smith’s improvement, Fig. 374, consists in the attachment of a tubular furnace, containing
water, to an ordinary tubular boiler, and thus adding some very efficient heating surface. Some




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experiments made in England, with a similar attachment to a Galloway boiler, gave very favorable
results. (See Ezgineering, xxii.) ¢
The Lowe boiler, Figs. 375, 376, is built of steel. It is a tubular boiler, lengthened at the front,
375. 376.









so as to form a chamber into which the products of combustion pass on their way to the tubes. It
has, also, a superheating drum. '
377.


/
The Galloway boiler, Figs. 377, 378, is a cylinder with an internal flue, consisting of two
furnaces at the front end, uniting into one back fine of an irregular oval form, this back
flue being crossed by conical water-tubes. It is constructed of
steel.
Fig. 379 illustrates the Pierce rotary boiler, which is a, cylinder
' revolving on trunnions, directly over the furnace. Encireling cups
17%;” are used around the tubes of the outer row, for the purpose of
mad'i‘“? // keeping them covered with water, and the tubes of the inner row
'1); are intended to form superheatmg surface. A comparison of an
economy trial of this boiler (experiment 65, p. 205) with the mean ,
of experiments 16 and 17, page 203, made in a boiler which did
not revolve, but was otherwise in conditions approximately the same.
but not as favorable, renders it doubtful whether the revolving
' , """"" " , ’ feature is of especial advantage.




/






!


160 BOILERS, STEAM.



Water-Tube Boilers—Figs. 380 to 388 represent sectional or water-tube boilers. The boiler, Fig.
380, used by Mr. Stevens in 1806, and new preserved in the Mechanical Laboratory of the Stevens
Institute of Technology, seems tohave been the earliest example of this form. The credit of being
_ 881.









the first inventor is usually given to a Mr. Moore, some 20 years later. Dr. Alban used a sectional
boiler in 1849, and Perkins in 1859. The Harrison boiler, Fig. 381, was probably the first sectional
boiler that was brought into general
















use. The reader will find descriptions 382‘
of many of the earlier forms of sec- @ \
tional boilers in “A Practical Treatise r,_E,A..T,-,_,H on Boilers and Boiler~ll1aking,” by W. ' '.' :7 “4“
P. Burgh, and “The Proceedings of the ' "
Institution of Mechanical Engineers,” ‘ I: __ -~ _ ;’ __, '
1865. :I_j=fi‘i'i=“ U
The Harrison boiler, Fi . 381, is eon- ' 7 ‘\ ‘\ ‘ f: U u .
structed of hollow cast-igron spheres, Q M N" 1‘ m - 5‘?
each 8 inches in diameter externally, - , and three-eighths of an inch thick, con- ,\ __, _ i- _ l '
nected by curved necks 3% inches di- Q U ' .__ _ 1.:
ameter. These spheres are held togeth- 'Q‘x _ , i O ‘
er by wrought-iron bolts and caps, and "_\ ‘ _ , -~_ in one direction are cast in sets of two \_\\ ‘ \N"'.'.
or four, with opposite lateral openings \ - .. _
to each sphere, and are called by the , "
inventor two or four ball units, as the case may be. These units connect by rebate-joints, accurately
made on the edge and fitting closely, making, when-drawn together, a steam and water-tight joint.
BOILERS, STEAM. 161


For an interesting account of experiments of the most severe character made with this boiler,
by the Committee on Science and Art constituted by the Franklin Institute, see Journal of the Frank-
lin Institulc, February, 1867.







383. '
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The Exeter boiler, Fig. 382, consists of a series of cast-iron sections, each of which forms a
complete boiler in itself, rectangular in form, 3} feet long, 3 feet high, and 4 inches thick, the iron
884.


being 34 inch thick. Each section is east with 12 openings through it, 2 inches by 12 inches.
These openings form fire-tubes, and increase the heating surface, while their walls tie the flat sides
885. ’ > 336.


E














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162 BOILERS, STEAM.

of the section together. Every angle is rounded inside and out; and the bottom and top faces of
each section have a wave-like form, to allow for contraction and expansion.
The sections are arranged over the fire on edge, transversely to the line of draught, with spaces of
1 inch to 2 inches between them. The lower part of each section is connected by an extra heavy
2-inch pipe extending through the wall of the setting to a main feed-pipe outside, common to all.
The upper part is connected, in a similar manner, to a main steam-pipe. The main feed-pipe has
plugged openings directly on line with the bottom of
each section, to facilitate the cleaning of the sec-
tions.
The construction of the “Acme” boiler will be ren-
dered plain by an inspection of Fig. 383.
The Babeock and Wilcox boiler, Fig. 384, consists
of a series of inclined tubes, connected at each end to
a manifold chamber, which latter chambers are con-
nected to one or more horizontal drums above them.
By means of diaphragm plates, the products of com—
bustion are deflected three times in their passage to
the chimney.
The general arrangement of the Howard boiler, an
English invention, is shown in Figs. 385, 386. A re-
port of a trial of this boiler, comprising many inter-
esting particulars, was published in Van Nosta'and’s
Eclectic Engineering llfizgazz'ne, xiv. It is, in many
respects, one of the most useful reports on a boiler
trial in print.
The tubes of the Root boiler, Fig. 387, are con-
nected at each end by a series of triangular plates
and erowfeet, the joints being formed by the aid of
rubber grummets. Contractions are thus produced
at the points of connection, with the intention of
causing the separation of steam in a dry state. It will be seen, from the location of the water-
gauge, that the upper rows of tubes form superheating surface.
In the Whittingham boiler, Fig. 388, the water is contained in the narrow spaces between the
two tubes shown in section, and the products of combustion first pass around the outer tubes, and
then through the inner ones, so that there is a large amount of heating surface, compactly arranged.
' The outer tubes are fitted at the ends in castings of a zigzag form The inner tubes are threaded
8ST.






on the ends, and secured by hollow nuts with faced collars, which also draw the outer tubes firmly
to their seats when screwed up. A vertical drum of considerable size is sometimes added, thus
increasing the water room.
A recent form of sectional boiler consists of a coil of pipe, through which the feed-water passes
by forced circulation. Great efficiency and safety are claimed for this arrangement.
Portable Boilers—The boilers used in connection with portable or self-contained engines are usually
of the locomotive or vertical variety. Particulars concerning their dimensions and performance will
BOILERS, STEAM 163

be found under the heading HEAT-ENGINES, and in this place only one or two of the more peculiar
forms are illustrated.
The 'Davey-Paxman boiler, Fig. 389, is a vertical boiler, having a set of bent and tapering tubes
889. 890.



Ex» .











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in the fire-box. Deflecting valves are placed at the tops of the tubes to change the course of the
water in its circulation.
The Shapley boiler, Fig. 390, consists of two cylindrical sections, the annular space between the
two containing fire-tubes being arranged radially.
The special forms of boilers used for steam fire-engines are described in the article ENGINES, FIRE.






















































\ ““ “\ \\ ==—_— -i-—“_= "-5-? 2?. j::—_—-—:_—:-=_
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a».
European Boilers.-—Figs. 391 to 396 show the forms of stationary boilers largely used in England
and France. ‘
The Lancashire boiler, Fig. 893, has two flues, in which the furnaces are located. The products
164 BOILERS, STEAM.

of combustion pass through these internal flues, then through the side-fines to the front of the boiler,
returning by the bottom flue to the chimney.
The Fairbairn boiler, Fig. 394, has three cylindrical shells, two of which contain flues with fur-
naces in them, the third being placed above, and connected by tubes. The products of combus-
tion, after leaving the internal flues, re-
turn through the side and bottom flues, 396‘
and pass to the chimney between the - - _ > _ \ ?
three cylindrical shells. \\\
The Elephant boiler, Fig. 395, has
three small cylindrical shells, connected """ "ff-=33%'=='='5=>====*=-—'EE?1*-- ) by tubes to the boiler proper above. ______ -_-__r-_- .___ ing" ' \
The products of combustion first pass -'—-— — —_:-_—:{Y_____—_-'['_~_ ;'1_?;>FI_I_—__—fl_' __ ' ._ .-
around the small cylinders, return to --—- ==~===II=" =”-—-'-=E=-~Y-'-
the front by a flue on one side of the
boiler proper, and pass to the chimney
through a flue on the other side. (For -~‘\-‘ - ------~-- ~ - ‘ - - ——
an account of a very thorough trial of -.
these boilers, see the “Bulletin de la --":311‘-‘-=‘-~=--—-U -== -_--—=-—-— Société Industrielle de Mulhouse," 1875, ' i3-‘I""’é;““’ “' "" ‘17"; L
an excellent abstract of which is con- _ ----------- .; ------------ _- g
tained in Engineering, xxi.) '
On pages 203 to 205 are the results of experiments with several of the boilers ‘ _ _ _ ‘ q _
that have been described. _ "-3" - 1‘112’ii-_-f:-'-';r_
Setting Boilm's.—In a majority of in-
' ' ' " F
stances, the stationary boilers in use in
this country are cylindrical, flue, tubu-
lar, or sectional, set in brickwork. Some notes in relation to the setting and fittings are appended.
The irons usually employed in setting a boiler in brickwork are: The front, tie-bolts, bearing-bars,
grate-bars, supports, damper, connection, and chimney-doors.
The front, shown in Figs. 397 and 400, should be made high enough to extend above the top of


































v


























398. 399.
l_
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:1 J E D b
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EUHIII I J— ' g
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the boiler, so that the side-walls and back can also be built up and the boiler covered on top. For
the sake of cheapening the price of the fixtures, some boiler-makers furnish a low front, so that,
when the boiler is set, the top is left uncovered. Although this plan reduces the cost of the fixtures
400. 401. . 402.





"'HHHHHHHHH HHHHJ



and setting, it is the dearest in the long run, since there is a great loss of heat by radiation from the
uncovered portion of the boiler.
The supports for the boiler may be of two kinds, a single support at the end for a boiler of
ordinary length, and intermediate supports for a long boiler‘. The best form of supportfor the end
of a boiler is shown in Figs. 398, 399, 401, and 402. The boiler rests on a cast-iron saddle, B,
BOILERS, STEAM. 165

,__fi
which is supported on rollers, O, the latter resting on a plate, D, on the brickwork. By this ar-
rangement the boiler is free to expand and contract under changes of temperature. Sometimes the
boiler is supported by lugs, D, Fig. 398, anchored in the side-walls; but this should only be done in
the case of very short tubular boilers, and the roller support is preferable for every case. Very
long boilers require to be supported at intermediate points. This is commonly done by means of
suspension-rods, which can be adjusted by nuts, but this practice is by no means commendable.
When a fire is made under a long boiler, the bottom becomes more highly heated than the upper
portion, so that the boiler tends to take a curved form. If rigid suspension-rods are used, this curv- '
ing is prevented, and in many cases fracture occurs, or the boiler is said to break its back. Mr.
Head, an English engineer, has devised a form of suspension-rod, which is-easily constructed and
effective. This is represented in Fig. 402. The suspension-rods, E, are attached to a plate, D, on
the boiler, and, instead of being rigidly secured by nuts to the guard, F, have stiff volute springs, G,
which keep the boiler in proper position when cold, the rods having lugs, e, to check the action of
the springs at the proper point. Of course, when the boiler is heated, the springs will allow it to be
drawn down, and it will return to its normal position when cooled. If the weight of water in the
boiler is considerable, suspension from the top might produce distortion of the circular form; and
to counteract this, a piece of angle-iron, H, may be secured within the boiler.
Tie-bolts are often used to connect the two side-walls. The ordinary form is represented in Fig.
403, the bolts passing through castings, B, which act as large washers.
The damper is generally a slide, as shown at E, Fig. 399, which is placed at the junction of the
back connection or connecting-flue with the chimney. Openings should be left large enough to per-
mit a person to enter the back connection and chimney, and these are closed by the connection and
chimney-doors.
The bearing-bars are the supports of the grate-bars. The front-bearer is often east on the
front, or bolted to it, and the back-bearer is laid on the bridge-wall. In the case of long grates, an
intermediate bearer is required, which is anchored in the sidewalls, and supported in the middle
on bricks, if the grate is also very wide. It is better, however, instead of using one wide furnace, to
divide it by walls or arches into several narrow ones, both for convenience and economy in firing.
Wide flirnaces have sometimes been divided in this manner, after the boilers were set, producing a
considerable gain of efficiency. The arrangement of the boiler front fixes the position of the grates,
or their distance below the boiler. There is not a great deal of difference in the practice of boiler_
makers, with respect to this distance, which is usually between 18 and 24 inches— generally nearer
the former figure.
It is obvious that the iron front can be dispensed with, if desired, and the boiler sustained on
brickwork alone. This is quite frequently done, but the plan does not appear to possess any special
advantages, since, if the setting is properly performed, it will be quite as expensive as if the iron
front were used. ~
The general arrangement of setting for a plain cylinder-boiler is shown in Figs. 397, 398, and 399,
and calls for little remark. In the engravings, the top of the boiler is covered with brickwork;
but it is a very common plan to run up the walls to a sufficient height, and fill in the space with dry
earth or sand. Whichever course is pursued, the brickwork should be carried up high enough
around the boiler to make a tight joint, so that none of the heated gases can escape. It will be
seen that an arch is turned to form the bridge-wall. This, however, is a matter of no impor-
tance; and if it is more convenient, a horizontal bridge-wall can be built, care being taken to leave
the proper opening between the wall and the boiler for the passage of the products of combustion.
An average value for the proper area over bridge-wall is three-twentieths of the area of the grates ;
and though in practice this area is very differently adjusted by different masons, the best results are
obtained when the area is an approximation to the figure given above.
In the engraving the grate-bars are set level. They are frequently dropped a little at the back,
on account of some supposed advantage in firing. There is no objection to this practice, and it is
extremely doubtful whether any benefit is derived from it. It will be seen that the front is secured to
the brickwork by bolts, which are built into the wall, with large washers on the ends. The boiler-
front, the side-walls, and the bridge-walls, should be lined with fire-brick set in fire-clay. If any pipes
are brought from the boiler through the brickwork, openings should be made for them, closed with
iron doors, so that they shall be readily accessible for examination and rePairs. It is better, how-
ever, to attach the pipes to the front or back of the boiler, where they need not be built in.
The setting suitable for a tubular or flue boiler is shown in Figs. 400 and 401. Here the products
of combustion, instead of passing from the back-connection to the chimney, return through the tubes
or flues to the front-connection, A, and thence pass to the chimney by the flue, E.
In Fig. 403 is shown the manner of setting a boiler in brickwork, with double walls and an air-
space, A, between, to prevent loss of heat from radiation. It is much more expensive than the
ordinary setting, and must be done with great care to make solid and stable walls.
The chimney may be constructed either of iron or brickwork, and made as high as is convenient.
It should be at least from 40 to 50 feet, for good effect with natural draught, and can, of course,
have its height increased to advantage. It is well to make the chimney with the same internal
cross-section throughout, with a circular rather than a square or rectangular section, and with a
smooth interior. For a square or rectangular chimney, make the section at least .17 and for a
round chimney .13, of the grate-surface; and there is no harm in making it larger, since its sec-
tion can easily be regulated by the use of the damper.
Where one chimney is used in common by two or more boilers, the fine from each should be
continued for some little distance into the chimney, or else there should be a flue of large dimen-
smns connected with the chimney, into which all the other flues discharge in such a manner as to
prevent the interference of the products of combustion from the several boilers.
166 BOILERS, STEAM.

Furnaces for Sawdzmt.--ll‘urnaces in which sawdust is to be used as fuel are represented in Figs.
403 and 404. The boiler should be quite short, and the grate-surface should be about twice as
large as for coal. Cone-grates, of cast-iron, as shown in the figures, are used. The furnace should
be set back some distance from the front, as shown in Fig. 404, leaving a flat plate, on which the .
403. 404.
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sawdust is first piled, and gradually pushed upon the fire. It is generally well to have at least two
distinct furnaces, which can be fired alternately. It is also necessary to have a high chimney or a
forced draught.
There are several special forms of furnace for burning waste material, such as sawdust and
wet spent tan. One of the best designs, as constructed by Mr. J. B. Hoyt, is shown in Fig. 405.





405.
x , I
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The furnace, or oven, as it is called, is near but not under the boiler, and the fuel is fed into the
furnace from above, through holes, which are always covered with tan when the furnace is in oper-
ation. The question of the efficiency of furnaces using wet spent tan as fuel has been the source of
extensive litigation in the courts, the voluminous testimony that was taken, however, consisting
principally of theories which a few simple experiments have overthrown. The most reliable infor-
406.
l










\
t


s
\\













mation about the performance and relative merits of detached furnaces for burning refuse material
is to be found in the “Report of Theron Skeel, C. E., on the Comparative Economies of Burning
Wet Spent Tan by Various Detached Furnaces.” A summary of the results obtained by Mr. Skeel
is appended.
BOILERS, STEAM. 167

Swnmarg of Experiments on Wet- Tan Furnaces, by Therm Skeel.
























. WEIGHT 0!“ A 008D POUNDS OF WATER EVAPORATED,
a or TAN, m rouxns. P6,. POUNDS OF TAX comma” PER HOUB‘ rnou AND AT 212°.
at (:5 Cent. 1
a g of Per Square Per Square 3" Square Per Square
g Water Total. Foot of Foot of For Pound of Tan. Foot of Foot of
a g; wet" Dry, in Grate Surface. Heating Surface. Gm Heating
g T811 Surface Surface.
'2’ Wet. Dry. Wet. Dry. Wet. Dry. Wet Dry. Per Hour- per Hour-
1 4,442 1,710.2 61.5 1,675 645 27.9 10.7 4.19 1.61 .893 2.319 24.7 3.79
2 4,294 1,571 .6 63.4 2,285 818 28.7 10.5 2.69, .98 1.117 3 .025 31 .7 3.86
3 4,225 1,571.7 62.8 1,440 536 18.4 6.8 1 .72 .64 1 .192 3.204 22. 2.25
4 4,275 1,645.9 61.5 1,419 546 18.2 6.1 1.71 .66 1.605 ~ 4.168 29.2 2. U}!
5 4,260 1,606. 62.3 1,376 519 10. 6. 1.66 .63 1 .48 3.954 26 .1 2.5
6 4,112 1,686. 59. 865 355 5.4 2.2 1.81 .73 1.68 4.098 9. 3.
7 4,270 1,917 .2 55.1 3,011 1.352 12.4 5.6 1 .5 .67 1.988 4.529 21.2 2.92
8 4,076 1,581 .9 61 .2 2,538 1,004 13.4 5.2 2 .72 1 .05 1 .79 4 . 613 24. 1 5.19,
9 4,076 1,581. 9 61 .2 1,942 1,754 10 .1 3 .9 2 .04 .79 2 .058 5 .304 20 .8 4.26
RATIO or TEMPERATURES. g 8
Per Pounds of a: g
Cent. Air supplied a
of Heating to 12:15:: per Pound REMABKB' 2 g
Ashes. Grate Sure G ,8 S _ of Dry Tan. Furnace. Chimney. D, :5
face. n} ur ' 2; 12:
ace.
2. 6 6.66 .042 . . . . . . . . . 700° Crocket Furnace—Flue Boiler . . . . . . . . . . . . 1
2.7 16.4 .071 22. 1,800" 580° "‘ “ “ “ . . _ . . . . . . . .. 2
s. . “ “ . . . . 1,900° 420° “ “ “ “ . . - - - - - - - - - - 3
‘ . . u. H 16. 1,9000 490= t; tt u u . _ _ _ _ _ _ D . _ ’ _ 4
n J u . _ _ _ 1,9()()° 455° “ “ “ “ , . . . . . . . . . . . 5
. 2.9 .019 18. 1,900° 580° Thompson “ “ “ . . . . . . . . . . . . 6
. . 8.2 .084 10.5 1.900° 510° " “ Tubular “ _ _ , _ , . _ _ _ _ _ _ 7
. - 4 . 75 .033 10. 2,000° 700° Hoyt "‘ Flue “ . . . . . . . . . . . . 8
" “ 10. 2,000° 580° “ “ “ “ . . . , _ _ _ _ _ _ _ _ 9











The detached furnace has also been applied, by Mr. Hoyt, to the combustion of bituminous coal,
as illustrated in Figs. 406, 407. F F F are the feed-holes for supplying coal. The furnace-door, D,
is only used to admit air through small holes, and to haul the fire, or clean it when necessary. It
will be seen that the walls surrounding the boiler and oven are hollow, and the air is drawn through
the hollow spaces intothe furnace through the small holes shown in the figures. S S are shelves on
which coal is placed before being pushed into the oven. For some results from experiments with
this furnace, see page 205. Straw-burning furnaces are noticed under ExemEs, STEAM, PORTABLE, etc.
‘ There are processes in use by which
407- coal dust is burned directly, either
by injecting it into the furnace
mixed with air, over an incandes—
cent bed of coals, or by the aid
of a steam or air blast in the
ash-pit. There are also patents for
forming solid blocks from coal
dust by pressure and the admixture
of products which make the par-
ticles adhere. It has been stated
that, if coal of good quality is
reduced to powder, and burned
by the first process noted above,
more economical results will be
obtained than by its use in the or-
dinary manner in the lump state.
This view, however, does not seem
to be confirmed by experiment,
but, on the contrary, the ordinary
method of combustion appears to
_ ‘ ‘ be the most economical. (See
Engineering and .Mining Journal, xxi., and the “Repert of the Chief of the Bureau of Steam Engi-
neering,” 1876.) Still, the process can be successfully applied to the combustion of dust, but, whether
or not more economically than the second process alluded to, can only be determined by experiment.
For manufacture of coal dust into blocks see the Journal of the Franklin Institute, February, 1874,
Van Nostrand’s Eclectic Ezgineering Magazine, April, 1874, and Engineering, September 2, 1870.
See also “Reports and Awards, Group 1., International Exhibition, 1876,” which contains descrip-
tions, by Frederick Prime, Jr., of the various patent fuel processes exhibited.
Mr. John E. Wooten has devised a method of burning anthracite coal dust without previous prepa-
ration. The furnace-grate has such small air‘spaces as to prevent the coal dust falling through in any
great quantity. A forced draught is supplied through a blast-pipe into a closed ash—pit. A steam



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168 _ BOILERS, STEAM.

blower is used to produce the blast, consisting of a steam-pipe with a discharge orifice about one-tenth
of an inchin diameter, discharging into the blast-pipe, which is open to the air at the outer end.
Automatic arrangements for supplying coal to furnaces are sometimes employed. Smith’s Auto~
matic Stoker, one of the most recent forms, is shown in Fig. 408. The coal is supplied to a hopper,
from which it falls into a revolving crusher, and
is broken to the proper size. It is dropped upon
revolving disks, furnished with fans, which throw
the fuel into the furnace, and distribute it evenly.
The grate-bars are so arranged that they can be
moved by a handle, as occasion requires, in or-
der to keep the fire bright.
A general description of mechanical stokers
may be found in the “Transactions of the So-
ciety of Engineers,” 1877, and “Proceedings of
the Institution of Mechanical Engineers,” 1869.
For an account of English practice in setting
boilers, see Engineering, xxi., xxii.
Grate-bars for boilertfwvmces are ordinarily
constructed of east-iron, and should have open-
ings for the admission of air equivalent to at
least .37 of their surface. Figs. 409, 410, rep-
resent two forms of bar in common use, both
of which are designed to be free from any ten-
dency to warp, the first on account of its peculiar
shape, and the second by reason of the inter-
locking arrangement, which is clearly shown in
the figure. Water-grates, consisting of pipes
through which water circulates, are sometimes
employed, and grates of fire-brick have been
used in special instances.
In burning coal, it is usually found desirable,
as has already been noticed, to admit some of
the air necessary for combustion above the fire.
It is generally admitted through holes in the
furnace-door; and sometimes, for the purpose
of effecting more thorough mixture, the air is
forced through the holes in small jets, mingled
with steam. Prideaux’s furnace-door is arranged
so as to admit a varying amount of air, great-
est after a fresh supply of coal is put into the
408.






l













furnace, and gradually diminishing as the coal / Q 410-
becomes ignited. In the “Sixth Annual Report
of the Cincinnati Exposition,” there are descrip- s

tions of several special forms of furnace-doors, gEiE-Ei-EJQ
and accounts of experiments made with them.
Feed- Water Heaters—If the products of combustion, after leaving the boiler, escape directly into
the chimney, they must pass off at the temperature of the steam in the boiler, at least. By causing
them to circulate around tubes or cylinders through which the feed-water is forced on its way to the
boiler, their temperature can be lowered, and the heat utilized in increasing the temperature of the
water. By the aid of the table on page 157 the gain by the use of heaters in the chimney, or fuel-
cconomizers, as they are frequently called, can be calculated for any given case. Suppose, for exam-
ple, that on adding fuel-economizers the temperature of the feed is increased from 60° to 180°,
the pressure under which evaporation takes place being 80 lbs., the evaporation per pound of fuel will
be increased in the ratio of 1.189 to 1.07, or about 1] per cent. It is to be remembered that as the
addition of a fuel-economizer reduces the temperature of the products of combustion, the tendency
is to diminish the draught so that a high chimney or a forced draught may be necessary. In practice
a high chimney is generally employed, and the economizer is of considerable dimensions, with more
heating surface than that of the boiler.
The term feed-water heater, as ordinarily used, is applied to arrangements such as coils or clusters
of pipes, and cylinders, in which the feed-water is heated by the exhaust steam from a non-condens-
ing engine. It is desirable that the passage of the steam should be obstructed as little as possible,
so as to avoid increasing the back pressure, while at the same time its heat should be imparted thor-
oughly to the water. Heaters may either be open, as when the exhaust steam comes in direct con-
tact with the feed-water, or the water may be forced through pipes which act as heating surfaces.
being heated by contact with the steam. With the former style, the feed-water must be drawn from
the heater by the pump, which must thus force hot water, while with the latter cold water can be
forced by the pump into the heater, and there heated, on its way to the boiler.
Some forms of heaters are intended to purify the water as well as heat it by the use of a series
of shelves or shallow basins, in which the solid material will be deposited as the temperature of the
water is increased.
All natural waters held various solid matters in solution or suspension; when in the latter state,
they admit of being removed by filtration; but no system of filtration, on a scale sufficiently large
to supply a moderate-sized steam-engine at a light expense, has yet come into practical use. How- ..
BOILERS, STEAM. 169 '
(It

ever, it occurred to an inventor several years ago to hit upon a very simple ' and effectual substitute.
And that was, instead of separating the water from the dirt, before passing it into the boiler, to sepa-
rate and collect the dirt from the water, after it is in the boiler, by means of a series of vessels,
shelves, or trays, placed up and down the boiler, constituting, in fact, so many portions of what
collectively might be considered a substitute for a false bottom,.upon or into which all the matters
held in suspension are deposited. This, in fact, is the whole of the principle of Mr. Anthony Scott’s
patent of 1827, which has been so frequently rcpatented and reregistered since that time, like many
bad copies of good pictures, some of them so very bad that the patentee, if he were living, would
not know that they were even meant for imitations.
These sediment vessels operate much after the same manner as certain quiet or still places do along
the banks of rivers, in causing sand or mud to accumulate in them; making so many places of
shelter, where any movable matters being accidentally deposited, they remain free from agitation and
not disposed to move out. In a boiler containing boiling water, of course the same principle pre-
vails, the steam rising from the boiler-bottom—the sole cause of cbullition in all cases—being the
agitating agent. In fact, the water never boils within the internal vessel or sediment receiver, how-
ever violently it may boil externally; and the more violently the water boils, the more rapidly the
internal vessel collects all loose sediment floating about in the water. Excepting for calcareous in-
crustations,-the process was perfectly successful in keeping a boiler clean. The only difficulty in its
practical application was liability to neglect in cleaning out the collectors themselves when they got
filled with deposit, and the necessity of emptying the boiler for that purpose.
For the above reasons it appeared desirable to the patentee to have his cleansing apparatus made
self-acting, that is, to clean itself out, without interruption to the working of the engine, or letting
down the steam ; which improvement R. Armstrong effected in 1829, when the first complete boiler-
cleansing machine was executed and applied to a boiler at the calico-printing works of Messrs. Thomas
Marsland & Son, in Stockport, who afterward had fifteen boilers so fitted. Since the above period
they have continued in general use in Lancashirc.
The general form of this apparatus is shown by Fig. 411. Many hundreds have been made and
adapted to various kinds of boilers, including those of railway locomotives and steamboats. In the
last-mentioned cases, and in all cases where there is no fire under the boiler-bottom, they are, gener-
ally speaking, unnecessary, except for the purpose of preventing priming, which they most effectually
do when that arises from dirty water. For this purpose the upper conicaLshaped vessel is made
with the narrow collecting apertures adjusted partly above and partly below the surface of the water.
In this way it is used by opening the valve at the end of the boiler, and putting the handle of the
agitator in .motion for half a minute, by which the contents of the receiver at the bottom of the
boiler are discharged upward through the pipe. on the right hand. This operation creates a current,







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SCALE.—-S:< inch = 1 foot~
Longitudinal Section and Elevation of Collectors.
which draws all the scum and froth that cause the priming from all parts of the water surface into
the collecting vessel and down into the receiver, whence they are discharged to the outside of the
boiler by a repetition of the process.
By thus skimming the dirt from the top of the water, clean, dry steam is supplied to the cylinder
of an engine instead of .a mixture of steam and dirty water, causing, in ordinary cases, such great
waste of power by friction on the piston and piston-rod, and unnecessary consumption of tallow.
A modern device of the same general character is shown in Fig. 412. The impurities in thewater
are drawn through the bell-mouthed orifices into the reservoir without the boiler, where they settle,
and can be discharged from time to time into a barrel placed at the side of the boiler. The up—fiow
pipe is placed where the water is presumably the hottest, and the down-flow pipe, from the outside
reservoir, discharges at the back end of the boiler. Bell-shaped mouth-pieces are used so that a
water-circulation will take place through the apparatus near the surface of the water, with considerable
variations in the water-level. -
In the case of the water of the ocean, there is no practical plan of rendering the water pure be-
fore forcing it into the boiler; and where fresh water_ is not used as feed, it is necessary to blow off
170 BOILERS, STEAM.

some of the water to prevent it from becoming too highly saturated. Blowing off is sometimes per-
formed at intervals from the bottom of the boiler, but the better practice is to maintain a continuous
blow-ofi near the upper surface of the water in the boiler. '
Lamb’s Blow-of Apparatus.——In this apparatus the mouth of the blow-off pipe within the boiler is
situated near the water-level, whereby it catches and removes from the boiler the particles-of impal-
pable matter, which, by their subsidence on the fines, occasion scale. ,
Mr. Lamb attaches a valve to the mouth of the blow-off pipe, regulated by a float, with the view
of preventing the steam from blowing ofi when the water has subsided below the said mouth, which
is situated about 12 inches beneath the average water-line. The float is made of copper, of the form
of an oblate spheroid, with a tube passing through it for the reception of a spindle, the position of
which in reference to the float is regulated by nuts above and below the float, which connect with
screw-threads out upon the spindle. The valve resembles a flute-key. The lower end of the spindle
is attached to the valvearm, so as to enable the float to exert a greater power, and the upper end of
the spindle moves in a guide attached to any convenient part of the boiler. By this apparatus the
operation of blow-ing off is continuously performed; but when the salt-gauge shows that the quan-
tity of water blown off is either needlessly great or insufficient, the position of the feed-cock is
altered so as to give a diminished or increased supply. When more feed-water is admitted, the float
upon the surface of the water opens the blow-off valve more widely, and permits a larger quantity
of water to be blown out ; and, when less feed-water is admitted, the contrary effect is produced. The
operation of the float, therefore, is to maintain the water at a uniform level, and also to preserve the
water within the boiler at a uniform density so soon as the right position of the feed-cock is ascer-
tained. In boilers which are thus worked, or to which brine-pumps or any continuous blow-off con_
trivances are applied, an efficient salt-gauge is indispensable, as there can otherwise be no intimation
of the accidental interruption of the operation, and much mischief may be the result. In the ordi-
413_ 414.
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nary way of blowing off, where the engineer keeps the blow-off cocks open until the water-level has
descended any given number of inches, it is certain that, if the water-level descends, a certain volume
of super-salted water has been ejected; unless, indeed, as has sometimes happened where there is a
difierence of pressure in the different boilers, one boiler has discharged its contents into the other
when all the blow-off cocks are opened at'once. But in the ordinary operation of blowing off one
boiler at a time, a determinable quantity of water is expelled by blowing out at determinate intervals
with a certainty which leaves nothing to the chances of acci-
dental derangement, and which the use of the salt-gauge in 415-
“the case of boilers fitted with any description of continuous
blow-off is indispensable to insure.
Covering Boilers.--Internally fired boilers, by which term
it is intended to designate those boilers in which the products
of combustion are only in contact with boiler-heating surfaces
on their passage to the chimney, are generally protected from
loss of heat by radiation by being covered with felting, plas-
ter, straw, or some other material that is not a good con-
ductor. Experiments 41, 42, page 204, show the advantage
of the covering, in the case of a small boiler in an open
shed. Figs. 413 to 415 represent two-varieties of covering
for boilers and steam-pipes. The Chalmers-Spence covering,
Figs. 413 and 414, consists of two coatings of asbestos ce-
ment separated by means of wire cloth, so as to form an air-
space, and the arrangement of H. W. Johns’s covering, Fig.
415, will be evident from inspection. An account of some
experiments, by J. C. Hoadley, on the economic effect of
applying the Chalmers-Spence covering to a boiler of the locomotive type, was published in
the Journal of the Franklin Institute, April, 1877. The following is a summary of the results
obtained:
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BOILERS, STEAM. 171
Economic Efi'eel of applying the Chalmers-Spence Covering.







PRESSSUBE or STEAM, m POUNDS ran souans men, ABOVE
THE armosrnzae.
140w 130w 120w 110m more com 80to 70w saw
130. 120. 110. 100. so. so. 70. so. so. ,
Ratio or‘steam radiated { Boiler uncovered. 13.7 13.3 12.9 12.8 11. _ 10.7 10.2 11.3 10.6
Rtpistepnadgi'eneratfed. B01125 egvzréad. .. 5.8 5.3 5.7 5.7 4.9 4.3 4.8 4.5 4.6
a 0 o r ation om cover r is-
tion from uncovered boiler . . . . . . . . . . .. l 42'2 40'4 44'3 44's 44'8 40'5 42'2 I 40' 43'8








Some experiments were made by E. Burnat, in 1859, to determine the value of various materials for
coating steam-pipes (see Journal of the Franklin Institute, March, 1875). A summary of his results
is contained in the accompanying table:
Summary of E. Burnal’s Experiments on Coatings for Steam-Pipes.








Pounds of Steam at l
9: Given Pressure, con- I Thermal Units radi-
g a Absolute Press. densed by Radiation, l ated per Hour, per
are of Steam,
m Z in Pounds per Hounper Square Square Foot of Sur-
Ifl E KIND OF NON-(JONDUCTING COATING EMPLOYED. per Foot of CastrIron, l face, under the same
in H Square Inch, } I b th. k . sun 1 C. , f
E k. within the I nc 1c ,m ucumiances, or a
p {:1 caspmm F Air, for a Difference Difl'erence of Tem-
Z 9'1 438' of Temperature of perature of One
One Degree. Degree.
1 ghe bars or uncovered cast-iron . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 .031 0.003024 2.874757
he cast-iron coated with common straw thickness of eov- .7 - '
2 l ering 1 .2 inch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "337 0'001012 0'9b1814 l
The cast-iron incased in pottery pipes coated with a mix- 1 I
ture of loamy earth and chopped straw, around which ‘
8 were wound warps of common straw, there being an an- 22.237 0.001164 1.10607 5 I
niular air-space between the cast-iron and the pottery 1
p pes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 The cast-iron coated with cotton-waste, one inch thick . . . . . . 22.337 0.001455 1 .382632
5 The cast-iron coated with old felt treated With caoutchouc. .. 23.867 0.00156 1 .4Tb‘Zl-1
6 ghe cast-iron coagedhwith M. Pimont‘s plastic composition .. 22.031 0.001657 1 .574912
he cast-iron wit t e same coating as in 6 painted white I -(
7 ‘l (the coating in both 6 and 7 was 2.4 inches thick) . . . . . .. f 28‘255 0'001539 1 “103655 I


Safeiy- Valoes.—A safety-valve, as its name implies, is designed to prevent undue pressure in the
boiler to which it is attached—whence the ideal valve is one which will rise as soon as the pressure
at which it is set is attained, will prevent the pressure increasing if the boiler is forced to its utmost
extent, and will close promptly as soon as the pressure commences to fall. It may well be doubted,
in the light of experience, whether it is possible to design a valve possessing all the above features ;
but they can be closely approximated, as will appear.
Before describing the forms and proportions of valves in common use, it may be well to consider
questions that are constantly arising in the practice of all who have charge of steam-boilers, viz :
1. To find the pressure per square inch at which a given valve will open.
2. To find where to place the weight on a given safety-valve, so that it shall open at a given press-
ure per square inch.
3. To find what diameter a safety-valve must have, all the other parts being known, to open at a
given steam-pressure.
4. To find the amount of opening afforded by a valve with beveled seat for any lift.
5. To find the diameter of a valve in order to give the required area of opening for a speci-
fied lift.
These problems are solved by the aid of the formulas given below:
Notation.
S = pressure of steam, in pounds per square inch.
D = diameter of valve, in inches.
L = weight of lever, in pounds.
V = “ valve, “
W : “ ball, “
l :: distance from centre of gravity of lever to fulcrum, in inches.
w = “ fl “ (C (C
P = u u “ valve 4: u
A = area of opening, in square inches, for given lift.
2) : lift of valve, in inches.
h : depth of valve-seat, in inches.
a : angle of bevel of valve-seat, or inclination to a vertical line, in degrees.
1. Pressure at which valve will open:
___Wx'w+L><l+Vxp
0.7854 x .Dgxp

1’72 BOILERS, STEAM.

2. Position of weight :
20__0.7854XD?X SX_p-LXl—-VXp
W

I 3. Diameter to open at given steam-pressure:
D:M(WX70+LXl+VXp ‘
0.7854X8Xp

4. Area of opening for° given lift:
(a.) For a lift less than depth of seat :
° A = 3.1416 X [D X 5 X sin. a+o‘°’ X (sin. a)2 X cos. a].
(6.) For a lift greater than depth of seat:
A = 3.1416 X [D X h X sin. a -I--h2 X (sin. (7)9 X'cos. a -I— D X (71—75)].
5. .Diameie?° for given opening and lift :
(a.) For a lift less than depth of seat:
D_ - X 71’ X (sin. a)SI X cos. a
3.1416 X '0 X sin. a
(b.) For a lift greater than depth of seat:
___A — 3.1416 X k2 X (sin. (1)2 X cos. a
Q 3.1416 X(hXsin. a—I-v—h)
The following table will be found useful in connection with the last two rules, and examples illu3°
trating the application of the formulas are appended:








ANGLE. Sine. I Cosine. I ANGLE. Sine. Cosine. ANGLE. Sine. Cosine.
20° .342 .940 f 31° .515 .357 41° .555 .755
21° .353 .934 32° .539 .343 42° .559 .743
22° .375 .927 I 33° .545 .339 43° .532 .731
23° .391 .921 34° .559 .329 44° .595 .719
24° .407 .914 I 35° .574 .319 45° .707 .757
25° .423 .9 )0 l 35° .53 .309 45° .719 .595
25° .433 .399 I 37° .502 .799 47° .731 .932
27° .454 .391 33° .515 .733 43° .713 .559
23° .459 .333 I 39° .529 .777 49° .755 .555
20° .435 .375 40° .543 .755 59° .755 .543
30° .500 .355 I








Examples.—-1. A given safety-valve has a weight of 50 lbs. 24 inches from the fulcrum, the lever
weighs 6 lbs., and its centre of gravity is 15 inches from the fulcrum ; the weight of the valve is 2
lbs., and its centre is 4 inches from the fulcrum. The diameter of the valve is 2 inches. At what
pressure will the valve begin to rise?
50><24+5><15+2><4
0.7354 X (2)3 X 4
2. The ball of a safety-valve weighs 100 lbs., the lever weighs 10 lbs., the valve weighs 2 lbs.,
and has a diameter of 3 inches. The distance of the centre of gravity of the lever from the ful-
crum is 25 inches, and the distance of the centre of the valve from the fulcrum is 5 inches. How
far from the fulcrum must the valve be placed, in order that the valve may open at a pressure of
100 lbs. ?

: 103.03 lbs. per square inch.
O._7854X(3)f_2<100X5~10X25—2X5
100
3. Weight of ball, 60 lbs.; lever, '7 lbs. ; valve, 3 lbs. Distances from fulcrum : ball, 30 inches;
centre of gravity of lever, 16 inches; centre of valve, 3 inches. Pressure of steam, ’70 lbs. per
square inch. What should be the diameter of the valve?
“<60 X 30+7 X16+3 X 3): 341 inches
0.7354- X 70 X 3 ' '
4. The diameter of a safety-valve is 21} inches, the seat is three-eighths of an inch deep, and has
a bevel of 25 degrees. What is the area of opening, for a lift of one-quarter of an inch ?
3.1415 X [2.5 X 0.25 X 0.423 + (0.25)2 x (0.423)2 x 0.905] = 0.35 square inches.
5. The diameter of a valve is 4 inches, the bevel is 35°, and the depth of seat one-quarter of an
inch. What is the area of opening for a lift of three-eighths of an inch ?
3.1415 X [4 x 0.25 X 0574+ (0.25)‘2 X (0.574)2 x 0.319-I-4 x (0.375 - 0.25)] = 3.42 sq. inches.
0. A safety-valve has a bevel of 32°, and the depth of seat is half an inch. It is to lift three-
eighths of an inch, and give an opening of 11} square inch. What should be its diameter?
1.5 - 3.1415 >< (0.375)2 X (0.53)2 x 0.343
3.1415 x 0.375 x 0.53
: 32.75 inches.




=—.. 2.23 inches.
BOILERS, STEAM. r13

6.....-
7. A safety-valve has a bevel of 33°, a depth of seat of one-quarter inch, and is required to give
an area of opening of 2 inches, with a lift of half an inch. What should be its diameter ‘2
_ 2
2 3.1416 x (0.25) X ((1545)2 >< M39 = 1.61 inch.
3.141s X (0.25 x 0.545 + 0.5 - 0.25)
Instead of weights, springs are sometimes employed to hold down safety-valves. The calcula-
tions, involving merely the condition that the valve shall open at a given pressure, are the same as
those previously employed, except that the tension of the spring is to be substituted for the weight
of the ball, this tension being first determined by experiment. Having ascertained the dimensions
of a spring most suitable for a given case, it is easy to calculate the dimensions of a spring for
any other case. Knowing, for instance, the cross-section of a spring adapted to one pressure on the
valve, make a proportion, thus-
Cross-section of , Cros-ssection of __ Pressure on , Pressure on
given spring ' required spring first valve ' second valve.
The pitch of the second spring, or the distance from the centre of one coil to the centre of
the next, is found by the following proportion:
of - of .. r1222: taster“ . 3"}: fissures?“
given Spring reqmred Spring of first spring of second spring.
Example—It is a common practice in proportioning the parts of direct-loaded spring safety-
valves to use a spring of the following dimensions: for a valve 3 inches in diameter and 100 lbs.
steam-pressure, a spring made of square steel, having a cross-section of one quarter of a square
inch, and a pitch of one inch, the side of a square equal in area to the cross-section being, of
course, half an inch. What should be the proportions of a similar spring for a valve 5 inches in
diameter, and a steam-pressure of 50 lbs. per square inch?

Areaof first 7.07inches.
Multiply by steam-pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Totalpressure on first valvc.. . . . .. . . . . 707
Area of second valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19.64 inches.
Multiply by steam-pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . *50
Total pressure on second valve. . . . . . . . . . . . . . . . . . . . . . . . . 982
To find cross-section of required spring:
0.25 : cross-section of second spring :: 707 2 982.
and, by the rule for proportion, the product of the two extremes (245.5), divided by the third term
(707), will give the second term. Now, 245 5 divided by 707 is 0.34724 inch, which equals cross-
section of second spring. The square root of 0.34724 is 0.589 +, and this is the side of a square
equal in area to cross-section of second spring.
To find pitch of second spring:
1 : pitch of second spring :: 0.5 : 0.589.
Here we solve the problem by multiplying 1 by 0.589 and dividing the product by 0.5, which gives
1.178 inch for the pitch of second spring.
In order to determine how large a safety-valve is required for a given boiler, the maximum evap-
oration of the boiler must be known. This, of course, can only be determined by experiment for
any special case, but the following numbers can be safely used in general practice : The number of
pounds of water evaporated per hour is equal to the area of the grate in square feet multiplied by
135, for stationary and marine boilers with natural draught ;
210, for stationary and marine boilers with forced draught;
600, for locomotive boilers.
Numerous experiments have been made to determine the opening required to discharge a given
weight of steam per hour, and the following rule, while not absolutely correct, gives results that
can be used with confidence :
A 1: Area of opening, in square inches.
W: Weight of steam, in pounds, to be discharged per hour.
P: Absolute pressure of steam, in pounds per square inch.
“7
_ 51.43 X P
Example—Suppose that a boiler evaporates 2,000 lbs. of water per hour, what should he the area
of opening afforded by the safety-valve, so that the pressure shall not exceed 100 lbs. per square inch ?
' Absolute pressure :: 100 + 14.7 = 114.7.
2 000 .
----’-----~ :: 0.339 square inch.
51.43 X 114.7
When a safety-valve is raised by the pressure of the steam in a boiler, it usually exposes a
greater area to the pressure. Hence, ,if the valve were loaded with a weight, it might be expected
that it would open wide at once from the unbalanced pressure due to the action of the steam on the
increased area. It is found in practice,-however, that the ordinary safety-valve only rises very
174. BOILERS, STEAM.

slightly when the pressure for which it is set is reached, and that it is necessary for this pressure to
be increased considerably to raise the valve unuch higher. With the opening of the valve, steam
begins to escape from the boiler with a high velocity, and in its escape it has to overcome the resist-
ance afforded by the opening. In this way its pressure is reduced near the orifice, so that, although
there is a greater area of valve to be acted on by the steam, the pressure is reduced. How much
the pressure will be reduced in any given case can only be determined by experiment, since the data
for a theoretical calculation cannot be given. Some experiments made in England showed that in
the case of a 3-inch valve, relieving a boiler at a pressure of 100 lbs. per square inch, the pressure
under the valve was 25 lbs. per square inch. It is probable that the pressure under a valve, when
opened, will vary with the form of valve and the pressure in the boiler, as a change in the valve
may vary the resistance opposed to the escape of steam, and a change of steam-pressure effects a
corresponding change in the velocity with which the steam issues from the orifice.
In the case of a safety-valve kept down by a spring, it must be evident that, unless arrangements
are made for increasing the upward pressure, when the valve is opened it will lift but slightly, since
every increase of lift requires additional force for the extension or compression of the spring. But
in whatever manner the valve is loaded, it would seem that the first step in proportioning it would
be to find what pressure is acting when the valve is opened. It will then be possible, knowing the
resistance that must be overcome to give the desired lift, to afford such an increase of area in the
open valve that the steam-pressure will balance the resistance. It must be remembered in this con-
nection that it is desirable to have the valve close promptly as soon as the pressure is reduced; and
unless some special provision is made for this, the valve, though it may open wide from the pressure
due to the increased area, will be prevented, from the same cause, from closing until the pressure
is greatly reduced
Numerous special forms of safety-valves have been devised, some of which are illustrated below.
More extended description, with records of experiments, are to be found in the Report of the Com-
mission appointed by Congress to examine life-saving inventions, 1868, “Transactions of the Insti-
tution of Engineers in Scotland,” xvii., xviii., and “ Report on Safety-Valve Tests by a Special Com-
mittee of the Board of Supervising Inspec-
tors of Steam-Vessels,” 1877. A large 416-
number of special forms of valves were - -------------- "-M'ZOfioclll‘fljd‘MdflC’ICJw/Z (fairly/15'
tested by the latter committee, and their
report contains much useful information. ' ,
Fig. 416 represents an ordinary lever i ' , In
safety-valve designed by the committee, ‘ 5 to be tested in connection with the other i Lg
valves. It will be observed that the ar-
rangement is such as to insure prompt
action and freedom from sticking.
By observing the lifts of the ordinary
valves, when discharging at different press-
ures, the committee obtained the follow-
ing rule for calculating the area of valve
that will give the required area of open-
ing for any particular case : Multiply the number of pounds of water evaporated per hour by 0.005 ;
the product will be the area of the valve in square inches. This rule gives a smaller area than
the similar formula proposed by the late Prof. Rankine, in which the multiplier is 0.006. It is
to be remembered that the valves used by the committee were constructed especially for the experi-
ments, and may have acted more effectively than the average; so that the multiplier given by Prof.
Rankine will probably be safer for general use. It may be added that rules of this form are the
only safe ones for general use, the ordinary formulas giving very discrepant results, as shown by
the following example in the report: The area of safety-valve required for the boiler on which the
experiments were made, at a pressure of 70 lbs., would be: For the rule of United States Board of
Supervisors, 37 square inches; for that of the English Board of Trade, 11.8 ; for that of the
French Government, 6.75; for that given by Molesworth, 18.88; for the first rule given by Prof.
Thurston, 8.3 ; for the second, 29 ; for that given by Rankine, 12 ; for that proposed by committee,
10. Attention has been directed to the discrepancies of these rules on several occasions; and in
spite of the distinguished authority on which they rest, it is reasonable to hope that all but the
last two will speedily find the oblivion they so justly deserve.
The committee observed that, when very large valves of the common form are used, their
action is not satisfactory, as at high pressure the lift is scarcely noticeable, the pressure being re-
lieved by a kind of tilting of the valve; and they fix the limit at valves having an area of 10
square inches, recommending that two or more valves be used, when a greater area than 10 inches
is required.
The valves offered for test were divided by the committee into six classes, according to their
construction :
1. Reactionary safety-valves, in which the escape of the steam is opposed by a lip or stricture,
with the idea that the reaction will force the valve farther from its seat. One form of this class is
shown in Fig. 417.
2. Disk safety-valves, in which a disk is secured to the valve having a greater area than the
valve, so as to force the valve farther from its seat when it opens. Fig. 418 is an example of this
class.
3. Annular safety-valves, with two seats upon an annular opening (as shown in Fig. 419), with
a view of obtaining a greater area of opening for a given lift.



\\
BOILERS, STEAM. 17 5
4. Double-seated safety-valves, of the same general form as the double puppet-valve, the upper
and lower parts being of different areas, so that they move easily and expose large areas of open-
ing. See Fig. 420.
5. Combination safety-valves, which are assisted in their operation by small auxiliary valves or
a combination of levers. One of this class is shown in Fig. 421.







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6. Piston safety-valves (see Fig. 422 for an example of this class), in which a piston connected
with the valve assists it to rise.
A uniform method of test was adopted for all these valves. Each was attached, in turn, to the
boiler, was set to blow off at 30 lbs., and was allowed to operate for 10 minutes, with a strong fire









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421.
422.
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in the boiler, was then set to 70 lbs. pressure, and the experiment was repeated. The following table
gives a summary of the results obtained with 12 of the competing valves, and 2 of the common
valves constructed by order of the committee. The table in the report contains results of the list of
176
BOILERS, STEAM.

22 valves, but the data were only complete in the case of 12, as the area of opening was not ob~
served ,for the others, or they were tested at different pressures.








g Q ~‘5 .5 SET TO ores AT 80 rousns. sn-r TO OPEN AT 70 rounns. g hi
k‘ 2 '5 . , a. m H Y _ °“ ,5 . ‘5 Greatest Greatest and “G Greatest Greatest and m is!
22‘ 5 Lame 0f valle' “>5 2 Class Of valve' 2 a? and Least least Area of (irattegland E: ’2; and Least Least Area anneal“? El 5;
2 g 2 °_ “ Excess of Opening in i e I", 05_ cf =1 Excess of of Opening , mi," 03 >3 a l
gm ‘2 0c; 72 Pressure. Sq. Inches. “g ressum' 2 Pressure. in Sq. Inches. n8 ressure' gm-
1 Ashcroft . . . . .. 5 Reactionary. .. . . . . . . . . . . . . . . . . . .. 2 0 1.231 6.1}, 67} 1
2 Crosby . . . . . . . . 5 "' 5 5}, 2% 1.257 2 1}, 29 5 4, 3 .729, .628 64, 6.1- 2
3 Chamberlain . . 5 “ 2 7, ' 1.580 27%, 2S 1 9%- .92 67'} 3
4 Hodgin . . . . . . . . 5 “ 2 6, 0 2.934 26}, 26 2 O 1.427 55}, 06 4
5 Orme . . . . . . . . . . 5 “ 1 16 .457 50 1 4 . 284 61 5
6 Richardson .. .. 5 “ 5 , 1- 869, 1.455 27%, 2} 8 32, 1} .691 _ 661-. 68 6
7 Borden . . . . . . .. 7 Combinati‘n 2 2, 0 11 7, 2b 4 4, l .é'i4 60, 671} 7
S Clement . . . . . .. 5 “ 3 1}, §~ 1 111 27}, 29 4 in 0 1.171 64}, 70 i 8
9 Cockburn.. . . . . 5 , Disk . . . . . . . 2 0 1 $2 27 2 i; 1.13 67%, 6.1} 9
10 Lynde . . . . . . . . 5 “ . . . . . . . 2 4}, 14 . 1 .11 26}, 29 5 0 .555 65. 6t} 10
11 Morse . . . . . . .. 6 Annular 1 0 1 42 27 8 0 .84 5:}, 6 i ll
12 Roch0W.. . . . . . 5 Piston . . . . . . 3 1}, {r 1 231 25% 28% 5 4, 3 1.231 66%, 66 12
13 Common, lever 5 % Committee’s l 2 1;}, 4% 929 28 1 5} .633 us 13
14 “ “ 10 valves. 1 . . . . . . . . . . . . . . . . . . . . . . 1 2 .725 68} 14












It will be observed that some of the special forms of valves, with considerably larger areas of
openings than the common valves, allowed the pressure to increase as much or more. This is prob-
ably due to the fact that the very form by which the greater lift was obtained made it more difficult
for the steam to escape, and thus rendered a larger opening necessary to discharge the same quantity
of steam. In the case of several experiments with the same valve, where the table shows consider-
able differences in the results, these were generally due to lack of adjustment, so that the best results
represent the action of the valve when properly adjusted. This remark applies both to the common
and special forms of valves. There is one peculiarity, quite. an important one, which the table does
not show, but is noted in the records given in the case of each experiment.
With the common valves, when the valve opened, the pressure gradually increased to the maximum,
when the boiler was forced; and when the pressure was allowed to fall, it closed at the points indi-
cated. \Vith nearly all the other valves, however, after the valve opened, the pressure fell below the
opening point, the valve sometimes closing several times, and the pressure falling below the opening
point several times, in the course of a 10 minutes’ trial; and sometimes the pressure fell at once and
the valve blew off at a less pressure than that at which it was set, during the whole trial. It is evi~
dent that this is not a desirable feature in a safety-valve, if safety can be secured without this loss;
and the records of the trial seem fully to confirm the opinion stated in the report, that the common
valve, represented in Fig. 416, is not excelled in any important particular by its competitors—at least
for stationary purposes. For use upon locomotives, and steamers in rough water, some of the special
forms may be advantageously employed, and the committee especially recommend three, constructed
on the reactionaryprinciple, viz: Ashcroft’s, Crosby’s, and Richardson’s (Nos. 1, 2, and 6 in the pre-
ceding table). It is believed that these recommendations are justified by experience.
The results of such experiments as have been described are not utilized in general practice as 'fully
as they should be, and there are many valves attached to boilers that are only safety-valves in name.
There is a simple experiment that every one who uses a safety-valve can make, to see whether he
has a valve that is proportioned to give the proper lift. Let him secure a cord to the lover or stem
of the valve, so that it can be opened by hand if necessary. (Indeed, it may be said, in passing,
that some convenient arrangement should always be fitted for opening the valve by hand, and it
should be used at least once a day, to keep the valve in working order.) Then, by shutting off steam
from the engine or wherever else it is used, and making up a good fire in the boiler, he can determine
in a very short time whether or not he has a safety-valve; and if it will not relieve the boiler auto-
matically it will be easy to give a larger opening by hand, so that the experiment will not be attended
with danger. This simple experiment is earnestly recommended to. every steam-user; for with a good
safety-valve in working order, the chances of a disastrous boiler-explosion are greatly diminished.
The best manner of loading a safety-valve has been the subject of animated discussion among en-
gineers. The opinion of the majority can be summed up as follows: '
Safety-valves for the boilers of locomotives and steamers, and in all cases in which they will be
subjected to oscillations and jars, should be loaded with springs. For stationary boilers, either
weights or springs can be used at pleasure. In employing a spring it is generally considered best to
arrange it so that it shall be compressed, rather than extended, when the Valve is raised.
Net's-class Exhaust—The noise caused by the escape of steam from a valve through the exhaust-
pipe, and the sound of the exhaust from non-condensing engines, are frequently objectionable. Figs.
423 and 424 represent Shaw’s exhaust-nozzles, for causing quiet escape and exhaust, which are said to
be very efiective. The construction will doubtless be evident from the figures. In Fig. 423 it will be
noticed that the steam, instead of escaping from the end of the pipe, is discharged through numer-
ous small openings. In Fig. 424 the steam escapes between coils of wire, by which, in the language
of the patentee, “all the noisome vibrations are absorbed upon the coils of wire.”
Water- Gauges.—The following are common varieties of water-gauges: the first the ordinary
gauge-cock, the second the glass gauge, and the third the float. The gauge-cock, on being turned,
shows whether it is Water or steam that exists at the level at which it is inserted. There are usually
three gauge—cocks inserted in each boiler, at different levels; and the rule is, to so feed the boiler
that there will be steam in the top gauge-cock, and water in the other two. The glass gauge consists
BOILERS, STEAM.
177

*—
of a glass tube set in front of the boiler, communicating in its superior portion with the steam-space,
and in its inferior portion with the water within the boiler, the position of the tube being so adjusted
that the water-level stands at about the middle of its length. The tube is connected at the top and
424.
428. .


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bottom to the boiler by means of sockets furnished with
cocks, so that the tube may be blown through by the steam
to clear it, and the water and steam may be shut off if the
glass breaks. It is unsafe to trust to the glass gauges
altogether as a means of ascertaining the water-level, as
sometimes they become choked, and the water continues to
stand high in the tube though it may have sunk low in the
beiler. If the boiler be short of steam, however, and a
partial vacuum be produced, the glass gauges become of
essential service, as the gauge-cocks will not operate in
such a case, for, though opened, neither steam nor water
will come out, but air will rush in. This sometimes occurs
in practice, and glass gauges are then found to be of es-
pecial value.
The float-gauge consists of a float resting on the surface
of the water, and communicating with an index, so that
the fluctuations in the water-level are, by reference to this
index, made apparent. The float is usually of stone or
cast-iron, but is so balanced by a counter-weight as to
make its operation the same as if it were a buoy of tim-
ber. In land-boilers a float is sometimes employed to regu-
late the admission of the feed-water, and the same float
may also indicate the height of the water within the boiler.
The feed-water is admitted from a small open cistern at
the top of the stand-pipe, as shown in Fig. 425. At the
bottom of the cistern is a valve, which the float opens or
closes, and into the cistern the water is poured by the feed-
pump. When the valve is open the water runs down into
the boiler, but when closed it runs away by an overflow
shoot. The foot of the stand-pipe penetrates to nearly the
bottom of the boiler, so that steam cannot escape by it, but
the water rises in the stand-pipe to a height proportionate
to the pressure of the steam, and a most effectual safety-
valve is thus provided, which will come into operation in
the event of a dangerous pressure being attained. In the
stand-pipe a float is 'placed, which rises and'falls as the
pressure of the steam varies, and opens or closes the
damper leading from the boiler-flue to the chimney. Some
stand-pipes are contracted in their diameter below the level at which the damper-float usually
operates, and danger has arisen from this cause; for the float has descended into this narrow neck
when there was no longer a pressure of
prevented the access of the feed-
water. The length of the damp-
er-ehain should be so regulated
as to obviate accidents of this
description.
Ashcroft’s Magnetic lVatcr-
Gauge, for stationary and steam-
boat boilers, consists of a mov-
able magnet in the inside of the
boiler, which controls a needle
on a dial outside of the boiler,
the connection between the two
being entirely magnetic.
Fig. 426 is a front view of
the dial, showing the needle and
graduation. Fig. 427 is a see-
tional view of the gauge.
A is a copper ball or float at-


stcam in the boiler, and by stepping up the passage it has




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tached to a brass rod, B, which
passes through a pipe into the
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end of which is affixed a steel
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in the pipe with perfect recdom, having no stuffing-box, valve connection, or packing of any kind
about it: hence there is no friction.
controlled by the magnet.
has no effect upon the gauge.
The needle on the dial moves on a polished silver pin, and is
It will constantly indicate the level of solid water.
Foaming or priming
The scale on the dial will indicate a rise or fall of 12 inches of water, each degree measuring 2 inches.
12
178 ~ BOILERS, STEAM.
The accompanying engraving (Fig. 428) represents Hoyt’s water-gauge, partly in section. It is a
simple mechanical invention for telling, at all times, the position of the water in steam-boilers. The
dotted circles show the connection with the boiler; the cock at the bottom is a blow-out cock for the
prevention of sediment. Its advantages are its durability, simplicity, and its constant and accurate
indication of the solid water within the boiler, the foam not being dense enough to move or afi’ect
the float, which, being filled with compressed air, is in no danger of loading or collapsing by the press-
ure upon its surface. The float is also directly connected with the indicating hand, by means of a
lever and shaft working in a steam-tight case elevated above the water, so that no sediment can col-
lect about the shaft, to prevent its always working with perfect ease and accuracy. N o packing is
needed, as the shaft, in passing through the case to connect with the indicator, forms of itself a per-
fectly steam-tight joint—not creating friction enough to prevent its working perfectly free at all
times. It is easily applied to all kinds of steam-boilers, locomotive, stationary, and steamboat.
















rkaur VIEW or WATT)? CUACE 00L!






BACK VIEW PF. sre'nnsnmrm 60065 COM/NED.













The Nicholas water-gauge, Fig. 429, is designed to show the height of
water in a boiler, when located at any level and at any distance from the
boiler. An ordinary glass gauge is placed in any desired position avvay
from the boiler, and connected to a cylinder interposed between the boiler
and its water-gauge, in the manner shown. The connecting-pipes and
detached gauge are filled with water to any convenient height, and some colored fluid is introduced
into the space above the water, so that, when the water-level changes in the boiler, it changes to the
same extent in the connecting-tubes, and causes a movement of the colored fluid in the glass, thus
indicating the amount of change.
Steam-Gauges.-The gauges commonly used for indicating the pressure of steam, water, air, and
other fluids, may be divided into two classes: gauges in which the pressure is measured by the
movement of springs, upon which the pressure acts, and gauges in which the pressure is balanced by
a column of heavy liquid, such as mercury. In all forms of steam-gauges, the connecting-pipe is
generally bent, so that the part next to the gauge shall always contain water when in use, in order
that the mechanism may not be injured by undue heat. Spring-gauges may be classed as those in
which the pressure is transmitted by action within the spring, or against the spring through the
medium of an elastic diaphragm. '
Both varieties are illustrated on page 186. Fig. 430 shows one form of the well-known Bourdon
gauge, in which the pressure acts within a coiled and flattened tube. When internal pressure is applied
to such a tube, the tendency is to change the flattened section into a circle, and thus to straighten the
tube, so that an indicating-hand attached to the end of the tube will be moved along the scale. This
BOILERS, STEAM. 179

w—a
form of gauge is sometimes arranged as shown in the figure, so that its accuracy can be tested at
any time by hanging a weight at the point indicated. The dial of the gauge has a working-scale, for
reading the indications of the hand when moved by steam-pressure, and a test-scale which is used in
connection with the weight. The gauge is tested, with the steam-pressure acting upon it, by hanging


on the weight, when, if the hand falls back to the same figure on
the test-scale as that at which it stood on the working-scale before
adding the weight, it indicates that the reading of the gauge is cor-
rect, while any variation from the former reading shows the amount
of error.
An improved form of the Bourdon gauge is illustrated in Fig.
431, both ends of the flattened tube being attached to the indi-
cating mechanism. "
Fig. 432 represents the spring of another variety of gauge, which
consists of two corrugated plates connected by a curved band. All
the parts of this spring expand when pressure is applied. In the gauges shown in Figs. 433 and 434,
the pressure is transmitted to the springs through elastic diaphragms. In Fig. 433 a coiled spring
is employed, and in Fig. 434 there is a plunger resting on elastic packing, the movement of this
plunger being resisted by a spring Within the case, of the form shown.
Spring-gauges are tested either by a mercury column or by hydraulic pressure from a test-pump, to
which another gauge, known to be correct, is attached. The square-inch test-valve, Fig. 435, is de-
435.




signed to be a cheap and simple substitute for the costly test-gauge. It
consists of a valve exactly one square inch in area, a seat which can be
connected with the test-pump, and a yoke to which weights can be hung
so as to load the valve to any desired extent, so that, when the apparatus is connected to a test-
pump, the valve will continue on its seat, until the required pressure per square inch is attained.
Edson’s recording steam-gauge, Figs. 436, 437, not only indicates the pressure at every instant, but
also makes a record, showing what the pressure was at any particular time, and gives an alarm if
the pressure exceeds a prescribed limit. The pressure is indicated by the movement of a spring in
the form of a corrugated steel disk, and a pencil attached to the indicating-hand presses against a
strip of paper which is made to move uniformly by the action of clock-work. Horizontal lines on
the paper form a pressure scale, and vertical divisions a scale of time, as will be evident from an in~
SDection of Figs. 438 and 439, which are reduced copies of two records of pressure for 24 hours each.
When the pressure exceeds a certain limit, which can be fixed at pleasure, a bell attached to the
gauge commences to ring, and at the same time connection is made with an electric bell situated
Wherever desired, which continues to ring until the pressure falls. When the gauge is used to ob-
tain the record of pressure during an experiment, as, for instance, the steam-pressure in a boiler-test,
or the water-pressure in the trial of a pumping-engine, the paper is made to move at a faster rate


180 BOILERS, STEAM.

than for ordinary use. It will be seen that this gauge maintains a constant watch 011 the care and
skill of the boiler-attendant, and might be very useful in the case of a disastrous boiler-explosion,
436.


mercury connected by a cord with a counter-balance, as shown in the sketch.
where no witnesses are
left to tell the press-
ure at the time of the
accident.
The instrument is
covered by a glass
dome, which can be
secured by means of
a strap and lock, pre-
serving the diagram in-
violate. _
In the other class
of pressure-gauges to
which reference has
been made, the press-
ure is balanced by a
column of heavy liquid,
usually mercury. The
siphon-gauge, Fig. 440,
is the form commonly
adopted for measuring
low pressures. It is
merely a bent tube con-
taining mercury, one
end of the tube be-
ing connected with the
boiler, and the other
being open. A light
stick is placed on the
mercury, which indi-
cates, by rising or fall-
ing, how much the col-
umn is influenced by
the pressure, a change
of level of one inch cor-
responding to a press-
ure of about one pound
per square inch: or
there is a float on the
This form of mercury-
gauge cannot be conveniently employed to measure high pressures, on account of the great length
of scale and tube required; and there
are several arrangements designed to
adapt the gauge to general use.
In the ordinary siphon-gauge, the
height of column necessary to balance
a pressure of one pound per square
inch being about two inches, a rise
of one inch corresponds to this press-
ure, since, for a rise in one branch of
the tube, there is a corresponding fall
in the other. Hence, if the pressure
from this gauge were transmitted to a
second siphon-gauge, a rise of one inch
in the first would producea rise of only
half an inch in the second, one-quarter
of an inch in a third siphon, and so
on. On this principle a compact mer-
cury-gauge for showing high pressures
has been constructed, consisting of a
series of siphons filled with mercury,
and connected by pipes in which gly-
cerine is used to separate the several
mercury columns.
Inthe manometer steam-gauge a glass
tube is inverted in a reservoir of mer-
cury. When the pressure on the sur-
face of the mercury in the reservoir is
that of the atmosphere, the mercury will
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rise in the tube nearly to the level of that surface (but slightly lower, owing to the resistance of the air
in the glass tube). As soon, however, as the pressure communicated exceeds that of the atmosphere,
BOILERS, STEAM. ' 181

the mercury will be forced up into the tube, and the inclosed air condensed, until its elastic resist.
ance is just equal to the pressure. The height of the mercurial column will of course vary with any
variation of pressure, and thereby indicate the degree of pressure at every moment by means of the
scale, which is divided, according to Mariotte’s law, into atmospheres, pounds, or the like.
488.


The high degree of pressure to which the last-described form of manometer may be subjected with-
out error from friction or loss of mercury, the permanent elasticity, and the everywhere existing and
exactly defined qualities of the material of resistance (atmospheric air, or other fluids of the same
440 nature), its comparatively small dimensions and conven-
' ient form, make it a very desirable instrument for meas-
Hb uring the pressure of steam. As usually constructed,
however, it has defects, which have prevented its general
use as a steam-gauge. Among these defects are the
coating and consequent opacity of the glass tube, by the
deposition of an oxide of mercury when acted on by the
inclosed atmospheric air; the expansion and. partial loss
of air from within the tube whenever any partial vacuum
is produced in the boiler, and so allowing the mercury
to rise higher in the tube with the same pressure; its
oscillation, especially when there is a varying pressure,
as in engines working expansively; the almost constant
tendency of the condensed steam to insinuate itself be-
tween the mercury and the glass, and to find its way into
the tube above the mercury; and the great inequality in
the divisions of the scale, arising from the peculiarities
of the law that governs the volume of aériform fluids
under pressure.
Some improvements, designed to correct these defects,
were patented, some years ago, by Mr. Paul Stillman, of
New York.
Fig. 441 is the usual form of the patent manometer for
showing a pressure up to eight atmospheres.
Fig. 442 represents the form of one for showing a
pressure up to 20 atmospheres.
Fig. 443 is the form used for showing less than 1 at-
mosphere. The arrangement of the glass tube is quite
similar in all the forms usually given to the instrument.
Fig. 444 is a longitudinal section through the centre
of the glass tube, in which A is the tube; B is an iron
piece in which the tube is firmly secured by means of the
stufiing-box G. It is screwed at one end to receive the
brass case 0, and in the middle to confine it in the reser-
voir of mercury into which the lower end of the tube is
to be immersed. D D are scales divided into atmospheres, pounds, or inches of press-
, ure, as desired. E'E are blocks to secure the scales in their proper places. F is a
J-ll gland which protects the lower end of the tube, and compresses the packing in the
lg stuffing-box G. H is a cap or plug loosely screwed into the gland to facilitate the
operation of charging the tube, and also, by admitting the mercury into the tube only
through the interstices of the screw, prevent its oscillation, and at the same time allow the orifice to
be made the full size of the tube whenever it may be necessary to clean the tube.
In Fig. 441 the reservoir for mercury is a deep cell, with an iron tube communicating from the
cock at the bottom to the middle of the chamber above the surface of the mercury. In Fig. 442 it is


FPFFF—liililtiil-llil'iliaD:



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(litttktktittttiliks






182 BOILERS, STEAM.

F
divided, the glass tube being inserted into a cell of greater depth, while the reservoir of mercury is in
the bulb, to which a suificient elevation is given to compress the gas within the tube to two or three
times the density of the atmosphere, according to the density of the steam of which it is to serve as
A the gauge. In this, as in the other form, an iron tube communicates
the pressure from the cock below to the surface of the mercury in the
bulb above. The subdivisions of the scale are by this means much
more uniform and distinct than when used at atmospheric pressure only.
In all cases, the mercury should be seen above the junction of the
tube with the tube-holder, so as to indicate the initial pressure, or 0.
In Fig. 441 it is brought up by partially exhausting the tube at the
time it is erected. In Fig. 442 it is forced up by the superincumbent
weight of the mercury in the bulb. The oxidation of the mercury
within the tube is prevented in the latter form of the instrument by
charging the tube with nitrogen or hydrogen gas; but in the former,
on account of the difficulty of preventing the admixture of atmospheric
air, while exhausting a portion of the contents of the tube, for the pur-
pose above referred to, atmospheric air only is used, and a drop or two
of naphtha, or other fluid answering the end, is introduced within the
tube, on the surface of the mercury, to prevent the oxidation.
When designed to Show a pressure less than atmospheric, but not
less than that shown by two inches of mercury, the tube is to be per-
fectly filled with mercury, and inverted in the reservoir, and the press-
ure will be determined by the number of inches sustained above the
level of the mercury in the reservoir below; but if it is to be used for
a pressure less than the weight of two inches of mercury—that being
the distance from the lowest visible part of the glass tube to the sur-
face of the mercury in the reservoir—~it will be necessary to use the
bulb shown in Fig. 442, but with such an elevation only as will bring
the surface of the mercury in it to a height equal to the lowest visible
part Of the glass tube; or it may be done equally well by using the







444.
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form shown in Fig. 442, if a scale is properly made for the purpose, and the bulb
elevated so as to compress the air so high in the tube as to allow the mercury to
have sufficient fall without going out of sight,
when the pressure of the atmosphere is removed
from the surface of the mercury in tnc bulb above.
It will be seen that either of these arrange-
ments would resist the tendency of such partial
vacuum as is generally formed in steam-boilers,
when they are allowed to cool down, from dis-
turbing the quantity of air within the tube of the
manometer
If the initial quantity of air or gas in the tube
be deranged by a change of temperature, or by
any other cause, it becomes necessary to know
the extent of the variation occasioned thereby.
To ascertain this (if inexpcclient to correct it at
once), a simple arrangement is adopted, viz.: 1.
To remove the pressure by closing the stopcock
and opening the small waste-cock between it and
the reservoir—this will allow the mercury to fall
to a place in which it will be at equilibrium with the atmos-
phere; 2. To note the point to which it descends. The varia-
tion from the original place of 0 will be, in addition to the pounds
shown on the scale-plate, such part of the whole as the variation
from 0 bears to the whole length of the tube above 0. To de-
termine this proportion, a series of decimals is placed on the
‘ scale at fixed distances, and the one of these nearest to where
the base of the column of air within the tube rests, is to be used
as a multiplier, by which the pressure of steam indicated on the
scale is to be multiplied. 'l'heir product, less the pounds of vari-
ation shown on the scale, will be the true pressure. Thus, for
example, if the mercury in the tube falls until the base of the
column of air rests at the decimal .96, which would be near
to the place due to 1 lb. pressure, and if, on opening tnc com-
munication to the boiler again, it should rise to 130 lbs., this
apparent pressure of 130 lbs. is to be multiplied by .96, and
deduct from their product the 1 1b., thus giving as the true
pressure 123.8 lbs., showing a variation of 6.2 lbs.
A very convenient and accurate mercury-gauge can be con-
structed on the differential principle—that is, the pressure can
be received on a small surface and transmitted to the mercury
column by a comparatively large one, so that a short column of mercury will balance a considerable
pressure in the boiler. Two applications of this principle are illustrated.


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‘ BOILERS, STEAM. 183

In Shaw’s gauge, Fig. 445, there is a double-headed piston, on the small head of which the steam
presses, and the large head transmits this pressure to an open mercury column. The heads are






446.
1* —\
U Q Q -
' F









Jik
IL







separated from the steam and mercury by rubber diaphragms, so that the piston can be fitted loosely,
without any tendency to leak. In the Stiles gauge, Fig. 446, a large iron cylinder fits loosely into
another cylinder containing mercury, and a small cylinder, or piston, working freely in its guide,
receives the pressure and transmits it to the floating cylinder, causing a rise of mercury correspond-
ing to the relative dimensions of the two pressed surfaces. _
Low- Water Alafms.—-Thesc attachments depend generally for their action either on the motion of
a float which opens the whistle-valve when not buoyed up by the water in the boiler, or on the direct
pressure of steam, which is only admitted to the whistle-pipe when the water-level is depressed, or on
the expansion of some portion of the attachment when exposed to contact with steam instead of water.
MARINE BOILERS.——On page 186 and following pages are given results of an important trial made
in 1865 and 1866 of vertical water-tube and horizontal fire~tube boilers of the dimensions given in the
following table:







Horizontal Fire-Tube Vertical \Vater-Tube
Boiler. Boiler.
Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10 ft. 4 in. 10 ft, 6 in_
Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 ft. 5} in 7 ft. 5} in.
Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9 it. 7 in. 9 it. 7 in.
Number of furnaces . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2
Length of each furnace . . . . . . . . . . . . . . . . . . . . . .. 6 it. 6 ft. 6 in
Width “ “ . . . . . . . . . . . . . . . . . . . . . . . 3 ft. 3 ft.
Total grate-surface . . . . . . . . . . . . . . . . . . . . . . . . . .. 86 sq. ft. 39 sq. it.
Number of tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 162 " 8
Length of tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 ft. 3 in. 2 it. 4} in.
External diameter of tubes . . . . . . . . . . . . . . . . . . . . 2} in. 2 in.
Thickness of tubes . . . . . . . . . . . . . . . . . . . . . . . . . . 0.109 in. 0.109 in.
Heating-surface: Furnace . . . . . . . . . . . . . . . . . . .. 96.57 sq. ft. 96.76 sq. ft.
" “ Back-connection . . . . . . . . . . .. 116.66 “ 73.97 "' i
“ “ Tube-boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147.07 “
“ “ 'l‘ubcs . . . . . . . . . . . . . . . . . . . . . . 701 .S “ 929 . S “
“ “ Smoke-box . . . . . . . . . . . . . . . .. 34.9 “ 17.21 “
“ “ Total . . . . . . . . . . . . . . . . . . . . . . . 949.93 “ 1264.81 “
Air-spaces in grates . . . . . . . . . . . . . . . . . . . . . . . . .. 11.23 “ 14.1 “
Tube calorimeter . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4.6 “ 5.54 “
Cross-section of chimney . . . . . . . . . . . . . . . . . . . . . 6.78 “ 6.78 “
Height of chimney above grate . . . . . . . . . . . . . . . . 60 ft. 60 it.
Weight of boiler.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89,480 lbs. 42,088 lbs. A

Fig. 463 gives views of a boiler designed by Mr. G. E. Emery, of New York, which is selected as
184
BOILERS, STEAM.
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BOILERS, STEAM. _ Y 185

,—
a good example of modern practice. The principal dimensions will be found on the plate, and the
peculiarities of construction are there clearly detailed. The large opening from steam-drum to
shell, which ordinarily would be a source of weakness, is strengthened by transverse braces arranged
very nearly in the direct lines of the strains, the same being crossed simply to permit the passage of
A 464.
B


7+
a man above and below them. The connection from drum to boiler is made through oval openings
of man-hole size, which do not materially weaken the main shell. The coning of back ends of fur-
nace-fines gives access from the central man-hole. The main longitudinal braces are screwed at
the ends, as shown, and pass between angle-irons, which stiffen the plates. All longitudinal seams
and those in flat surfaces are double-riveted, and the furnace-fines are stifiened by flanging ends of
sections outward, and riveting flanges together through calking rings.
The sectional boiler, several varieties of which have been illustrated, and which is now success-
fully used on land, has been tried in ocean-steamers, but so far with but indifferent success, many of
the tubes being destroyed in a short time, probably on account of imperfect circulation under the
rapid rate of evaporation required. It is not improbable, however, that this difficulty will be over-
come. (In the “Transactions of the Institution of Naval Architects,” 187 6, is a paper containing an
account of 'the experiments that have been made with sectional boilers at sea. This paper may also
be found in Engineering, xxi., and an abstract of it in Chief-Engineer King’s “Report on European
Ships of War.”)
Proportions of Boilers—The water-heating surface of a boiler is all the surface which has flame
or. heated gas from the furnace on one side and water on the other. Surface which has flame or hot
gas on one side and steam on the other is superheating surface.
The area for the passage of the products of combustion, taken at any section of their course after
leaving the furnace and before arriving at the chimney, is called the draught area or calorimeter.
Ordinarily, when not otherwise specified, the term refers to the area through or around the tubes of
fire and water-tube boilers, and through the fines of fine boilers, although it is equally applicable, as
has already been stated, to the area over bridge-wall, or at any other section of the boiler. In some
forms of boilers the products of combustion pass directly from the furnace to the chimney—as, for
instance, in cylinder, locomotive, and a few sectional boilers ; in others, such as boilers with tubes
or flues above the furnace, the products of combustion turn once before reaching the chimney; and
in examples similar to the drop return flue-boiler, the Lancashire boiler, and other varieties that
have been noticed, the products of combustion turn twice in their passage to the chimney. Exam-
ples might be given of still a greater number of deflections of the heated gases. It must be evi-
dent that the boiler which is so designed that it has the highest furnace and the lowest chimney tem-
perature will evaporate the most water by the consumption of a. pound of fuel. The furnace tem-
perature, when the combustion is complete (as is practically the case in well-designed boilers of any
type), depends upon the amount of air supplied for combustion, and this is governed principally by
the area for the passage of the products of combustion, or the calorimeter. The calorimeter affects
the performance of a boiler in another important particular. When it is very large, the hot gases,
in passing over the heating surfaces, are not broken up and mingled in such a manner as best to
impart their heat to the water, and, by reducing the calorimeter, a more efficient action can often be
produced. Until the importance of the calorimeter was first announced by Chief-Engineer B. F.
Isherwood, it was commonly supposed that the performance of a boiler was almost entirely depend-
ent upon the ratio of the heating to the grate surface for any given rate of combustion; and this
principle is still to be found in many engineering treatises, and is acted upon, to a large extent, in
practice.
The best rules that can be given for designing boilers are drawn from experience; and the three
tables that follow, containing a summary of some of the most extensive and complete boiler experi-
ments that have ever been made, will be of great value to those who study them carefully.
981
'wvaas ‘sasuioa
Summary of Experiments with Horizontal Fire-Tube Boiler, 1865, 1866.

















II] (fl
2 POUNDS OF COMBUSTIBLE PER POUNDS OF WATER EVAPORATED, RATIO CZ) '
fl , noun. rnom AND AT 212’. 54‘
hi [=1
63 Per Cent Per Cent. of m
005 of Refuse: Draught. Evaporation REMARKS. fig
6* P S P S Per Square Per Square 0,. H ,. Of Tube for DmUght' 1‘“
2’. er quilts er quare Per Pound of Foot of Grate F act of Heat- en mg Calorimeter 9:.
Q Total. Foot of Grate Foot of Heat»v . . to Grate i=1
m 5 face. in surface Combustible. Surface, per mg Surface, surface. to Grate m
g at g ‘ Hour. per Hour; Surface. Z Z
1 699 19.43 .736 9.55 224.4 8.5 26.4 .128 17.4 Natural. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 1
2 711 19.75 .748 9.43 232.9 8.82 “ “ 20. “ . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2
3 704 19.54 .746 9.52 185.8 7.04 “ “ 21.3 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 718 18.77 .716 9.55 179.3 6.79 “ “ 23. “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5 473 13.13 .497 11.5 150.7 5.71 “ “ 22.3 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . , 5
6 608 16.9 .64 10.71 180.8 6.85 “ “ 23.2 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7 282 7.84 .297 12.45 98. 3.71 “ “ 23.7 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
8 535 17.82 .562 10.79 192.2 6.06 31.7 .153 21.7 “ G. 8. reduced to 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
9 260 8.65 .273 12.2 105.5 3.33 “ "‘ 18.9 “ “ “ 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9
10 424 17.68 .448 11.52 203.6 5.15 39.5 .192 22. “ “ “ 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
11 209 8.71 .221 11-65 101-9 2-58 “ “ 16.4 “ “ “ 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
12 ' 344 19.1 .362 11.52 219.7 4.16 52.8 .256 22.8 “ “ “ 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
13 . 152 8.43 .16 12.29 103-7 1.96 “ “ 20.3 “ “ “ 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13
14 257 19.02 .27 11.27 214.7 3.05 70.4 341 20.4 “ .“ ‘ 13.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14
15 ' 109 8.08 .115 12.53 101. 1.43 “ “ 23.3 “ “ “ 13.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15
16 256 7.12 .27' ~ 12.71 90.4 3.43 ' 26.4 .128 19.6 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
17 645 17.92 .679 9.99 178.8 6.77 “ "' 16.1 “ . . . . . . . .. 17'
18 135 3.75 .142 13.08 48.8 1 .85 “ “ 13.5 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
19 601 16.69 .632 9.96 166.3 6.31 “ “ 18.6 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . 19
20 437 12.15 .46 11.05 134.3 5.09 “ “ 16.7 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . Q . . 20
21 635 17.64 .668 10.45 184.8 7.01 “ “ 17.6 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
22 565 15.68 .594 10.6, 166.4 6.31 “ “ 19.4 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
23 ' 438 15.2 .461 11.52 174.8 5.3 33. .16 20.9 “ G. 8. reduced to 28.8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23
24 400 18.51 .421 11 152 214-6 4.88 44. .213 22.5 “ ..... “ “ 21.6 ............................. .. 24
25 423 14.6 .111 11.59 169.4 5.16 32.8 .159 20.2 “ “ “ 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25
26 663 18.43 .698 10.44 191.4 7.25 26.4 .128 17. " I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
27 _ 733 20.35 .771 7.51 153.2 5.81 “ “ 18.1 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
28 668 18.56 .703 9.47 176.1 6.67 “ “ 15.7 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . 28
29 772 21.43 .812 7.41 158.6 6.01 “ “ 18.2 " 29
30 671 18.64 .706 9.75 181.4 6.87 “ “ 16.9 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . . . . . . . . . . . . . . . . 30
31 482 21 .92 .128 11 ..20 245.3 5.68 43.2 .209 _ 16.3 " . . . . .. G. 8. reduced ,tO 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
32 669 18.58 .704 10.78 199.8 7.57 26.4 .116 16.2 “ ... .. Ferrules in 4 upper rows of tubes . . . . . . . . . . . . . . . . . . .. 32
33 665 18.49 .701 10.78 199.8 7.57 “ .102 16.3 “ . . . . . . “ all tubes . . . . . . .Q . . . . . . . . . . . . . . . . . . . . . . . . . 33
34 671 18.64 .706 10.91 202.7 7.68 “ .095 16.4 “ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 34
85 597 16.59 .694 11.42 189.2 7.92 23. .114 19 .4 “ . . . . . Upper row of tubes plugged . . . . . . . . . . . . . . . . . . . . . .. .. 35
36 600 16.67 .779 11.19 185.9 8.69 21.4 .1 19.5 “ MOI'G tubes plugged . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .. 36
37 628 17.44.- .661 , 11.26 196.6 7.45 26.4 .128 22.2 “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37


'wvms ‘szm'noa
Z181
Summary of Experiments with Horizontal Fire-Tube Boiler—(Continued).





é
o
g POUNDS OF Eggnvsrmw PER Pomms or WATER nvnom'rnn, :13
a 31 FROM AND AT 212°. RATIO 2
a: m
In
no: per cent D ht ger Cent of g
1 m I ' u
2 Per Square Per Square Per Square Per Square 0f Tube Of Refuge. “8 10352112211111. REMARKS' g
a Total. FooL of Grate Foot of Hemp Per Pound of Foot of Grate Foot of Heat- or Healing Calorinlet h
g Surfm_ ing swim. Combustible. Surface, per ing Surface, to Grate to Grate" 12d
2 Hour. per Hour‘ surface' Surface. 1 g
:a
38 66‘) '18 59 ‘ z
' 1' 10.68 194;, 7_5 23 10.124 179 , 6 6B “ 4 JES Natgral. . . . . . Iflat deflecting plate in back connection . . . . . . . . . . . . . . 38
41 805 22-37 347 10-11 198.2 7.51 “ “ 17's 11 concave T1 “ “ “ .......... 39
42 780 2167 ' 10' 223 7 8-47 “ “ 163 7 t Two Phates “ “ ....... 1. 40
43 7% 21'76 '221 9-8‘5 214.4 8.12 11 11 18-5 iPZ- gm .................................................. .. 41
44 778 21.62 .331 9.2:) 201.4 7 63 1‘ 11 17:7 “n-
. . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42
45 797 22-15 .839 11.06 139.8 9.08 11 .1 2M “ 9 1‘38 ................................................. .. 4s
46 546 15.16 .634 1.36 251.9 9 54 11 11 18 9 “ 9.1% .................................................. .. 44
47 536 14-88 1516 12.0.? 152.7 7.64 22.9 114 20's Nam,l - .................................. ........... .. 45
48 549 15-24 “574‘ 189.2 7.17 21; 4 '129 2115 11"“ UPPQI‘ row ofwbes mugged ...................... .. 116
49 780 21:66 .1821 11,18 {1354 7.02 “ “ 20.3 “ 1 . . . . . . . . . . . . . . . . . 1 . . . . . . 1 . . . . 1 . . . . . 1 . . . . . . . . . 1 . . . . . . . . 1. 47
50 518 lg 1’4 . 241.9 9.16 11 ‘1 24 2 Fan 1 . 1 1 1 1 1 . 1 1 1 . 1 1 1 1 1 1 1 . 1 1 . 1 1 . . . ..1 1 . 1 1 1 . 1 1 1 1 1 1 . 1 . . 1 1 1 1 .. 48
51 659 153 .347 12.02 241>.1 6 96 135.2 .149 22'4 “ - 10.1 .. ........ .................................... .. 49
52 6.“ 18' 63 8-16 1'5 {76 264 _128 18:2 Jet 6-1 G. S. reduced to 27. Ferrules in 4npper rows of tubes. 50
1 . 1 1 . , k ' 7' ‘ ' “ y p - 1 1 - 1 1 . u 1 1 u 1 1 1 ~ 1 u - 1 . ~ c u a u u u n ' . I 1 u v - I - . ~ a n n n 1 1 -
824 “'9 11' {‘9 Nat‘nral. 55 H “ “ “ n 1 . n . 1 1 - 1 - 1 1 1 - 1 1 1 c u u - u ~¢~ 1 - 1 . - 1 1 1 1 .1 58
2,? 17:76 1; Ferfulesin t - ‘ ' - . i ‘ H o 0 - - .l t - ....‘ \ “ ..'. ‘. ...-..H-.'.'-.“‘:::: - u I . ..
gs 1373 11.127 156.8 7,118 19:9 T‘wo uppcrrows oftnbes plugged............ 6b 403 11:31 1%} 147.2 8,152 I” :0.“ 21: “ 1931-1111 :: :2 I: I: as
61 310 8 62 .643 _ - 132.2 8.08 15.5 ,057 13] 11 " ‘ ' ' 1.“! “ u . . . 1 . . . . . . . . . . . . . .1 59
62 210 5'82 '11‘ 12.28 106. 7.91 13.4 043 21 4 11 1‘3" “ “ ........... .. so
63 .05 6 “ .1... SD; \1 u 1; “ . I . . . v “nu: 1 1 1 1 1. 64 507 1111111 1213-1 2.113 9.1 1014 2'1'3 11 I: 1: :1 1: 62
r. I .I r _ b). n. 1 ' ‘ -\-a' ‘ c ~ - n v u . u \ - i - .\
12.11; 1:17.). 11.15 174.8 6.62) 2914 '95”; J 11111-111011 111 11111111 g2
67 356 11-42 11.2135 11111.5 6.88 11 11 1“: .. “ :1 ................................ .. 65
68 571 18.28 '452 11 '01 3'27 4° 4 '142 15-4 “ - G s 101111111111 81 '15 """"""""""""""" " “6
119 452 14.51 '359 1147 W's 4'98 “ “ 15- “ .1111 '11 ' 11 ° 1; ---------------------------- 1. 67
70 157 5.03 '125 12.63 " 4'13 “ “ 13.9 “ _ 11 11 11 -------------------------- -- 68
71 123 8.42 .13. “'21-, 1.57 “ *1 1773 11 " 7‘ “ “ - 1 1 - - 1 - - 1 - . . . . . . . . 1 1 1 1 . . . . . . 1. 69
72 ‘ ~r .1 15, “ .... leerruljs 1 t b n v - n 1 1 1 1 1 1 1 - 1 1 . 1 1 1 - u ~ u 1 . a 1 . 1 1 .1 73 870 10 26 '389 11"81 3.09 “ H 136 1‘ “ (1 mull ('8 1 1 1 . 1 1 . . 1 1 . . 1 . . . 1 . . . 1 . 1 . . . . , _ . , _ _, 71
1 1 . 4.6 “ 11 1373 11 u u 1 1 . 1 1 . . . 1 . . . . . . . . . . . . . . . . 1 . . . . . . . ..

















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'wvms ‘sau'noa
681
Summary of Experiments with Vertical Water-Tube Boiler, 1865, 1866—(C0ntinued).
















rd
‘2’ POUNDS OF counus'msm PER POUNDS or warm; svarorwmn, RATIO
1; nova. FROM AND AT 212°.
8
Q Per Cent. of
q 5:? Draught. Evaporation REMARK3~
L2 for Draught.
a: Per Square Per Square P P d or Per Square Foot FIZZ: faith Of Heating Golf Tum:
g Total. Foot of Grate FootofHeat- Cfmbfi‘ible of Grate Sur- mg Surface to Grate "game"
' 7
5 Surface. ing Surface. face, per Hour. per Houn Surface. surface.
Z
87 545 15.14 .481 12.81 198.8 5.5 85.1 .154 20.8 Jet. 5.95 G. S. reduced to 86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
88 587 16.81 .465 12.57 205.4 5.85 “ “ 16.4 “ 4.34 “ “ 86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
89 496 12.71 .892 13.11 166.6 4.45 82.4 .142 15.9 “ 8.77 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40 879 15.92 .081 12.74 201.9 3.8 58.1 .288 15.9 Natural. G. 8. reduced to 28.8 . . . . . . . . . . . . . . . . . .
41 675 17 .8 .584 11 .82 195.5 6.08 82.4 .129 15.8 J et. 5.66 Calorimeter reduced by plates . . . . . . . . . . . . . . . . . . . . . . .
42 662 16.97 .524 11.54 195.5 6 04 " .114 16.5 “ 7 .89 “ “ rods in tube spaces . . . . . . . . . .
43 646 16.56 .511 11.85 195.9 6.04 “ .142 16.9 “ 5.86 Chimney reduced to 4.14 . . . . . . . . . . . . . . . . . . . . . . . . . . .
44 667 17 .1 .528 11 .89 194.9 6.02 “ .114 16 6 “ 5.25 Celerlmeter reduced by rods in tube spaces ......... . .
45 558 14.82 .408 12.01 171.6 5.8 “ .125 18.8 Natural. . . . . . “ “ “ “ . ..... . ..
46 505 12.94 .869 12.89 160. 4.94 “ .111 17.6 “ . . . . . “ “ “ “ ......... . .
47 486 12.45 .855 12.61 157.5 4.86 “ .1 18.4 “ . . . .. “ “ “ “ .. . . ..... . .
48 599 15.87 .781 11.22 175.5 8.76 19. .126 18.8 Jet. 5.48 Bars in upper tube spaces . . . . . . . . . . . . . . . . . . . . . . . . . ..
49 596 15.29 .899 11.01 168.3 9.9 17. .11 19.1 Jet. 5.55 Bars in upper tube spaces . . . . . . . . . . . . . . . . . . . . . . . . . . .
50 869 9.47 .292 12.8 126. 8.89 82.4 .1 18.6 Natural. .. . . . “ between tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
51 449 11.51 .355 18.15 151.8 4.69 “ “ 22.2 “ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . ..
52 248 6.86 .196 13.4 85.2 2.68 “ “ 17.4 “ ..... “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
53 687 17.69 .504 11.28 198.2 5.65 85.1 .154 20.1 Jet. 5.99 “ “ “ G. S. reduced to 86. . . . . . . . . . . . .
54 666 17.08 .527 11.15 189.8 5.86 82.4 142 17. “ 4.8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
55 602 15.44 .477 11.7 180.2 5.56 “ “ 22.5 “ 5.95 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
56 671 17.22 .582 11.08 189.2 5.84 " “ 17.4 “ 4.9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57 657 16.88 .519 11.76 198.2 6.12 “ “ 18.2 “ 4.59 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
58 782 20.06 .619 9.8 197. 6.08 " “ 18.2 Fan 8.98 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
59 779 21.65 .617 9.28 200.8 5.7 85.1 .154 17.8 “ 4.56 G. 8. reduced to 86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
60 1,050 26.98 .831 7.17 192.9 5.95 82.4 .142 16.8 “ 6.87 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
61 167 4.27 .132 14.87 61.5 1.9 “ .1 12.1 Natural . . . . . Bars between tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
62 679 17.4 .587 12.51 217.5 6.71 “ .142 16.7 Fan 6 65 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
68 760 19.49 .602 12.47 242.5 7.48 “ “ 17 4 “ 7.88 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
64 786 18.87 .582 18.82 280.6 7.12 “ .1 17.8 “ 8.19 Bars between tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
65 887 8.65 .258 14.06 117.7 8.68 “ .111 28.8 Natural. “ “ “ . . . . . . . . . . . . . . . . . . . ....... ..
66 550 15.29 .486 11.38 172.9 4.98 85.1 .154 19 6 Jet. 5.80 G. 8. reduced to 86. . . . . . . . . . . . . . . . . . .. .. . . . . . . . . ..
67 304 7.78 .24 14.86 115.9 3.58 82 .4 .1 20.8 Natural. . . . . . Bars between tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
68 545 18.97 .481 13.89 187.6 5.79 “ .111 20.9 Jet. 8.81 “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
69 824 8.81 .257 13.75 114.7 8.54 “ .1 16.1 Natural. ..... “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
70 701 17.98 .555 12.14 217.8 6.72 “ .142 20.9 Fan. 12.08 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
71 668 17.12 .529 12.98 222.3 6.86 “ .1 19 .1 “ 8.06 Bars between tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
72 488 12.51 .385 12.95 148.4 4.59 “ .142 18.7 Jet. 4.7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. - . . . . . . .

NUMBER FOR REFERENCE.


()(511
'WVHIS ‘suu'nou
Summary of Experiments with Vertical Water- Tube Boiler, 1865, IBM—(Continued).







{:1
% POUNDS 0F COMBUSTIBLE PER POUNDS OF WATER EVAPORATED, RATIO
g noun. FROM AND AT 212°.
E3
[1*]
m Per Cent.
5 of Refuse.
{=7 Per S uare .
g T Per Square Per Square Per Pound of Per Square Foot Foot 0;.1H cab 01‘ Heating cgiggfier
m otal. Foot of Grate Foot of Heat- Combustible of Grate Sur- in Surface to Grate to Grate
5 Surface. ing Surface. ' face, per Hour. pi Hour. ’ Surface. Surface-
Z
73 492 12.61 .389 13.1 - 165.1 5.1 32.4 .142 20.2
74 661 16.95 3.66 6.18 104.2 22.5 4.6 068 19.5
75 261 6.7 1.45 8.14 54.5 11.8 “' “ 16.3
76 495 12.7 2.74 7.03 89.3 19. “ “ 17.8
77 683 17.5 .54 12.75 204.8 6.32 32.4 19.1
78 665 17.05 .526 12.43 194.9 6.02 “ “ 18.3
79 246 13.64 .194 12.66 162.7 2.31 70.3 .111 18.
80 570 14.62 .451 12.19 178.2 5.53 32.4 .1 18.3
81 180 9.96 .142 13.31 132.5 1.88 70.3 111 19.5
82 103 5.94 1084 13.44 79.6 1.13 “ " 14.9
83 495 12.68 .391 12.09 152.5 4.71 32.4 .142 16.4
84 400 10.26 .317 13.16 134.6 4.16 “ “ 14.
85 403 10.32 -319 13.11 134.9 4.16 “ “ 13.6
86 572 14.66 .453 12.59 184. 5.68 “ “ 16.1
87 390 9.99 .308 13.23 131.9 4.07 “ “ 16.2
88 779 19.96 .616 12.03 240. 7.41 “ “ 16.1
89 393 10.08 .323 13.2 132. 4.23 81.2 “ 15.2
90 457 11.72 .37 ' 12.55 147.4 4.73 “ “ 17.2
91 77 17.37 -557 12.16 211.1 6.76 “ .1 17.5
92 392 10.05 .345 12.89 129. 4.43 29.1 142 15.5
93 491 12.58 .412 12.63 158.8 5.46 “ “ 17.9
94 401 10.28 -381 12.68 129.5 4.8 27. “ 13.8
95 509 13.06 434 12.05 157.2 5.82 “ “ '16.6
96 392) 10.14 -407 12.5 126.3 5.07 24.9 “ 14.6
97 563 14.50 -585 11.77 171-1 6.87 " “ 16.4
98 402 10.32 -452 12.08 124.6 5.47 22.8 “ 14.2
99 543 13.93 -611 11.64 162.6 7.13 “ “ 16.5
180 fig: 1g.gg -?0% 12.;9 124.4 6.01 20.7 “ 13.7
. - 6 . 177- 8.55 “ “ 18.5
102 396 10.15 -54 11.64 118.3 6.29 18.8 “ 15.8
103 636 16.31 -867 10.69 174.4 9.28 “ “ 16.5
104 394 10.1 -612 11.41 115.1 6.98 16.5 “ 16.










Per Cent. of
Draught. Evaporation
for Draught.
Jet. 7.36
Natural. . . . . .
H
“ IIIII
Fan. 8.05
" 7.97
Jet. 10.07
“ 4.05
Natural. . . . . .
H
“ . . . ..
“ . . . . .
“ .. . . Jet. 5.14
Natural . . . . .
Fan 7.97
Natural . .
‘5
Fan 7.77
Natural .. . . .
“ .. . . .
“ . . . . .
“ . . . ..
“ . . . ..
“ .. . . .
“ .. . . .
“ ' u I n o
“ .... .



ce'
0
Z
c:
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H
h
re
a:
REMARKS. g:
{:4
01
re
a:
2
p
Z
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 78
Tube spaces closed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
“ " " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
“ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 76
Plates in tube spaces. Chimney reduced to 3.9 . . . . . . 77
n ts n u u u ' ' . _ , .
G. 8. reduced to 18. Calorimeter reduced . . . . . . . . . . . . 79
Calorimeter reduced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 80
G. 8. reduced to 18. Calorimeter reduced . . . . . . . . . .. 81
“ “ “ " “ . . . . . . . . . .. 82
Deflecting platcsiu tube box .. . .. 83
~1 a “ ':"""':::::::::::12:: 3%
~* “ “ 1.11'111 ' . . . . . . . . .. se
1‘ ~‘ “ ....I...IIII.....II..... s?
“ “ “ . . . . . . . . . . . . . . . . . . . . . . . . SS
3 rows of tubes removed . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
‘- “ ‘ " . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
“ “ “ “ Calorimeter reduced . . . . . . . . . 91
5 “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . .. 92
“ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
"- “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . 94
‘1 ‘~ “ ~* 1...... ............I . . . . .. 95
12 “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
“ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . .. 97
15 “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . 98
h ‘- ‘ “ II . . . . . . . . . . . . . . . .. 90
18 1‘ 1‘ “ ....1::...:: 100
~1 ‘~ “ e I::."‘:....::: ......... .. 101
21 “ “ “ ....III. .......... .II..... 102
e *1 “ =* ........I ................ .. 103
24 “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104




'wvems ‘sue'noa
I61
Summary of Experiments with Boilm's of Various Forms.

POUNDS OF COMBUSTIBLE

POUNDS OF WATER EVAPORATED,



















g 3 PER noun. FROM AND AT 212°. RATIO 0F 22%
z a ' Per 5 E]
H m 06”" REMARKS. m 83
Q 5 Per Square Per Square Per Pound 1?" Square Per Square Heating to Draught or S E
D g Total. Foot of Grate Foot of Heat— of Combus- Fact 0f Graze 1900‘; Of Heat- Grate Sur- Area to Refuse' D g
2‘ Surface. lug Surface. tlble. surlfim’ P" mg smrm’ face. Gm“ 3"" 2
our. per Hour. face.
I.—I'IOBIZONTAL FIRE-TUBE Bormns, wrrn 'rrm TUBES ss'ruausn ABOVE run Funuaes, INTERNALLY FIRED.
1 51 4.7 .341 9.43 44.7 3.22 13.9 .092 14.9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ‘ » 1
2 101 9.38 .674 9.08 85.2 6.12 “ “ 14.7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ‘3
3 146 18.49 .969 8.45 114. 8.2 “ “ 18.6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3
4 196 18.18 1.306 8.21 149.2 10.72 “ “ 17.7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4
5 241 22.34 1.605 7.96 178. 12.86 “ “ 24.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5
6 139 12.89 1.113 8.25 116.3 9.18 11.6 .069 22.1 Lower row of tubes plugged . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7 143 13.2.1 1 .436 8.88 118. 12.75 9.3 .046 20. Two lower rows of tubes plugged . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
8 133 12.32 1.781 9.07 111.7 16.15 6.9 .023 24.9 Three “ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
9 1115 12.18 .706 9.24 112.4 6.46 17.2 .115 19.6 Grate reduced to 8.64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9
10 75 11.51 .505 9.29 108.7 4.61 22.8 .158 22.9 “ “ 6.48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
11 52 12.13 356 9.82 113.8 8.42 34. .229 21.4 “ “ 4.32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Ex erlmental 11
12 147 17.04 .935 8.46 144. 8.28 17.2 .115 17.8 “ “ 8.64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. } oiler. 12
13 139 21.5 .941 8.2 171. 7.6 22.8 .158 21.6 “ “ 6.48.. . . _ . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U. S. Navy-Yard, 18
14 90 20.85 .613 s . 29 165 .1 4 . 27 84. .229 24 . 4 “ “ 4.32 ...................................... .. Brookb'n- 14
15 124 11.5 .993 8.53 98.2 8.47 11.6 .069 16.4 Lower row oftubes plugged . . . . . .‘ . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15
16 101 9.33 1.009 9 .08 84.7 9.16 9.3 .046 15.4 Two lower rows of tubes plugged . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
17 68 6.31 .912 11.16 70.4 10.04 6.0 .023 15.6 Three “ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
18 144 13.34 .958 8.7 116. 8.34 13.9 .068 19.2 Ferrules in tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
19 144 13.29 .955 8.69 115.4 8.3 “ .013 20. “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
20 49 4.49 .323 11.23 50.4 8.62 “ .019 22.4 “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 20
21 150 18.85 .995 8.54 118.3 8.5 "' .092 16.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21
22 143 13.21 3.135 6.42 84.7 20.11 4.2 .067 20.8 All tubes plugged . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 22
23 147 13.62 3.232 6.43 87.6 20.81 “ .047 17.9 “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
24 93 8.5; 2.0%? 17.28 67.8 16.08 2“ .028 27.2 “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2g
25 887 9.8 .3 1.‘ 111. 4.33 5.6 13 8.7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
26 442 10.29 .425 11.22 122. 4.71 e “ ms ............................................................ .. % Ur 53,3333“ 26
27 426 10.32 .589 11.16 114.1 4.45 17.5 .078 19 .8 Two upper rows of tubes plugged . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' 27
28 698 14.1 .582 11.22 158.2 6.54 24.2 .14 19.4 Area of openings in furnace doors. 128.4 sq. in.. . . . . . . . . . . . . .. ‘ 28
29 700 14.15 .585 11.1 157. 6.49 “ “ 19.9 “ “ “ “ 108.1 “ . . . . . . . . . . . . . . . .. 29
30 728 14.71 .607 10.9 160.3 6.62 “ “ 18.3 “ “ “ “ 91.7 “ . . . . . . . . . . . . . . . . . 30
31 776 15.67 .647 10.75 168.4 6.96 “ “ 17.7 “ “ “ “ 25.6 "' . . . . . . . . . . . . . . . .. 81
32 723 14.6 .603 10.73 156.6 6 .47 “ .124.- 17.4 Ferrules in tubes. Air holes us in 28 . . . . . . . . . . . . . . . . . . . . . . . . .. 32
as 666 18.46 .556 11. 14a. 0. 12 “ .108 18.7 " “ r " ........................ .. U q revmue as
34 648 13.08 .54 11.26 147 .4 6.09 “ .094 18.8 “ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . .. r stagger Miami 84
35 579 11.7 488 10.85 127. 5.25 “ .068 19. “ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . .. ‘ ‘ 35
36 675 13.63 664 10.85 147 .8 7 .21 20.5 .112 19.9 Two lower rows of tubes plugged. Air holes as in 28 . . . . . . . . . . . 36
37 '58 11.88 .707 11 .31 134.3 7.99 16 . 8 .084 21 .5 Four “ “ " “ “ . . . . . . . . . . . 37
38 516 10.42 .795 10.77 112.2 8.56 13.1 .056 21.4 Six “ “ “ “ “ . . . . . . . . . .. 38
39 594 11.79 .495 11.3 135.5 5.6 24.2 .14 21.7 Alr holes as in 28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39
40 489 9.87 .408 10.9 107.5 4.44 “ “ 16.4 “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 40







7361
'wvnms ‘ssn'noa
Summary of Experiments with Boilers of Various Forms—(Continued).

POUNDS OF OOMBUSTIBLE
POUNDS OF WATER EVAPORATED,











g kg PER noun. FROM AND AT 212°. RATIO OF ‘5 m
In (:2 Per “4 g
g 8 09"" REMARKS 5 a";
m P S P S . D ht f ' m
2 {2 Per Square Per Square Per Pound Fog: “(132:6 Fog: 09:1221 Heatzng to Artsagto Reguse' E E
D g Total. Foot of Grate Foot of Heat- of Combus- f _ . Grate Sur- D g
2‘ Sin-face. ing Surface. tible. sur age, per mg surface’ face. Grate sup 7‘
Hour. per Hour. face.
IL—HORIZONTAL FIRE-TUBE BoILERs, INTERNALLY FIRED, OF THE LOCOMOTIVE TYPE.
41 85 16.04 .731 ' 9.47 151.8 6.98 21.9 .101 21.6 Uncovered, extreme temperature 682" . . . . . . . . . . . . . . . . . . . . . . . . $ Small locomotive 41
fig 72% 11).? 8.18 “ i‘ 22.8 Covered with felt, extreme temperature 585° . . . . . . . . . . . . . . . . . boilerin open shed.
‘ 4. . - 1 . .8 5.05 28.5 . 88 16.9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
44 709 18.12 .46 10.7 141.6 4.97 “ _ .151 16.6 Ferrules in tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l U. S. steamship 44
45 712 18.18 .462 10.79 142.2 4.99 “ .123 18.2 “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [ Kansas. 45
:6! .878 16.57 1%.: 42“ 6 “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. J . . 6 .8 8. 1. ~ . . 0.
48 9. .26 10.1 84. 2.4 v - . - . - e s - I - . e - . - - l s u o - - s . . . u u a u a e e - s - - - 49 694 4.72 .208 11.82 51.5 2.27 I 22.7 .15 15.1 Waterman‘s experimental boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 49
IIl.—UPI>ER RETURN-FLUE BOILERS, INTERNALLY FIRED.
.2
50 982 15'21 ‘723 8'54 129's 6'15 21'1 l .114 } 12'5 I U. S. steamship Shoekok'on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
51 571 8.84 .42 8.52 75.8 8.57 “ “ 12.5 51
52 902 9.1 .488 8.67 78.8 8.79 20.8 i 11.1 U. s. steamship James Adger ................................ ._ 52
1V.—-DOUBLE RETURN DROP-FLUE BOILERS, INTERNALLY FIRED.
.114
58 180 8.45 .125 18.46 46.4 1.68 27.7 g g 25. U. S. steamship Whitehead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. .115
54 528 9.87 .428 11.45 107 .2 5. 21.9 a .1g7 } 18.4 U. S. steamship Morse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.1 9
V.—SEOT10N4L 0R WATER-TUBE BOILERs, EXTERNALLY FIRED.
.071 '
55 184 6.8 .808 10.58 71.5 8.59 22. g } 22.7 Howard boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
56 411 12.43 .244 9. 111.8 2.2 50.8 1062 9.3 . ‘ 56
57 .163 I 1 ‘ 64 “ “ }Exeier b011er . . - . . . . . . - . . . . . . . . - - . . . . . . . . . . . . . - . . . . . . . . . . . . . . r . 58 161 10.71 .268 10.69 114.6 2.86 40. 10.8 “ Acme ” boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
59 623 18'68 '37 10'33 141's 3'83 86‘9 ‘g 7'9 Babcoek 85 Wilcox boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
60 896 8 . 69 .235 11.87 103 . 2.79 “ “ 10.2 60





'wvms ‘san'noa'
861
Summary of Experiments with Boilers of Various Forms—(Continued).

























POUNDS 0F OOMBUSTIBLE POUNDS OF WATER EVAPORATED RATIO OF
g #5 PER noun. F1101! AND AT 212°. 9; ,5
i“ 9 Per {a g
a P S r P S ua Dra ht ceili’t. REMARKS' é g
g M per Square P" square per Pound Fog: ofqGuta‘tae F02: ofqHeli- Heating to Arezgto R970”. 5 E
D E Total. Foot of Grate Foot of Heat- of Combus- s r i S f Grate Sur- G te S _ D H
27 Surface. ing Surface. tible. urHm’ per “g “r we" face. I m “r z a
Our. per Hour. face.
VL—EXTERNALLY—FIRED BOILERS, VARIOUS Fonms.
61 269 4.89 .184 12.18 59.6 1.57 87 .9 .118 7 .7 Lynn Water-Works, horizontal tubular . . . . . . . . . . . . . . . . . . . . . . . 61
62 411 10.55 .428 11.18 117.9 4.72 25. .141 11.1 Ganowa bone 62
68 307 7.83 ‘316 11‘56 91.1 8.65 11 111 y 1‘. . . . . . . . . . . . . . . . . . . . . . . - . . . . . . . . . . . . . . . . . . . . .. 68
64‘ 237 9'48 1'182 10'04 95'2 11'87 8' l :042 8'4 Pierce boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 64
65 99 .19 99* .1 22
66 . . 1 . .5 8.8 . . 9. ‘
67 I 8 .28 . 1 2 .86 u . 1 % e - v . ¢ e I n o u - - - 1 Q . ~ o - u Q u 0 E u s - . . l a ~ . s . s . ~ u 8 e < u - . ¢ - . . l - 68 1,888 11.89 .296 10.65 126.7 8.15 40.2 g 11.8 Brooklyn Water-Works, drop flue. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . 68
' I219
69 188 12.6 .856 11.75 147.5 4.5 86. j. .143 } 9.9 Cumberland coal .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hoyt furnace, 69
70 226 14.8 .18 12.46 192.1 2.25 88. “ 10.2 “ “ Heater in chimney . . . . . . . . . . . . . . . . . . . . . . . . . .. drop-flue boiler. 70
71 229 15.8 .48 11.69 178.4 4.92 86. “ 20. American Cannel coal from Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
72 160 5.9 .22 9.56 54.1 2.04 27 . .391, 80. N. Y. Hospital, ordinary iurnace, American Cunnoi . . . . . . . . . . . . .. 72
. )
78 212 9'42 ‘274 11‘22 105's 8'07 84'4 l .086 } 10'6 Lowo boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 78
74 186 6.06 .175 11.87 71.7 2.08 “ 4:64 11.8 74
75 885 16.86 .549 10.18 166. ' 5.57 29.8 <3 11.8 Ronehamp coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 75
70 179 9.09 .291 10.9 94.0 8.1 “ ' *~ 14.7 “ “ ............................................ .. Lancasm‘e Mile“- 76
77 885 16.82 .548 10.26 167.4 5.62 “ “ 14.4 “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' 77
78 298 14.54 .488 8 . 65 125.7 4.22 “ “ 9 .9 Baarbrfick “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
79 917 17.27 .57 10.02 179.1 5.71 90.9 3 i 14.1 Rouchamp coal ............................................. .. ‘ _ 79
90 186 9 .20 .806 10 .70 99 . 5 8 .28 “ ' “ 14. “ “ ......... . .. ................................. . . Emma“ “‘1” so
81 809 15.89 .508 8. 66 188.2 4 .4 “ 4:64 9 .1 Sanrbriick‘ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
82 820 15.59 .815 11.2 174.6 8.58 49.5 g :888 18.8 Ronehamp coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 82
.712 r Fairbairn boiler.
88 186 9.07 .188 10.52 95.4 1.98 “ “ 18.4 “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 88
84 297 14.5 .298 9 .27 184.4 2.72 “ “ 10.6 Saarbriick “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . . . . . . .. J ' 84



SI
194. BOILERS, STEAM.

Reference has already been made to two of these tables; and the third gives results of expert.
ments with boilers where the proportions were varied, and with some Of the principal varieties of
boilers in use. All the experiments in these tables, with a few exceptions that are noted, were made
with anthracite coal Of good quality; and they were all conducted for a suih‘cicnt length of time to
furnish valuable standards of comparison, with the exception of experiments 56-60, 62—67, 78 and
74-, which lasted but 8 hours each, and are in some other respects less reliable than the remainder,
Nearly all the experiments, however, it must be remembered, were made with clean boilers, and
with firemen rather more skillful than the average; so that for ordinary practice, with boilers of simi-
lar design, the results are liable to be somewhat reduced.
It will be Observed, in the third table Of experiments, that in several instances there is more than
one value Of the ratio of calorimeter or draught area to grate-surface. This is because the calorim-
eter varied in different sections Of the course of the gases. It also varied in some other instances
that are not noted because the data could not be obtained; and in all instances where a single
ratio is given, it refers to the tube or fine calorimeter for tubular or fine boilers, and to the most
restricted section for other varieties. The experiments in the third table are taken from “Ex-
perimental Researches in Steam-Engineering,” “ Reports on Tests of the Lynn and Lowell Pump-
ing-Engines,” Van Nostrand’s Eclec/z'c Eiwgineering zllctgazine, xiv., “Report of Boiler-Tests at the
Centennial Exposition,” and “Bulletin do in Société Industrielle de Mulhouse.” The data are,
however, in some instances more complete than in the original publications.
To properly discuss these experiments would require more space than is allowed, and the reader
who desires to turn them to account will find them worthy of careful study. Some few hints as to
methods can only be given. The table Of experiments with the horizontal fire-tube boiler, for in-
stance, can be rearranged so that the experiments take rank with respect to the total combustion per
hour, the combustion per hour per square foot of grate-surface, or any other heading that is consid-
ered important, and, with each arrangement, some valuable facts will be disclosed. To give a single
illustration, suppose it is required to design an horizontal fire-tube boiler for a slow rate of combus-
tion—say, from 7 to 9 lbs. of combustible per square foot of grate per hour. Pick out all the experi-
ments in the first table where the combustion is between these limits, and it will be found that about
the same economy will be produced, whether the boiler be built Of the ordinary proportions, or
whether the heating surface and calorimeter are considerably reduced—so that the latter arrange-
ment is to be preferred as the cheapest.
It is believed that those tables are suliiciently extended to aid in the design of a. boiler for most
circumstances that occur, and, in nearly every instance, the normal proportions given are representa-
tive of good practice, while the varied proportions frequently show how this practice can be im-
proved.
The general conclusions that seem to be warranted by these experiments and others of a similar
character can only be briefly alluded to. As boilers are ordinarily designed, the vertical water-tube
boiler with the tubes above the furnace is the most economical, because it breaks up and mixes the
gases most thoroughly. It is probable, however, that nearly any other form Of boiler can be made to
produce the same economy by a proper variation of calorimeter and heating surface. SO far as mere
economy of evaporation is concerned, therefore, it seems to be a matter of indifference which form
is selected; but in regard to economy of construction, great variations will be found to exist.
The accompanying table will be found useful in proportioning the heating surface and calorimeter
of tubular boilers. Its use will be readily understood by inspection :
Dimensions of Boiler Tubes.














I
' EXTERNAL “new INTERNAL EXTERNAL sun- INTERNAL sIrR- INTERNAL i
Muss FACE, PER FOOT FACE, PER FOOT FM“)
DIAMETER. ‘1 ~ DIAMETER. 0F LENGTH_ OF LENGTH, OROSS~SEOTION. :rF'R
In In In In In In Square In Spinre In Square In Square In Square In Square In
Inches. Feet. Inches. Inches. Feet. Inches. Feet. Inches. Feet. Inches. Feet. Inches.
1.25 1042 .072 1 .106 .0922 47.1 .3272 41.7 .2896 .96073 .006672 1.25
1.5 125 .033 1.334 .111 56.5 .3927 50.3 .3492 1.3977 .009706 1.5
1.70 147.8 .095 1.56 .13 66.1 .4582 58.8 .4084 1.9113 .013273 1.75
2. 1667 .095 1 .81 .1508 75 . 4 .5236 63 . 2 .4739 2.573 .017868 2.
2 .25 1875 .095 2.06 .1717 84 . S .5891 77 .7 .5398 3 .3829 .023145 2 .25
2.5 2 182 .109 2.232 . l9 )2 94.2 .6545 86. .5974 4.09 .028403 2.5
2 .75 2292 .109 2. 532 .211 108.7 .72 95 .5 .6629 5 . 0352 .034967 2 . 75
3. 25 .109 2.782 .2313 118.1 .7854 104.9 .7283 6.0786 .012213- 3.
8.25 2708 .12 3.01 .2508 122.5 .8509 113.5 .788 7.1153 .049415 3.25
3.5 .2917 12 3.20 .2717 132. .9163 122.9 .8573 8.3469 .057965 3.5
3.75 3125 12 3.51 .2925 141.4 .9818 182 3 9189 9.6762 .067196 3.75
4. 3333 134 3.732 .311 150.8 1.0472 140.7 .977 10.924 .075964 4.
4.5 375 134 4.232 .3527 169.7 1 1781 159 5 1.1079 14.066 .097683 4.5
5. 4167 .148 4.704 892 188.5 1 809 I77 3 1.2315 17.379 .12069 5.
6. 5 .165 5.67 47’5 226.1 1 5708 218 8 1.4344 25.25 .17535 6.
7. .5433 .165 6. 67 .5558 263 .9 l .88 26 251.5 1 .7462 34.861 .24265 7.
, 8. .6667 165 7.67 .6892 301.8 2.0944 289.2 2.008 46.204 .32086 8.
9. .75 18 8.64 .72 339.3 2.3562 325.7 2.262 58.63 .40715 9.
10 . 8333 293 9 . 594 .7995 377. 2 . 618 361.7 2.5117 72.292 .50203 10 .








l
1
1
i
1
When the calorimeter of a boiler is one-eighth of the grate surface, the best conditions for maxi-
mum combustion exist; and if a slow rate of combustion is employed, both calorimeter and heating
surface can be reduced without loss of economical eiieet. There are many boilers in use toulay, burn--
BOILERS, STEAM. 195

W—
ing coal at slew rates, that could have half their tubes plugged up, or could be made just so much
smaller, and evaporate as much water as before ; while, if the tubes were half as many and twice as
long as for maximum combustion, thus reducing the calorimeter and preserving the heating surface,
the economical effect would be increased.
Boilers set in brickwork are ordinarily less economical than those internally fired, on account of
the greater loss by radiation.
The reader who consults the works from which these experiments are taken will find the above
principles discussed at length. .
The diameter of tubes to be chosen for any special case will depend upon their length. A good
length for 3-inch tubes is 12 feet, and the diameter can be diminished or increased 1 inch for each
decrease or increase of 4 feet in the length of the tube, and in similar proportion for any other vari-
e
ation in length. Thus, for tubes 4 feet long, the diameter may be .121 X 3 z: 1 inch, and for tubes
18 feet in length the appropriate diameter is X 3 : 41} inches. These lengths are for maximum
combustion; and when the rate is reduced, the tubes can be lengthened.
The proportions of water and steam room in boilers vary greatly. A ratio that is quite common
in good practice is an allowance of 60 per cent. of the whole capacity of the boiler as water-room,
and the remaining 40 per cent. as steam-room. In many instances the space is equally divided be-
tween steam and water room ; and a less proportion of steam room than 40 per cent. of the whole
capacity is not considered advisable, except in cases of slow combustion, as boilers with an insuffi-
cient supply of steam-room frequently prime.
Priming is the tendency of the water in the boiler to foam and pass in a state of spray into the
cylinder along with the steam; and when in too great a quantity to escape through the steam-port in
the return stroke, it infallibly breaks down the engine. This effect must invariably iollow the prim-
ing of a sufficient quantity of water in the cylinder of a beam-engine in a factory, because it is not
and cannot be expected to be calculated to withstand a sudden blow, and such it is in reality. For if
the water primes into the cylinder in the down-stroke, it must remain on the top of the piston until it
strikes against the cylinder cover in the tip-stroke, with more or less violence according to the quantity.
From the incompreSsibiIity of water, the ciiect is the same as if a piece of iron of equal thickness to
the depth of water on the piston was suddenly inserted in its place. The tremendous effect sometimes
produced when a large engine breaks down from this cause may easily be conceived; for, as the vacant
space left for clearance at the top of the cylinder is generally about the same depth in large as in
small engines, the intruding body of water strikes the cylinder-cover with a proportionately greatn-
force. Generally the accident does not end with merely straining or breaking the crank-pin, which
may be the extent of the injury in small engines; but the momentum of the beam is added to that
of the fly-wheel, and their combined force is exerted directly in splitting the cylinder, or tearing off
the cylinder-cover, thus eifectually demolishing all the rods and gearing. Priming arises horn in-
sufficient steam-room, an inadequate area of water-level, or the use of dirty water in the boiler; the
last of these faults may be remedied by the use of collecting-vessels, but the other defects are
only to be corrected either by a suitable enlargement of the boiler, or by increasing the pressure and
working more expansively. Closing the throttle-valves of an engine partially will generally diminish
the amount of priming, and opening 'the safety-valve suddenly will generally set it astir. A steam
vessel coming from salt into fresh water is much more liable to prime than if she had remained in
salt water or never ventured out of fresh. This is to be accounted for by the higher heat at which
salt water boils, so that casting fresh water among it is in some measure like casting water among
molten metal, and the priming is in this case the eiiect of the rapid production of steam. One of the
best palliatives of priming appears to be the interposition of a perforated plate between the steam-
space and the water. The water appears to be broken up in dashing against a plate of this descrip-
tion, and the steam is liberated from its embrace. In cases in which an addition is made to a boiler
or steam-chest, it will be the best way not to out out a large hole in the boiler-shell for establishing a
communication with the new chamber, but to bore a number of small holes for this purpose, so as to
form a kind of sieve, through which a rush of water cannot ascend. In locomotives the same end is
attained by the use of a perforated steam-pipe. extending from end to end of the boiler. Such a con-
trivance draws the steam off equally from the surface instead of taking it from any one part; and
boilers provided with it are enabled to work with so small a steam—space that the steam-domes are
now being taken away from locomotives altogether. This expedient has not yet been adopted in steam
vessels, though it appears to be applicable to them also with advantage. In some boilers priming ap-
pears to be mainly caused by a malformation which prevents the water from circulating freely, and
the steam has therefore to pass up through the water, oecasioning a great agitation, instead of the
water being enabled to circulate with the ascending steam. The evil may be mitigated in such cases
by the addition of pipes to the exterior of the boiler, which will permit a descending current to be es-
tablished, to replace the water carried upward by the steam. This tendency of the water to lise into
the cylinder is always considerably promoted by the very usual situation of the steam induction-pipe
at the back end of the boiler, and seems to arise partly from the constant circulation of the water,
which causes a current at the surface to set in the direction of the length of the boiler from the
ll‘fmt end to the back. This circulation of water takes place in all oblong boilers, with a cer-
tain velocity depending on the ratio that the intensity of the heat in the furnace bears to the
quantity of water to be kept heated, and is entirely independent of other causes, producing acres,
which take their rise over the fire, and gradually increase in height as they pass toward the back
part of the boiler.
The term “ horse-power,” referred to a boiler, has no definite meaning. In the early days of the
steam-engine, when there was little difi‘ercnce in the details of engines and boilers, it usually hap-
196 BOILERS, STEAM.

M
pened that a boiler large enough to furnish one engine with steam would answer for any other of the
same size; and as the power of the early engines was in direct proportion to their size, a boiler of
certain dimensions would furnish steam for an engine developing a definite horse-power, and hence
was said to be a boiler of a certain horse-power. But, as improvements were introduced, and various
forms of boilers and engines were adopted, it was found that the size of a boiler was not always a
measure of its efficiency, and that different engines required very different quantities of steam to de-
velop a given horse-power. Thus it frequently happens that what is a 10-horse-power boiler fer one
engine, or the boiler which furnishes steam to develop 10 horse-power in that engine, may only be a
5'-horse-powc_r boiler for a more wasteful engine. Under these circumstances, it is impossible to de-
cide what the horse-power of a boiler is, in case of dispute. If, on the contrary, the rating of the
boiler is based upon its evaporation under given conditions, a simple experiment will settle whether
it is working up to its rating. The reader will find a good discussion of this subject in the “Reports
of the Committee of the Franklin Institute on the Mode of determining the Horse-Power of Steam-
Boilers.” All the members of this committee agreed that the boiler should be rated according to its
actual evaporation rather than by its dimensions; and while some members thought that a horse-
power should correspond to an evaporation of 1 cubic foot of water per hour, from and at 212°,
others considered that it was not advisable to adopt any standard for horse-power. This is probably
the view of the majority of engineers.
{Pet-ting Bot/wa—If the object of a boiler-test is simply to determine how much water can be
evaporated under given circumstances by that boiler, it is only necessary to weigh the coal and feed-
water, and ascertain the quality of the steam, in order to know whether the apparent evaporation
correctly represents the performance. The trial should be continued for 24 hours at least, in order
to obtain average conditions. It is a good plan, before commencing the trial, to raise steam in the
boiler, then haul the fire, clean out the ash-pit, and start a new fire with wood, beginning the test as
soon as the coal thrown in is kindled, and charging all the coal put into the furnace after the new
fire is started. At the time of starting, the height of the water in the boiler should be noted, and it
should be left at the same height on concluding. The fire should be maintained of uniform thick-
ness throughout the trial, and not allowed to burn out toward the end ; and at the time of closing the
test, the fire should be hauled as rapidly as possible, and the weight of the contents of the furnace,
in a dry state, should be taken at once. The weight of the contents of the ash-pit should be added
to the above, and deducted from the total weight of coal, giving the weight of combustible consumed.
In weighing out the coal, during the trial, it should be done at regular intervals, and a constant
weight should be supplied each time, to avoid errors. The feed-water may be drawn from one or
more tanks placed on platform scales, filled up and drawn down to the same weights each time, so
i that the total feed~water can be obtained at once from a tally of the number of tanks.
Having made these observations, if the water has been evaporated into saturated steam, the quo-
tient obtained by dividing the weight of feed-water by the weight of combustible will give the result
required. In the majority of well-designed boilers the result so obtained will be practically correct.
This cannot be known in advance in any particular case, however, and it is important to determine the
quality of steam furnished during the experiment. A simple and accurate method of making this de-
termination will be explained. Provide a tank with an orifice at the bottom, and place within it a
coil of thin pipe, the lower end of which is brought through the side of the tank near the bottom,
and furnished with a cook. The upper end is to be connected, when in use, to the steam~space of the
boiler. During the trial, steam is to be admitted to the coil through a well-felted pipe, and water to
the tank to condense the steam, so that, knowing the pressure of steam, the weight and temperature
of the condensed water, and the weight, initial and final temperature of the condensing water, the
quality of the steam can be calculated. In order to determine the weight of condensing water, first
ascertain, by experiment, how much water the orifice in the bottom of the tank will deliver for dif-
ferent heads of water in the tank, and, this once determined, it will only be necessary to observe the
head in the tank during the experiment. Another preliminary experiment must be made with this
apparatus to determine the heat lost by radiation and evaporation, which is ascertained by heating
the water in the tank to temperatures similar to those used in the experiment, and noting the loss of
temperature and weight for definite intervals of time. The pipe leading to the coil should be con-
nected to the boiler at such a point that it obtains an average quality of steam. If it draws its sup-
ply from the centre of the steam-pipe, this will generally be accomplished. (Those who are specially
interested in this question will find a very good discussion by Prof. Him, the inventor of the best
plans in use, in the “ Bulletin de la Société Industrielle de Mulhouse,” 1869.) The manner of mak-
ing the calculations from the data observed in connection with this instrument will be illustrated by
an example. (Some of the constants required for the solution are taken from tables of the proper-
ties of steam and water, in the article STEAM.) Suppose that in a certain test the total weight
of coal supplied to the furnace was 4,476 lbs., the weight of feed-water 84,700 lbs., and the weight
of coal and ashes drawn from the furnace and ash-pit 795 lbs., so that the combustible was 4,47 6 -
795 : 3,681 lbs. Hence the apparent evaporation was = 9.4 lbs. of water from the temper-
7
ature of the feed per pound of combustible, if the steam was dry.
Suppose that an instrument was used for testing the quality of the steam, such as has been de~
scribed, and that the observations were as follows: Pressure of steam by gauge, 70 lbs.; weight of
steam condensed at temperature of 95°, 234 lbs.; initial temperature of condensing water, 64°; final
temperature, 92° ; head of water in tank, 24.5 inches; time of trial, 30 hours; and that previous ex-
periments with the apparatus showed that, under the observed head, 4 cubic feet of water weighing
62.1 lbs. per cubic foot were discharged from the tank per hour, and that the loss of heat by radia-
tionuand evaporation from the tank was 1,422 thermal units per hour. Then the amount of heat im-
BOILERS, STEAM. 197

parted to the condensing water per hour was 4 X 62.1 X (92 -- 64) +1,42“ : 8,377.2 thermal units,
and since = 7.8 lbs. of steam were condensed per hour, each pound of steam imparted 8’377g'z =
1,074 thermal units to the condensing water ; and as the condensed steam was discharged at a tem-
perature of 95°, the total heat required to condense a pound, and cool it to 32°, was 1,074 +95 -—
32 :: 1,137 thermal units. The total heat of a pound of dry steam above 32°, at the observed press-
ure, is 1,178.5 thermal units, so that the steam generated in the above experiment contained some
moisture, the amount of which can easily be determined. Calling to the heat of the water, corre-
sponding to the observed pressure, H the total heat of a pound of dry' steam, h the heat per
pound, determined by experiment—all referred to 32°—-the per cent. of moisture in the steam is
H— It X 100 _1,17s.5-1,137
h-w _ 1,137—286.2
ure, calling L the latent heat of the steam, is


X 100 = 4.9. The proportion of dry steam in a pound of the mixt-
h—w l,137-—286.2
= ——~- ~~--~~—- :: 0935 l .
L 892.3 ° b
If the temperature of the feed-water in the above experiment was 64°, each pound of water would
require 1,178.5— 32: 1,146.5 thermal units for its conversion into dry steam, while the actual
amount of heat imparted to each pound of water was 1,137 —- 32 = 1,105 thermal units. Hence the

actual evaporation was 115%} = 0.9638 of the apparent, and the actual evaporation from the tem-
, .
perature of the feed per pound of combustible was 9.4 X 0.9638 : 9.06 lbs., or 9.06 X 1.18 = 10.69
lbs. from and at 212°.
While an experiment similar to the above, if carefully performed, gives the exact data required of
the performance of a particular boiler under special circumstances, it is not sufficiently in detail to
be of much general value, since there is nothing to tell the circumstances under which this perform-
ance was realized, or to enable a comparison to be made with other boilers. Mr. lsherwood has well
said that, if every engineer were to leave on record the particulars of a single complete experiment
made by him, the science of engineering would be much more advanced than is actually the case.
The reader who consults engineering literature in search of such experiments will be surprised to
see how few complete records are to be met with. From the thousands of boiler-experiments, whose
records have been published, there are very few that furnish much useful information, since it gen-
erally happens that the very data required for some important comparison are missing. The only
way to avoid this, in making an experiment, is to give all the data, which, briefly expressed, comprise,
in the case of a boiler-experiment, complete dimensions of the boiler, heating surface and how dis-
tributed, calorimeter, chimney dimensions, drawings of the boiler, all the data taken on the trial, all
the constants and formulas used in the calculations, and a general discussion of the results. The
data mentioned refer not only to weights, pressures, and temperatures, but also to any incidents that
occur, however unimportant they may seem. In regard to the experiment, it should be made to in-
clude, if possible, temperature of furnace and chimney as well as of steam, air, and feed-water—the
air-supply should be measured, and the products of combustion analyzed when practicable—and the
effect of various rates of combustion and of varying the boiler proportions should be tried, if op-
portunity occurs. The kind of coal used should be described, its action noted, and, if practicable, its
analysis given. It is by experiments such as these, as already shown, that the only true knowledge
of correct boiler proportions can be obtained.
The importance of showing clearly the distribution of the heating surface will be evident from the
consideration that the efficiencies of different parts vary so greatly. Thus, in the tubular boiler, as
ordinarily designed, the heating surface in the furnace and back connection evaporates about 50 per
cent. of all the water; and the first foot of the tubes exposed to the heated gases is sometimes more
effective than all the remaining length. By giving the distribution of the heating surface, one of
the causes of the efficiency or inferior performance of a particular boiler is frequently disclosed.
The effect of varying the rate of combustion in a boiler gives results that are very useful for pur-
poses of comparison. In the ease of several boilers, whose durability and safety are equal, that one
rates the highest which evaporates the most water per square foot of heating surface per hour, for
a given rate of combustion per hour, referred to the same unit, for the reason that heating surface
costs money. As results of tests are commonly stated and comparisons made, the evaporation of
one boiler is compared with that of another, without any reference to the rate of combustion in each
when referred to the heating surface; so that the results, when properly compared, might be reversed.
This is sufficiently shown from the experiments recorded in another part of this article; and as it is
sometimes important to make the reduction, a table calculated from Prof. Rankine’s formula (see
“Treatise on the Steam-Engine and other Prime Movers ”) is appended, by which the reduction can
be effected approximately. Of course, whenever two different types of boilers are to be compared,
they should be tried at the same rate of combustion per square foot of heating surface, if possible.
The feed-water heater referred to in this table is one located in the chimney, the heat being im-
parted to the water by the products of combustion.
Example—In a certain competitive trial of two boilers, with heaters, and. natural draught, the rate
of combustion in the first was 0.5 lb. per square foot of heating surface per hour, and in the second
1 lb. The first evaporated 13.2 lbs. of water from and at 212° per pound of combustible, and the
second 11.1 lbs., so that the first evaporated about 19 per cent. more than the second, under these
conditions. If they had both been tried at the rate of combustion of the first, the second would have
.84
evaporated ~5- X 11.1 = 13.32 lbs., or would have been about 1 per cent. more efficient than the first.
Although the principles just stated for recording boiler experiments have not been followed in
the records contained in this article, for the obvious reason of restricted space, an endeavor has been
198 BOILERS, STEAM.
—_
made to give the results in a form sufficiently complete to render them useful in practice ; and the
reader who desires more detailed accounts will consult the references.
Relative Efiez'ency for Dtfl'erent Rates of Combustion.




RELATIVE EFFICIENCY.
Pounds of Combus-
t‘bl" P“ 3‘1"“ NATURAL DRAUGHT. FORCED DRAUGHT.
F oot of Heat—
ing Surface per
noun Boiler with Feed- Boiler without Feed- Boiler with Feed- Boiler without Feed-
water Heater. water Heater. water Heater. water Heater.
.1 1 1. 1. 1.
.2 .955 .946 .971 .969
.3 .913 .906 .945 .941.
.4 .875 .861 .919 .911
.5 .84 .827 .896 .888
.6 .808 .79 .878 .865
.7 .778 .761 .851 .844
.8 .75 .729 .831. .824
.9 .724 .705 .811 .805
1. .7 .678 .792 .78
2. .525 .503 .644 .632
3. .42 .397 .542 .523
4. .85 .33 .468 .456
5. .8 .232 .412 .399
6. .263 .246 .368 .356
7. .233 .218 .332 .321
8. .21 .196 ~ .303 .292
9. .191 .173 .278 .268
10. .175 .163 .257 .247







Construction of Botlm's.—The following rules, giving about one-eighth the ultimate strength of the
material for the working strain, and following the proportions recommended by the best authorities,
will be found useful in practice. They can readily be adapted to any other factor of safety greater
or less than 8; but, taking into account the rapid deterioration of steam-boilers, and the violent
strains to which they are frequently subjected, it is very questionable whether greater pressures or
less thickness should be permitted, on principles of true economy. The reader will find interesting
data relating to this subject in Fairbairn’s “ Useful Information for Engineers,” Rankine’s “Treatise
on the Steam-Engine,” Van Buren on the “Strength of Iron Parts of Steam Machinery,” “ Reports
of the English Boiler InsuranceAssociations,” “Proceedings of the Institution of Civil Engineers,"
xlvi., “Proceedings of the Institution of Mechanical Engineers,” 187 2, Grashof’s “Festigkeitslehre,”
and “Des Ingenieur’s Taschenbuch, von dem Verein ‘Hiitte.’ ”
.Notation.
K = diameter of rivet, in inches.
1) = length of rivet under head, in inches.
1 : lap to be given to joint, in inches.
p = distance between centres of rivets, in inches.
T = thickness of plate, in inches.
P : working pressure of steam, in pounds per square inch.
D : diameter of cylindrical shell, or flue, in inches.
L : length of cylindrical flue, in inches.
R : radius of circular plate, in inches.
m : length of rectangular plate, and side of square plate, in inches.
n : breadth of rectangular plate, in inches.
(Note that m > n.)
S : distance between centres of stays, in inches.
d =- diameter of round stay, in inches.
A: area or cross-section of stay, in square inches.
1. Diameter ofrivets.
2, for plates up to 5,3,- inch in thickness.
K_ T X 1.5, for plates from %- to 2- inch in thickness.
_ 1.25, for plates from 8‘ to $2- inch in thickness.
1.125, for plates from % to 1 inch in thickness.
2. Length of rivets.
v = 4.5 x T.
3. Distance between rivets.
(a.) Single riveted joints.
6, for plates up to ,1; inch in thickness
_ T x 5, for plates from 31- to 9; inch in thickness.
p _ 4, f or plates from to 1,2- inch in thickness.
3, for plates from g to 1 inch in thickness.
BOILERS, STEAM. 199

b——-——
(b.) Each line of rivets, double riveted joints.
7, for plates up to J; inch in thickness.
__ T X 6, for plates from i to 116 inch in thickness.
P "' 5, for plates from 11,; to 135 inch in thickness.
4, for plates from fig to 1 inch in thickness.
. Lap of joint.
Single-riveted Double-riveted
joint. joint. ,
6, 10, for plates up to %- inch in thickness.
l = T x % 4.5, 7.5, for plates from i} to 55 inch in thickness.
4, 6.7, for plates fromif to 1 inch in thickness.
. Working pressure for cylindrical shells.
Single-r1 veted
shells.
.P'::g><il
Double-riveted
shells.
12,000, for steel shells.
9,000, for wrought-iron shells.
6,400, for copper shells.
10,000,
7,500,
5,000,
. Thickness of cylindrical shells.
Double-riveted
shells.
000008333, for steel shells.
0.0001111, for wrought-iron shells.
0.0001563, for copper shells.
Single-riveted
shells.
0.0001,
0.0001316,
T: P x D x 0.0002,
. Working pressure for cylindrical fines of wrought-iron, exposed to external pressure.
T2
LXI)X
a
.P = 1,950,000 ><

bxc'
. Thickness for cglindricalflues of wrought-iron, acposed to eaternal pressure.


Tz1/(000000051282 x P x L X D x
bdxc .
a)
N era—In the two foregoing formulas, the values of the constants, a, b, and c, are as follows:
9.
0.4 for flues from .061 to .087 in. thick. 0.75 for flues from 13 to 25 inches long.
0.45 it u u u 0.7 u u u 51 u
0.5 “ “ .119 “ .159 “ b: 0.65 “ “ 51 “110 “
0.55 “ “ .159 “ .205 “ 0.6 “ “ 110 “253 “
0.6 “ “ .206 “ .261 “ 0.55 “ “ 223 “ 628 “
0.65 “ “ .261 “ .325 “ 1.2 for flues from 2.4 “ 4 in. in diameter.
[0.7 “ “ .325 “ .399 “ 1.3 “ “ 4. “ 6.5 “ “
0.75 “ “ .399 “ .483 “ 1.4. “ ‘.‘ 6.5 “ 10.2 “ “
0.8 u (6 u u c _ 1.5 u H fl (t u
0.85 it (C u u 1.6 H H (t H u
0'9 H H u .8 u u u (t 33. u u
0.95 “ U .8 (6 it 1-8 H U 33‘ 4‘ 47. (i 4‘
1. it u u u 1.9 u u (L u u
Working pressure for flat plates, secured at the edges.
(a.) Circular plates.
T2 Cast-iron plates. Wrought-iron plates. Steel plates.
P = is x 3,750 9,000 15,000
(b.) Rectangular plates.
T9 4+ 4
P: Ali—7L) 5,000 12,000 20,000
m x n‘2
(0.) Square plates.
T2
.P 2 -§ x 10,000 24,000 40,000
m
10. Thickness for flat plates, secured at the edges.
(a.) Circular plates.
_ Cast-iron plates. Wrought-iron plates. Steel plates.


T: R x V? X 0.018257 0.011785 0.0091287
(b.) Rectangular plates.
T: m2 x n x V ( P ) >< 0.014142 0.0091287 0.0070711
m4+ n4
(0.) Square plates.
T: m x V? X 0.01 0.006455 0.005
200 BOILERS, STEAM.

11. Working pressure for stayed surfaces.
T3 Copper plates. Wrought-iron plates. Steel plates.
P : S; x 17,000 27,000 45,000
12. Thickness for stayed surfaces.
_ Copper plates. Wrought-iron plates. Steel plates.
T: S x VP >< 0.00767 0.0060858 0.0047141
13. Wow-kin ressure or sta s.
- g p f y Wrought-iron stays. Copper stays.
P : E;- X 4,000 3,000.
14. Area of stage.
A : P x S2 x 0.00025 0.000333.
15. Diameter of stays.
d: V(1.2732 x A).
The following table for converting vulgar fractions into decimals will be found useful in connec-
tion with these rules.







Halves. Fourths. Eighths. Sixteenths. Decimals.
1 . . . . . . . . . . . . . . . .. .0625
1 . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . .125
3 . . . . . . . . . . . . . . . . . .1875
1 . . . . . . . . . . .. 2 . . . . . . . . . . . .. 4 . . . . . . . . . . . . . . . .. .25
5 . . . . . . . . . . . . . . ... .3125
3 . . . . . . . . . . . . . 6 . . . . . . . . . . . . . . . . . .375
7 . . . . . . . . . . . . . . . .. .4375
1 . . . . . . . . . . . 2 . . . . . . . . . . . . 4 . . . . . . . . 8 . . . . . . . . . . . . . . . . .5
9 . . . . . . . . .5625
5 . . . . . . . . . . . .. 10 . . . . . . .. .625
11 . . . . . . . . . . . . . . . .. .6875
8 . . . . .. 6 . . . . . . . . . . . .. 12 . . . . . . . . . . . . . . . .. .75
13 . . . . . . . . . . . . . . . . . .8125
7 . . . . . . . . . . . .. 14 . . . . . . . . . . . . . . . .. .875
15 . . . . . . . . . . . . . . . .. .9375
2 . . . . . . . . . .. 4 . . . . . . . . . . .. 8 . . . . . . . . . . . .. 16 . . . . . . .. 1.


Examples—1. For a single riveted joint of t-inch plates, the diameter of rivets : 0.125 x 2 =
0.25 inch.
2. For the same joint, the length of rivet under the head : 0.125 x 4.5 = 0.5625 inch.
3. For a double riveted joint of al-inch plates, the distance between centres of rivets in each row
: 0.5 x 5 = 2.5 inches.
4. The lap to be allowed for a single riveted joint of i-inch plates : 0.25 x 6 = 1.5 inch.
5. The working pressure for a cylindrical boiler, 32 inches in diameter, made of wrought-iron
plates 5; inch thick, single riveted, : x 7600 = 59.375 lbs. per square inch.
6. The thickness for the plates of a cylindrical boiler, double riveted, 60 inches in diameter, made
of copper plates, for a working pressure of 40 lbs. per square inch, :: 60 x 40 x 0.0001563 =
0.375 inch.
Nora—In the double riveting to which these rules apply, the two rows of rivets are staggered, that
is, the rivets of one row are midway between those of the other. The rules are designed for shells
that are truly cylindrical, a condition that is only approximately fulfilled with the ordinary lap joint.
In some instances cylindrical shells are constructed with butt joints, covering strips uniting the two
plates. These rules refer to the resistance of a boiler to longitudinal rupture; and as the resistance
to transverse rupture is twice as great, it is not uncommon to make the joints in cylindrical shells
double riveted in the longitudinal seams, and single riveted in the others.
7. The working pressure for a cylindrical flue of wrought-iron, 20 inches i1; diameter, 80 inches
0.37 5)2 0.7
80 X 20 X 0.65 X 1.6
= 115.35 lbs. per square inch. If the flue were 120 inches long, the other conditions being the
(0.375)2
120 X 20 0.6 x 1.6
Since the strength of a fine decreases as its length is increased, it is customary, in the construction
of a flue having a large diameter and considerable length, to divide it into a series of short flues, by
attaching bands or stifiening pieces at short intervals, usually bands of angle-iron secured to the fine
by socket bolts. I ‘
8. The thickness for a wrought-iron flue, 30 inches diameter, 40 inches long, exposed to an exter-
nal pressure of 60 lbs. per square inch = M(0.00000051282 x 60 x 40 x 30 x 0_____'7 :61‘7) =
long, three-eighths of 5.11 inch thick, exposed to external pressure, :: 1,950,000 ><

same, the working pressure : 1,950,000 x = 83.42 lbs. per square inch.

BOILERS, STEAM. 201


0.26 inch. In this example it will be seen that one of the constants has to be determined by trial,
since it depends on the thickness of the plate, which is unknown.
9. The working pressure for the flat head of a cylindrical boiler, unstayed, 20 inches diameter,
(0.5)2
(10)2
10. The thickness for a steel plate, unstayed, 12 inches square, exposed to a pressure of 40 lbs.
per square inch, = 12 x 4/ 40 x 0.005 = 0.38 inch.
11. The working pressure for a wrought-iron plate, stayed at intervals of- 7 inches, and three-eighths
I 2
(0'675) x 27,000 = 77.48 lbs. per square inch.
7'1
made of wrought-iron half an inch thick, = x 9,000 = 22.5 lbs. per square inch.


of an inch thick, =
12. The thickness for a steel plate, exposed to a pressure of 100 lbs. per square inch, with stays 5
inches from centre to centre, : 5 x V100 x 0.0047141 : 0.24 inch.
13. The working pressure for copper stays, having an area of 0.5 square inch, and placed 8
inches between centres, : x 3000 2 23.4 lbs. per square inch.
T812
14. The area for wrought-iron stays, 5 inches between centres, for a pressure on the plate of 100
lbs. per square inch, :: 100 x (5)2 x 0.00025 : 0.625 square inch.
15. The diameter of a round stay, whose area is 0.625 square inch, :: 141.2732 x 0.625)
= 0.892 inch.
As before remarked, if these rules are to be changed so as to give the proportions with a different
factor of safety, the change can easily be made by altering the constants. Thus, if a boiler is to be
proportioned with only five-eighths as much strength as these rules give, multiply the constants in the
rules for working pressure by Q.
Riveting machines are generally used in the construction of modern boilers with plates more than
half an inch thick. The riveted joints, whether hand or machine riveted, are then made tight by
chipping and calking the seams. Sometimes the edge
of the sheet that is to be calked is planed before the
jomt is made.
An important improvement in the mode of calking
joints has recently been introduced. It is illustrated
in Fig. 465, which sufficiently shows the nature of the
improvement.
1Vhere holes are cut in boilers for man and hand
hole plates, and for connection with steam-drum, the
sheet should be strengthened by a band around the
edges of the opening, which band should be of angle-iron in the ease of large openings.
Any pipe that is attached to a boiler should be secured by flanges in preference to being screwed
into threads cut in the sheet.
The tubes of boilers are secured to the tube-sheets by expanding them slightly at the inner or outer
or at both edges of the sheets. Formerly this was done with a hand-tool and light hammer, but
tube-expanders are now employed almost exclusively. The two forms in common use are Prosser’s,


467.










M
.....,l’_/%/,4'_gfil/m ' I
a,“ \ 5'/
466.







Figs. 466 and 467, and Dudgeon’s, Fig. 468. The former, it will be seen, consists of an expanding
hollow plug, in sections held together by a spring. In using this tool, it is inserted into the end of
the tube, and expanded by the action of a tapering mandrel driven into it, turning the expander
slightly after each blow. A collar, Fig. 467, is sometimes used in connection with this tool, which
cuts off the end of the tube while it is being expanded. From the form of the sections, this tool ex-
pands the tube on the outside of the sheet, as well as the inner.
The Dudgeon expander has a series of rollers which expand the tube when forced outward by the
action of a tapering mandrel, which needs only to be turned a few times to do the work. It is stated
that this tool has been used to stop leaks in tubes, with steam in the boiler.
Incrustatz'on and Corrosion—The action of the filtering feed water heater, which removes the solid
202 BOILERS, STEAM.

‘
impurities from the water before it enters the boiler, has already been referred to. This device
proves very efficacious in many instances, but there are some qualities of feed-water that cannot be
purified in this manner. None of the water used in marine boilers can be rendered pure by me-
chanical means ; and where surface-condensers are not employed, it is found impossible to prevent in-
crustations forming on the sheets and fines. The scale or incrustation on the heating surfaces of a
boiler, being a bad conductor, reduces the evaporative efficiency; and if it is very thick, the material
of the boiler frequently becomes overheated, and is thus rendered worthless. There are many so-
called scale-preventives in the market, most of which, however, should be used with caution, since
it is difficult to find anything that will attack incrustations, that is not also liable to injure the iron.
An account of a number of these preparations, with their analysis, is contained in a “Report on
“later for Locomotives and Boiler Incrustations,” by C. F. Chandler. Among the best preventives,
in the case of spring waters, are crude petroleum, soda ash, and tannate of soda. In using any of
these remedies, the boiler should be blown off and washed out frequently. The scale can frequently
be softened by allowing the water to remain in the boiler after the fire is hauled, until it is quite
cool, and then letting it run out. Preparations which act mechanically and soften the scale have
been used with some success. Tobacco-juice was tried for some time in vessels of the United States
navy, and it was found that, while the amount of deposit was not diminished, it could be more easily
removed. (See “Experimental Researches in Steam Engineering”)
At the present time, surface-condensers are used with nearly all marine engines, and, in general,
the amount of incrustation is not great. With the first introduction of the surface-condenser, how.
ever, a greater evil than that of incrustation was developed, which at one time threatened to prevent
the further use of this form of condenser. It was found that the interior of the boiler, where a sur-
face-condenser was employed, corroded very rapidly, particularly in spots over the fire, so that in a
few months the crown-sheet was nearly eaten through in places. Although the cause of this cor-
rosion is not definitely known, it is believed to be due to the action of the grease which is carried
from the cylinder into the boiler, and possibly in a slight degree to galvanic action between the brass
tubes of the condenser and the iron of the boiler. Whether or not this is the true reason, an effective
remedy has been discovered, which consists in tinning the condenser tubes, and allowing a very thin
coating of scale to form on the interior surfaces of the boiler. As this scale, when deposited from
salt-water, is sometimes dissolved, Mr. F. J. Rowan recommends that an artificial coating be pro-
duced, by feeding in a thin whitewash of calcium sulphate and magnesium hydrate.
In this brief notice of corrosion and incrustation, it has only been possible to touch upon the
most prominent points. For useful information on this subject, reference is made to the “Reports
of the Hartford Boiler Insurance Association,” and “Boiler Inerustation and Corrosion,” by F. J.
Rowan.
Boiler Explosions—At the present time there are numerous companies that are willing, for a small
premium, to insure a steam-user against loss from boiler explosions, and that succeed, by a rigid system
of inspection, in preventing nearly all accidents to boilers under their charge. The boiler insurance
companies of England have, for a. number of years, made a careful investigation into the circumstances
attending every boiler explosion occurring in that country, so that the ultimate causes of such acci-
dents are no longer in doubt. Explosions occur because the steam pressure is allowed to exceed the
proper limit, or because the boiler, weakened in some manner, is no longer able to sustain the ordi-
nary working pressure. The mysterious theories in regard to boiler explosions, that were formerly
prevalent, are accepted by few intelligent engineers at present. Many of them have been directly
disproved by experiments (see Journal of the Franklin Institute, 1836, 1837, 1872); but the most
convincing proof is the fact that these explosions do not occur when boilers are properly managed.
The investigations of boiler-insurance companies show that the proper pressure is often exceeded in
a boiler, on account of the use of a defective steam-gauge or a so-callcd safety-valve that is too small
to relieve the boiler, is overloaded, or stuck to the seat. One of the most noteworthy explosions that
ever occurred from a defective safety-valve was on the British steamer Thunderer, July 17, 1876.
(For an account of this explosion, and the thorough investigation that followed, see Engineering, xxii.)
A boiler becomes weakened, so that it will not sustain the ordinary working pressure, by cor-
rosion, internal or external, by being overheated, which is frequently caused by incrustation, by groov-
ing of the plates, caused by unequal expansion, or on account of lack of adjustment of the braces.
All these points have been thoroughly investigated by the difierent boiler-insurance associations, and
much valuable information is contained in their reports. (For an account of government regulations
in various countries in regard to the inspection of steam-boilers, see The Engineer, xxxix.) The gen-
eral result of all the investigations is to show that safety from accident can only be assured by
thorough inspection at frequent intervals, and that the hydrostatic test alone is not sufficient, cases
being on record in which a boiler has exploded at less than the pressure attained just before in a
hydrostatic test. Indeed, the hydrostatic test, with cold water, often injures a boiler; and it is pref-
erable to fill the boiler with water, load the safety-valve to the desired pressure, and heat the water
gradually until it opens the valve by expansion. There are many defects, however, that this kind of
test does not show, and that can only be discovered by careful inspection, external and internal. In
this inspection, the eye must be assisted by the ear, one of the most delicate tests being the sound of
the material when tapped with a light hammer. In the case of the disastrous explosion on the
steamer lVestfield, July 30, 1871 (see Journal of the Franklin Institute, 1871), the sheet was
weakened by corrosions, a fact that was not disclosed by the hydrostatic test made a short time
before, and that could only have been discovered by the hammer-test, according to the testi_
mony of an experienced inspector. In the practice of private boiler-insurance associations, the
hydrostatic test new occupies a secondary position, being used mainly in the case of new boilers,
while personal inspection with the hammer~test is the rule for boilers that have been in service for
some time. R. H. B.
BOILERS, SUGAR. 203

W-
BOILERS, SUGAR. See SUGAR-MAKING Macrrmsav.
BOLSTERS are used to support a piece of work at a proper distance above an anvil while being
punched or drifted: consequently, the greater the length of drift that protrudes beyond the work,
the greater is the height or thickness of the bolster. Some sorts of bolsters consist of thick circular
wings having holes of various diameters; other bolsters are slotted or may have a long narrow gap.
The forging of one of this class consists in bending one end of a long bar and closing the work
together until the gap is of the proper width. After the bolster is finished, it is cut from the bar,
which serves as a handle during the forging.
BOLT-MAKING MACHINERY. See NAIL-MAKING MACHINERY.
BOLTS. See MILLS, GRAIN.
BOND. See MASONRY.
BONE -BLACK APPARATUS. See SUGAR'MAKING MACHINERY.
BOOKBIN DIN G MACHINERY. There are two kinds of bookbinding, known respectively as
“ cloth-case ” and “extra.” The first is the cheapest, and that in which machinery is employed; the
second is usually done by hand. After printing, the sheets go to the binder in quires, and are
folded at the rate of from 10,000 to 12,000 per day in folding machines (see BOOK-FOLDING MA-
CHINE). The sheets are then laid in piles, collected in sets to form the book, examined, and pressed
in a smashing machine (see PRESS). The volume next passes to the sawing machine preparatory to
sewing. Several volumes are taken together, and in an instant five revolving saws make as many
cuts in the backs, of a size sufficient to admit the bands of twine to which the sheets are sewed. A
late improvement in sawing sheets consists in gathering the sheets of a set in two heaps, odd signa
tures in one pile, even in the other. Slanting cuts are then made in the backs. The result is that
when the sheets are gathered in proper sequence, the cuts cross, the binding-thread passing through
the continuous orifice formed by their intersection. This is claimed to give a very strong binding.
Boolcsewing is now mainly done on book-sewing machines (see SEWING MACHINES). This done, end
papers are pasted on the book, and its free edge is cut in a cutting machine (see PAPER-CUTTING
MACHINERY). A backing machine then spreads the back and forms a groove for the boards. The
cover is prepared of millboard and cloth, and stamped in an embossing press (see PREss). Finally,
the book is pasted on the sides, placed in the cover and pressed until dry. A very complete descrip-
tion of the hand-processes for both cloth-case and extra binding will be found in the article “ Book_
binding,” in the “American Cyclopwdia.”
BOOK-FOLDING MACHINE. An apparatus for folding sheets of books for sewing and binding.
In Fig. 469 is represented a simple form of the Chambers machine. The operator transfers a sheet
to the table A, which has a transverse slit across its middle. The revolution of the pulleys oper-
ates a rock-shaft B, carrying a curved arm with a folder 0 at its extremity, which presses the
sheet down through the slit in the
table, where it passes between rollers
which double it and deliver it into a
receptacle A at the end of the ma-
chine. To fold an octavo, the once-
foldcd sheet is again presented to a
folding edge, when it is carried to a
second set of rollers which squeeze it
flat, and it is thence led to a trough,
where the folded sheets are collected.
BOOT-MAKING MACHINERY.
See SHOE-MAKING MACHINERY.
BORING MACHINE. See DRILL-
me we BORING Maemmas.
BORT. See Dranown.
BOSHES. See Fvawacss, BLAST.
BOTTLE—MAKING. See GLASS-
maxme Macnmsnv.
BRACE, DRILL. See DRILLS.
BRAKE. This term is applied—
(1) to a machine for separating the
bark and pith from the fibre of hemp
and flax; (2) to a kneading-machine
(see BREAD awn BISCUIT MACHINERY); (3) to the handles of a firc~engine pump; (4) to an iron crotch
with a sharp reentering angle, used in basket-making, to peel the bark from the osiers; (5) to a
heavy snaffle used for subduing unruly horses; (6) to a frame for confining refractory animals while
being shod, etc.; %7) to a friction strap, band, or shoe, applied to machinery to afford resistance (see
DYNAMOMETERS); 8) to a vehicle for breaking horses, consisting of the running-gears and a driver’s
seat, without any carriage-body. Brakes for wagons consist of rubbers or shoes so arranged as to
be pressed against the wheels by a system of levers operated by a handle near the driver’s seat.
Sled or sleigh brakes are usually spurs brought into action by scraping on the ground.
BRAKES, CAR. These are the subject of numerous inventions, the result aimed at being to stop
a railway train within the shortest possible distance. When the brakes are applied to a railway train
to stop its motion entirely, the propelling or tractive force is taken ofi at the same moment; and
their object is then to convert the his viva of the train into mechanical work by means of fric-
tion, the result being heat.
Railway brakes are single or non-continuous when they are applied to a car singly, and continuous
when they act simultaneously on all or on several cars of the train. There are also continuous and



204 BRAKES.

automatic brakes; or, more properly speaking, some of the continuous brakes, under certain cir-
cumstances, can be made to work automatically. In all cases the braking force is applied to the
wheels, blocks of metal being pressed against their rim, creating friction. The difference between
the various brakes exists only in the manner in which this force is transmitted to the blocks—com-
monly called shoes—from the motor, whether the latter be steam or air pressure, the force of gravi-
tation, or human strength. .
HAND-BRAKES.—T118 ordinary hand-brake is operated by a brakeman from the platform or the roof
at either end of the car. It consists of a vertical rod supported and kept in position by brackets.
0n the upper end of the rod is a hand-wheel, and to the lower end a chain is attached, which, when
wound up on the rod, acts on two horizontal wooden bars, suspended from the frame of the car-
truck or the car, their ends being fitted with metallic friction-blocks, which press against the wheels.
The vertical rod is held stationary by means of a small ratchet-wheel and detent on the platform or
the roof when the brakes are put on, and is released when the motion of the train is stopped. There
are various other forms of hand-brakes. Screw-brakes are often used on locomotives, in which the
bar carrying the friction-blocks is pressed against the wheels by means of a red, the other end of
which is attached to one arm of a bell-crank; the other arm of the crank is pulled by a rod provided
with a screw-thread working in a fixed nut. Pressure on brake-blocks is sometimes exerted simply by
the weight of the brakeman, who stands at one end of a lever acting on the bars.
As the speed of railway trains has been increased, the necessity for better devices to effect quick
and powerful action of brakes has augmented ;. and thus steam or other pressure has been substitu-
ted for human strength, and continuous brakes have been invented, all tending to increase safety
and prevent accidents. Abundant instances may be cited wherein the safety or destruction of a fast
train has depended upon whether two seconds or eighteen elapsed between the application of the
brake and the development of the retarding force on the wheels.
M. Marié has determined that a theoretically perfect brake should stop a train running at 38 and
50 miles an hour respectively within the following distances:
In bad weather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 767 feet and 1,377 feet.
In medium weather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 “ 715 “
In fine weather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 “ 300 “
Under best conditions.............................. 197 “ 344 “
In order to determine the space in which quick stops could be elfected by means of the tender-
brake, application of brake to rear car, use of sand on rails, and reversal of engine, Captain Tyler,
in 1875, caused the following trials to be made on the Derby, Castle Donnington 8t Trent line, Eng-
land. There were four trials. In the first all available means were used to stop the train, viz.:
tender-brake and one guard’s van-brake at rear of train applied, sand used, and engine reversed, and
steam against it with the Lcchatelier tap open. The gradient was level ; the train, the total weight
of which was 102 tons 7 cwt. 2 qrs., was running at the rate of 49.9 miles per hour when the brake
was applied. The result was that 54 seconds were occupied in stopping the train, which, after the
application of the brake, ran a distance of 807 yards. In the second experiment all available means
except reversing the engine were used: gradient, 1 in 330, up, and level; speed, 49.9 miles; time, 60
seconds ; distance run, 843 yards. In the third experiment all available means were used, and when
the engine was reversed, the regulator was allowed to remain wide open all the time: gradient, 1 in
220, down; speed, 52.5 miles; time occupied, 55 seconds; distance run, 867 yards. In the final ex-
periment all available means were used. When reversing the engine the steam was first shut off,
then the lever was pulled into back gear, and then steam was turned on again as in the first experi-
ment: gradient, level; speed, 52.5 miles; time, 50 seconds; distance, 787 yards. The weather was
fair, and the rails slightly greased. This will suffice to show the efficacy of the old system of brakes
when aided by quick reversal of the engine.
STEAM-BRAKES.——ThGSG consist either of apparatus independently attached to the locomotive, or of
mechanism which, besides transferring the propelling power, is also employed to retard the motion.
An example of the first kind is a steam-cylinder placed on the locomotive between the driving-wheels,
with two pistons and rods projecting in opposite directions, and acting on the friction-blocks. Steam
admitted between the two pistons, through a pipe provided with a cock leading from the boiler,
presses on the blocks, and is exhausted at the will of the driver through a separate cock. The sec-
ond kind of steam-brakes is not used in this country. They continue to be employed in Europe,
although they are far from being as effective as continuous brakes are. Of these there are several
types: 1. In the Lcchatelier system a pipe is led from the exhaust-pipe of the engine to a small
closed vessel which is connected with the boiler by two other pipes, each furnished with a cock. One
of these communicates with the boiler above and the other below the water-line, and by means of them
a mixture of steam and water can be introduced into the closed vessel, and from it led by the pipe
first mentioned to the exhaust-pipe. This provides for the admission of a mixture of steam and
water into the blast-pipe when the engine is reversed, and the pistons then pump this mixture instead
of air and dust (the latter of which would damage the working portions) into the boiler. 2. The
method proposed by Zeh involves the compression of the steam, by shutting the exhaust-pipe, and
placing the valve-gear on a high grade of expansion ; thus the steam has to perform but little work,
and the escape of the expanded steam is also prevented, and the latter is thus compressed at the
backward stroke of the piston. 3. The compression of air in the cylinders has been proposed by
M. de Bergues as a locomotive brake. The regulator and the blast-pipe are shut; the admission-pipe
is connected with an air-vessel, which has a safety-valve; the exhaust-pipe is put in communication
with the atmosphere; and the valve-motion is reversed. The counter-pressure is thus increased to a
certain degree independently of the pressure in the boiler; but the disadvantages are many. 4. M. de
BRAKES. ' 205

w
Landsce’s brake acts upon the principle of producing the retarding power by using steam from the
_ boiler as a back pressure upon the pistons in a more advantageous manner than with the reversing
of the valve-gear. The steam in front of the piston is pressed back into the boiler, and acts thus by
its repression upon the piston in comparison with the compression produced in the cylinder. 5.
Krauss 8t Co.’s plan consists in an arrangement by means of which the steam can be made to enter
the cylinders through the exhaust-pipes, instead of through the ordinary steam-pipes, the blast nozzle
being at the time closed, and the steam admitted through the exhaust-pipes being pumped back partly
into the boiler, and partly into the steam chests, from which it escapes through an adjustable valve
into the chimney. Of course the engine is not reversed as in the Lcchatelier device.
CONTINUOUS BRAKES.—-Th8 main requirements to be sought for in selecting a railway-brake which
may be placed with confidence u'pon high-speed trains may be summarized as follows: 1. It must
be capable of application to every wheel throughout the train, if so desired. 2. It must be so
prompt in its action that no ap-
preciable loss of time occurs be-
tween the time of its application,
and the moment when its full
power can be exerted throughout
the train. 3. It must be capable
of being applied by the engineer,
and at any desired point through-
out the train. 4. It must be ca
pable of application by engineer
and train-guards acting in con-
cert, or by either independently
of the other. 5. It must under
all circumstances be capable of
arresting the motion of a train
in the shortest possible distance.
6. It must be so arranged that
in the event of the failure of any
one of its vital parts, such fail-
ure must record itself by the ap~
plication of the brakes or other-
wise ; so that the train, if in mo-
tion, may be automatically arrest-
ed, and the existence of aldefect
be thereby made known. 7. It
must, in the event of a train
breaking into two or more parts,
be capable of immediate auto-
matic application to every ve-
hicle, under all conditions. 8.
It must be simple in its construc-
tion and in its mode of working,
and not be more liable to de~
rangement in any of its parts
than any other portion of the
mechanism on the train. 9. The
duties it is called upon to per_
form must be done by the ap-
paratus itself, and not by the
addition of any auxiliary contriv_
ance called in to aid an appli-
ance which cannot of itself fulfill
the necessary conditions. 10. It
should preferably be inexpensive
for first establishment, and neecs- ‘
sarily cheap in maintenance; for if the latter condition be not fulfilled, constant watching and fre.
qperét repewals would be required, and the eighth requirement named above would not be com.
' p ie wit 1.
Continuous brakes may be divided into four varieties: 1. Those operating throughout the train by
rods and chains and similar mechanical devices. 2. Those in which the mechanism is operated by
electro-magnetism. 3. Those in which water is forced through pipes, which thus serves as a means
of transmitting the power, or hydraulic pressure is otherwise applied. 4. Those in which the
braking devices are operated either by compressed air or by air at normal pressure through the
production of a vacuum. Prominent types of each variety will be considered: _
1. Guam AND Mscnamcar. BRAKES.—-Tl1€ operation of the Oreamer brake, Fig. 470, may be
described as follows: To the ordinary hand-wheel and brake-shaft (for winding up the brakes)
is attached a drum, A, or loose pulley containing a strong spiral spring This spring is wound
up by a reverse motion of the brake-shaft, to which is attached an arm and pawl, G, taking into
a circle of ratchet teeth on the top of the drum A. When the spring is wound ready for use, it
is held‘in check by a lever, B, from the extremity of which passes a branch line to the top of the
car at D, and connecting about 3 feet forward to the bell-cord. The branch-line is attached to the
470.








am BRAKES

W
lever B by a ring in such a way that, when the lever is drawn up vertically, the ring disconnects.
This is rendered necessary to insure the working of the brakes by the bell-cord, whether the train is
extended on an up grade, or contracted on a down grade. The attachment of the branch line of
each car, some 3 feet forward, enables the engineer to apply the brakes of all the cars simultane-
ously, by pulling the bell-cord, and at the same time it does not interfere with the bell-cord as a
means of enabling the conductor to signalize the engineer. When the conductor pulls the bell-
cord it rings the bell, and simply makes slack on the several branch-lines connected with the brake,
but does not operate the brake. The conductor, brakeman, or even passengers, however, can, if an
emergency arises in any part of the train, instantly close all the brakes, by pulling the bell-cord, or
any accidental separation of the train produces the same effect, namely, bringing the retarding force
on all the cars into instant action.
The Hebcrle'in Brake is not a true continuous brake, though it may be fitted to every car in the
train, the plan being, however, to divide the train into sections, including one brake-car in each, and
the operator in this car can apply the brake to his own car, and to one or more others in connection
with it. The brakes are applied to the wheels by a friction-pulley, which engages with a friction-
wheel on one of the axles of the engine or of the brake-car. The revolution of this wheel winds
up a flat link chain, and this pulling on a set of rods under the cars applies the blocks to the wheels.
By pulling a cord, which extends through the cars, a detent is thrown out of gear, and the friction-
pulley, which is hung on a weighted bell-crank lever, is sufiered to fall into contact with the friction-
wheel on the axle, and the brake is applied as soon as the train has run far enough to wind up the
slack of the chain. The cord is kept taut, so that in case a car runs from the track, or becomes
detached, a strain is brought upon the line, and the brakes are immediately applied.
The Clark and l'Vebb Chain-Brake is about the same as the preceding, the brake being applied
by the tightening of a chain which is attached to a drum beneath the van, this drum being 'so
mounted that it can, when desired, be driven by bringing it into contact with a friction-wheel fixed
on the van axle.
Fay’s Continuous Brake—Each carriage has a shaft passing along it from end to end, a screw on
this shaft actuating the brake-levers. The shafts are coupled up between each pair of carriages by
a square bar, of which one end carries a coupling-wheel; the other end slides in a socket forming
part of the shaft beneath one of the carriages. The square coupling-bars thus transmit the rotary
motion from one shaft to the other, while the sliding movement of the bar just mentioned allows
for the play of the buffers.
Becker’s Continuous .Frz'clz'on Brake is an ingenious invention, in which the momentum of the train
_ is employed for the creation of the retarding power. lts principal part, the friction-gearing, consists
of a horizontal axle, suspended by movable arms, I), Fig. 472, from the car frame. This axle carries
a fixed sheave, A, Fig. 471, at each end, and on each sheave is a friction-ring B, fitted so loosely as
to enable it to turn easily on the sheave. These rings are placed opposite the tires, and, according
as they are intended to press against the tires or to grip the flanges of the wheels, are made cylin-
471. _ 472.
21
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drical or with grooves. They may be brought into contact with the tires or lifted from them as de-
sired. When in contact, the rings receive motion from the wheels with the same peripheral speed,
and the friction between the rings and the sheaves winds up a chain fastened to their axle, C, Fig. 47 2.
The latter, being connected in the usual way to the friction-blocks, presses them against the wheels.
Since the winding up of the brake-chain is not effected directly by the revolving friction-ring, but
by means of the axle and fixed sheave working within it, the axle can only be turned until the chain
has been fully wound up, When it will remain still and be in no way affected by any further motion
of the friction-ring, however long it may continue to revolve. The friction-ring does not come to a
standstill until the wheel with which it is in contact ceases to move. By means of this peculiar com-
bination of the ring between the driving-wheel and the mechanism which sets the broke in action,
not only is the desired effect obtained in every case and for each special demand, but the usual con-
cussions on the first application of the brake are, it is claimed, avoided, and the skidding of the
wheels rendered impossible. The brake is instantly thrown out of gear when the friction-ring is
withdrawn from the periphery of the wheel. The control or intermediate gear which serves to de-
termine the position of the friction-ring with regard to the tire of the wheel, either by bringing it
into contact with or removing it from the latter, consists of an axle fitted to the framework of the
BRAKES. 207


carriage, with a winch-handle at each end, and carrying a fixed double-grooved sheave, round which
in opposite directions are wound chains, two of which connect with the friction-axle. If the trans-
mission-chain be tightened, a partial revolution of the sheave is effected; and by the other chains
the friction-gear is either brought into contact with or withdrawn from the wheel. In whatever
direction the chain may be pulled, the action is always the same. It being important to have
all the brakes in the train begin to act simultaneously, it was necessary to provide a compensa-
tion for changes in the length of the train; and this was accomplished by carrying the chain from
car to car, through three pulleys, E, F, G, two stationary and attached to each end of the coupled
cars, and the third held at its centre by two rods, the other end of the rods being pivoted in the cen-
tres of the other pulleys. The three pulleys represent thus the corners of a triangle with a flexible
base (which would represent here the play between the cars) and height, and with two sides of a
constant length. Around these sides the chain is carried from car to car, and its length is thus con-
stant, and-unaffected by. any slack in the train. An apparatus on the tender, which can be also
placed at any point of the train, or in several places, pulls on the chain by means of a crank or a
hand-wheel, and puts the brakes on. To this end, after the train has been made up and the ordinary
coupling fastened, the whole of the friction-sheaves, as well as the side winches, are let down until
the friction-rings are brought into contact with the tires; the transmission-couplings are then fast-
ened between the carriages by being brought together and bolted, and the transmission completed
by passing the end of one chain over the centre pulley and fastening it in the ring on the chain of
the next wagon. The surplus piece is then hung up and fastened as a reserve chain, as shown in
Fig. 471. The junction of the chains is chosen at such a point, that with the maximum motion of
the chain, either by tightening up or slacking out, it cannot pass over either of the pulleys. The
tension thus kept on the transmission-chain while running is so uniform, and so entirely independent
of the position of the carriages, that an application or taking off of the brakes is said to be instan-
taneous throughout the length of the train. If, for instance, the disk-handle of the brake-spindle on
the tender be suitably operated, the whole transmission-chain will be raised or tightened up, and each
particular friction-sheave removed from the tires. In the event of the train breaking in two or more
parts, the separated parts would immediately be automatically acted on by the brake. Another advan-
tage which this brake possesses over many other continuous brakes is, that its action begins without
any shock, but gradually, although its maximum power is developed in a very short time. The inventor
claims that by this brake any train at the highest speed can be brought to a standstill in all weathers
in 1,476 feet. For results of trials, see Ezginew, x1.v., 76.
2. ELECTED-MAGNETIC BRAKEs.—Aclrard’s Brake (French).-—Each carriage of the train is supplied
with a galvanic battery of six Daniell cells. These batteries are connected with each other, and with
the engine foot-plate, by means of four insulated wires passing through the whole length of the train.
By means of these wires two distinct currents may be created, either of which may be closed or
broken by altering the position of a handle placed before the engine-driver. In the frame of each
car is a transverse arbor above the forward axle, upon one end of which is fixed a strong ratchet-
wheel. A lever, pivoted at a point behind the axle and lying thereon (when the apparatus is work-
ing) carries at its extremity a click, which falls into the teeth of the ratchet. The axle has a cam
at the point where the lever crosses it, and this cam, at every revolution of the wheel, lifts the lever
sufficiently to advance the ratchet one tooth. On the ratchet arbor is a powerful electro-magnet,
and also on the arbor are two loose barrels carrying armatures; when the magnet is excited these
armatures are fixed by its attraction, so that the barrels then turn with the magnet. To each bar-
rel is attached a chain, which is thus wound upon the barrel, and through which the levers are oper-
ated to apply the brakes to the wheels.
3. HYDRAULIC Beams—Barker’s Hydraulic Brake (English) comprises a pump, a cistern, and an
accumulator for collecting and storing the power, a regulator and an apparatus for applying that
power in retarding the speed of the train. The pump, which is double-acting, is worked by mech-
anism in connection with a friction-wheel, which is brought in contact with one of the car-wheels.
From the cistern, which holds about 25 gallons, the water is pumped into an accumulator, the piston
of which is forced up against the resistance of spiral springs. In order to render the action of the
accumulator as nearly constant as possible under the constantly varying conditions of train-length,
there is an ingenious automatic arrangement whereby the pressure is always maintained in the
accumulator sufficiently high for any emergency.
The arrangement for distributing and utilizing the hydraulic power for the purpose of retarding
the train consists, first, of a pipe 1} inch in diameter fixed under each carriage. The main pipe
is made continuous from a regulating apparatus (which controls the passage of water from the accu-
mulator) throughout the whole length of the train, by means of flexible tubing connected to the
pipes by ordinary union-joints. From the main pipe are lateral branches leading to hydraulic cyl-
inders. These are each 4 inches in diameter, and one is provided for every wheel to which it is
desired to apply brake-power. Each wheel has two brake blocks, and the ram of the cylinder is
fixed to the block nearest to it, the cylinder itself being connected by a pair of rods to the block,
on the opposite side of the wheel. On the water beingr admitted to the cylinder, or rather pressure
being put upon the water already contained in the cylinder, both blocks are forced on the wheel. In
order to withdraw the blocks upon the removal of the water-pressure from the ram, a spiral spring
is placed inside each cylinder. Upon the ram being relieved from pressure, the tension of the spring
forces a portion of the water back into the cistern for further use, and at the same time clears the
brake-blocks from 'the wheels. An ingenious automatic eontrivance preserves a given amount of
clearance, and causes the wear of the blocks to be followed up. The apparatus may be worked
from the locomotive as well as from any car.
The McBride Hydraulic Brake (American).——In this apparatus the power is derived directly
from the steam-pressure against the water in the boiler, this pressure being communicated to a pipe
208 BRAKES.

4‘.
filled with water and running from the tender underneath all the cars of the train. The water is
first conveyed from the tender-tank to a 3-way cock, which is placed on the locomotive, where it is
always under the control of the engineer. Another pipe leads from the cock to the boiler below
the water-line; a third pipe leads from the same cock and runs under the cars, the connections
between the cars being provided for by means of hose couplings with self-closing valves. Under
each ear is a cast-iron cylinder with a piston, the rod of which is connected to the brake-levers.
The pipe at each end of the train has an air-cock, to allow the air to escape while the pipe is being
filled with water. As long as the train is running, the communication from the tender to the pipe
running under the cars is kept open, thus keeping the pipes and brake-cylinders constantly full of
water. The train can be stopped by a turn of the lever, which operates the 3-way cock and closes
the communication between the tender and pipe under the cars. This cock is so constructed that
the communication between the water-tank and boiler can be shut off so as to prevent the press-
ure from acting on the water in the tank. To relieve the pressure and to take oiT the brake, the
engineer simply turns the lever back to its original position, and the brakes are instantly off, the
surplus water being forced back into the water-tank by the recoil spring on the brake-levers.
The Henderson Hydraulic Brake (American), Fig. 473.—Between the wheels of each truck is placed
a cylindrical vessel of cast-iron, the ends of which are formed of two dish-shaped flexible dia-
phragms of India-rubber, secured to the drum and making an air-tight joint at the periphery by
flanges bolting thereto. Two rams, working in opposite directions, are fitted against and into the
hollow part of the diaphragms. Their outer ends are attached by rectangular flanges and bolts


473.
©
to the brake-beams, carrying the brake-shoes. When pressure comes between the diaphragms it
simply forces them apart, projecting the rams, which act immediately on the brakes; and, when
the pressure is relieved, the atmosphere reacts on the area of the rams and forces them back,
assisted by the tendency of the diaphragms themselves to recover their normal position. The power
is transmitted from an hydraulic press operated by a double-acting steam-cylinder, the valve of
which is worked by the engineer.
In the annexed engraving, Fig. 473, the brake-shoes are arranged outside the wheels, and hence
one of the diaphragms and rams is dispensed with. A is the double-acting pressure-engine, O the
valve thereof, B B the pressure-boxes, and E is an especial water-tank for use where the water
from the boiler is not employed.
Clark’s Hydraulic Brake (English).—The brakes are actuated by one cylinder under each car-
riage. The water under pressure is supplied as follows: Under the foot-plate of the engine is a
vertical cylinder, having an horizontal cylinder connected to it near its upper end. To the verti-
cal cylinder is fitted a deep piston, and to the horizontal cylinder a plunger, which actuates the
brakes on the engine-wheels. The cylinders between the piston and plunger are filled with water,
a pipe leading from the tender-tank, and fitted with a valve opening inward, making up losses by
leakage. To apply the brakes steam is admitted under the piston in the vertical cylinder; and this
piston, rising, forces outward the plunger already mentioned, and also furnishes a supply of water
under pressure to the pipes, and thus applies the brakes.
4. AIR-BRAKES—ThGSG may be subdivided into those operated through a vacuum and those oper-
ated by compressed air.
Vacuum—The Sanders Vacuum-Brake (English) differs materially from others of its class, inas-
much as, instead of a vacuum being employed to apply the brake, it is made use of to retain the
brake-blocks out of contact with the wheels. In other words, the brakes in their normal condition
are “ on,” and the blocks are withdrawn from the wheels by the action of the atmospheric pressure
exerted upon diaphragms, from the other side of which the air has been partially exhausted. The
means by which this system is carried out consists of an exhausted pipe extending the entire length
of the train, connected between the carriages by flexible pipes and couplings, and an exhausted drum
under each carriage, by which the brakes are released when the train is in motion. The pipe and
apparatus are exhausted while the train is standing by means of a steam ejector, through which the
steam, which is now used as a “blower,” passes before entering the chimney of the locomotive.
When the vacuum is once created, very little power is required to maintain it; and when the train is
in motion the requisite exhaustive action is effected by a small pump worked from one of the piston
cross-heads of the engine.
Smith’s Vacuum-Brake.-—-In this device the blocks are applied to one side of each wheel by the col-
lapsing of India-rubber cylindrical bags, which are supported by internal rings, so that when the air is
exhausted from them they collapse endwise, and thus act on the brake-levers. Throughout the train
there extend two lines of pipe, the various bags being connected to one line while the other extends
right through to the rear, where it is connected to the first-mentioned line by the coupling-up of the
BRAKES. , 209

rear hose-pipes on the last vehicle. The exhaustion of the air from the pipes is effected partly by a
couple of steam ejectors on the engine, and partly by exhaustcrs fixed one in each brake-van, and
driven by a wire rope, which passes over a grooved pulley, cast in one piece with a friction-pulley,
which can be brought into contact with another friction-pulley fixed on the van'axle. The movable
f riction-pulley is forced against the axle-pulley by means of a spring, but, when the train is running,
the two pulleys are held apart by a kind of trigger arrangement, which is connected by a cord with
the collapsing bag with which each car is fitted. The effect of this arrangement is that, immediately
the bag begins to collapse from the ejector of the engine being set at work, it releases the trigger,
and thus brings the friction-wheels into contact, and causes the exhauster to be driven.
The Westinghouse Vacuum-Brakc.—In this system the vacuum is produced by an ejector which is
represented in Fig. 474. Steam is admitted into this through the pipe A, and escapes through the
' 474 annular opening 6 b and the central jet FF G, which creates an in-
' duced current up the pipe 0 C'. This communicates with the two
_ pipes D D, which are connected with the brake-pipes. Under each
car are two India-rubber collapsible cylinders, similar to the bellows
of an accordion. ,When a vacuum is produced inside of these cylin-
ders, the atmospheric pressure is exerted on the outside to compress
them. Iron rings are inserted in the inside so as to prevent the cyl-
inders from collapsing sideways, so that the atmospheric pressure is
exerted on the heads. One of the heads is bolted fast to the car, and
the other is attached to the brake-levers, so that whatever pressure is
exerted on the movable head is communicated to the brake-levers,
thus applying the brakes. Where the collapsing bag as above de-
scribed is not used, a cylinder is placed vertically, and at each side
of it there is hung a lever, having joizted to it, at an intermediate
point, a toggle-lever. The two toggle-levers have curved abutting sur-
faces, and each is traversed by a pin, which rests upon a cross-head
attached to the piston-rod. The effect is that, as the piston rises on
the air being exhausted from the cylinder, the toggle-levers are drawn.
upward and the hanging levers are forced outward. To the lower
ends of the hanging levers are coupled the thrust-rods leading to the
brake blocks, and thus the latter are applied to the wheels by the
upward movement of the piston.
Compressed-Air .Brahes.—- The Westinghousz Automatic Brake.—
The Westinghouse atmospheric brake, in its original form, consisted
of an air-pump operated by a steam cylinder on the engine. This
pump forced air of any required density into a reservoir usually placed
underneath the foot-board of the engine. Eath car was provided with
a cylinder and piston underneath the body. The piston-rod was con-
nected with the brake-levers, and the air-reservoir communicated with
the cylinders by pipes, which were connected together by flexible hose
between the cars. When it was desired to apply the brakes, the com-
munication between the reservoir and the brake-cylinders was opened
'; _/ by turning a cock so that the supply of compressed air stored up in
the former could flow into the cylinder, and would then force out the
' pistons and thus apply the brakes. IVith this apparatus it was found,
however, that some appreciable time was required to allow a suflieient quantity of air to flow
through the pipes to fill the brake-cylinders under each of the cars. The time consumed, of course,
increased with the number of cars, because not only was the length of the pipes through which the
compressed air had to flow increased, but the number of cylinders and, of course, the quantity of air
were increased in like proportion.
There was also another difficulty encountered. In case of the breakage of a car-coupling in a train,
which occasionally happens, the locomotive runner would sometimes apply the brakes to the portion
of the train connected to the engine, and thus arrest its speed. As the connections of the air-pipes
were separated by the breaking of the coupling, it was, of course, impossible for him to control the
speed of the cars which had broken loose by means of the atmospheric brake. Accidents sometimes
resulted in this way by the rear cars running into the front part of the train.
In the automatic brake the construction is simplified, and but one line of pipe is used. The com-
pressing apparatus, consisting of a steam-cylinder A and pump B, Fig. 47 5, is bolted to the boiler or
frame, and steam for its operation is taken directly from the boiler through the pipe a, the amount
being regulated by the throttle, while the exhaust is led by the pipe a' to the smoke-stack. The air
enters the pump B by the pipe 6, and is forced through the pipe into the reservoir 0, Fig. 47 6. The
pipe c leads to one opening of the three-way cock D, and, from a second opening, is extended be-
neath the foot-plate, and, by a flexible hose, connected to the pipe on the tender. A differential pis-
ton-valve movement is used, in which the difference in area between the two ends is such that, when
steam is admitted between them, the tendency of the valve is to move upward, which gives a down-
ward stroke to the main piston. W hen the main piston reaches the bottom of its stroke it operates
upon the reversingvalve-rod, causing the valve E to uncover a port by which steam is admitted
above the piston 1", which, by excess of pressure, causes the main valve to descend, exhausting from
the upper part of the steam-cylinder, and admitting steam below the main piston. As the main
piston completes its upward stroke, the valve E is again moved so as to exhaust the steam from the
reversing cylinder, whereby the reversing piston is moved upward, together with the main valve, by
the difference of pressure between the two valve-pistons.


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14
eio BRAKES.

Figs. 4'77 and 478 show the application of the automatic brake to an ordinary 8~whecled car.
Fig. 4’77 is an inverted plan, and Fig. 47 8 an end-view.
The brake-cylinder A, Fig. 477, is bolted to a plank, and securely fastened to the longitudinal tim-
bers underneath the car. The piston of this cylinder has a cross-head, a, having an arm, I), to which
the spring releasing lever c is connected. To this cross-head a is attached one end of the lever d,
the opposite end of which is connected to the brake-rod c. On the end or head of the cylinder A,
opposite the cross-head a, is a bracket, 3;, which acts as a fulcrum for one end of the lever f, the
other end of which is also pivoted to‘anothcr brake-rod ; the levers d and j' are connected by a tie-





















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rod, g. These levers are so arranged that if the piston be thrust forward, carrying the cross-head
a, the two rods 0 e will approach each other, and thus apply the brakes. The levers d and fare held
in an horizontal position by the bracket h (a portion of which is represented as broken away in Fig.
477), made of light wrought-iron, and attached to the frame of the car. The brake-pipe B is ar-
ranged as ncar the centre of the car transversely as is convenient, and the stopeoeks are near
each end of the car. The auxiliary reservoir R is also attached by iron straps to the bottom
of the car, and into one end is screwed a pipe, connected to which is the triple valve D. As the
action of the brake is to a very great extent dependent upon the working of the triple and leakage
valves, in order to understand how the pressure of the air is controlled, it is necessary first to under—
stand clearly the action of this ingenious and beautiful eontrivance. Fig. 479 represents a section
of the triple valve, and Fig. 480 a section of the leakage valve. -
BRAKES. 211

The triple valve has a case, or body, with three connections for half-inch gas-pipe, the connection
from the main pipe being through the port E; a second pipe-connection from the port 1” leads to
the brake-cylinder, while the remaining port, shown in dotted lines back of the valve 12, is connected
to the auxiliary reservoir.
This case contains the body
of the four-way cock, 17,
and valve-chamber, B, and
has also a piston-chamber,
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chambers by the end of the ~ I“; - »-__-~_ é


stem sliding in the hollow
cap 5, screwed into the up-
per end of the case. A slide-
valve, 12, is fitted loosely be-
tween a shoulder and collar
of the stem of the piston, and moves with it. In the chamber B under this slide-valve are two ports
or passages, b and cl; the first, passing through the plug of the four-way cock, 17, connects with the
port F, and thence to the brake-cylinder. The port cl communicates directly with the atmosphere,
and with a cavity, a, formed in the valve
55 479. 12 ; and the port 6 constitutes a discharge-
‘ passage for the release of the compressed
air for the brake-cylinder after the applica-
tion of the brakes. The piston 4, packed
with a ring, 1], has a central port, 9, lead-
ing into the opening It through its stem,
which is the only passage for air between
the chambers A and B. Into the lower


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\ ' _ end of the case is screwed the cap 6 with
7, m :4 x a rubber packing-ring, 10, interpose’d be-
Jam :9“ i. 2; w“g§ tween it and the chamber A. This cap has
a i \ V4 5' ~ a chamber containing a stem 7, with a col-
lar, between which End the second cap, 9,
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is the spring 8, pressing the stem and col-
lar with considerable force against the up-
per end of the chamber containing them.
This stem, 7, passes a short distance into
the chamber A, where it is turned down at
g, so that the port 9 in the piston may slide
over it and against the shoulder thus formed.
A small needle, long enough to pass into
the passage h, is fitted in the end of the
I \ .
stem wlnch enters the port g, and serves to
keep the passage free from dirt.
From the main brake-pipe, the air enters
by the port 13', and then, by the passage a
through a suitable opening in the plug of
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\ the four-way cock 17, passes on through
:f/ holes drilled in the cap 6 into the bot—
tom of the chamber A, where, acting on
% i the piston 4, it forces it with the slide-
\ valve 12 into the position shown, openingr
‘\ § the port 9 at 9’, whereby the chamber B
_t § and auxiliary reservoir connected there-
‘ § with are charged to the same pressure, this
pressure being maintained throughout the
train in all of the reservoirs and main brake-pipe. To fully apply the brakes, air is discharged from
the main pipe, and consequently from the chamber A, when, by excess of pressure in the chamber
B, the piston 4 is forced down, closing the port {7, and forcing the stem 7 with its spring so as to
permit the piston to seat itself on the rubber packing-ringlO; at the same time the valve 12 is moved,
so as to uncover the port 6, establishing communication from the chamber B, and consequently with
the auxiliary reservoir to the brake-cylinder. To release the brake, air is again admitted to the. main
pipe and chamber A, causing by excess of pressure the piston 4 with valve 12 to assume the posi-
tion shown in the drawing, whereby the ports I) and d are brought in communication through the
cavity c; at the same time the port 9 is opened for recharging the reservoir. To apply the brake
lightly, a slight reduction of pressure is made in the brake-pin and chamber A, which causes the
piston to move so as- to uncover the port 6, applying the brakes and reducing the pressure in the
chamber B. As soon as the pressure is reduced so that it about equals that in the chamber A, the
spring 8, acting against the collar of the stem '7 and piston 4, moves the valve far enough to close
the port 6 without releasing the brakes. The force admitted to the brake-cylinder will depend
altogether upon the reduction of pressure in the main pipe and chamber A, such reduction being
entirely under control.
212 BRAKES.

To prevent the application of the brakes after the engine is disconnected from the train by such
reduction of pressure in the brake~pipcs as may result from leakage, a small valve, the construction
of which is clearly shown in Fig. 480, 18 inserted in the pipe between the port F and the brake-cyl-
inder. This valve consists of a case, 15, with a cap, 13, having a rubber face, 16, and within the
chamber of this case a valve, 14, which is acted upon by air-pressure entering the lower port. When
the air enters this port slowly, as resulting from a leakage in the brake-pipe, or other slight reduction
of pressure, the valve 14 remains in its position, such air passing around and to the atmosphere,
without setting the brakes. When the brakes are being operated the valve is seated upward against
the rubber face 16, preventing the escape of air. A drip-cup, H, is screwed on the cap 9 of the
triple valve, and is provided with a cock. The plug 17 of the four-way cock, by a quarter turn,
brings the ports E and F in connection, whereby the air passes directly from the brake~pipe
to the brake-cylinder for the direct application of the brake, without charging any of the other
parts. Both triple and leakage valves are arranged perpendicular in the pipes, as shown in the
drawings. .
In the operation of the brakes, the couplings between the cars are connected in the usual man-
ner, and the handles of all the cocks in the main brake-pipes are turned down so as to open them,
excepting the one at the rear end of the train, which is turned so as to close the end of the pipe.
When it is necessary to detach any portion of the train, the cooks must first be closed to prevent
the escape of air and the application of the brakes.
Each reservoir, R, is provided with a small cock, which may be opened to release the brakes if
they should be applied accidentally when the pipe is disconnected from the main reservoir. A










































482.
431.
1,..::'.".:::::::::::::::;;.: ::s
all Hill I I‘ "l
at ll II: I"
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branch leads to a valve located in the water-closet in the car, and the handle of this valve has a
cord-attachment which passes through the interior of the car. If this valve be opened by an em-
ployé or passenger in the train, the air will escape from the brake-pipe, and the brakes thus be
applied to the whole train. The escape from this valve is led through the bottom of the car.
Figs. 4-81 and 482 represent the application of an atmospheric brake to the driving-wheels of a
locomotive.
The brake is applied to the driving-wheels by means of a cylinder, [1. The piston-rod K of
the cylinder is connected by the cross-head 6 and two links with the cams 15, 15, which are
attached to the brake-blocks L L. When compressed air is admitted underneath the piston in
the cylinder H, it is obvious that its action on the cams 15, 15 will force the brake-blocks against
the wheels.
The Sleel and Jllclnnes Brake—This is applied under two different arrangements : that in which
the cylinders are placed at the end of each carriage, in which case two brake cylinders are employed
for each vehicle, and that in which the cylinder is placed at the centre of the carriage, in which
case one cylinder is employed for each vehicle. The air-compressing engine, mounted on the loco-
motive, consists of steam-engine and air-pumps. When the air is let out through the pipes from
the reservoir, it enters the upper end of each cylinder, and escapes through a valve in each to the
BRAKES. 21 3

MW
receiver. Instantly, then, the pressure per square inch of area on both sides of the pistons is in
equilibrio; but by virtue of the area of the upper side of the piston being greater than that of the
under side, by a quantity represented by the area of a cross-section of the piston-rod, the pressure on
the upper side preponderates by that amount, and this, together with the weight of the brake-gear,
immediately causes the pistons to descend to the bottom of the cylinders, in which position the
brakes are ofl’. The air is kept constantly on, and to apply the brakes it is only necessary to open
any one of the valves in the air-pipes, which can be done either by engineer, trainhand, or passen-
ger, in either of which cases the air escapes from the upper sides of the pistons, and that on the
under side not being able to escape—its pressure closing the valve by which it entered—immediately
expanding, lifts the pistons and applies the brakes.
In the SickcLs Air-Brake a spring is used to apply the brake and air-pressure to take it oif. The
apparatus is thus in principle similar to the \Vestinghouse, with the exception of the spring. The
normal condition of the train is with all the brakes applied by the action of the springs. If the
engineer wishes to start the train, he lets on the air-pressure, which detaches the spring and leaves
the wheels free to move; the pressure is kept upon the pipes, and so long as this is done the brakes
are kept released. To apply the brakes a portion of the whole of the condensed air is let off, and
the action of the springs applies the brakes. If there be any defect in the connecting-pipe, the
result cannot be serious, the only effect being that the engineer must stop and repair the pipe, and
reéstablish' the air-pressure before the wheels can run. By means of a cock in each car, leading to









the air-pipe, the conductor can apply the brake from any car to the entire train ; and this he can do
as gradually or as suddenly as he pleases by regulating the discharge of air from the pipe.
The Loughr’idgc Air-Brake, Fig. 483.—In this brake the air is compressed by a pump, which is
worked by an eccentric on the front driving-axle. The air is pumped into a reservoir under the
tender. It is necessary to run about half a mile to produce a pressure of 80 or 90 lbs. per square
inch in the reservoir. When that pressure is reached the pump is stopped, but is always started
again after a stop is made. The air is applied to the brakes by small cylinders under each of the
cars, which are connected to the air-reservoir by half-inch pipes. These are coupled together
between the cars by flexible hose. The annexed engraving represents the form of this brake em-
ployed in the trials referred to further on. The inventor, however, at the time of the preparation of
this work,is engaged upon important improvements, calculated to add materially to the efficiency of
the apparatus. He has devoted many years to the study of brakes, and he considers that “the
indispensable requirements of a power-brake are an automatic governing power of the force, be the
force what it may, capable of being graduated by the engineer or tminmen to deliver in pounds the
pressure required; to utilize the maximum adhesion of the train in emergencies, and never slide
wheels, the lighter degrees of force for other purposes to be regulated by the throttle or cock ; to
carry always a stored force in the reservoirs much greater than the pressure required in the pipes
and cylinders; to insure several brakings before the air is reduced to a minimum pressure; to be
able to brake the lighter cars in proportion to their relative weight with their fellow-cars in the
train, and to be capable of graduating the force to the load.”
Mr. Loughridge has devised an ingenious arrangement of cut-ofi’s, on the diaphragms of which the
air acts when forced from the reservoir to the pipes and cylinders. When the pressure in these
diaphragms is equal to the required braking force, however uneven in the different cylinders, by rea-
son of their respective cut-offs having been set by suitable gauges to suit difl’erently weighted cars,
the diaphragms give way and valves close, cutting off the air and preventing any increased pressure.
on the brake.
Tss'rs or BRAKES.-—Tl]6 following, explaining a simple rule for determining theoretically the
retarding power of a good continuous brake as a means of comparison with actual reported results,
is taken from the “Annual Report of the Railway lilaster-Mechanies’ Association ” for 1875:
“Let us suppose that a train consisting of an engine weighing 30 tons, with a tender weighing
20 tons and six cars weighing 20 tons each, in all 170 tons of 2,000 lbs., is running at a speed of
40 miles per hour on a straight and level track. It is required to know the distance in which said
train can be brought to a state of rest, and the time consumed after shutting cit steam and apply-
ing the brakes, which are assumed to be fitted to the tender and six cars. A speed of 40 miles per
heur is equivalent to 58.7 feet per second, and by the law of gravitation a body projected vertically
into the air, with an initial velocity of that amount, will ascend 53.5 feet before it is arrested by
the force of gravity. Similarly a railway-train, moving on an horizontal track at the same speed, will
be brought to a state of rest after shutting off steam, if a retarding force can be applied equal to
its own weight. The resistance of the atmosphere is not taken into account in either case at pres-
1'16
'SHXVHH
Results of Experiments on Conlz'nuous Brakes.


CL ASS OF EXPERI-
MENT

Percen tage
Equivalent Dis-




. Resistance in Resistance in tances which
afwelghzd Speed of T. Distance Stat Pounds per Ton, Pounds per Ton, Would have
BRAKE Total 'Weight of orzu‘lvrfis 115g Train when 19fdOFiu- run after re deduced lrom Dis- deduced from been run had REMARKS
' Train. to bFehs Brakes were 11'.“ gt Application R2“ tance run, after Time occupied in Speed been 50 '
B akw “5 applied. ma mg op' of Brakes. 5' Application of making Stop Miles per Hour
1' fitets (1; ere Brakes (R1), when Brakes
e . were applied.
Tons. Cwt. Lbs. Seconds. Feet. Lbs. Lbs. Feet.
Clark & Webb’s . . . . . . . . . . _ . . . . . . . . . . . . . . . 241 9 1 16.5 494 63 2,889 Dry. 82.77 87.22 2,437
Steel & Mclnnes‘s . . . . . _ . . . . . . . . . . . . . . . . . . . 197 7 1 20.5 49.} 86 8,205 "‘ 61 .70 63.89 8.270
Clark’s hydraulic . . . . . . . . . . . . . . . . . . . . . . .. 198 4 0 22.3 411} 831 3,265 Wet 60.56 65.80 3.381
Smith‘s vacuum . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 12 2 20.2 49% 87 3,591 “ 55.06 63.16 3,664
Westinghouse‘s vacuum . . . . . . . . . . . . . . . . . . 204 8 0 20 .9 4‘. ,1; 96 3,705 “ 53 .37 57.24 3,780
Westinghouse’s automatic . . . . . . . . .. . . . . . . . 208 4 0 81.1 56 22 1,020 Dry 248.11 282.55 813
Clark‘s hydraulic . . . . . . . . . . . . . . . . . . . . . . . . . 198 4 0 58.7 5+1- 2l 1,070 " 204.31 288.07 901
gay’sl; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 186 13 0 85.3 4&-
1,018 “ $133 224 30 1.1530
mit ’s vacuum . . . . . . . . . . . . . . . . . . . . . . . . . .. 195 12 0 87 . 474 ' ,20 “ . 188. 0 1, 0 - 0. v
Clark st Webb‘s ......................... .. 241 9 1 62.2 4st 21 1,384 “ 142.21 171.25 1,412 { 93251339335311; bfgak °f
génker’shhydraulic . . . . . . . . . . . . . . . . . . . . . . . .. 210 2 0 81 42.4 34 1,633 “ 13%.46 161.60 1,6? “ PP g-
' v ‘ uum . . . . . . . . . . . . . . . . . . .. . "' . . "
Stiéf‘tmt‘iiiiéi? ...................... .. 18% i 1’ 21.8 5231 1‘21 33%.. ‘7 92.23 118.18 23173
Westinghouse’s automatic . . . . . . . . . . . . . . .. 203 4 0 94.3 52 19 913 “ 230. 304.49 844
Clark’s hydraulic . . . . . . . . . . . . . . . . . . . . . . . . . .. 198 4 0 71.5 52 221L 1,212 “ 180.04 253.71 1,121
Fay’s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 18 0 85. 444} 27} 1,165 Wet. 134.05 179.62 1,471
Smith’s vacuum . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 6 2 95. 41a} 29 1,448 Dry. 136.6 189 .5 1,477
Clark & Webb’s . . . . . . . . . . . . . . . . . . . . . . . . . . 241 9 1 51.7 474 29 1,887 “ 136.2 181.8 1,481
Barker’s hydraulic . . . . . . . . . . . . . . . . . . . . . . . . . 210 2 0 94.4 50 82 1,549 “ 184.2 176. 1,503
Westinghouse‘s vacuum . . . . . . . . . . . . . . . . . . . . 204 8 0 94.5 52 841- 1.728 Wet 126 .3 166 .3 1,598
Steel 8r. McInnes‘s . . . . . . . . . . . . . . . . . . . . . . . .. 197 7 1- 81.8 491} 84%- 1,608 “ 128.6 160.4 1,636
Westinghouse‘s automatic . . . . . . . . . . . . . . . . . . 203 4 0 94.3 52 18 840 Dry. 259.8 820.6 777
Fay & Smith‘s vacuum on engine and tender 203 12 1 94.2 57} 28 1,400 “ 188.9 227. 1,007
Smith’s vacuum . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 .12 2 87.3 454 22 920 “ 181.6 229 .6 1,111 Engine reversed.
Fey‘s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 13 0 85.2 45} 22 928 Wet. 180. 229.6 1,121 Engine reversed—brakes of rear
Clark 82 Webb’s . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 0 1 51.7 ' 464 221- .97 9 Dry. 17 8.2 232. 1,182 section of train believed to have
Barker’s hydraulic . . . . . . . . . . . . . . . . . . . . . . . 210 2 0 94.4 49;- 25 1,116 " 177 .4 219 .8 1,189 been slightly applied before sig-
(8313318285 1%I%%es‘s . . . . . . . . . . . . . . . . . .. . . . . .. 197 7 1 81.8 g9} 34 1,132 ‘2 174.2 228.9 1,158 1121.
ar ' e ‘s . . . . . .' . . . . . . . . . . . . . . . . . . . 241 9 1 58.7 1% 4} 1,0 ‘ 89.7 27 .6 1,014 En 'ne reversed.
gteel & Mclnnes‘s . . . . . . . . . . . . . . . . . . . . . . .. 197 7 1 81.8 464 23 1 970 Vlgct. :ll'ig .9 224.4 1,512; “ »
ay‘s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 18 0 85.2 451} 27 ,095 r . 5 .6 187. 1, 2
Clark‘s hydraulic . . . . . . . . . . . . . . . . . . . . . . . . .. 198 4 0 71.5 50% 27 1,429 “y 145.5 208.61 1,387
Westinghouse’s vacuum . . . . . . . . . . . . . . . . . .. 204 8 0 94.5 494 82 1,517 Wet 130.4 171.7 1,548
Westinghouse‘s automatic . . . . . . . . . . . . . . . . .. 203 4 0 94.8 5 '1} 20 930 Dry 257 .7 302-5 783
Clark 82 Webb’s . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 9 1 49.3 3.4 15 600 “ 209.9 292.8 961 Tender-brake not used.
glarlis hydraulic; . . . . . . . . . . . . . . . . . . . . . . . .. 198 4 0 45.7 411- 281} 1,815 “ 119.4 $92.8 1,342 “ “ “
' ’ . . . . . . . . . . . . . . . . . . . . . . . . . ' ". ‘ “ - 5. . ° “ “ “
Fig}; . . . . . . . . . . . . . . . . . . . . . . . . . . . % 33% “ 132 Engine and tender brake not used.
gesltilgrh‘ouggs automatic . . . . . . . . . . . . . . . . . . 203 4 0 24.9 484 69 2,258 Wet. 27.34 69. 38 3,310
ar e ’s . . . . . . . . . . . . . . . . . . . . . . . . . . 241 9 1 9 .5 43} 94 3,2 9 “ 6.‘ 9 51 . 7 4, 59 En ine reversed.
Westinghouse‘s automatic . . . . . . . . . . . . . . . .. 111 15 0 100. 531- ;61} 869 Dry. 263.8 858% 766 ' g
' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 17 0 100. 42 5 1,007 “ 141.4 86. 1,427
Steel 81 Mclnnes‘s . _ . . . . . . . . . . . . . . . . . . . .. 108 0 0 87. 451} 281- 1,320 “ 126.6 178.8 1,594 Hand-brakes in vans not used.













BRAKES. ' 215


ent. Now, the retarding forces available for stopping a train are the friction of the brake-shoes
upon the wheels, the axle-friction, the rolling friction of the wheels upon the track, and the resist-
ance of the atmosphere. The brake-friction bears a certain proportion to the pressure applied, and
varies somewhat with the condition 01' the weather, but one-sixth of the pressure applied may be
considered as a fair average allowance. The pressure upon the brakes is limited by the weight on
the wheels fitted with brakes, and the weight on the wheels must always exceed the sum of the
brake-pressure and axle and rolling friction to prevent sliding of the wheels. If we allow one ton
for axle and wheel friction, to he on the safe side (it is actually less than half that amount), it will
leave 139 tons available for brake-pressure, and one-sixth of this, 23% tens, or 46,333 lbs., will be
the brake resistance. To this we must add the axle and rolling friction, and the resistance of the
atmosphere, which, at the speed indicated, may be set down in the aggregate at 14 lbs. per ton
of train, or 2,380 lbs., and the total resistance will then be 48,713 lbs., or one-seventh of the
weight of the train. If, as before shown, a train will run 53!; feet in 1.82 second, if the retard
ing force is equal to its own weight, it will run seven times that distance, or 374 feet if the
retarding force is one-seventh of that amount, and will consume about 13 seconds of time.
But this calculation is based on the assumption that the full brake-pressure is applied at the instant
of shutting ofi, which is never the case in practice. With the original Westinghouse brake, three
or four seconds are usually consumed in getting full brake-pressure upon a train of six cars, and
it will be safe to assume that a distance of 160 feet will be passed over before the full effect of the
brake can be exerted; and if this distance is added to that previously given, the total distance
run after shutting off and applying the brake will be 534 feet, and the time required may be roughly
stated as 16 seconds.” .
The table on page 226 shows the results of experiments on continuous brakes made on the Midland
Railway, England, June, 1875. The tests marked A were on stopping trains by tender and van brakcs
only worked by hand. The trains were each started from a r< gnlar starting-point, and were given more
than three miles to get up speed. The stops represent the best attainable, with ordinary tender and
van brakes worked by hand, as the point at which the signal to apply brakes was known, and every-
thing was in readiness. The data will serve as a certain basis of comparison from which the pow-
ers of the continuous brakes may be judged. Experiments B were on stopping trains by tender-
brake, van-brakes, and continuous brakes applied by guard on flag or cord signal. Experiments C
were on stopping trains by the application of engine, tender, and continuous brakes, no sand being
used; the supposition being that the driver saw danger. Experiments D represent cases in which
the driver does everything in his power to stop on receiving the signal. Engine, tender, and contin-
uous brakes are applied, sand used, and the engine is reversed in cases where no engine-brake is
fitted. Experiments E were on stopping trains on a signal given to the rear-guard, or at somc inter-
mediate point on the train, the driver being then signaled to apply brakes. The supposition is that
danger is discovered by a rear-guard or passenger. Experiments F resemble the last in the fact
that the signal to stop was given at the rear of the train, but differ in the driver taking no active
part in the stopping, but merely shutting off steam on feeling that the brakes had been applied.
Experiments G were on stopping trains by the use of the engine and tender brakes only, the engine
being reversed when not fitted with a brake. Experiments H show the eifect. of parting-trains when
running by a slip coupling, the continuous brake then being required to etfectivcly control the two
portions of the parted train.
In the table on page 226, which is condensed from that prepared by Engineer-ing, vol. xix., experi-
ments which failed wholly or partially are omitted. Descriptions of the brakes will be found else-
where in this article.
A competitive trial occurred in January, 1877 , between the \Vcstirghouse vacuum and the Smith
vacuum brakes on the North British Railway, with, among others, the following results: speed 55
miles per hour; number of seconds occupied in making stop: Smith, 28 ; Westinghouse, 21. Num-
ber of feet occupied in making stop: Smith, 1,375; Westinghouse, 910. At aspccd of 30 miles
per hour, the Westinghouse effected stop in 13 seconds and 328 feet. At 29.5 miles per hour, the
Smith effected stop in 17.25 seconds and 480 feet. Total weight of train and load fitted with Smith
brake, 173 tons; portion braked, 86.55 per cent. of total weight of train; total weight of train and
load fitted with Westinghouse brake, 166 tons 10 cwt.; portion braked, 86.02 per cent. of total
weight of train. For full table, sec Engineering, vol. xxiii., No. 57 5.
The Lough/ridge Air-Brake.—'-This brake, constructed as shown in the engraving on a preceding
page, was tested in February, 1876, on the Baltimore & Ohio Railroad, with the following result:
total weight of train (10 coaches), 1,150.2240 tons; brakes applied to 92 out of 96 wheels; speed
of train when brakes were applied, 42.61 miles per hour; time occupied in making stop, 16 sec-
onds; distance run after application of brakes, 589 feet 8 inches. This was a test conducted under
terms of contract with railroad named.
The Henderson. Afr/draulic Brake—The following tests, reported in the Car-Builder, vol. vi., No.
3, were made in March, 1875, on the “Test Chester & Philadelphia Railroad. Train consistcd of loco—
motive, one baggage and three passenger cars, weight- not stated.
(1.) Train stopped while traveling at rate. of 35 miles per hour, on down-grade 15 feet to mile,
31 720 feet and 22 seconds. Steam-gauge pressure at dead stop, 104 lbs. Brake-gauge pressure,
5 bs.
(2.) Train stopped on same grade, 30 miles per hour, in 22 seconds and 870 feet. Steam-gauge
pressure, 105 lbs. Brake-gauge pressure, 90 lbs.
(3.) Train stopped on down-grade of over 30 feet, 30 miles per hour, in 31 seconds and 780 feet.
Steam-gauge pressure, 92?; lbs. Brake-gauge pressure, 90 lbs.
The following table shows the results of trials of the brakes named conducted in Germany in
August, 1877:
210 BRAKES.
Table of Results, corrected for Speed, Friction of Train’s Gravity, and Undue Brake-Block Press-
ure, Trains consisting of Engine braked on the Driving- lei/heels, 11 'encler braked on all Wheels,
Four Carriages braked and .Il'wo unb'ralced.‘


l Distance from Point of
Pressure on Brake-Blocks in ' PERCENTAGE REDUCTION OF MOMENTUM.


! Speed. , _ m . , applying Brake to Point at
Miles per Hour. §:;;:3tfi):_;gg‘oii§iilzslf which the Momentum is ,
i ' Yedu‘md’ as Show“ W ostlnghouse. Hehcrlelu. I Steel. Smith.
é Fm s2 13 0 12 70 11 0
f '- lTlk‘ a 5 I o
t 46'“ °° 437 i 20.63 17.05 15.33 14.00
i 55.9 50 656 25.74 £139.92 21.98 N 20.14
E A . . .. 59.43 9 5 40.85 0 results.
- *6” 3 S7 “5" i 00.32 N 54.041 48.50 No results.
. , 75.93 0t trier . 51.85 Not tried.
4“ 113 437 i 00.24 Net tried. 44.31 Not tried.






46.6 51) 984 54.70 89.13 35.18 41.8.) }


Some very remarkable trials were made on the London, Brighton, and South Coast Railway, in Eng-
land, conducted by Captain Douglas Galton and Mr. Westinghouse, in May and October, 1878. (See
Engineering, xxv., 469; xxvi., 386 and 399.) Their object was to determine the coefficient of fric-
tion between the brake-blocks and the wheels, and between the wheels and the rails, at different
velocities, both when the wheels are revolving and when skidded.- For this purpose a special brake-
van, fitted with the Westinghouse automatic brake, was built, and four ingenious self-recording
dynamometers, designed and applied by Mr. Westinghouse, were used. Two of them recorded the
retarding force which the friction to the brake-blocks exerts on the wheels; the third, the force
with which the brake-blocks press against the wheels; and the fourth, the force required to drag
the van. A self-recording speed-indicator, designed by the same gentleman, was used. Numerous
diagrams were taken, showing the average tangential strain, the brake-block pressure, the speed
of the pair of wheels to which brakes were applied, the speed of the train,'and the traction on
the draw-bar. The conclusions are as follows: 1. The pressure with which the brake-blocks are
applied to the wheels should be as high as possible, short of the point which would cause the
wheels to be skidded and slide on the rails. 2. The rotation of the wheel is arrested as soon as
the friction between the brake-block and the wheel exceeds the adhesion between the wheel and the
rail, and therefore the amount of pressure which should be applied to the wheel is a function of the
weight which the wheels bring upon the rail. The value of this function varies with the adhesion ;
hence with a high adhesion a greater pressure can be applied, and a greater measure of retardation
obtained, than with a low one. 3. In practice and as a question of safety it is of the greatest im-
portance that, in the case of a train traveling at a high rate of speed, that speed should be reduced
as rapidly as possible on the first application of the brakes. For instance, a brake which reduces the
speed from 60 miles an hour to 20 miles an hour in say 6 seconds, has a great advantage as regards
safety over a brake which would only reduce the speed from 60 miles to 40 miles an hour int-he same
time. 4. The friction produced by the pressure of the brake-block on the wheel is less as the speed
of the train is greater; to produce the maximum retardation so far as speed is concerned, the pres-
sure should thus be greatest on first application, and should be diminished as the speed decreases, in
order to prevent the wheels from being skidded (or sliding on the rails) in making a stop. 5. The
coefficient of friction decreases as the time increases during which the brakes are kept on; but this
decrease is slower than the increase of the same coefficient due to the decrease of speed; it has, there-
fore, little influence in the case of quick steps. 6. The maximum pressure should be applied to the
wheels as rapidly as possible, and uniformly in all parts of the train. 7. To prevent retardation from
the dragging of the brakeblocks against the wheels when the brakes are not in use, care should be taken
that the brake-blocks are kept well clear of the wheels (say half an inch) when in a state of inaction.
483A.

















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's'44-4-4-4-a-4-4- ‘ ++++++
Automatic Application of Brakes by Electricity—An ingenious device has been adopted on the
Northern Railway of France, by means of which brakes are applied automatically when the signals
are against a train. The general principle involved is, that when the train passes a signal against
BREAD AND BISCUIT MACHINERY. 217

"—
it, a brush of wire on the engine comes in contact with a raised wedge at the side of the_rail, and
closes a battery circuit. The moment this occurs the engine-whistle is sounded, and steam is turned
on to the ejector and the brakes applied, without any action on the part of the driver or guard.
This apparatus is illustrated in Fig. 483 A, which shows an engine and portion of a train fitted up. A
is the double ejector producing the vacuum ; B, balanced steam-valve ; C, electro-automatic whistle;
D, vacuum-gauge; E, counterweights under whose action the valve B opens, when the movement
which opens the electro-automatic whistle C sets at liberty simultaneously the lever which carnes
the counterweights; F, vacuum-cylinders acted on by the ejectors and working the brake-levers;
I, wires establishing the electric communication from one end of the train to the other, and conduct-
ing the current to the Hughes electro-magnet of the electro-automatic whistle; T, iron tubes form-
ing air-conductors. By putting the commutators in the cars in contact with the earth, the electrlc
current acts on the bells at the head and tail of the train, on the whistle C, and at the same moment
on the lever with counterweight of the steam-valve B, which opens itself, and applies the vacuum-
brake. The contact required to put the brake on can be made by causing the wire brush under the
engine-step to come in contact with the wedge-piece shown between the rails. The dotted line shows
the wire connected with the signal and battery.
BREAD AND BISCUIT MACHINERY. Good fermented bread is best made from the flour of
wheat. The essential constituents of wheat flour are starch, also called farina or fecula, gluten,
and a little albumen. According to Vogel, 100 parts of wheat flour contain of starch 68 parts,
gluten 24, gummy sugar 5, and albumen .2; but these proportions vary with the goodness of too
wheat.
The starch of wheat flour is very nutritive. Gluten is a mixture of vegetable fibrine, and a small
quantity of a peculiar matter containing nitrogen, called gliadine, to which its adhesive properties are
due. The small proportion of sugar in wheat flour enables it to ferment on being mixed with water,
without the addition of yeast. Thus the dough of wheat flour, by spontaneous fermentation, becomes
converted into leavcn.
During the rising of the dough, carbonic acid is formed at every part, and is prevented from
escaping by the gluten, which forms a kind of adhesive web. The formation of this gas causes the
dough to swell in every direction, and the particles of starch to separate, in which condition the pro-
cess is arrested by the heat of the oven, so that when the bread is cut open, it contains many cavities,
each of which in the dough contained a globule of carbonic acid.
In the preparation of wheat for the manufacture of bread, the ground grain is usually separated
into three parts, the flour, the pollard, and the bran ,' the flour forms, on an average. about three-
fourths of the wheat ground. The white flour is pleasing both to the eye and taste, and there is a
strong prejudice in favor of white bread; hence various methods of bleaching are resorted to, but it
is doubtful if the whitest bread, even supposing it to be pure, is conducive to health and economy.
By rejecting the bran, as we do when using only the finest flour for bread, we actually lose a large
amount of nourishment of the most important kind. According to Liebig, the separation of bran
from the flour is rather injurious than useful to nutrition. By using unbolted flour for bread the
product is increased at least one-fifth. From the several varieties of flour obtained by bolting, three
kinds or classes of bread are manufactured : 1. Wheaten bread, or firsts, which is made of the finest
flour. 2. Household bread, or seconds, which is somewhat coarser. 3. Brown bread, thirds, which is
made of flour of various degrees of coarseness. For making firsts, the flour is entirely separated
from the bran or husks; in the other descriptions the bran is not entirely removed, but the coarse
broad bran is separated from the coarsest flour.
The baker generally takes a portion only of the water which he intends to employ in making the
required quantity of dough, at a temperature of from 70° to 100°, and containing a portion of salt
necessary to give the bread its proper flavor. Yeast is next mixed with the water, and then a portion
of flour is added, always less than the quantity intended for the finished dough. The mixture is
covered up and left in a warm situation. In about an hour this mixture, termed the sponge, thus set
apart, begins to ferment. It swells out and heaves up, evidently in consequence of the generation of
some internal elastic fluid, which, in this instance, is carbonic acid gas. When no longer capable of
retaining the pent-up air, it bursts and subsides. After the second or third rising and dropping of
the sponge, the baker interferes, otherwise the bread formed from this dough would be sour. At
this period he therefore adds to the sponge the remaining portions of flour and water and salt, neces-
sary to form the dough into the required consistence and size, and next incorporates all these ma-
terials with the sponge, by long and laborious kneading. The dough is left to itself for a few hours,
during which time it continues in an active state of fermentation throughout its whole extent. After
a second kneading, to distribute the gas within it as equally as possible throughout the whole mass,
the dough is weighed out into portions requisite to form the kinds of bread desired. These leaves
are once more set aside for an hour or two in a warm place, and the continued fermentation soon ex-
pands each mass to about double its former volume. They are now considered fit for the fire, and
are finally baked into leaves, which, when they quit the oven, are nearly twice as large as when they
entered it. The gas contained in the bread is expanded by the heat throughout every part of the
leaf, and swells out its whole volume, giving it the piled vesicular structure. Thus a well-made and
well-baked leaf is composed of an infinite number of cellules, each of which is filled with carbonic
acid gas, and lined with, or composed of, a glutinous membrane; and it is this that communicates the
light, elastic, poroustexture to bread.
Various arrangements are in use for making bread by machinery. The usually laborious occupa-
tion of kneading and mixing the dough is now perfectly well performed by mechanical means, and
automatic ovens receive the dough and return it baked to the basket. Thus large quantities of per-
fect bread are made expeditiously and at a low price.
Aerated Bread—The apparatus devised by Dr. Dauglish for the manufacture of aerated bread is
218 BREAD AND BISCUIT MACHINERY.

_‘
represented in Fig. 484. The water-chamber A and mixer B are cast in one piece, and communicate
by an equilibrium-pipe and valved aperture; the water-chamber also communicates with awater-tank
and with the gas-generating chamber E, through pipes whose discharge is controlled by cocks. The
flour and salt are admitted to the water-chamber from the tank. When the gas attains a pressure
of 100 lbs. per square inch, it is allowed to pass through the water, which, when thoroughly charged,
is admitted to the mixing-chamber, where it is mingled with the flour and salt by revolving beaters.
The receiver is secured to the mixing-chamber B, and communicates with it by a slide-valve so ar-
ranged that it cannot be choked by dough. The two vessels are also connected by an equilibrium-
pipe, so that the pressure of gas may be equal in

484. each, allowing the dough to fall into the mixing-
chamber by its own gravity. From the receiver the
i.- dough is passed to the baking-pan, by means which
allow of its being surrounded by air or gas under
.... h pressure, thus lessening the escape cf the gas inclosed
' A in the dough. The baking requires to be conducted
in a peculiar manner. Cold water being used in mix-
ing, the expansion of the dough on rising causes a
great reduction of temperature, as much as 40° be-
low that of fermented bread when placed in the
even; this, with its slow springing until it reaches
the temperature of the boiling-point, renders it es-
sential that the top crust should not be formed until
the very close of the process. The furnaces, accord-
ingly, are so arranged that the heat is applied through
the bottom, and at the last moment, when the bread
is nearly baked through, the upper heat is applied,
and the top crust formed.
An improved method of making aerated bread is
known as the “ wine process,” and consists in form-
ing a wine from malt by mashing, and afterward set-
ting up the vinous fermentation in closed vessels.
Four gallons of the so-called wine are mixed with
~ the necessary water for a sack of flour, drawn into
a closed vessel, and aerated—that is, charged with
carbonic acid gas, like soda water. This soda wa-
' ter is then mixed with the flour (in strong, closed
,_______~ vessels), and kneaded by arms driven by machinery.
E_ -_ The dough formed is drawn off by machinery (thus
dispensing with any intervention of the human hand)
into the required loaf-sizes, and at the same moment as the carbonic acid gas passes out of it, the
dough is raised and vesiculated, and ready for the oven, the whole time required for forming
a sack of flour into loaves not being more than half an hour. The effect of the new wine pro-
cess on the flour is that the gluten cells of the starch are softened and broken up, and the dough
is thus entirely altered in its character. Instead of being tough and harsh as formerly, the dough
now becomes soft and elastic; it is easily kneaded, requiring only half the power to work the knead-
ing arms, and the atmospheric pressure required in the vessels is only about 20 lbs. to the inch, in-
stead of 90 lbs., as hitherto. The use of such low pressures, besides being a great pecuniary gain, is



llllliiliilllllllllllllllllllllllll!








of considerable importance in giving to the bread a soft and beautiful pile-like texture. The dough,
when prepared by the wine process, also soaks and bakes with the greatest ease, and at an oven-heat
of 100° less than the oven-heat hitherto required for aerated bread. The starch of the flour is now
changed into dextrine, while the gluten is uninjured, and the bread has a sweet and agreeable flavor,
free from that acidity and bitterness always more or less present in fermented bread. .
Bread-making lilachinerg/r—With Watson’s bread-making apparatus, Figs. 485 to 488, the entire
operation, from the mixing of the flour and the other ingredients to the final deposrt of the dough in
the oven. is done by machinery. Fi". 485 is a side elevation. Fig. 486 is an end View. Fig. 487 is
BREAD AND BISCUIT MACHINERY. 219

w—
a section of the mixing and expressing vessel, with the agitator; and Fig. 488 is the same, with the
expressing-piston in place. A is the mixing-cylinder, having a hinged cover a, and at one end a
sluice-door L, which can be raised for the exit of the dough. The agitator, which is first placed in
the cylinder, consists of a series of twisted pieces of iron D, Fig. 487, which, when rotated by the gear-
ing shown, tend to force the dough out at the sluice-door. The flour, water, etc., being inserted, are
thus mixed and left for a time to rise. The agitating apparatus is then removed, and replaced by
the piston C, Fig. 488, which, by means of the rack and gearing shown, moves so as to force the
dough through the opened sluice-door at a regulated thickness and upon an endless web, .51, Fig. 485.
While traveling upon this web the dough is submitted to dusting with flour from the vibrating dust-
box R. The dough then passes under the dividers 7', Fig. 486, which separate it into blocks of suit-
486. 487.
I





















able size. It is then transferred to a truck U, which is caused to travel with its lead to the even,
where the dough is transferred to another truck which is pushed forward into the even by hand.
Berdan’s automatic oven has two stories. Underneath the oven is a furnace, from which the heat
is conducted to and through the even, by means of fire-brick tubes ; and the furnace is so constructed
and arranged that, by means of a self-acting damper attached to a piece of metal, which opens and
shuts as the metal contracts and expands, the heat in the oven can be regulated and kept constantly
at the same temperature. The mercury stands at about 292’. There are four doors or entrances to
this oven—two in the lower and two in the upper story. Within the oven is an endless chain, to
which arms are attached, and upon which thirty-two forms are laid, about two feet apart. This
chain can be moved either by hand or by steam power (the latter being used for convenience and
economy in the present case, there being a steam-engine on the premises), and revolves perpendicu-
larly through the oven at just such 433 .
rate of speed as is required to bake '
the bread with a single revolution.
The péz‘risscm', or mechanical
bread-maker, invented by Cavillier
8t (30., of Paris, consists in a strong
wooden trough, nearly square, with
its two longest sides inclined, so
as to reduce the area of the trough
in the direction of its width, and
adapt it to the dimensions of a
cast~iron roller, the axis of which
passes through the ends of the
trough ; the bottom of the trough
is semi-cylindrical, leaving a small
space between it and the roller,
which space is adjustable by le-
vers. All along the top of the
outside of the roller is fixed a knife-edge, which, with the roller, divides the trough into two com-
partments. Upon the axis of the roller is a toothed wheel, which takes into a pinion; this pinion is
turned by a winch, and communicates thereby a slower motion to the roller; and the roller, by its
rotation, forces the materials or dough through the narrow space before mentioned left between it
and the bottom of the trough—the knife-edge on the top of the roller preventing the dough from
passing it. Being thus all forced into one of the compartments, the motion of the roller is reversed
by turning the winch the contrary way, which then forces the dough back again through the narrow
Space under the roller into the first compartment; in this manner the working of the dough, alter_
nately from one compartment to the other, is continued until completed.
Another plan is to make the trough containing the dough revolve with a number of heavy
balls within it. The trough in this case is made in the form of a parallelopipedon—the ends being
square and each of the sides a parallelogram, whose length and breadth are to each other as five to
one. One side of the trough constitutes a lid, which is removed to introduce the flour and water, and
the trough is divided into as many cells as there are balls introduced. The patentee states that by


220 BREAD AND BISCUIT MACHINERY.

the rotation of the trough the balls and dough
are elevated together, and by their falling
down the doughwill be subjected to heat-
ing, similar to the operations of the baker’s
hands.
Instead of employing a revolving cylinder,
it is fixed; an agitator is made to revolve,
having a series of rings angularly attached to
an axis, extending the whole length of the
trough.
Bismz't or cracker making, as practised in
large baking establishments in this country,
includes three distinct operations exclusive
of baking: 1, mixing; 2, braking or knead-
ing; 3, cutting or panning. In the first op-
eration, the cylinder-mixer is generally used.
It is raised some distance "from the floor, and
is provided with sheets for flour, milk, but-
ter, sugar, etc. It consists of a nearly cylin-
drical pan of iron suspended loosely on a
shaft which runs through its centre, and is
supported by bushes in a cast-iron frame on
each side. This shaft carries four stirrers
set 6 inches apart, and shaped like an in-
verted U. They approach within 1% inch of
the circumference of the pan. The driving
power is from one end by a toothed wheel
gearing into a pinion on another shaft. The
outside of the pan is provided with a wheel
and toothed segment for lifting the cover and
tipping over the can. The capacity is gen-
erally 1 barrel of flour, and the time required
for mixing is 80 minutes. From the mixer
the dough is carried to the brake or roller,
of which two kinds are used, viz., the simple
and return brake. Table brakes are also em-
ployed, but only for very tender dough. In
the simple brake, as the dough passes under
the iron rollers it is folded, and this process is
continued until the dough is perfectly smooth
and even in texture. The machine runs at
about 180 revolutions per minute. F ig. 489
represents a return-brake with fluted roller,
the object of tinting being to accomplish the
work more quickly.
From the brake the dough is carried to
the cutting-machines, which are of various
kinds ; those commonly used are the cylinder
and the stamper. The latter is in more gen-
eral employment in this country, as the cylin-
drical machine is much more expensive with-
out being correspondingly beneficial. The
stamper is made in two forms: that which
requires the scrap, or the portion between
the crackers, to be removed by hand; and
the English machine manufactured by Vicars
of Liverpool, in which, by an ingenious ar-
rangement of wooden fingers, the crackers
are forced downward into a pan, while an
ascending apron carries the scrap into a box.
A machine of the first class consists of an iron
framework, having at one end a pair of rollers
which reduce the dough to about an eighth of
an inch in thickness. The upper roller is ad~
justablc; the cutter is in the centre of the
machine. An endless web of felt passes un-
der the cutter and over a bed-piece of hard
wood, covered with rubber three-tenths of
an inch thick to resist the force of the cutter.
The web is stretched over rollers on each end
of the machine, one of which carries a ratchet-
wheel moved by an eccentric on the cutter-
shaft. The motion is such that when the
sweat
willful
mu m m
I
~_..__ -._ ...
if; l-
ll,
‘ 'l'V- l I 1"
-< d!
l‘. J’III' || i ._ a I
- __-._. - ‘
~..._.__~__
__-_____
____ “_
I
‘ .
M-
x-
h


BREAD AND BISCUIT MACHINERY. 221


stamper is down the web is stationary; and as it rises it moves forward just sufficiently to bring
fresh dough into place. The cutters are made of gunmetal and fitted with bristle cjeetors for both
biscuit and scrap. This machine is used principally for raised crackers. It makes about 1m) revo-
lutions a minute, and has a capacity of 30 barrels of flour a day.
Fig. 490 represents an improved form of stamper manufactured by John McCullum of New York.
The frame is the same as that of the English machines; the gauging-rollers are heavier, and are
provided with a gauge-wheel. The movement of the aprons—of which there are three. viz., that
which carries the dough direct to the cutter and the pan, the scrap elevator, as also that 01 the brush
and gauge rollers—is by means of eccentrics on main and cutter shafts working ratchets. This
motion is easily adjustable to alter the movement of the aprons and rollers. An improvement on
this machine is used in the extensive establishment of Messrs. E. J. Larrabee & Co. of Albany (to
whose courtesy we are indebted for the facts presented in this article), which affords a continuous
feed, and in which the biscuits and scraps are separated by a finger device, the biscuits going into pans
and the scrap to the brake to be worked
over. The machine makes 60 revolutions
on soft dough and 80 on hard. Its ca-
pacity is 20 barrels of flour a day. The
cutters make from 18 to 40 biscuits at
each motion. '
In the so-called “snap” machine the
box which contains the dough has its
bottom perforated with round holes bev-
eled inwardly. The dough being placed in
the box, screws driven by suitable gear-
ing force down a piston, which causes a
certain amount of the dough to be driven
out of the holes in the box. Knives
placed opposite each hole then cross over
and sever the exuded portions, which
fall upon pans placed to receive them.
This machine has a capacity of 20 bar-
rels of flour in 10 hours. The “Rout
press ” is similar in construction, the
dough being pressed through dies and
carried to pans, when it is cut into suit-
able lengths. '
In the mechanical manufacture of bread
and crackers, the process of baking has
been greatly improved in this country.
Two forms of even are chiefly used, viz.,
the revolving wheel and the endless chain.
Fig. 491 shows a section of the Ra-ney
oven. It is built of brick, the walls be-
ing 8 inches thick. Passing through the chamber is a shaft, on which is fixed a wheel, to which
are.hung the pans. The diameter of the wheel is such that during the revolution each pan is
brought within 18 inches of the fire. The fire is built upon an open grate flush with the floor of the
furnace, the ash-pit being immediately under it. The fine is situated on a level with the grate and
at the back of the oven. The top or crown is built in the form of a double arch, which forms con-
cavities to receive the superheated air and steam; In this way the darkening of the tops of the
crackers by excessive heat is prevented. The wheel carries twelve shelves, which, being hung
loosely, always remain level. Motion is imparted to it by means of a worm working on a cog-wheel
attached to the shaft. The speed is regulated by a brake-wheel on the. face of the oven. The door
of each oven, 18 inches high and extending across the oven, is provided with an adjustable closer.
The shelves carry 4 pans, which are made of either sheet-iron or coarse wire-netting, according to
the kind of dough to be baked. In the operation of baking, the pans being inserted, the baker
starts the wheel, which revolves toward him "from above downward; this brings the shelf half'way
tov the fire, and the operation is repeated until the first shelf and baked crackers appear at the open-
in". The temperature ranges from 250° to 450°. The time required varies according to the size of
the biscuits or other material. tread usually requires 35 minutes; raised crackers 3 minutes; fancy
crackers from 8 to 6 minutes. The capacity of the oven is 50 barrels of flour a day. In the endless-
chain oven the shelves are attached by pulley-blocks to an endless chain which passes over the fire.
For principles of bread-making, sec “Report on Vienna Bread,” by Professor Hosfoid, in “ Re-
ports of U. Gomn'iissioners to Vienna Exposition, 1873.”
Among the new machines for bread and biscuit making introduced within the last ten years are a
kheading-machine for mixing and kneading all kinds of doughs both for crackers, biscuits, cakes, and
bread. These are built with a capacity of mixing from 1 to 12 barrels of flour at a time, the mixing
of a batch being effected in from 10 to 15 minutes. The rolling of the dough into sheets preparatory
to cutting it into crackers is done both with the old style of plain brakes and also by the more
modern return or reversible brake. The rollers of the return-brake are easily adjusted so as to ad
mit and break a large mass of dough, the process being greatly facilitated by reverse gearing, by
means of which the operator can roll the dough through the rollers and back as often as required to
thoroughly break it, after which, by closing the rollers a suitable distance apart, thin sheets of dough
are made which are finally put through the cuttinganachine.
491.
. . .. ‘ -||]|H|[|1Hm* ' l .l'. r.
l" "H. 5u992lti.“"LLlf_L'11il-7i-; _ ,_ ,,j'ru"ft_ . ,lifljfip - -_ .
‘ I i l ‘ ‘ , _ i , II,
.v I ,
'l
I.



222 _ BREAKER, OR CRUSH ER.

In biscuit-cutting machines marked improvements have been made. A duplex or so-called con-
vertible-cutting machine which is adaptable to cutting, stamping, and handling all the various kinds
of plain and fancy biscuits which are at present pro-
duced in this country, is represented in Fig. 491 A.
The novel feature of this machine, as constructed by
Messrs. Fowler & Rockwell, of New York City, is that
the cutting~apron or belt on which the biscuits are out
can be readily arranged so that it will place the biscuits
on pans fed into the machine for the purpose and re-
move the scrap, or extended to the end of the machine
to permit the baker to remove the crackers as fast as
they are cut, as is requisite with some varieties of his-
euits.
The varieties of ornamental and plain biscuits,- crack-
ers, and cakes which have been designed and produced
with dies or cutters made to suit and work in the above
and similar cutting-machines, are almost endless. Ma-
chinery for working soft-cake doughs has also been
much improved. Mitchell’s Patent Cake-Machine is
designed for forming cakes from soft or batter doughs
and placing them on pans for baking. The bake-pans
are placed on the table, and are carried by means of
a chain (with an intermittent movement) under the
douglrbox, the table, rising intermittently to receive
the deposits of dough which are ejected through a
plate at the bottom of the dough-box, which plate is
provided with openings to suit the size of cake re-
quired. Each machine is provided with a number of
plates, each differing from the other in the size and
shape of the openings adapted to the different kinds
of cake to be made. The plates are interchange
able.
The Mitchell machine is also provided with a wire
knife used for the purpose of working a stiffer dough
into cakes than that used in the above-described pro-
cess. To make cakes with the wire-knife attachment,
the dough when pressed through openings in the plate
at the bottom of the dough-box is cut- off by the knife,
which travels with a reciprocating motion across the
openings in said plate. The wire knife, being attached
to the table, falls with it after having completed a cut,
returning while the table is dropping and arriving at
the position for making the next cut when the table
is in preper position. The cakes thus cut are of a uni-
form size and of the weight required, and fall upon
the bake-pan in regular order. As the pan travels out
from under the dough-box it is taken away by an at-
tendant, another pan following.
The ovens used universally by the cracker and bis-
cuit bakers of this country are the revolving reel ovens,
which have not changed materially in the last decade.
On the other hand, quite a large variety of special ma-
chines fer bakers’ use have been' introduced. Among
these may be mentioned cake-making machines, in
which heaters are so arranged as to imitate the pecul-
iar rubbing-up motion given to the dough by the hand
and arm; “whisking-machines” for beating eggs, in
which brooms or Whisks of wire are rapidly vibrated;
fruit-cleaning machines, in which impurities are re-
' moved from fruit by agitators working over concave
sieves; and an ingenious arrangement of lamp and reflector for illuminating the interiors of ovens.
For mixing small quantities of dough, one form of machine has kneaders working in opposite directions,
which, from their peculiar shape and motion, catch the dough at a different point at each revolution.
BREAKER, OR CRUSHER. A machine for breaking and‘ crushing minerals which reach the
surface in large solid blocks or masses into fragments that can be easily handled, preparatory to
placing them in machines for reducing them to still smaller fragments or to powder. The sledge is
the simplest and most common tool for this purpose; and it is followed by spalling hammers, until
none of the fragments are much larger than the fist. Until within a few years this was the common
and only way of breaking up ore into sizes suitable to be fed into mortars of stamp-batteries; and
it is still used where only small quantities are to be broken, and the extent of the operations does
not justify the expense of obtaining suitable machines for the purpose.
The first attempts upon the Pacific coast to substitute machine for hand labor in spalling ore were
in the direction of stamps of unusual weight, raised by cams to a height of 4 feet, and allowed to
491 A.


BREAKER, OR CRUSHER. 223


drop upon the mass of rock to be broken. Stamps of this kind, either single or two in a battery,
were placed at the superb mills erected near Aurora, at the Real del Monte, and at the Antelope.
They weighed 2,000 lbs. each. There were no mortars, but a solid bed or anvil was surrounded with
massive grates, made of bar iron, through which the fragments could drop. Masses of ore, from 1 to
2 feet in diameter, could be rolled in and subjected to a succession of blows. The two heads could
break up about 2 tons an hour, but with an enormous expenditure of power, as is evident when we
consider that for each blow a ton weight of stamp was to be raised 4 feet, and also that the smaller
the mass to be broken the greater was the force of the blow. Thus, when a mass of quartz, say 6
inches in height, lay upon the anvil, the stamp fell upon it from a height of 3 feet 6 inches; but
when a block 2 feet high, which needed a much harder blow, was upon the anvil, the stamp fell only
2 feet. Similar stamps were in
492- use at Washoe and at Virginia,
but were soon abandoned because
of their manifest defects and cost.
At the Quincy mine, on Lake
Superior, heavy hammers have
been used for breaking up coarse
gangue containing ore, which are
managed after the manner of the
machines in use for breaking up
large ore-masses. They are espe-
cially serviceable for coarse pieces
of native copper, which cannot be
broken in the crushers, in separat-
ing the copper from the gangue
united with it, and in hammering
clean the lamps of copper.
77w Blake Breaker and Crush-
er, invented by Mr. Eli \Vhitney
Blake of New Haven, Conn, is
one of the most effective machines
of its class. Fig. 492 shows a
side-view or elevation of this ma-
chine. The circle Dis a section of
the fiy-whcel shaft, which should
' make from 225 to 250 revolutions
per minute. The larger circle L, inclosing .D, is a section of the eccentric. F is a pitman or connect-
ing-rod, which connects the eccentric with the toggles G G, which have their bearings forming an
elbow or toggle joint. H is the fixed jaw; this is bedded in zinc, a quarter of an inch thick, against
the end of the frame. F P are chilled plates against which the stone is crushed ; when worn at the
lower end they can be inverted, and thus present a new wearing surface. The cheeks I I fit in re-
cesses on each side, and hold the plates in place; by changing the position of the cheeks from right
to left, when worn, both will have a new surface. J is the movable jaw; this is supported round
the bar of iron K, which passes freely through it, and forms the pivot upon which it vibrates. L is
a spring of India-rubber, which is compressed by the forward movement of the jaw, and aids its re-
turn. M ~M are bolt-holes. .B is the fly-wheel; C, the driving-pulley; Q Q Q Q, oiling-tubes; R
R R R, steel bearings; T, bush and key. Every revolution of the crank causes the lower end of
the movable jaw to advance toward the fixed jaw about one-fourth of an inch and return. Hence, if
a stone be dropped in between the convergent faces of the jaws, it will be broken by the next suc-
ceeding bite; the resulting fragments will then fall lower down and be broken again, and so on until
they are made small enough to pass out at the bottom.
The following table shows the principal facts that relate to the sizes of machines that are used
generally for the making of road-metal:
Table of Sizes and Capacity, Blake‘s Stone Breaker.













Product per H
NUMBER. Size, or receiving Capacity. Hour in Cu- Total Weight. Proper Speed. orseipognr
bic Yards.* reqmre '
Inches.
A 10 x 4 3 4.000 250 4
1 10 x 5 3 6.700 180 5
2 10 x T 5 8,000 250 6
3 15 X 5 6 9,100 180 9
4 15 x 7 6 10.400 180 9
5 15 x 9 7 13,300 I 250 a
6 15 x 11 7 11.000 180 9
8 20 x 15 .. 32.600 150 12
'I 15 x 13 z“, .. 11,760 180 9
9 24 x 1\‘ .. 37,500 1‘25 12
10 .10 x121; a 7.000 230 9

* The amount of product depends on the distance the jaws are set apart, and the speed. The product given in the
table is due when the jaws are set 1* inch open at the bottom. and the machine is run at its proper speed and dili-
gfintly fed; but it will also vary somewhat with the character of the stone. Hard stone or ore that breaks with a
snap will go through faster than sandstone. A cubic yard of stone is about one and one-third tons.
“i Coarse or preliminary breakers. i: Plaster crusher. '
004
BREAKER, OR CRUSHER.
I'm!

To make good road—metal from hard compact stone, the jaws should be set from 11'; to 1?; inch
apart at the bottom. For softer and for granular stones they may he set wider.
Hall’s Break-m- is similar in principle and mode of action to the Blake machine, but differs in vari-
ous modifications and details. The movable jaw is made in two pieces, each half the width of the
fixed jaw; and the parts are driven by separate toggledevers and eccentrics, so that they make :11.
ternate strokes. This alternate movement is turned to account to draw back the jaws, the forward
movement of one jaw drawing back the other, and vice versa. The faces of the movable jaw are
delachable, and are held in place by wedge-shaped bolts which may be easily tightened. The fixed
jaw also has two sets of faces, the upper set being of wider pitch than the lower, and being so
arranged with respect to the movable jaw that the teeth of the latter work opposite a space in the
fixed jaw. In the lower parts of the fixed jaw, on the other hand, the pitch is finer, and the teeth
are directly opposed to the teeth of the movable jaw. The arrangement is claimed to give the jaws
an improved cubing action.
Brown’s Breaker consists of an upright circular shell, in which is a vertical shaft, the upper ex-
tremity of which is pivoted in a balLand-socket bearing in the cover surmounting the shell or case.
The lower end of the shaft is pivoted in the hub of a bevel-gear. This gearing is placed in an eccen-
tric position with reference to the centre of the hub. The breaking head, which is placed near the
upper portion of the shaft, receives an eccentric gyratory motion from the eccentrically placed bear-
ing in the hub of the gear below, and advances successively toward every portion of the outer wall,
crushing the ore between chilled faces on both the wall and the head. It is claimed that a breaker
of this type weighing 7,500 lbs. will crush 10 tons of ore per hour, and that one of 20,000 lbs. has a
capacity of 20 tons per hour.
The Alden Breaker is designed to work upon material on the principle of abrasion, instead of on
the generally adopted principle of direct compression or impact. It breaks, crushes, and pulvelizes
by rasping and rubbing fragment upon fragment between the dies, and upon the horizontally corru-
gated steel faces thereof; the motion of the rubbing surfaces being obtained by the oscillation of the
dies. They both swing at the same time, in one and the same direction, and to an equal extent. At
their delivering extremities they are held together (closely or otherwise, according to the character of
production wanted) in such a manner that the distance apart from face to face is the same at all
points of the stroke. The dies are hung upon shafts, the ends of which project through the sides of
the frame, and take connecting-rods which at their other extremities receive the studs that jut out
from the sides of a rectangular yoke. This yoke surrounds the free hanging ends of the dies and
moves on a nearly horizontal plane, alternately pushing and pulling the dies within it the full dis-
tance of the stroke, and imparting the rubbing effect. The regulation of the set of the dies to dif-
ferent grades of production is efiected by means of adjustable steel keys. The connection between
the yoke and crank is direct by way of a pitman. The crank-shaft, fly-wheels, and pulley do not re-
quire special mention.
Table showing Capacities, etc., of Alden Breaker.


NUMBER. Dimcn ions of Receiver. Gross Weight. tg°4grlsg,fgie_ n. r. requisite.
Lbs. Lbs. per Hour.
4 14 X 8 19.000 1,501) 15 to 20
6 12 X 3 10.000 1,000 12 to 15
7 10 X 3 4.500 . . . . 1i)
8 10 X it} 800 400 5
9 5 X l} 6U0 150 2
10 1% x {5,- 80 . . . . hand-power.







CRUSHING Roms—1. 0re-Rolls.--By means of crushing rolls, gangue of about the size of the
fist can be reduced sufficiently to separate the dead rock from the ore mixed with it. Fig. 493 will
serve to give an idea of the general form of the crusher which has for many years been used in Corn-
wall for ore-dressing.
wrought-iron bolts. In the construction here shown, the rollers are kept in contact by India-rubber
springs or buffers of great elastic force, one on each side of the frame. Each buffer is composed of
O
O


4
6 rubber disks an inch thick, separated by a disk of iron a quarter of an inch thick. The necessary
initial pressure is obtained by means of two strongly-made screws in the axes of the buffers ; and by
screwing up or unscrewing the nuts on these screws the pressure may be increased or diminished,
according to the necessities of the case. It is evident that it would not answer to rigidly fasten the
rolls in contact. - The accidental dropping of a steel tool, such as a drill or a hammer-head, between
.-
The rolls are supported by very strong bearings, in a frame strengthened by .
BREAKER, OR CRUSHER. 225

pf
them, would break the machine; and moreover, they would not crush as fast and well without a
certain amount of yielding to the materials carried through between them. The use of rubber
springs offers a method of giving the necessary resistance, which increases with the degree of separa-
tion of the rolls, whereas with weighted lovers the pressure is constant. In practice it is found that
the product of rolls geared together is greater than when one is carried around merely by the friction
of the stuff crushed. It is also usual to have three or more rolls where the crushing is wholly done
by rolling. The upper pair are set so as to take in large masses; and to increase the hold of the
surface of the rollers upon the masses, they are made fluted. The fragments falling from this first
pair of rolls are divided between two pairs set below and pressed closely together. The diameter of
crushing rolls varies from 14 to 34 inches (27 inches is a common diameter), and the length or
breadth of face from 12 to 22 inches. The rolls at the mine of Devon Great Consols in Cornwall are
very large, having 34 inches diameter and 22 inches face, and a pressing force on the rolls of 458
cwt., revolving 7 times per minute, and crushing 65 tons in 10 hours, at a cost of 2} pence per ton.
At present smooth rolls are in common use for dressing ores. The middle products from the jig~
ging process—in which, for instance, galena is intermixed with blende or gangue, and which, as a
rule, are not more than .78 inch in diameter—are ground in rolling mills with less diameter of rolls.
In the coarse rolls, which work with the very heavy pressure of from 20 to 25 tons counterweights,
it is advisable not to exceed a velocity of the circumference of over 65 to 7 2 feet, because otherwise
fractures easily occur, on account of the resistance of the counterweight. In the Rhenish ore-dress-
ing establishments, where rubber or steel springs are used for pressing the rolls together, 196 and
even 294 feet velocity of circumference is allowed, without, however, increasing the working capa-
city, with the consequently rcduced pressure of rolls, as compared with slower work and a heavier
pressure. The more or less soft nature of the ore must in each case decide which treatment it is
advisable to use. The use of springs has lately been preferred, in order that the softer ores may not
be crushed too fine and loss be thereby created. The danger of fracture is essentially lessened by
transmitting the driving power by means of belts or friction-rolls. In such contrivances for fine
crushing the position of the rolls is fixed by set-screws. The two axles on which the annular rolls
are fastened are provided with a pair of toothed wheels working into each other, and such a length
must be given to the teeth that they will not be thrown out of gear when the rolls separate. Coarse
rolling-mills have, therefore, involute gearing with very deeply cut teeth. The annular roll is worn
away rapidly by hard material, and is therefore generally made of either chilled iron or cast steel.
It is essential to be able to turn down the rolls from time to time, because they wear unevenly.
From 50 to 60 tons of rolling stufi, varying as the gangue mixed with the ore is silicious or cal-
careous, can be worked up in 10 hours in a coarse rolling-mill constructed on the English model, and
requiring 10 horse-power to run it. From 5 to 20 tons can be worked up in the same time in a flat
rolling-mill, with from 2 to 4 horse-power. In Schwarzmann’s friction rolling-mill for fine reduction
at Ammeberg, Sweden, a rotating flat disk, driven by the engine, is inserted between each pair of
rolls, and carries them with it, working in a similar manner to a collar-mill.
Among the various other forms of ore-crushers, akin to rolls, are the following: 1. Two conical
disks are keyed to inclined shafts having powerful set-screws to adjust the width of the space be-
tween the disks. The ore or stone is fed into a shoot, and, falling between the inclined disks, is
subjected to a pressure as it passes into the gradually contracting space, and is thus crushed. 2. A
concentric roller, with teeth of varying sizes as the throat narrows, bites upon the ore, which is
gradually comminuted between the jaws as the ore is rocked. Mills for finely pulverizing ores will
be found treated under MILLS, ORE.
2. Coal-0mshers.—The comminution of coal takes place either for the purpose of breaking up
the coal obtained into pieces of a suitable size for the market, or to separate the coal from the ac-
companying foreign ash-producing portionsfislate, iron pyrites, and earthy coal—and then to wash
it clean. In both cases the endeavor is so to arrange the rolls that they act on the pieces of coal as
little as possible in a crushing or “grinding way, but more in a splitting manner, in order to obtain the
smallest possible amount of worthless coal-dust in the first case, and in the second to avoid grinding
into fine dust the soft pieces of fuller’s clay and clay-slate, which cannot be separated from the fine
coal-dust in the further dressing. Rolls for breaking up anthracite were first employed in Pennsyl-
vania in the year 1843, according to Gatzschmann. Afterward diamond-shaped, blunt, tooth-like
projections working toward one another were added to the rolls in that locality, while the body of the
rolls themselves, made of east-iron, was provided with indentations arranged in right and left spirals
crossing each other. The toothed rolls, on the one hand, produced much useless coal-dust, and, on
the other, it was found necessary to throw away a roll when a few teeth were broken out. Cylindri-
cal rolls have been advantageously used with cast-steel teeth inserted, whose peculiar construction is
shown in Fig. 494, A, B, 0. Smooth cylindrical holes of exactly equal diameter are bored radially,
in lozenge-shaped places opposite each other, in the casing of the rolls, and into these holes the steel
projections, provided with cylindrical shanks so as to fit accurately, are driven firmly. The lancet-
like projections are slightly bent in the direction of the motion, in order to seize and split the pieces
of coal with more certainty. If a tooth breaks off, the shank still remaining in the cylinder is driven
through the hole and a new tooth is inserted. For this reason the toothed roll, though at first cost
somewhat dearer than the old east-iron one, is much cheaper in the end. Besides, the work is in-
creased with the same power. and the loss in worthless dust is diminished. The machine represented
likewise shows various important improvements for the safety of its working in regard to the motion
and bearings of the shifting roll, which can be recommended for ore-crushing mills also. The bronze
bearings, for instance, are provided above and below with parallel planed surfaces, so that they can
be shoved into a box-like cavity in the roll frame. The middle portion of the bearings forms an
upright cylinder, from which the ends of the bearings project sidewise like annular shoulders. Ellip-
tlcal cast-iron rings lie, as brake-pieces, between the bearings and the set-screws; the latter are ad-
15
226 ‘ BREAKWATER; '


justed equally by means of a motion common to both. If such a brake-ring gives way, the roll, with
its bearings set free, can recoil without obstruction, while the other bearing turns on its cylindrical
part. By means of this arrangement, which works in a similar manner to the hall-joint journals, as




494.
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smooth a revolution as possible of the axle is produced with diminished friction and wear, notwith-
standing thc heavy vibrations to which the movable roll is exposed. The box-like frame-pieces are
each provided with an accurately-fitting cover, which prevents the lifting and sliding of the movable
bearing.
In Germany, rolls which are provided with sharp, project-ing ribs are used in the crushing mills
of coal-washing establishment-s. To prevent the interfering of these ribs, they are wound round the
cylindrical roll in steep helices laid crosswise, so that lozenge-shaped depressions remain between the
ribs; but even for such coal-washing establishments the improved American toothed rolls with nar-
rower roll~space may be adapted. See “The Mechanical Dressing of Ores and Coal,” by E. I“.
Althan, in “ Reports of Judges of Group I., Centennial Exposition.”
BREAKWATER. A kind of artificial embankment, dike, or rampart, formed of large stones, and
erected for the purpose of protecting the entrances of harbors or roadsteads from the effects of vie»
lent winds, by breaking the force of the waves of the sea; the shipping, moored behind it, lying
perfectly secure. The most celebrated works of this description are these of Cherbourg-in France,
Plymouth, Portland, and Holyhead in England, and Delaware Bay in this country. The experience
obtained by the construction of breakWaters, and by the action of waves upon coasts exposed to
their greatest violence, establishes the principle that blocks of stone of large dimensions only can
be depended upon to retain their places. Mr. James Walker, President of the British Institution of
BRICK-MAKING MACHINERY. 227


Civil Engineers, advanced the opinion in 1841 that a partial vacuum is created by the action of the
waves, and the atmospheric pressure being taken off, for an instant, the mass of stone is the more
readily influenced by the forces acting upon it. (02ml Engineer and Architect’s Journal, September,
1841.) If the whole atmospheric pressure were taken off the surface, it would be equivalent to the
removal of a weight represented by a column of rock 114; feet deep, weighing 1.75 lb. to the
cubic foot. Under such circumstances, and exposed to the action of a wave 20 feet high, which is
capable of moving masses of rock 7% feet deep, stability would be insured only by the addition of
this amount to the 11% feet. But as it is not probable that a large proportion of the atmospheric
pressure is ever thus removed, and as 22 feet is regarded as the maximum height of waves, a depth
of solid stone of 15 feet, used as a coping, would probably resist all action of the waves.
Best Form of Breakwater.—-li‘rem the fact that any settlement of the foundation is far more peril-
ous to a vertical than to a sloping wall, there seems good ground for believing that the ordinary
method of forming the low-water parts of deep harbors with large masses of rubble-stone or of
concrete blocks, is in most circumstances the best and cheapest kind of construction when a vertical
wall is to be adopted. Loose rubble or blocks of concrete, after being acted upon by the waves, are
less liable to sink or to be underwashed, than when a vertical wall is founded upon a soft bottom.
Loose concrete blocks above low water form an excellent protection to the upright wall. Two pre-
cautions should, however, be kept in view: first, the wall should be founded at a sufficiently low level
to prevent underwashing 12 to 18 feet below low water; and second, in all cases where the structure
is to act simply as a breakwater and not as a pier, there should be no parapet, the absence of which
relieves the foundation. lVhen pitched slopes are adopted, great benefit will be found to accrue
from leaving a wide foreshore at the bottom or toe of the slope. Much, however, depends on local
peculiarities in selecting the best design for any work, and the nature of the bottom is in all cases
important. Where the bottom is soft, a high vertical wall should not be attempted.
WORKS FOR REFERENCE.—Th€ construction and history of many of the principal breakwaters will
be found fully treated in the great work of Sir John Rennie, 2 vols, 1854. Modern systems of break-
water construction and harbor improvements are discussed in Stevenson’s “ Design and Construction
ef-Large Harbors,” London, 1875. Details of construction of lake breakwaters and improvements
in harbors in the United States appear in the yearly reports of the Chief of Engineers, U. S. A. See
also the files of Engineering (London), Engineering News (New York), and of Transactions of the
American Institute of Civil Engineers, and of the Society of Civil Enginrers; also Rankine’s “Civil
Engineering (last edition), Reid on “ Natural and Artificial Concrete ” (London, 1879), and Powell on
“Foundations and Foundation Walls (New York, 1889).
BRICK—MAKING MACHINERY. Bricks are masses of clay moulded commonly in rectangular
blocks, baked, and employed for building purposes. American bricks vary in size in the different
States, running from 7% to 8% inches in length, 4 to 4%; in width, and from 2;} to 24; in thickness.
The weight is commonly reckoned at 4 lbs. to the brick, but this varies with the size, the amount of
pressure to which the clay is subjected, and the heat applied in baking. English bricks are com-
monly 9 inches long, 41} wide, and 2% thick.
Material.—-Thc best brick-clays are composed of silica three-fifths, alumina one-fifth, and the re-
maining fifth of iron, lime, magnesia, soda, potash, and water. Where there is an excess of alumina
over the silica, the bricks are apt to crack in burning; the presence of silica remedies this by ren~
dering the bricks more porous. Where sand is added to the clay it should be clean, sharp, fusible,
and not too fine ; proper selection and proportion insure a hard, strong, ringing brick of good color.
For the finer grades of bricks, a finer sand may be used. F oundery sand (“ fire-sand ”) is not at all
suitable ; good building-sand should be a proper material.
The quantity of sand or other substances required for any clay can only be determined by actual
experiment. Sandy clay, or loam, and calcareous clay, or marl, are also used for brick-making; but
if much lime be present the compound may be too fusible. (lxide of iron is rarely absent. in the
process of burning it is converted into peroxide, and imparts to the whole brick its red color, more
or loss deep according to the degree of oxidation.
American clays, of course, vary somewhat. Those in Maine are light; in Massachusetts and Rhede
Island they are more fatty. The Croten, Haverstraw, and other clays, on the Hudson River, are net
of the best quality—containing an undesirable “quieksand,” and being long in burning; besides
which the bricks are likely to “ whitewash ” under the influence of weather. The Connecticut and
Northern New Jersey clays resemble those of the Hudson. The belt extending along the eastern
portion of Pennsylvania, down through parts of Delaware, Maryland, and the District of Columbia, is
Of the finest grade of loamy clay, producing bricks of the greatest hardness and cherry-red color;
those of Baltimore being slightly the best in respect. to the color of the finer grades. The brick-clay
of Ohio and Indiana resembles that of Pennsylvania. The clay used in the vicinity of Chicago, be-
lng that obtained in excavating the “slips” in the rivers, is not only limy, but contains lime-pebbles,
which renders it extremely difficult to work. In St. Louis the material is of loamy nature, with veins
of. what is called “ joint-clay,” which makes the bricks crack and check in drying and split in burning.
The Milwaukee clay is of a plastic nature ; it burns white, owing to the absence of iron. The Italian
Clays are plastic, and need no sanding. In France, the clays in the northern part are loamy and
quite good, and about 2 metres deep ; they gradually improve toward the southern portion. Cuban
and South American clays are poor both in strength and color.
. Burning Brick—The annular furnace for burning brick, invented by Hoffman, Figs. 503 and 504,
IS extensively employed. A large annular chamber, with openings at the sides for the reception of
the bricks, is constructed with a central chimney and with removable divisions for separating the
annulus into different parts. When the furnace is filled with unburned bricks, heat is applied to
one division, the smoke and hot air escaping into the adjoining one, which is the next to be burned,
iihc air for maintaining combustion being received through the compartment last burned, whereby the
228 BRICK—MAKING MACHINERY.

bricks in it are cooled. Each compartment of bricks or other articles is thus burned in turn, the
waste heat of the burning compartment continually drying the compartment before it, and taking the
heat of the one behind. The letters a a, Fig. 503, mark the circular arched furnace, having doors,
I) b. Flues, c 0, lead to the circular chamber, e a, surrounding the chimney, d. Valves of cast-iron
are made to close at pleasure the orifices of the
fines. Movable slniees in the dividing walls 503'
allow of communication to be made or closed mm
between the chambers; h h are plugs through


which the coal, in powder, is introduced, under-
going calcination. The advantages of this fur-
nace lie in its great economy of fuel.
Fire-Brick.—The following is condensed from
a paper on “ Refractory Materials,” by Dr. T.
Egleston, read before the American Institute
of Mining Engineers, 1876. The materials of
which fire-bricks are composed are generally fire-
clays, which are hydrated silicates of alumina,
containing from 50 to 65 per cent. of silica, 30
to ’75 per cent. of alumina, and 11 to 15 per
cent. of water. The clay contains (besides pot- 504'
ash) soda, lime, magnesia, and iron, and is gen- , erally less refractory in proportion to the extent ‘
of these elements found in it. \Vhen it 0011-
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tains from 6 to 10 per cent. it will generally
melt; when the clay is silicious, 3 or 4 per cent. "
of other substances make it fusible; when it
is aluminous, 6 or 7 per cent. of oxide of iron
does not make it lose its refractory qualities.
The clay which, according to Brognaud, is most
refractory when deprived of its hygrometric wa-
ter, has the composition: Silica, 57.42; alumi-
na, 42.58. Silica alone cannot be used without
being ground, and, as it has no binding prop-
erty like alumina, a small portion of binding
material is added to it. For the Winas brick,
which is the best substance to resist heat alone,
this material is lime. The brick is made of
quartzose sandstone, which is first heated in a
furnace and then thrown into water to break it
up, and is then ground. The amount of lime
required to bind it together is 11} per cent., and
the joints between the bricks are filled with the
same material. At a temperature of 2,200° C.-—about 4,280° Fahr.—these bricks will last four
weeks in the roof of an ordinary furnace, and in that time will be reduced—by abrasion of the
flame, and dust, and slightly from chipping—from 9 to 2 inches. The bricks conduct the heat so
badly that, at this temperature, which is a bright white heat on the inside of the furnace, it is only
just warm on the outside. Ordinarily, the bricks seem to be fluxed away by the dust, which circu-
lates with the gases. In the Siemens furnace, where there is no dust, they give out from weakness.
Very few clays can be used as found. They must be, as it were, suspended in some infusible ma-
terial, which will prevent, as far as possible, the mechanical effects of the heat, and allow, at the
same time, of a certain amount of expansion and contraction, while preventing both in too great a
degree. These materials are usually quartz-sand or pulverized quartz, burnt clay, old bricks, serpt n-
tines, talc, graphite in powder, and not infrequently small coke, when the ash is not to be feared,
and when graphite either cannot be had,ror cannot be used on account of its high price. \Vhen the
mixture is made in the place where it is to be used, without previous burning, it is generally made of
one-fifth plastic clay and four-fifths burned clay or quartz, or one-fourth lean clay and three-fourths
burnt clay or quartz. This is done to avoid contraction. It is a most economical construction, even
in blast-furnaces, and is coming moreand more into use.
The clay, when mined, is left exposed to the air under sheds, and is cleaned and carefully dried,
and is afterward mixed with the substances with which it is to be incorporated, which are classified
by numbers, varying according to the size of the sieve-holes through which they will pass. The quan-
tity and quality of the mixture will determine the refractory nature of the material to be produced.
A friable paste with large grains and quite porous resists a great heat. One with fine grains, close
and compact, splits at a high heat, especially if it is not homogeneous. The manner in which the
mixture is made also influences the quality of the brick quite as much as the material. In some
works in Belgium, after taking all the ordinary precautions to make the mixture perfect, it is sub-
mitted to a succession of shocks continued for some time, until it is found by experiment that the
-materials are perfectly mixed. It has been found by long experience that the bricks so made kept
their form perfectly, while others, made of exactly the same mixture in the ordinary way, contract.
The paste made and the article completed, it must be dried or “tempered.” This is commenced in
the open air, and, if possible, out of the draught. If the draught cannot be excluded, the place where
the drying takes place is slightly heated, commencing at a temperature from 60° to 70° F ahr., and
keeping it up from 25 to 30 days, then increasing it from 80° to 100°, leaving the article as long as


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BRICK—MAKING MACHINERY. 229


possible, and so on, an active ventilation, but the same temperature, being kept up. The article
should remain in a temperature of from 150° to 180" for at least 6 weeks. Bricks do not generally
require so much care; ‘but crucibles and retorts do. Long experience has proved that there is a great
economy in conducting this process of tempering as slowly as possible, and that it influences materi-
ally the refractory naturc of the article. It is found, by actual experiment in crucible works, that
those crucibles made from the same mixture, tempered during 6 to 8 months, last more than three
times as long as those which had been tempered only 2; so that, in general, the older the article be-
fore being burned the better.
The essential qualities of a good brick may be stated as follows:
1. Uniformity.
2. Regularity of shape, and the power to retain it under all circumstances, which involves perfect
unity of composition.
3. Strength to resist the different pressures required under different circumstances.
4. Its cheap price.
N 0 material yet manufactured entirely fulfills all these conditions. A good brick should not
only resist high temperatures, but sudden changes of temperature, without alteration of any kind,
such as crushing, splitting, etc., and, at a high temperature, should undergo the least possible change
of form. In general, it may be said that bricks which have undergone a very high temperature in
the manufacture are less likely to contract afterward. Shrinkage is generally due to insufficient burn-
ing, or to a too small proportion of old material in the mixture, and generally occurs in aluminous
bricks. Its chief evil is in allowing the flame to penetrate the open joints, and give the dust an op-
portunity to out between the bricks ; for any cause which produces eddies in tne flames, such as hol-
lows or projecting surfaces, is certain to effect the destruction of that part of the furnace. Silicious
bricks have, on the contrary, a tendency to expand under the influence of intense heat. This is true
to such an extent that, in the steel furnace where they are used, provision must be made for slacken-
ing the tie-rods when the fire is being raised, and tightening them when it is being cooled.
The crushing weight of an ordinary fire-brick, cold, is from 600 to 1,000 lbs., but some of the best
have been known to resist as high as 3,000 lbs. to the square inch. To insure the safety of the
structure and the success of the process, it should not only retain its power of resistance, but should
not undergo any change of form nor soften materially under long-continued heat, and, at the highest
possible temperature, should support more than double the strain required without attention. In the
walls of the fireplace those bricks will be best which are dense, and contain an excess of silica. In
the hearth they should contain an excess of alumina. In the arch they should be nearly pure silica,
alumina, or magnesia. Bricks in a roof give out from shrinkage, cracking, or splintering. Splinten
ing takes place when silicate bricks are made of impure mixtures, usually from too much fine mate
rial and from imperfect burning. Bricks which are liable to splinter are generally cross-grained and
dense, with a smooth eonchoidal fracture when made from improper mixtures, and when from bad burn-
ing they generally ring like a cracked vessel. All good bricks wear off evenly.
DECAY 0F BRICKS.—Dl‘. John C. Draper has investigated the causes of decay in brick and stone,
and determines the same to be: ' '
1. Roughness of surface favoring the deposition of dust.
2. Vegetable growths favored by dust and moisture.
3. Percolation of water through interstices and fissures.
4. Action of frost.
5. Action of acid vapors in the air.
The disintegration due to frost he finds to equal a loss of substance of 74 parts in 10,000 for red
and 24 parts for white brick, or in the ratio of 1 for the latter to 3 for the former. The friability
due to heating and sudden chill causes a loss of substance of 82- parts in 10,000 for red and 43 parts
for white brick, which gives a ratio of 1 for the white brick to 2 for the red. The chemical ingredi-
ents of air that act on building-materials are carbonic, nitric, sulphuric, and sulphurous acids. 011
subjecting bricks to the action of these acids a loss of 33 parts of substance per 10,000 for red
and 7 parts for white brick was noted. Ratio of disintegration, for white 1, for red 5. Evidence
is thus afforded of the resisting power of hard, compact brick.
The absorbent capacity of bricks, according to the report of an English committee, is indicated by
the following table:
Average Taking up of lVater by Bricks set in a Depth of ll'ater of TIITCC-fO'tH‘fllS of an Inch.







, rrzacm'men or SATURATION.
' Contents in .
SPECIMEVS 0F BRICK' Cubic Inches. In H 1, In K In 5% In 14
Hour. Hour. Hours. 5 Hours. 1
' ' I
I
No. l.—Best made by hand, which absorbed 15 inches of water i i
m all ...................................................... .. 100' 6” 44 l 56 70.6 | 100 1
N0. 2.—l\'[annfactured brick, absorbing 85 in all . . . . . . . . . . . . . . . . .. 15-‘6’ 4" $0 55 55 t 160 l
1‘10. 3.——Sarne, absorbing 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117’ 41 75 93 100 ‘
N9- 4.—Same, pickled 38 hours, and absorbing in all 14.3 cuuic l
inches of water ............................................. .. 111' 41" as 36.4 50 75.7 '
No. 5.——Good hand-made brick, absorbing 14 . . . . . . . . . . . . . . . . . . . .. 95' 6" 47 59 63.7 5 90 5
No. 6.—Same, absorbing 25.6 ................................. .. 100' a" 40.75 I 64.4 as 98.4 ,

The capacity of several of the specimens to give off the moisture absorbed, at a given tempera-
ture, 1s represented in the following table, in which the drying of the six bricks adduced in the fore-
gomg table was annotated in all its features:
230 BRICK—M AK IN G MACHINERY.


Table showing the Capacity of Bricks to give of jlloz'stm'e.









TEMPERATI'RE, 36.53o FAIIR."~PERCENTAGE OF \VATER GIVEN OFI'“.
NUMBER \Vnter in ..__.-__.< - -... ~ . A _ n . .-. ~_ "My ~~ m-~ Mum ~-- ~» --~-~-
Cubic Inches. Hours, I
434' Day, 1. ‘ Days, 2. Days, 3. Days, 4. Days, 6. Days, 0. Days, 11.
I . . . . . . . . . . . . . . . . . . . . . . . . .. 15 3.57 2 63.6 78 81 82.9 94.3
‘2 . . . . . . . . . . . . . . . . . . . . . . . . . .. 35 8.5 32.1 50.6 69.1 51.4 86.4 90.1 96.8
3 . . . . . . . . . . . . . . . . . . . . . . . . .. 21 4 34.7 61.2 75.5 81.6 85.6 89.3 96
4 . . . . . . . . . . . . . . . . . . . . . . . . . .. 44 3 50 63.6 72.7 76.4 78 82 82
6 . . . . . . . . . . . . . . . . . . . . . . . . . .. 25.6 3.4 36.5 54.2 74.6 81.3 86.4 89.8 91.5




BRICK MACHINES, for the mechanical moulding of plastic clay, are so exceedingly numerous that it
is impossible in the limits at present disposal to convey to the reader other than a general idea of the
more prominent types. Many not here represented will be found described in Reports of Judges of
Group II., Centennial Exposition. The following examples are classified in the manner proposed by
Mr. E. II. Knight.
CLASS I. Those machines in which a slab of clay exudes from the pug~mill, and is cut up into
lengths which form bricks. The cutter is a wire or knife, and either travels with the slab while
cutting, or makes a square transverse cut across the moving slab.





Examples. Clayton and IIowlett’s machine (English), Fig. 505. The rough clay A is taken from
the heap in barrows and wheeled up an incline, or it is drawn up the incline by suitable mechanism.
It is shoveled into the feeding-hopper B, in which revolves a shaft carrying several small knives,
which cut up the clay and press it down upon the rollers incased in B. The crushing-rollers then
force the material to the pug-cylinder C, in which revolves a strong shaft, having knives spirally
arranged upon it, which thoroughly pug or mix the clay and at the same time force the homogeneous
mass toward the end D of the cylinder, where
506- it passes through the moulding orifice to the
~. ~ ' I , ~ cutting-off table, shown separately in Fig. 506.
When a stream of clay sufficient to cut the
desired number of bricks has been expressed
upon the receiving-rollers a, a single cutting-
wire I) divides the mass.
The portion thus removed is drawn forward
by hand to the table 0 in front of the wires
d, and the stream from the machine is again
allowed to escape and again out off, the opera-
tion thus being rendered continuous. In order
to cut the separated section into bricks, the
wires are caused to pass through it by oper-
ating the handle 0, which simultaneously transmits motion to the pinions f, the racks g, and the
whole rack-frame h, carrying with them the series of wires (Z, and also the plate-table c and platen
z', causing the plate-table c to pass from under the clay through which the wires are passing, and to
be replaced by the portable platen Another movement cf the handle returns the parts to their
original position and the platen with the now formed bricks upon it is removed.
In the Tiffany wet-clay machine (Canadian) the impelling screw-shaft revolves in an opposite




-"' ~ It!
flees:_-.::-
m
_ /_ I!IIIII!_II


BRICK-MAKIN G MACHINERY. 231
‘ .
direction from'the temperi
The bar of clay issues upon a
ng-serew; its shaft passing through that of the latter, which is hollow.
bed of rollers, and is cut into bricks by four wires fixed in an oscilla-
tory frame. Fig. 507 represents
a machine in which the tempering-
device is separate, the impelling-
worm being replaced by a piston
fitting tightly in the reservoir B,
and driven by a screw and bevel
gearing. The clay issues in a slab
b of the width of a brick, which
is cut by disks I into ribbons as
wide as the length of a brick.
These last are cut into blocks by disks J (spaced apart the width of a brick) borne on a mandrel
whose bearings_are in a carriage moving transversely in ways. The bed is made in sections E,
which are passed along in succession by rack and
pl
507.
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1
mon.
CLASS II. Those in which the clay passes from
the pug-mill into moulds in which it is pressed,
and from which the moulded brick is discharged.
Variety 1. Machines in which the moulds are on
the upper or adjacent surface of a mould-wheel re-
volving in an horizontal or vertical plane, the moulds
being brought successively below or in face of the
pug-mill by which they are charged. In one case
the pug-mill is-vertical, in the other horizontal.
The machine shown in Fig. 508 has a vertical
pug-mill in which the clay is tempered and mixed,
and is forced therefrom into moulds wherein it is
pressed by an S-shaped spiral wiper. The pistons
with their wheels and the inclined track below them
are represented. A triple pressure-machine is manufactured, in which the charge of each mould-
table is first leveled off with a straight edge, then successively compacted by a roller, compressed
with a toggled piston and follower from below, and by cams and toggles above. Any variation in


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PhiCkHGSS is prevented by sinking a panel in one face, any deficit of clay simply permitting the sink-
ing of_a deeper panel, and not affecting the thickness of the brick. This is a crude clay-machine,
of which there are now manufactured many different types. .
232
BRICK—MAKING MACHINERY.

In Hall’s machine, Fig. 528, the place for putting the moulds into the machine when sanded is on
the opposite side from the pit; the press is on the side lateral with it; the central track is parallel
Q7 52S.
(lit
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lllll

with the pit; the carriage, or support of the moulds, when in the press, rests and is firmly held by
the eccentrics. In connection with the carriage is an adjustable table containing friction-rollers.



The outside arrangement of
the throw-out is composed
of several parts: 'a grooved
roller; a slotted arm; a mov-
able or adjustable catch;
and a catch in connection
with the balance-arm, to
which is attached a small
weight. If there is any ob-
struction in the machine by
a stone, or a mould being
caught, or in any way, then
the throw-out remains at rest,
thereby insuring perfect safe-
ty against any obstruction in
using these machines. The
weight shown balances the
throw-out, and causes it to
work perfectly free and easy.
The cross-bars are placed .in
the centre of the mud~box and
around the shaft; the knives
are bent a little back, in such
a manner that they can run
close to the bars, operating
like a pair of shears. \Vith
this improvement, these ma-
chines grind the clay in the
most thorough manner.
The trucks are put in un-
der on the track far enough
to receive the first mould of
brick; this mould, as it is
thrown from the press, is car-
ried by its own weight on the
friction-rollers to the truck;
the next follows on and moves the truck along the width of it; and so on until loaded, when it is
taken out in the yard and dumped in the usual manner. The next truck is put in position, and the
loading goes on as before.
BRICK—MAKING MACHINERY. 233


Martin’s machine, Fig. 529, is similar in general appearance to that just described. The moulds
are delivered by the power of the. machine while the press is on, so that the bricks are not drawn up
while delivering; wherefore it delivers the bricks very stiff, with well-defined edges and good square
rners.
co The lever connected with the haul-out is arranged with a movable centre, held by a friction-pulley,
so that, should a stone or any hard substance get into the mould, or if by any means the mould should
be obstructed, the lever simply moves forward, thus giving time to remove it without stopping the
machine, and preventing any part of the machine being broken. Then, by raising the small lever
connected with the friction-
pulley, the centre moves back,
and the machine operates as
before.
Variety 5. Those in which
the clay is moulded by force
of a reciprocating piston or
pistons.
To this variety belong a
large number of small hand-
machines similar in general
appearance to Carnell’s, Fig.
530. This is worked by
throwing the movable top-
plate over the brick, by
means of the handle. Then
the lever-bar on the left is
depressed, which turns the
axle on the right side, and
so moves the tumble-joint
producing the pressure. The
latter is previously set to
any desired degree by means
of the proper screws and
nuts. When the pressure is
relieved and the top-plate
shifted sideways, the pressed
brick is pushed out of the
mould by the elevation of
its bottom.
In Large’s (English) ma-
chine, Fig. 531, a plunger a
is employed, to which a ver-
tical reciprocating motion is
imparted by the shaft 1).
The mould is filled, iron
plates being inserted both
above and below the bricks. The charged mould is brought under the plunger and its contents pow-
erfully compressed. It is then pushed on over an opening in the table, where a second plunger forces
the brick out upon a palm held up to it by a counter-weighted rod h. As each brick is removed the
palm ascends to receive another, and the empty mould is removed.
Variety 6. Those in which the moulds are reciprocated beneath a pug-mill.
Brick-machines may also be classified without regard to difierence in manner of moulding, as those
which use dry or untempered clay directly from the bank; those which use wet clay or mud, necessi-
tating subsequent drying of the bricks; and those which themselves temper the clay. For machines
operated by steam or horse power, a production of 30,000 bricks per day is in most cases claimed;
for hand-machines the production varies from 2,000 to 4,000 bricks for the same period.
ltbrms, etc., of Brick—Fig. 532 represents dovetail bricks. In the extremities of each brick are
pressed or cut dovetail mortises, which, when the former are placed end to end, come together. Into
these portions a connecting piece of suitable form is slipped, which holds the bricks tightly together
mortar at such points being merely auxiliary. Universal-angle bricks are represented in Fig. 533.
By combining these' bricks angles of various shapes can be made with the walls, the apex of the
angle having an ornamental finish. Hollow bricks are made for purposes of warming, ventilating,
and removing moisture from walls. It is stated that there is an advantage of 29 per cent. in favor
of the hollow bricks over the ordinary bricks, in addition to a considerable diminution in the cost of
carriage or transport, and 25 per cent. on the mortar and the labor.
_ The following are some other forms of brick: “Air-brick” is a grating the size of a brick let
into a wall to admit air. “ Arch-brick ” usually means the hard-burned, partially-vitrified brick from
the arches of the brick-clamp in which the fire is made and maintained. A brick made voussoir-
shaped is known as a “ compass ” brick. A “ capping ” brick is one made for the upper course of
a wall. The name “clinker” is given to a brick from an arch of the clamp, owing to the hard,
glassy sound emitted when struck. “ Stocks ” is a name given locally to peculiar varieties of brick,
such as gray stocks, red stocks, etc. “Pecking,” “place,” “sandal,” and “ semel ” brick are local
terms applied to imperfectly burned or refuse brick, Burr brick, or those vitrified by excessive heat.
Bricks are glazed or rendered waterproof by a composition which gives them a vitreous surface.
531.


234 BRICK—MAKING MACHINERY.
%
This is performed by treating the surface with a flux which meets the silex of the brick; or it may
be applied to the surface in solution, the liquid being afterWard expelled by heat. Resinous com;
pounds have also been used to render the surface non-absorbent. Bricks have also been treated
with soluble silicate of soda, which has been decomposed, leaving the insoluble silex in the pores
of the brick. Pigments added to the glazing compounds give an ornamental appearance.


The average specific gravity of brick is 1.841; the weight of a cubic foot, 115 lbs.; the cohesive
force of a square inch, 27 5 lbs. ('l‘redgold). Brick is crushed by a force of 562 lbs. per square inch
(Rennie).
Other Jlfachz'nes related to Ba'ick-malciazg.—Special machines are constructed for crushing and pul-
verizing .clay only. The essential feature of the device illustrated in Figs. 534 to 538 consists. in
the use of a revolving screen working on a stationary axis set at a slight inclination from a 1101i-
zontal position, and having attached to or suspended from it lugs or crushers, which, by their weight,
serve to pulverizc the clay; the stock or clay being fed in at one end of the screen, which by its
revolving motion carries or drags the stock under the lugs or crushers, thereby breaking and pound-
ing it; the pulverized clay falling through the apertures of the screen, and the waste or hard lumps
and stones mixed up with the stock being expelled at the back or lower end of the screen.
I Fig. 539 is a machine for making flat tiles, flooring tiles, etc., of any desired breadth or thickness.
It may also be adapted to the manufacture of tubes for drain-pipes or other purposes. To the bot?
tom of the pug-mill is fixed a funnel-shaped hopper 28, the materials in which, after being forced
_ 536.
It? a ‘



=



a






' L
_4






through a mouth 24, formed of the required shape, are received upon boards 25, and, when cut to the
proper length, are removed to sheds for drying. In order to equalize the surface of the clay after it
has come out of the hopper, a roller 26, turning in bearings on acurved arm, which is fixed to a hinge-
joint, gives to the material any pressure that may be required, byloading it accordingly. The dotted
lines 27, 27, in the same figure, exhibit another funnel-shaped hopper, for the purpose of making
(BRICK—MAKING MACHINERY. 235

. pipes or‘tubcs, by means of a centre core 28, between which and the cylindrical continuation of the
hopper the material is forced by the action of the pug-mill, and produces a tube, which, after the
machine has made a certain length of it, is cut off, the tube being turned round to render the inside
smooth previously to its being removed. ,
Figs. 540 to 542 represent one of the direct-action steam machines constructed by John White-
head & (10., of the Albert Works, Preston, England, fitted up with the patent metallic compressed-
air die for the manufacture 'of socketed sanitary or drain pipes.
Fig. 540 gives an elevation of the vertical-acting machine; Fig. 541 shows in plan the patented















537. m, -_.-, 53a -1
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J5
A
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n sew-Tee
., Jigs-2.“. w
r~ 4: _
4.“- £212?" x; W: - l
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metallic die for making three 6-inch pipes simultaneously, similar in form to the sanitary pipe repre-
sented in Fig. 542. The upper cylinder of this machine is the steam cylinder, and is constructed in
the same manner as those in ordinary use in steam engines. It is, of course, made of various dimen~
sions in accordance with the size of
the clay cylinder below it, and of the
pipes intended to be made in these
machines. The piston-rods have a
ram attached to them, which, upon
steam being admitted to the cylinder,
descends and forces the clay in the
shape of pipes out of. the clay cylin-
der, which is immediately below it.
It will be seen from Fig. 540 that the
admission of steam through the steam-
chest is' under easy control of the at-
tendant by means of a handle close
to him. The clay cylinder is fitted
with an expanding mouthpiece at the
bottom, by means of which pipes of
large diameters are obtained. The
dies fer both small and large pipes
are attached to the before-mentioned
mouthpiece; and on referring to Fig.
540 a balanced receiving-table will be
seen immediately under the die. As
the pipe comes from the machine this
table continues to fall; and, as soon
as the pipe is removed, it rises with
its face against the die in readiness
for the ram to descend and push out
another pipe. During the time the ~
socket of the pipe is being formed,
the table is held fast by a wedge actu-
ated by a lever, the handle of which ‘-
is shown in Fig. 540, in the hand of -
the man in charge. 0n the attendant releasing the table, and onsteam being admitted above the
piston, the ram continues its downward course, and the pipe or pipes, as the case may be, issues
through the die.
A simple machine for making drain-pipe is represented in Fig. 543. The material is mixed in the
upper cylinder, and pressed into the mould below, the latter being held up to its place by the weights
shown, and hence easily removable for the extraction of the moulded pipe, which is of the form
shown on the right, 1 .

























ass BRICK—MAKING MACHINERY.

Slag Bricks—Figs. 544 and 545 represent an improved press for the manufacture of bricks
from blast-furnace slag. ' The pressure is given by two cast-steel cams, which are fixed upon- a
forged steel shaft 71} inches in diameter. This shaft, resting on bearings between two strong A-frames,
is put in motion by very powerful double-geared spur-wheels, the first motion shaft having a heavy fly-
wheel upon it to steady and equalize the pull upon the strap. The pressure cams, marked B on the
diagram, act against rollers fixed upon two steel cylinders or rams X. These rams transmit the pres-
sure to the moulds in the table marked 0. The table is circular, and contains 6 pairs of moulds, so
that 4 bricks are pressed at one time, the table remaining stationary during the operation. At the
same time the bricks are being pressed, 2 other pairs of moulds are being filled up with material—-
510.















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while the other 2 pairs are delivering up the 4 bricks
pressed at the previous revolution of the cam shaft.
The bricks are pushed out of the mould by smaller pis-
/ tons marked .D, acted upon by the separate cams marked
E. The moulds are lined with changeable steel plates
three~sixteenths of an inch thick, and the sand and lime
is fed into them by two pug-mills N. These pug-mills are fitted with 6 knives each, so as the
more thoroughly to mix and chop the spongy slag along with the lime. The table is shifted
round by a kind of ratchet motion, also worked by a cam on the outside of the frame-work marked
F, and acting upon the weigh-bar and levers F1. Immediately above the pressure-cylinders are
two pressure-stops G, which are held down by the heavy-weighted levers H. These levers H,
therefore, receive the whole pressure put upon the bricks; and in case there should be too much
sand getting into the moulds, they simply lift up and relieve the strain. The weights I can be
weighed at option, and thus form an exact gauge of the pressure upon the bricks. The moulds are
generally filled so as just to lift the levers in ordinary work. The filling is easily regulated by the
set of the knives on the pug-shafts, which press the material into the moulds O, and one side of the
pug'mill cylinder is made to open so that the knives are accessible at any moment. The pug-mills
are filled by means of the measuring and mixing apparatus placed on the floor immediately above the
brick press. The mixing and measuring apparatus is very simple and efficient, and works without
any trouble. The slag-sand is tipped into a hopper by large barrows, which are lifted up by a heist.
At the bottom of this hopper there is a revolving cylinder with ribs cast upon it, which, revolving
under the hopper, carries a certain thickness of sand, the thickness having been previously regulated

BRIDGES. 237


to the requirements of the press. The slag then falls upon a sieve, which separates any large pieces
of slag in a solid state, and at the same time allows the falling sand through the sieve to fall like a
shower. The lime is fed into a separate hopper, and is regulated very much like the feed of corn
into millstones. The lime then passes down a sheet, which forms part of the slag-sand sieve, where
it meets the shower of sand—falling together with it—thus getting thoroughly mixed. As before
stated, this lime is selenitic lime, and is prepared upon the works. The bricks, when taken from
the brick-press, are placed upon spring barrows, holding 50 each. They are then taken and stacked
in sheds, where they are allowed to remain about 5 er 6 days, after which they are simply stacked
outside in the weather to harden. The percentage of loss is very little, not amounting to 2 er 3
per cent. In fact, when once the bricks are upon the barrows there is little or no waste.
Each machine is capable of turning out about 10,000 bricks per day. The following are a few of
the advantages claimed for these concrete slags and bricks, viz.: Being pressed, they are perfectly
uniform in size and thickness; they are much cheaper than ordinary red bricks, compared in weight
with which they will weigh one ten per thousand less; and there is this further advantage, that there
are no wasters or halves. For inside work there is a great saving both in bricklaying and mortar,
more especially when plastering, the walls being of uniform thickness; and the bricklayers like
544.
545.


them, because they can do more work with less labor, the bricklayer’s laborer finding he has a ten
per thousand less to carry, as well as considerably less mortar. Another remarkable property of the
slag brick is that the jeincrs can drive nails directly into them without splitting, and thus, for skirt-
ing and door-work, they are saved much trouble in plugging the walls. And finally, the longer the
bricks are kept the harder they get.
BRIDGES. Bridges are constructed of various materials; usually of wood, stone, brick, iron, or
steel. These are arranged in a variety of forms, as in arch, girder, truss, and suspension bridges. In
their various positions, the members of a bridge are liable to strains of compression, extension, and
detrusion. Most of these strains may be determined theoretically by the composition and resolution
of forces. The ability of the material to sustain such strains has been ascertained by numerous
experiments. See STRENGTH or MATERIALS.
Arched Bridges of Stone or Brick—The forms of arches are varied; the semicircular, segmental,
elliptical, parabolic, pointed, and three or more centered arches, are all used, but the most common in
this country is the segmental. See ARCHES.
The following technical terms are explained by reference to 546. Each individual arch-stone
is termed a “ voussoir ; ” the one occupying the highest point of the arch is called the “keystone.”
The exterior and interior lines of the arch are termed respectively “ extrados ” and “ intrados ; ” the
ass " BRIDGES.

highest portion of the intrados is called the “crown of the arch,” as lines b b and a a. The surface
upon which the first veussoir rests is called the “ skew-back,” of which a b is a line. The horizontal
line at a is termed the “springing-line” of the arch. The strains upon an arch arise from the '
gravity of the structure and the load imposed upon it. Although they act vertically, yet the result-
ing forces act in different directions, and with diverse intensities. These have been the subject of
much careful study and numerous experiments connected with the construction of such bridges.
Considerable light may be thrown upon the strains and resulting forces in the arch by the following
graphic representation: Let a b a, b, (Fig. 546) represent one-half of an arch loaded. Through the
centre of gravity of the loaded half arch draw the perpendicular O P. Then from A, one-third of
the depth of the crown from the top, draw









the horizontal line A (1* From 0 draw 6 f
the line C B, intersecting the spring or
skew-back of the arch a, b, at B, one-third
of its depth from the face. Measure from a
C by scale a distance 0 1’, representing the
weight of the half arch loaded; then from
B draw a line parallel with A 0, meeting \\\
the line C B in D ,- then will PD represent the amount of the hori- \\
zontal force acting at the crown of the arch, and C D will represent 3 5,
the line of thrust and the force acting at the skew-back. (9
That the centre of pressure between the vousseir may be within
safe limits, any joint may be selected, and the portion of the loaded arch
lying between such joint and the crown may be treated in the manner above 0
described by drawing a perpendicular through its centre of gravity, and using
the pressure PD as a constant. Then, if the resultant of these two forces
falls within the middle third of the veussoir joint, a sufficient degree of sta-
bility will be assured, provided the voussoirs are of sufficient depth. ’ The 7,, g
objection to this method of solution is the difficulty in obtaining the perpen-
dicular line through the centre of gravity. Dr. Schefller has presented a very
simple method for obtaining this line, as follows: Divide the half arch, with 1;
its lead, into sections by vertical lines from the joints of the voussoirs at the
extrades. Draw a line vertically through the middle of each section. Multi-
ply the arca of each section by the horizontal distance of its centre line from
the vertical line passing through the crown of the arch. Take the sum of
the products of all the sections lying between any joint and the crown of the I
arch, and divide this sum by the sum of the areas of said sections; this will
give the horizontal distance of the centre of gravity of that portion of the arch between its crown
and the joint taken, within a sufficient degree of accuracy for general practice.
The depth of voussoirs cannot be computed by simply providing against crushing, but must be
made deep enough to permit of considerable latitude in the line of pressures. To meet these
requirements, Pref. Rankine gives the following formula: Depth of keystone in single arch in feet
: 4’ .12 x radius at crown, and for a series of arches V .17 x radius at crown.
The abutment, to be capable of supporting the arch, must have the resultant line of pressure de-
rived from the arch-thrust and its own gravity fall within its base a safe distance. This is deter-
mined as follows: Having found the line of thrust of the loaded half arch at the skew-back, as here-
tofore described, produce the line C D thus found, intersecting the vertical drawn through the
centre of gravity of the abutment at C. Lay off from the point of intersection C, D, equal to the
force 0 D acting on the skew-back. Also layoff on the vertical the distance 0', H equal to the
weight of the abutment. Completing the parallelogram, then will 0, I represent the line and
amount of pressure intersecting the base of the abutment about one-third of its width from the
exterior, a limit of stability safe in practice.
The point of intersection at any bed between courses of masonry may be ascertained by regard-
ing such bed as the base of the abutment, and proceeding as above. In the abutments of flat
arches, although the line of pressure may fall amply within the base, yet the thrust may be suffi-
cient to cause rupture by sliding upon some one of its courses of masonry. Stability is assured
when the angle with the horizontal, which the resultant of the thrust of the arch and the weight of
that portion of the abutment above the joint in question makes, exceeds the angle of friction of the
material used. Should there be danger apprehended, the bed-joints of the courses may be inclined
from the horizontal, as a further security.
In the construction of arch bridges, it is necessary to erect a framework which shall sustain the
lower voussoirs until the keystone is set and the arch becomes self-sustaining. See engraving of
Waterloo Bridge. ,
Arched bridges are also built of wood, cast and wrought iron, and steel. As most of these arches
are built in conjunction with trusses, they will be further referred to under the head of “ Trussed
Arch Bridges.” Perhaps there is no branch of bridge-building where theory has been so inadequate
to furnish practical rules as in the proportions of an arch. The proper depth of the crown or key-
stone is still left to empirical rules. For smaller culverts of 15 to 30 feet span, the usual construc-
tion is to make the arch from 1 foot 6 inches to 2 feet deep. Arches in stone are seldom turned less
than 1 feet deep, whatever may be the span; brick arches for less than 10 feet span-are generally 8
inches, and this depth is required by building acts.




* The theoretical point where the centre of pressure would occur in a perfectly rigid and evenly balanced arch is at
one-half the depth‘of the crown ; one-third is here taken as the proper practical variation.
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THE ST. LOUIS BRIDGE OVER THE MISSISSIPPI RIVER.
BRIDGES. 239








547. 549.
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Perronet has given as a rule for the depth at the crown the formula d : .07 'r + 1 foot,- in which
formula '1' is the greatest radius of curvature of the intrados. This formula is applicable to arches of
less than 50 feet radius; but beyond this it gives greater dimensions than in ordinary practice. In
order to facilitate investigations on the stability of arches of the more usual forms, M. Petit calcu-
lated a series of tables, of which we give the abstract for circular arches, as the class occurring most
frequently in practice. .
-To find the thickness of abutment necessary to support the thrust of the arch, multiply the coeifi~
cient found in the table for the particular case by- 3.8, and the square root of the product multiplied
by the radius, r, of the intrados, will give the extreme thickness of the abutment.






COEFFICIENT 0F HORIZONTAL THBUST AT THE CROWN.
RATlO Fig. 541. Fig. 549. Fis- 548-
on THE _
RADII, s:4h s=5h s=6h s=6h s:10h s=16h
R 1—05 1—3265 l—s i—ss 1—13 1—325
l- h “ " b " ' h h ‘ h ‘_ h " ‘
1.50 0.191 0.2l7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
1.45 0.168 0.192 . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
1.40 0.162 0.169 0.154 0 147 0.147 0 147 0 145 .....
1.85 0.158 0.147 0.148 0.180 0.126 0 126 0 .24 .....
1.30 0.148 0.148 0.187 .123 0.106 0.106 0.104 .....
1.25 0.128 0.189 0.126 0.114 0.100 0.056 0.084 0.072
1.20 0.111 0.181 0.110 0.102 0.091 0.070 0.066 0.056
1.15 0.092 0.119 0.091 0.086 0.079 0.068 0.049 0.041
1.10 0.063 0.103 0.067 0.065 0.062 0.052 0.042 0.027
1.05 0.088 0.082 0.088 0.088 0.037 0.084 0.029 0.019









Example.——What is the horizontal thrust, and what the thickness of abutment, necessary to sup-
port an arch of 10 feet span and 2 feet rise?

—8 z 5), therefore s =: 5h. 1; = 7: = 3.625. r :- 3.625 x 2 : 7.25 feet.
h 2 h 2
By Perronet’s formula, d = 0.07 x 7.25 + 1 = 1.50. R = 7.25 + 1.50 z 8.75. E :: = 1.20,
'l‘ . 0
By the table against 1.20, under the column s :: 5h, we find 0.102 as the coefficient of thrust; 150
lbs. being taken as the average weight of a cubic foot of masonry, the absolute thrust per square foot
of surface is 0.102 x 150 x 7.252 = 804 lbs. V 0.102 x 3.8 x 7.25 24.50 feet, thickness of abutment.
The formula gives the thickness of abutment, supposing the height infinite; for low abutments, the
thickness may be reduced, for common spans, about 10 per cent.
In the loading of a semicircular arch, especially, the tendency of a weight applied at the crown is
to raise the haunches. This is to - be counteracted by a- backing of masonry at these points, called
the spandrel backing. When the arch is to be covered with earth, care should be taken in loading
the arch evenly at both sides. The same remark applies to the setting of the arch-stones on the
wooden centres while in process of construction.
The dimensions of some of the most noted arch bridges in the United States and Europe are:












. 5 Depth Depth at
- LOCATION. Material. Ferm of Arch. Span. Rise. m Crowm Spring.
ii. in. ft. in. ft. in. ft. in.
Manchester and Birmingham Railroad . . . . . . . . . . . . . . Brick . . . . Semieircular.. 18 9 6 1 6 Uniform.
“ it it \0 . . _ ' ‘ . - . ~ - I . - . st . i ‘ . Lt 8 is
London and Brighton ' “ . _ . . .. “ .. “ 30 15 1 6 2 8
“ Blackwell “ . . . . . . . . . . . . . . “ . . . Segmental. . ST 16 4 1} Uniform.
Great Western “ . . . . . . . . . . . . . . “ . . .. Elliptical. . . . . 1‘28 24 3 5 7 14
Orleans and Tours “ . . . . . . . . . . . . .. Stone. .. Semicircular.. 27 7 2 71- Uniform.
Stirling Bridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ Segmental... . 60 13 65 8 6 4 .
Carlisle “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ Elliptical. . .. . 65 21 3 9 7 4
Shunes “ . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . .. “ . Segnnental... T4 9 8 2 4 5 6
IIutcheson“ . . . . . . . . . . . . . . . . . ~ . . . . . . . . . . . . . . . . . .. “ “ ... 79 18 6 8 6 4 6
Jena “ .' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. “ .. “ 71 9 10 9 5
Cabin John, Washington Aqueduct . . . . . . . . . . . . .. “ Elliptical. . . .. 220 57 25 4 16
Licking Aqueduct, Chesapeake and Ohio Canal . . . . . . “ . “ . . . . . 90 15 2 88
Ldonocacy “ “ “ “ .... .. “ . . “ .... 54 9 2 5
Falls Bridge, Philadelphia and Reading Railroad. , .. ‘f . . .. Segmental .. . 78 25 8 0
Chestnut Street, Philadelphia . . . . . . . . . . . . . . . . . . . Brclgsmnifi } “ ' ' 60 ‘18 2 5
James River Aqueduct, Virginia . . . . . . . . . . . . . . . . .. .. Stone.. .. “ 50 '1 2 66 -
Tonoloway Culvert, Chesapeake and Ohio Canal. . . g ,L “ . . . 40 15 2
High Bridge, New York City . . . . . . . . . . . . . . . . . . . . .. Stone . . Circular... .. SO 40 2 5 2 5
240 BRIDGES.

_ Waterloobridge, hondon, by Rennie, is considered a masterpiece. It was commenced in 1810 ; it
is a level brldge, having 9 arches, each 120 feet span and 35 feet rise, and it is 42 feet 4 inches
wide between the parapets.
550.
-> 11,—— "f....m~__
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\-_.
Details of one of the Arches and Centreing of Waterloo Bridge.
The bridge across the Seine, at Neuilly, built between the years 1768 and 1780, by Perronet', is a
very celebrated structure; it is also a level bridge, consisting of 5 elliptic arches, each of 128 feet
span and 32 feet rise.
551.


Elevation of one of the Arches or Neuilly Bridge.
552.


Transverse Section of Neuilly Bridge.
Girder Bridges—The simplest form of bridge is one composed of beams supported at their ends,
spanning an open space, with a floor or roadway built upon them. The load such a structure will
bear is simply that which each beam will bear multiplied by the number used. The weight a single
rectangular beam will safely bear, when loaded 2at the middle and supported at each end, may be
found by the following formula: W: in which W: the weight, b the breadth, d the
depth, and Z the length, of the beam in inches. R is a variable quantity, depending upon the mate-
rial used, and represents the safe limit of pressure per square inch. For wood 1,000 lbs. is usu-
ally taken, and for iron 10,000 lbs—about one-sixth of their ultimate strength. See STRENGTH OF
MATERIALS.
Wooden beams or “girders” are generally rectangular. Beams of iron or steel are mostly built
of the I or T form, and frequently with riveted flanges. The capability for sustaining loads de-
pends materially upon the method of support and the application of the load. The relative weights
the same beam will sustain under the various conditions are given below :
Beam supported at one end, loaded at the other end . . . . . . . . . . . . . . . . . . . . . . . . . . 1’
“ “ “ load uniformly distributed . . . . . . . . . . . . . . . . . . . . . . . . 2
“ “ at both ends, loaded at middle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
“ “ “ a load uniformly distributed . . . . . . . . . . . . . . . . . . . . . . . 8
Beam firmly fixed at both ends, load uniformly distributed . . . . . . . . . . . . . . . . . . . . . 16
The tubular bridge is properly classed as a girder bridge, and is the crowning point in the use of
the girder. Each span, in effect, is simply an immense girder.
The Conway Tubular Bridge was built by Robert Stephenson, and has one span of 400 feet, consisting
of two tubes placed side by side. A peculiar feature of its construction was the fact that each tube
was built entire, then floated to and raised into position by hydraulic power. The Britannia Bridge,
BRIDGES. 241

Fig. 553, across Menai Straits, is of similar character. It was also built by Stephenson, has two
spans of 230 feet each, two of 459 feet each, and is 103 feet above the water. The Victoria Bridge,
by the same, across the St. Lawrence at Mon-
treal, is also a tubular bridge, and is the largest
in existence, being 6,538 feet long. It has 24
spans of 242 feet each, and a central span of
330 feet. Each tube spans two openings, be-
ing fixed at the centre, and free to expand or
contract at either end.
Pile Bridges consist of timber “stringers,”
or beams, supported at short intervals on piles
driven in the ground in rows at' right angles
with the stringers. Upon these rows of piles
caps are laid, which support the stringers on
which the floor or roadway is laid.
Truss Bridgea—Simple beams or girders are
only applicable to small spans, 15 to 20 feet
being the usual limit. For greater spans framed
structures are necessary, forming what are called “truss bridges.” The general principles of the
“ truss ” may be shown briefly as follows :
The problem in all trusses is to transmit vertical forces, acting at unsupported points, to the points
of support, or piers. We will first consider the case where the loads are equal and placed at equal
distances from the piers. Let A B C, Fig. 554,
be a simple truss loaded at A, and let the line
A 6 represent this lead. Then, by the resolu-
tion of forces, the strains upon the members
A B and A O are represented by the lines A a
and A 0. These are again resolved at B and
CintoBgand Bfat B, and Ci and Ck at
g ALL; 0. The two vertical forces Bf and C i are
8711' 11\11 neutralized by the piers; the two opposite hori-
' ' _ zontal forces, B y and O k, neutralize each
other, producing tension on the tie B 0. We see in this that the vertical forces acting at the piers
are equal to the whole load; and that, although horizontal forces are developed, yet they do not
bear any part of the load, but are simply
evolved in transmitting the weight to the' 555-
piers, which eventually bear it all. A e L D
This form of bridge-building is applica-
ble to spans of from 15 to 30 feet. 5 d
For greater spans, the additional mem-
ber A D, Fig. 555, is introduced, the tie ,
rods at A and D dividing the span into 4 * ' 7
three parts. A d and D122, representing A l\
the weight acting at A and D, are re- s 79 ° F
solved into the equal vertical forces Bh
and C o acting at the piers, the opposing horizontal strains A e and DI compressing the beam A D,
and the opposing forces B i and O 1' producing tension on the tie B C. If the truss be lengthened,
. 556 as in Fig. 556, and loaded at the additional
A L ' D points L and P, though these weights would
P be transmitted as before to the piers through
a A B and D 0', yet they may be suflicient to de-
flect the beams A D and EF, as shown in Fig.
556. To obviate this, the additional braces L E
B E F C and P E, Fig. 557, are introduced, resting upon
the supported points E and R Through these
A ' D D the weights acting at L and P are transmitted
' to E and F, thence by the rods A E and D E
Z to A and D, and thence by the braces A B and
D C to the abutments. The truss may be fur-
- ther lengthened, as in Fig. 558, but the action
5 E F C of all the parts may be shown to be precisely
553_ the same as in the more simple cases.
The vertical strains are transmitted to the
a ' abutments, while the horizontal strains
neutralize each other by compression of
the upper and tension upon the lower
chord. The same result may be obtained
55,, by using vertical posts and inclined ties,
‘ or by the inversion of the truss, as shown
in Fig. 559. The various parts should
'9 ‘be in proportion as the strains they are
to bear, as follows: Let w represent the
_ . - weight upon one panel, at the number of
























16
242 BRIDGES.

panels, p the length of a panel, h the height, and :: VP? ‘+ 72.“, the length of a brace. The cen-
tre braces should each be suflicient to transmit the_weight upon one panel, the strain being
The end braces should each be sufficient to bear one-half the whole weight, their strain being lag-0;.
t
The intermediate braces should be in due proportion from the centre to the ends. The vertical rods
should each be as its adjacent brace toward the centre multiplied by the factor The strains upon the
6
upper and lower chords are equal, the former being a strain of compression and the latter of tension.
At the ends this equals the strain upon the end braces multiplied by the factor {)3 2 1'22-2078. At the
t
_ . nw .
centre the strain is —8—h—. These formulae are applicable only to a truss uniformly loaded. If the
truss be unequally loaded, the conditions are somewhat mod-
ified, as seen by Fig. 560. The horizontal strains B y and
C k are equal and opposite as before; but the vertical strains
B j' and 02' are found to be in inverse proportion to the
horizontal distance of the load "from each pier. If the truss,
Fig. 555, be loaded only at D, the horizontal force Di not
being neutralized by the equal and opposite force A c, a
distortion takes place, as shown in Fig. 561—the weight
depressing the point D and raising the points A and E. If
a brace be introduced from E to .D, Fig. 562, it prevents
this distortion; such a brace is called a counter-brace. A
similar brace from A to F prevents flexure when the load is at A. .
As may be seen by Fig. 561, the load at D develops a force at A acting upward.
The consideration of this force is of the greatest practical importance, and the existence of a force
acting upward appears to have been overlooked by
many practical builders, as in some very important 561-
structures no means have been used to guard against
its effects. -
The consequence is that, in a straight as well as
in an arched truss, a weight at one side produces a
tendency to rise at the other side.
The effect of this upward force is to compress the B
diagonals in the direction of the dotted lines, Fig. 563,
and extend them in the direction of the braces; but
as the braces, from the manner in which they are
usually connected with the frame, are not capable
of opposing any force of extension, it follows that
the only resistance is that which is due to the
weight and inertia of a part of the structure. When
the load is uniform this is sufficient, because the
weight on one side is balanced by an equal weight
upon the other, and every part is'in equilibrium. But when the bridge is subjected to the action of
a heavy weight, as a locomotive engine or a loaded car rapidly passing over it, and acting with
impulsive energy upon every part at different instants, it is obvious that no adequate resistance is
offered by a truss composed of only the three series of timbers
563. already described. Yet we find that such a truss has been used
a , _ for a large proportion of the bridges that have been erected,
\x sometimes with and sometimes without the addition of an arch,
‘\ an appendage which, although it adds to the vertical strength,
“ diminishes but little the effect of the force under consideration.
_ No one who has had an opportunity of observing it can have
failed to notice the great vibration produced in such bridges by the passage of a loaded vehicle. In
long bridges, the undulations produced by the passage of a car can be felt at a distance of several
spans. ,
The remedy for this defect is obvious: it is only necessary to prevent the diagonals in the direc-
tion of the dotted lines from shortening, or in the direction of the braces from lengthening, and the
upward force will be effectually resisted. "
This requires either that counter-braces should be introduced in the direction of the dotted diagonals
of the last figure, or that the braces themselves should be capable of acting as ties, or additional tics
placed in the direction of the braces. .
It follows, from the preceding exhibition of the effect of a variable load, that no bridge, either
straight or arched, which is designed for the passage of vehicles, and particularly of railroad trains,
should be constructed without counter-bracing or diagonal ties. It is only in aqueducts, when the
load is always uniform, that they can with any propriety be omitted.
Efi'ecz‘s of 002072MP-b’1‘610’inff—The consideration of the action of counter-braces leads to some very
singular but important results.
Let the truss be loaded with a weight so as‘to produce some deflection; it has been shown that the
diagonals in the direction of the braces will be compressed, and in the direction of the counter-braces
extended. Suppose that the extension of the last-named diagonals is sufficient to leave an appreciable











E F C









BRIDGES. 243

interval between the end of the counter-brace and the joint against which it abuts, and that into this
interval a key or wedge of hard wood or iron is tightly introduced: it is evident that, upon the re-
moval of the weight, the truss, by virtue of its elasticity, would tend to regain its original position ;
but this it cannot do, in consequence of the wedges at the ends of the counter-braces, which prevent
the dotted diagonals from recovering their original length, and the truss is therefore forcibly held in
the position in which the weight left it; the reaction of the counter-braces producing the same effect
that was produced by the weight, and continuing the same strain upon the ties and braces.
The singular consequence necessarily results from this, that the passage of a load produces no ad-
ditional strain upon any of the timbers, but actually leaves some of them without any strain at all.
To render the truth of this assertion more clear, we will confine ourselves to the consideration of a
single rectangle, and suppose that the effect of the fiexure caused by an applied weight has been to
extend the diagonal A O by a length equal A p, and to compress the -
brace B D by an equal amount.
The point 19 will evidently be drawn away from A, leaving the inter-
val A p.‘ If a wedge be tightly fitted into this interval without being
forcibly driven, it evidently can have no action upon the frame so long
as the weight continues; but, upon the removal of the weight, it becomes
forcibly compressed, in consequence of the effort of the truss, by virtue
of its elasticity, to return to its former position. This effort is resisted
by the reaction of the wedge, which causes a strain upon the counter-
brace A 0 sufficient to' counteract the elasticity of the truss; and as no
change of figure can take place, it follows that the brace 31) cannot
recover its original length, and therefore continues as much compressed as it was by the action of
the weight. .
The etffect of a weight equal to that first applied will be to relieve the counter-brace A 0, without
adding in the slightest degree to the strain upon BD.
As regards the effect upon the chords, it is evident that the strains are only partial, and tend to
counteract each other. The maximum strain in the centre is estimated by the force which would be
required to hold the half truss in equilibrium if' the other half be removed; and this is dependent only
on the weight and dimensions of the truss. In fact, if we examine the parallelogram A B C D, we
find that the effect of wedging the diagonals will be to produce strains acting in opposite directions at
, A and B, and destroying each other’s effects ; the strains produced by wedging any rectangle cannot
therefore be continued to the next, and of course can have no influence upon the maximum forces at
the centre. \
As the vibration of a bridge is caused principally by the effort to recover its original figure after
the compression produced by a passing load, it follows that, if this effort is resisted, the vibration
must be greatly diminished, or almost entirely destroyed.
This accounts for the surprising stiffness which is found to result from a well-arranged system of
counter-braces.
In proportioning the parts of a truss liable to a moving or unequal load, the case of greatest pos-
sible strain should be assumed, viz., that of the truss with its maximum uniform load with an addi-
tional load placed at the centre.
Let Wrepresent the weight of the truss and its uniform load, 20 the greatest load ever applied at a
single point, p the length and h the height of a panel, and b the length of a brace.
The braces at the gentre should be sufficient to bear the greatest strain ever to come upon a single
w


point, and equals
2 h'
The intermediate braces are proportioned as before in accordance with their position.
The tension on the rods is equal each to that of the adjacent brace toward the centre multiplied
{it-
b
The strain upon the end braces each equals <-—— + 20) ~—
by the factor
The strainsugrzon thle upper and lower chords are equal, being greatest at the centre, where they
1 I
each equal (—8— + K. At the ends they each equal + 70) If, however, the number of
panels should be even, then the strain upon the lower chord will be in excess of that upon the upper
. . a .
throughout its whole length by the quantity The strains upon the counter-braces are small as
compared with the other parts, being greatest at the centre, where it is advisable to make them equal
to the middle braces. These should be permanently strained by adjustment while the truss is dis-
torted by its maximum moving load applied at various points. By this means a perfect rigidity is
secured, as previously referred to.
Inclination of Braces—1. The braces must not be so long as to yield by lateral flexure.
2. The chords being unsupported in the intervals between the ties, these intervals must be limited
by the condition that no injurious flexure shall be produced by the passage of a lead. 011 the other
hand, as the ties approach each other, the angle of the brace increases ; and when the intervals be-
come small, the number of ties and braces is greatly increased, and with them the weight of the
structure.
The true limit of the intervals can be readily determined when the size of the chords and the max-
imum load are known; for it should evidently be such that, when the load is at the middle, the flexnre
should not exceed a given amount.
244 BRIDGES.

566.
LW. lo
a



The floor-beams, or roadway supports, should be sufficient to bear the greatest load ever applied at
a single point. .
Lateral Bracing—To prevent the lateral swaying of the bridge, principally caused by high winds,


and to preserve the trusses in their proper relative positions under all circumstances, a light system
of lateral bracing is introduced both at the top and bottom.
QUEEN PnsT Tquss







W _ s W
KING F051" Tfiuss








WH'PPLE PM"?









MEC’ALL/QM - %— PAHABULlB/ABCHED
NM
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TDWPIE'E LATTICE.
BRIDGES. 245

Camber.—Because of the elasticity of the materials used in bridge-construction, it is the custom
in practice to construct with a “camber,” or slight rise at the centre. This is in proportion to the
span, and, according to Trautwine, should not exceed 1 inch for every 50 feet in span.
To illustrate more plainly the strains to which the several members of a bridge-truss are subjected,
a system of “graphic statics” may be employed, which was first practically used, so far as we
know, by Mr. Dudley Blanchard in the construction of bridges about 1858. It consists in represent-
ing the measure of any force by a line at right angles with the direction of that force, and hence
{I
w —.d_
,p/
’ ____,_’_


- ,1“
represents by comparative breadths the relative strength required in any bridge member. In Figs.
565, 566, let a weight be applied at the joint 6. Let its quantity be represented by the line a c; then
completing the triangle a b c, by lines at right angles to the direction of the supporting members,
the strains upon each member will be as the sides a b and b c. Fig. 567 is an illustration of this
method applied to a truss, in which the strains on the various members of the truss A B U D
are indicated by the breadth of such members.
Fig. 568 shows the most common forms of the truss bridge now in use, and their comparative
meritsare discussed in Merrill’s .“Iron Truss Bridges for Railroads,” to which, with Wood’s “Con-
570.
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structionof Bridges and Roofs,” Shreve’s “Construction of Bridges and Roofs,” Boller’s “Iron
Highway Bridges,” and Haupt’s “Theory of Bridge-Construction,” the reader is referred for a more
complete analysis of the subject.
The arched or bowstring truss, though of the arched form, is substantially a truss, and the propor-
{ions of its parts are calculated in the same manner Particular care must be had in the counter-
racing.
A great advance has been made in the construction of truss bridges within the past twenty years,
principally by the substitution of iron for wood. \Vooden bridges of importance are very rarely
built now. One of the most remarkable structures of this kind in the United States is the bridge
(Fig. 569) at Havre de Grace, over the Susquehanna River. It is 3,271 feet long, divided into 12
spans, resting upon granite piers. It is constructed on Howe’s plan, and combines great lightness
and strength.
A good example of a bridge on Fink’s system is found in the railroad bridge (Fig. 570) over the
Ohio River, at Louisville. Its
length is 5,21% feet, divided
into 23 spans, supported by 24
stone piers. Its height is‘about
961, feet above low water, and
width about 27 feet.
Timsed- Arch Bridges are
those so framed that the en-
tire weight is supported by the
arch; the load, before acting
upon it, being first distributed,
and the direction of its press-
ure changed, by the intervention of a truss, Fig. 571. The truss should be so constructed as best to
resist the tendency to rise when the arch is unequally loaded, and need be only sufficiently strong to




246 BRIDGES. '

bear the moving load, and to firmly counter-brace the arch, the weight of the entire bridge itself
being borne by the arch alone. For wooden bridges of long spans this is the best known form, and
, ,_ several remarkable structures of this
//1l / 1’” type have been built. Figs. 57 2 and
I
l , 4, ' - 573 show the construction of the two
l n / y . most noted American trussed arches
/ / I ' v of wood. The first consists of three
1 ,/ arches, the centre one being of 195
feet span, and the other two of 150
feet each. The second has a single
arch of 34-Ohfeet span, with only 20
feet rise—the largest wooden arch

'


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. y \ ever built.
The recent completion of the St.
W - Louis bridge, by Captain James B.
Eads, is the crowning effort in bridge
construction of this type. It consists
of three arches, the centre one of
which has a span of 520 feet, and
the other two of 515 feet, and each
with a rise of 60 feet. There are
two main piers and two abutments,
the foundation of one being 120 feet
.} ,


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4 ll










' I lv '11,! underwater. 'The arches are formed
is: :05 with top and bottom chords in sec-
;li! ,jl -. ' d , ‘ 'g tions of steel tubes 16 inches in di~
.1 7;, ~;;, / .g 93 ameter, composed of staves 12 feet
lilqll' aw, ' 5.): ? '2‘ long, banded together by steel thim-
,,|| IE w :5 bles or couplings. These top and
.f '9', ' g - é bottom chords, 12 feet apart, are
i j. 'I/ I ' 5 2,” connected by a triangular system of
'1' .5 ' ' 3, .3 bracing, constituting an arched truss
" o
. . l-l
of great strength combined with exs
treme lightness. ’
Lattice Bridgea—One of the most
simply-constructed types of bridges
is the lattice bridge. If of wood, it
may be built entirely of plank of
uniform size; the braces crossing
each other, generally at right angles,
are fastened by a pin or “ treenail ”
of hard wood, and the chords are so
constructed as to break joint. The
objections to this type of bridge are
its liability to warp and the entire
lack of proportion in its parts. The
first objection is obviated by placing
a double truss on each side of the
bridge, so riveted together as to act
as one. Its advantages are in the
simplicity of its construction. They
may also be built of indefinite length,
and sawed off to suit the span re-
quired.
Lattice bridges have been success-
fully used in spans of as great lengths
. as. 150 feet; and in Europe iron lat-
tice bridges, with their parts in prop—
' er proportibn, have been built of
300 feet span and upward. The
most common form in this country
is the “ Towne; ” but, as iron is
now taking the place of wood, those
types of bridge requiring less ma-
terial are more generally preferred.
As the proportions of the valious
partsdepend upon the amount and
character of the load a bridge is to
sustain, this point should be care-.
fully considered in designing each
particular structure. The liability in practice is to underestimate this load for short spans. The
following table gives the proportion of loa'd‘to span, as recommended by a committee of the Ameri'
can Society of Civil Engineers, for highway bridges: . . , . i i
m
Elevation of the Schuylkill Bridge.
Elevation of the Upper Schuylkill Bridge.




BRIDGES. 247








POUNDS PER SQUARE FOOT.
For City and other For Towns and Vil- l Ordinary Country
SPAN' ' Bridges, when Travel lages, and Districts ; Bridges—Travel in-
ls heavy and having well-bsUnsted frequent and Loads
frequent. Roads. ‘ light.
60 feet and under. 100 lbs. 100 lbs. I 75 lbs
60 to 100 feet. 90 “ 75 " l 66 “
u u it t6. 50 “
150 “ 200 “ 70 “ 60 “ l 50 “
200 “ 800 “ 66 “ 50 “ 40 “
it H‘ H 50 H I 35 “


And for railroads as follows:





SPAN on PANEL. ‘ P SPAN 0a PANEL. Prlfifsolféfifial
l‘} a
)1
Under 12 feet. I 6,000 lbs. i; Under 75 feet. g 3,000 lbs.
u If) it 5,500 n u 100 st 2,750 tt
“ 20 “ ‘1 5,000 “ I. “ 150 “ l 2,500 -
*- 25 “ 5 4,500 “ .i 150 to 175 “ ' 2,500 “
“ 30 “ ! 4,000 “ 5 175 "‘ 200 “ 2,400 “
“ 50 “ 1 3,250 r 5 200 “ 300 r 2,250 “

Suspension Bridges are best adapted for long spans, and have been successfully constructed with
spans more than twice as long as any other form of bridge. These bridges are usually constructed
with chains or cables passing over towers, with the roadway suspended beneath. Each end of the
chains or cables is securely anchored. On the towers the cables rest in saddles, which are movable,
so that the strains do not tend to overturn the towers.
The deflection of the cable usually employed is between one-tenth and one-fifteenth of the span.
The unloaded cable assumes the form of the catenary; but loaded with the suspenders and the
,road-bed, it approaches the parabola.

w
The tension upon a cable is approximately obtained by the formula T :2 M 419 + y 1'; in which
, x
w represents the weight equally distributed, a: the deflection of the cable,land y the length of the
one-half span.
The length of the cable equals 2 y ‘1 + 31%.
A bridge constructed with the road-bed supported only by vertical suspenders would lack stiff-
ness, as it 'would be deficient in that which corresponds to counter-bracing in truss bridges; and
thus some discredit has attached to the earlier bridges of this type, which were lacking in this re-
spect. I w .
By trussing the road-bed and using inclined stays extending from the top of the towers, and par-
tially supporting the roadway for some distance out from the tower, a sufficient degree of stiffness
is obtained.
Iron suspension bridges of large span are of comparatively modern date. The first one built in
England was by Sir Samuel Brown, across the Tweed at Berwick, in 1819; its span was 449 feet.
The longest span in Europe is at Fribourg, in Switzerland, built by M. Chaley in 1881-’4. It has
' a span of 870 feet, and is 174 feet above the river. Its cables are made of iron wire.
One of the most important bridges of this class in the United States is the Niagara Falls Suspension
'Bridge, constructed by John A. Roebling, C. E. This bridge hasa span of 821 feet 4 inches, from
centre to centre of towers. Its form is a slightly-curved hollow beam or box, of a depth of 18 feet;
width of bottom 24 feet, and of top 25 feet. The lower floor is used for common travel, while the
upper is appropriated to railway business and sidewalks. The two floors are connected by two trusses
of a simple construction, so arranged that its resisting action operates both ways, up as well as down.
The suspenders are 5 feet apart. The beamsof the upper and lower floors are connected by posts
arranged in pairs, leaving a space between for the admission of the truss-rods, which extend each
way to the fourth pair of posts at an angle of 459. These rods therefore cross each other and form
a diamond work. They are 1 inch diameter, their screw ends 1% inch.
There are 4 cables of 10'inches diameter, ‘eacll composed of 3,640 wires of small No. 9 gauge, 60,
wires forming one square inch of solid section, making the solid section of each cable 60.40 square
inches, wrapping not included. Each of the four large cables is composed of seven smaller ones,
which are called strands. Each strand contains 520 wires; one of these forms the centre, the six
others being placed around it; the ends of the strands are passed around and confined ill cast-iron
shoes, which also receive the wrought-iron pin that forms a connection with the anchor chains. Dur-
ing the wrapping process the whole mass of wire was saturated with oil and_ paint, which, together
with the wrapper, will protect the cables effectually against all oxidation. There are 64 diagonal
stays, of lfi-inch diameter rope, above the floors, equally distributed among the four cables. They
are fastened to the suspenders by small wrappings, so as to form. straight lines; they are not con-
tinued over the towers to the anchorage, but are secured. to the saddles,'and allowed to move with
them. To the under side of the lower floor‘ 56 stays , are attached, “which are anchored in the rocks
248 BRIDGES.
\

below, and occupy positions calculated to insure against horizontal as well as vertical motions. The
anchorage of the back chains was formed by sinking 8 shafts into the solid limestone rock that here
composes the uppermost stratum of the cliffs. Three of the pits on the New York side are sunk
to a depth of 25 feet. The fourth one, southeast, was sunk only 18 feet, on account of the great
influx of water and difficulty of baling. The surface of the rock on the Canada side being 10
feet higher than on the New York side, the depth of the shafts was increased that much, and
the height of the towers above reduced in proportion. Each shaft has a cross-section of 3 x 7 feet,
enlarged at the bottom to a chamber of 8 feet square. The anchor chains are composed of 9
links, all of which are 7 feet long, except the uppermost or last one, which is 10 feet. The first
or lowest link is composed of 7 bars, 7 x 14 inches, and is secured to a east-iron anchor plate by a
pin of 31} inches diameter ground upon its seat. The next link is composed of 6 bars of the same
size, and 2 half bars on the outside. The aggregate section of each is 69 superficial inches; from
the fourth link up, the link on the chain curves, and the section is gradually increased to 93 super-
ficial inches.
On the top of each column a cast-iron plate was laid down, well bedded in cement, 8 feet
square and 215 inches thick, and strengthened by three parallel flanges for the reception of two
independent saddles. Each saddle rests on ten cast-iron rollers, 5 inches in diameter and 251}
inches long, placed close together. The ordinary pressure upon each tower, being about 500 tons,
makes each roller bear 25 tons. These rollers admit of a slight movement of the saddles, when-
ever the equilibrium between the land and the suspension cables is disturbed, either by changes
of temperature or by passing trains. l
The table on page 272 gives the leading characteristics of the most celebrated long-span bridges
of the various types, showing more particularly the comparative lengths of their maximum spans.
The use of steel wire for the cables has made still longer spans possible.
The “East River Suspension Bridge,” Fig. 574, between the cities of New York and Brooklyn,
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designed by John A. Roebling, and built by his son Colonel W. A. Roebling, has its cables composed
of steel wire, having a strength of 160,000 lbs. per square inch; whereas iron wire would sustain
but little more than one-half that amount, and iron bars less than one-third. This bridge is sup-
ported by four cables, each 151} inches in diameter. The main span is 1,595.} feet, and the side
spans 930 feet each, making the suspended portion 3,45% feet in length. This, with the approaches
-—2,5331} feet—make a total length of 5,989 feet. The height of the roadway above high tide is
135 feet, the height of the towers 27 2 feet, and the width of the bridge 85 feet.
The mode of constructing the wire superstructure of this bridge was as follows:
The wire came from the factory in large coils, some 5 feet in diameter. These were dipped in oil,
dried in the air, and dipped again and again until a moderately thick coat of hardened grease had
changed their bright zinc-lustre into a dirty yellow; then they were carried up on the top of the
anchorage, reeled off on large wooden drums, and from these last they were paid off as required.
The carrier-rope was simply an endless wire cable, which started frbm the Brooklyn anchorage,
passed over the two piers in turn, then to the New York anchorage, on top of which are two
horizontal pulleys, around which it led, then back to Brooklyn, and finally, after passing around
an immense horizontal engine-driven drum, the ends were joined. One part of this carrier-rope
carried wire for one inner main cable, the other part for the corresponding outer main cable. On
each part was attached a traveler-wheel, which is represented in Fig. 575. This was a light
wheel of wood and tin, turning in bearings suspended from the rope; braces were arranged in
'SH’SCIIHH
6176


LOCATION. ‘ Length. Longest Span. Material. Type. Character. Designer. - REMARKS.
Feet. Feet.
Waterloo Bridge, London . . . . . . . . . . . . . . . . . . . . 120 Stone . . . . . . Elliptical arch .... . . Highway . . . . . . . . . . . . . . . . Rennie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cabin John, Washington aqueduct . . . . . . . . . . . 220 “ . . . . . . Circular “ .. . . . Aqueduct . . . . . . . . . . . . . . . . Meigs .... . , . . . . . . . . . . . . . . . . . . . . . . . . . .
0maha bridge . . . . . . . . . . . . . . . . . . . . . . . . . 2,750 250 Iron . . . . . . . Post truss . . . . . . . . . Railway . . . . . . . . . . . . . . . . . American Bridge Company . . . . . . . . .
Leavenworth bridge . . . . . . . . . . . . . . . . . . . 1,000 340 “ . . . . . . . “ “ . . . . . . . . . Railway and highway. . . . . “ “ “ . . . . . . . . . . .
Poughkeepsie . . . . . . . . . . . . . . . . . . . . . . . .. 4,595 525 “ . . . . . . . Truss . . . . . . . . . . . . . . Railway . . . . . . . . . . . . . . . . . " . “ “ . . . . . . . . . . . In process of construction-
Fairmount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 848 “ . . . . . . . “ . . . . . . . . . . . . . . Railway and highway. . . . . Keystone “ “ . . . . . . . . . . .
Newport and Cincinnati . . . . . . . . . . . , . . . . . . . . . 420 “ . . . . . . . Linville truss ..... .. Railway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Susquehanna ...... . . . . . . . . . . . . . . . . . . . . . . . . ~807 “ . . . . . .. Truss . . . . . . . . . . . . . . “ . . . . . . . . . . . . . . . . Phoenix Iron and Bridge Company. . ..
Upper Schuylkill .... . . . . . . . . . . . . . . . . . . 840 840 Wood . . . . . Segmental arch .. . . Highway . . . . . . . . . . . . . . . . Wernwag . . . . . . . . . . . . . . . . . . . . . . . . . . . . Destroyed by fire.
ShLouis.‘ ............ ........... .. 1,550 520 Steel .... .. “ “ Railway.. ............. .. .................. ........ .. ‘
Pittsburgh . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,245 800 Iron . . . . . . . Suspension . . . . . . . . Highway . . . . . . . . . . . . . . . . American Bridge Company . . . . . . . . . . .
Niagara . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 821 “ . . . . . . . “ . . . . . . .. Railway and highway.. . .. John A. Roebling . . . . . . . . . . .. . . . . . . . . .
Fribonrg, Switzerland . . . . . . . . . . . . . . . . . . . . . . . 889 “ . . . . . . . “ . . . . . . .. Highway . . . . . . . . . . . . . . . . Chaley. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1,010 “ . . . . . .. “ . . . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . Charles Eliot, Jr . . . . . . . . . . . . . .. . . . . . .. Destroyed by tornado.
Cincinnati . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,220 1,057 “ . . . . . . . “ . . . . . . .. Highway . . . . . . . . . . . . . . . . John A. Roobling . . . . . . . . . . . . . . . . . . . .
New Niagara . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1,2‘29 “ . . . . . . . “ . . . . . . . . " . . . . . . . . . . . . . . . . . . . . . . . .. '. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Victoria bridge . . . . . . . . . . . . . . . . . . . . . . .. 10,500 . . . . . . “ .. . . . . Tubular . . . . . . . . . . . Railway . . . . . , . . . . . . . . . . . Stephenson . . . . . . . . . . . . . . . . . . . . . . . . . .
Conway “ . . . . . . . . . . . . . . . . . . . .. . 400 400 “ . . . . . . . “ . . . . . . . . . . . Highway . . . . . . . . . . . . . . . . “ . . . . . . . . . . . . . . . . . . . . . . . . . .
Britannia “ . . . . . . . . . . . . . . . . . . . . . .. 1,378 459 “ . . . . . . . “ . . . . . . . . . .. p “ . . . . . . . . . . . . . . .. “ . . . . . . . . . . . . . . . . . . . . . . . . . .
Hammersmith . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 422 “ . . . . . . . Suspension . . . . . . . . “ . . . . . . . . . . . . . . . . Tlernay Clark . . . . . . . . . . . . . . . . . . . . . . . .
Menai Strait . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580 “ . . . . . . . “ . . . . . . .. “ . . . . . . . . . . . . . . .. Telford . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
East River.. . . . . . . . . . . . . . . . . . . . . . . . . . . 5,989 1,595 'Stcel . . . . .. “ . . . . . . . . Highway and railway. . . .. John A. Roebling . . . . . . . . . . . . . . . . . . . .











5330 BRIDGES.

connection with it to prevent oscillation. Over this wheel the bight of the wire to be laid was
passed. One end of the wire was fastened, the other went to the reel; thenithe drum of the car-
575 rier-rlopg tturntgd, sing the lighield
‘ attac 1e 0 1e a er, sare
Aamwvw~w on its journey. The wire grad-
" ually unwinding from the reel,
the wheel traveled on over the
piers, and finally came to rest
on the New York anchorage.
There the bight of wire was
slipped out of its groove and
put around a massive iron shoe
(Fig. 57 6), and then the motion
of the carrier-rope was reversed,
and the empty wheel returned.
At the same time another wheel,
carrying another bight of wire
for the second cable, started
across. And thus the work con-
tinued, a filled wheel constantly
going out and an empty one re-
turning—two strands of two dif-
ferent cables being thus simul-
- taneously made. “
As each reel of wire was exhausted, the end from
another was coupled on by means of the device shown
in Fig. 577. The coupling is a hollow cylinder, with
two concave threads in inverse directions meeting at
the centre, exactly fitting the ends of the wires, in
which the convex threads are cut, naturally in opposite
directions, so that the same turn of the coupling screws
in both at once, and the sharp edges of the cylinder
are then beveled down. Thus the wire of each strand
is continuous, and, once fastened at the Brooklyn end,
was reeled on or 01? till the whole strand was laid.
After each wire was laid it was brought to the same curvature as the wire preceding it. To do
this, after the carrier had passed the wire from the anchorage over the saddle at the top of the
pier, it was stopped, and a tackle was attached. To ascertain the requisite amount of distance
to be raised or lowered from the -
top of the pier to the anchorage,
flagmen were stationed on the
cradles, of which there were three
between the piers, who reported,
by means of prearranged moves
of their flags, to the fiagman on
the top of the pier, the amount
of deflection there was in the
wire, and it was accordingly raised
or lowered, as demanded.
When the requisite number of
wires was laid to form a strand,
an apparatus called a “buggy”
was attached to this strand, and
made to travel upon it. The
workmen in the buggy gathered
the wires into a bundle, and re-
tained them with a pair of pecul-
iarly-shaped tongs, and tempora-
rily bound the strand with wire
at intervals of about 28 inches.
‘When 19 strands of the cable
were finished and placed side by
side, the wrappings about the
strands were removed, and the
entire 5,700 wires were bound to-
gether by encircling wires, so as
to form a solid cable. After each
strand was bound, the yoke, seen
suspended above the massive sad-
dle, Fig. 578, upon which the
strand rests, was lowered; the
clevises, of which there are four,
were removed, and, elasping the


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mass of cast-iron weighing 23 tons, and having 16 radial arms.
strand, were bolted in their
former places. The capstan
nut, seen at the top of the
framework over the yoke,
was rotated; and as it re-
volved on the screw to which
the yoke was suspended, it
raised both yoke and strand
until the latter was clear of
the pulleys on the saddle.
The pulleys were then re-
moved, and the strand low-
ered away into its bed in the
saddle underneath the pul-
leys. The clevises on the
yoke were then uncoupled,
the yoke raised out of the
way, the pulleys put in place,
and another strand was laid
similar to the previous one.
The saddles, to which ref-
erence has been made, are
four massive castings rest-
ing on the top of each pier,
and each one holding in its
embrace one of the cables.
The pulleys over which the
strand passed were used for
convenience in laying the
strand, and were removed
entirely when the cable was
completed and placed in its
saddle. To allow for the
difference in unequal con-
traction and expansion of
the cable from anchorage
and pier, and between the
piers, the saddle rests upon a
series of iron rolls, which al-
low of a change of its place,
as the force of contraction
or expansion is brought to
bear upon it.
Fig. 579 represents the
bridge while in process of
building, and shows the loca-
tion of the cradles above re-
ferred to.
Figs. 580 and 581 repre-
sent a section of one an-
chorage, and a perspective
view of one of the massive
anchor-plates of the East
River Bridge. In each an-
chorage there are four of
these anchors, each being a
Each plate is embedded in concrete
on the third course of stone (Fig. 581), the second course being somewhat thinner immediately
beneath, so as to form a species of socket.
Through the apertures left in the centre of the

plates the first set of bars for the chains is,

placed. Each chain consists of 10 sets of links,
and two chains lead from each plate. The cor-
responding links of each pair of chains contain
together about 19 bars. A glance at Fig. 581
will show that the tendency of the cables is
to upset the anchorage on its front edge. The
strain on each cable is estimated at 1,833 tons.
The East River Bridge was opened in 1884.
Its total cost from anchorage to anchorage, ex-
clusive of land damages, was $5,600,000.
The Proposed Hudson River Suspension Bridge

is to extend between New York City and Hobo-


BRIDGES. 253

ken, N. J. Mr. Gustave Lindenthal proposes to split the cables and insert between them the bracing of
the stiffening trusses, the weight of the chords of these trusses being then entirely saved, and the braced
cables form a true inverted arched rib, capable of resisting deformation. On this system spans of
6,000 ft. could be constructed for railway traffic, with steel cables having a tensile strength of 170,-
000 lbs. per sq. in., which is that of the cables used in the Brooklyn Bridge. At the present time, how
ever, suitable wire could be obtained having a strength of 240,000 lbs. per sq. in., and with this even
larger spans could be built. The proposed bridge over the Hudson River has been designed with a cen-
tre span of 2,850 ft., and two side spans of 1,500 ft. each. The roadway is to be carried at a height
of 150 ft. above the water. The arched ribs are to be made of steel-wire cables with bracing between
them as described above, the cables being 50 ft. apart. There will be but two such ribs to each
span, though there will be six tracks of railway on the platform of the structure.
The following table gives the estimate of the cost and details of this bridge as compared with those
of other of the largest similar structures now in existence:

\

BRIDGES. lam" 1 Brooklyn. Forth. ' PM?!" St. Louis.
ver, l I keepsie.
1. Type of construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Rigid Partially Steel can- Alternate Steel
suspendedi stiffened tilevers. cantilever arches.
wire-cablel suspen- and
arches. l sion wire trusses of
‘ cables. steel.

2. Length of bridge in each case without the approaches,
but including the anchorage or abutment .. . . . . . . . .. 7,340 ft. 3.700 ft. 5,400 ft. 8,100 ft. 1,700 ft.
8. Longest span of each bridge, centre to centre of bearing. 3,100 ft. 1,596 ft. 1,710 ft. 530 ft. 520 ft.
1;. Number of railroad tracks that can be used for trains. . . * 14 2 2 2 2
. Capacity. Expressed in number of freight-trains each
500 ft. long, and weighing 800 tons, which each longest
span may carry with the same coefficient of safety. . . . 20 11} 4} 2 2
6. Capacity. Expressed in number of passenger-trains
each 500 ft. long, weighing 550 tons fully loaded,
which each longest span may carry in ordinary opera-
tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2 6 2 2
. Average weight of superstructure per lineal foot of span. 45,000 lbs. 7,400 lbs. 19,200 lbs 8,200 lbs. 8,600 lbs.
. Average weight of steel and iron of superstructure per
lineal foot of span, without rails, railings, and floorings. 42,000 lbs. 6,200 lbs. 18,400 lbs. 7,300 lbs. 7,000 lbs.
. Average weight of steel and iron of superstructure per
lineal foot of track, without rails, railings, and floorings. 3,070 lbs. 3,100 lbs. 9,200 lbs. 3,650 lbs. 3,500 lbs.
10. Total cost of construction without approaches, without
woo-q







right of way, and without interest account . . . . . . . . . . . 828.5 M. 35.6 M. $13 M. $2.6 M. $5.3 M.
11. Cost per lineal foot of bridge . . . . . . . . . . . . . . . . . . . . . . . . . . $3,880 $1.610 $2,407 $8.40 $3,150
12. Cost per lineal foot of track . . . . . . . . . . . . . . . . . . . . . . . . . . . $278 $305 $1,203 $420 $1,575

The Firth of Forth Bridge (Fig. 581 A), was designed and built by Messrs. Fowler 8: Baker. The
total length of structure is about 1%; mile. The main bridge is made up of three immense cantilever spans
connected by short suspended spans. The approaches are made of ordinary lattice girder-spans 168 ft.
in length. There are three main piers, made up of four smaller piers of granite-faced masonry. The
height of these small piers is 36 ft., diameter 55 ft. at the bottom and 49 ft. at the top. Each of
these piers contains 48 steel bolts 2% in. in diameter by 24 ft. long, for anchoring the structure. Part
of the foundations below low water was put in by the use of open dams, and part of them by the pneu-
matic process. Two of the piers were located where there was a depth of 72 ft. at high water, and
where the bottom was rough and sloping. The sloping bottom was levelled up with bags of sand to
give caisson an even support. The rock was then taken out and the caisson lowered until it reached a
full level bearing on the rock. At Queensferry all four piers were founded upon caissons sunk to bed-
rock or into a hard bowlder-clay bed overlying the rock. The greatest depth below high water was
89 ft. The time required for placing all the caissons was about two years. The greatest air-pressure
used was about 35 lbs. In all the work of sinking the caissons there were no deaths of workmen
attributable to working under heavy air-pressure.
The superstructure of the main bridge consists of two cantileverspans 1,710 ft. in length each and
two spans 675 ft. each (being the shoreward arms of cantilevers). The approaches are made up of
spans 168 ft. each. The middle or suspended spans are 350 ft. each in length, included in the 1,710 ft.
above noted. These suspended spans are 50 ft. deep at the centre and 41 ft. at the ends. Their weight
is about 896 tons each. One end is fixed to the cantilever arm and the other end is movable for ex-
pansion. The spans connecting the four columns of the main piers, which may properly be called
towers, are, two of them, about 150 ft. each, the third being some 265 ft. The distance from the water-
surface to the tops of the main towers is 360 ft. The clear head-room under the centre of the bridge is
152 ft. at high water. The tower columns are 120 ft. apart at the base and 35 ft. apart at the top. One
of the 1,710 ft. spans weighs about 17,900 tons. The heaviest rolling loads known only make about
900 tens, or say 5 per cent. With assumed wind~pressure of 56 lbs. per sq. ft. the estimated lateral
pressure on each 1,710-ft. span is 2,240 tons, or 2% times as much as the rolling load. The main
compression members are cylindrical tubes, as that form gives the greatest strength with the least
weight. The largest tubes are 12 ft. in diameter, the shell being about 1]; in. to 1,7,» in. thick. Each canti-
lever tube is subject to a pressure of 2,555 tons from dead load, 1,145 tons from live load, and 3,270
tons from wind. The tension members are similar to our ordinary heavy latticed structures, being
composed of plate and angle sections, and being formed into trusses having top and bottom chords
which are about 12 ft. apart in the maximum. The lower parts of the bed-plates on the piers are
made up of several steel plates riveted together.
The Howe Tmss Wooden Bridge at Albany, Oregon, spans the Willamette River. Its dimensions
254
BRIDGES.









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BRIDGES. 255

are unusual for a wooden bridge, and the draw-span is the largest of its kind in the world. The
total width of the river (610 ft.) is crossed by two spans of 175 ft. each. The draw-span is 260
ft. lon . ' '
ThegSt. Louis Mercha/nt Bridge crosses the Mississippi at St. Louis. It is 2,420 ft. in length, and
has three independent steel trusses, each 520 ft. long. The bridge is built on pneumatic casings '70
ft. long and 28 ft. wide for river-piers and 26 ft. wide for shore-piers.
The Fort Madison (Mississippi River) Bridge has eight panel truss spans, and is 1,925 ft. long.
The Richmond Bridge, on the Richmond, Fredericksburg and Potomac Railroad, is about 2,300 ft.
long, and consists of eleven pin-connected deck-spans of 176 ft. each over the river, and 180 ft. of
viaduct of 30 and 60 feet girder-spans at each end. The floor is about 90 ft. above the bed of the
stream. The river-spans rest on iron towers about 46 ft. high above the masonry piers. The trusses
were designed for a load of two 100-ton engines, followed by 4,000 lbs. per ft. .
The Poughkeepsie Brz'dge extends across the Hudson River at Poughkeepsie, N. Y. It consists of
three cantilever spans of 548 ft., and two connecting spans of 525 ft. The clear headway is 160 ft.
for the cantilever and 130 ft. for the trussed spans. The bridge rests on four masonry piers stand-
ing on timber caissons sunk to a depth of 125 ft. below high water. On the piers rest steel towers 100
ft. high, 16 ft. by 60 ft. at the base, and 16 ft. by 30 ft. at the top. The bridge is calculated to carry
a rolling load of 3,000 lbs. per ft. run on each track, with two engines of 85 tons each; the wind-
pressure provided for is 30 lbs. per sq. ft. '
The Memphis Bridge is the third largest of its kind in the world. There are five spans and six
piers, including the anchorage pier. The east shore 'or cantilever span is 225.83 ft. ; the main span,
consisting of two cantilever arms and one intermediate span, is 794.42 ft. ; one continuous span 621.06
ft., and one deck span 338.75 ft., making a total length of 2,597.12 ft. in the bridge proper. The
structure is extended west of the main bridge by an iron viaduct 2,500 ft. in length, followed by a
3,100-foot timber trestle, and nearly a mile of embankment to a junction with the existing track of
the Kansas City, Fort Scott and Memphis Railroad, a few hundred feet west of Sibley, Arkansas. This
embankment crosses the St. Louis, Iron Mountain and Southern Railroad, and the Little Rock and
Memphis Railroad, and has a connecting track to both roads. The river-piers are sunk to depths
varying from 75to 131 ft. below high-water mark. All were sunk by the pneumatic caisson process,
and are of masonry from the Caissons to the bridge-seats. -
The material of the main bridge is steel. Some idea of the immensity of the steel parts used may
be obtained by knowing that the main posts are 80 ft. high and weigh 28 tons. Many of the pieces
weigh 10, 12, and 16 tons. The main pin of the cantilever truss is 14 in. in diameter, and weighs
2,200 lbs. _ \
The New London Bridge, crossing the Thames River, Connecticut, is principally noted for having the
longest double track draw-span in the world. The total length of bridge between centres of abut-
ments is 1,423 ft., made up of two spans 310 ft. each, two spans of 150 ft. each, and a draw-span of
503 ft. The spans are arranged symmetrically above the pier-draw, the principal dimensions of
which are as follows: The width centre to centre of trusses, 28 ft. 4 in.; end height between cen
. tres of chord, 25 'ft.; centre height between centres of chords, 71 ft.; the distance from base of
rail to masonry on pivot-pier is 19 ft. 1 in. The diameter of turn-table is 32 ft., and is rim-bearing.
There are 58 cast-steel wheels 20 in. in diameter and 10 ft. face, and weighing 800 lbs. each. The
load is distributed to the drum from eight equidistant points. The weight to be moved in swinging
bridge is about 1,300 tons. The draw-span is equipped with a double oscillating engine 10 in. by 7
in. stroke. The average speed is 17 5 revolutions per minute. The end arrangement runs out in
15 seconds, and the draw can be opened in 2% minutes.
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581 C.



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_ The Defer-in Bridge, at Benares, India, is an important link in the Indian system of railroads. The
river Ganges at this point is more than 3,000 ft. wide, and the total length of the bridge is 3,568 ft.
The mam stream 1s crossed by seven spans of iron girders of 356 ft. each, supported on brick piers.
But less than half the brickwork of these great piers is visible, no less than 120 ft. of the masonry
being below water, and 82 ft.- representing foundations carried into the sandy bed of the river, which
here in the rainy season has a depth of 92 ft., with a velocity of 20 ft. per second. The total cost of
the bridge, not including the approaches, was about $3,000,000.
256 BRIDGES.

The Arthur Kill Bridge, over the tidal river separating Staten Island, N. Y., from New Jersey, is
800 ft. long. It consists of two shore-spans of 150 ft. each, covered by fixed trusses, and two draw-spans
of 206 and 204 ft. each on the clear. The total length of the drawbridge is 500 ft. It can be opened
or closed in about two minutes. The lower chords of the draw-trusses are about 80 ft. above mean high
water. The draw contains 656 tons, and each of the approaches contains 85 tons of metal. The total
cost of the bridge was $450,000.
The Luiz I Bridge, Oporto, Portugal (Fig 581 c) crosses the Douro River between Oporto and
Villanova da Gaia. Its extreme length is 1,278 ft., and it presents many novel and interesting feat-
ures. It has two roadways, one of them 160 ft. higher than the other. There are three principal
parts, the upper platform, the main arch, and the lower platform. The outward thrust of such an ,
enormous arch would be tremendous at the piers upon which it rests, but the lower platform, like the
taut string of a bow, receives part of this strain. The arch is 250 ft. above low water, and a span of
566 ft. Its thickness at the key is 26 ft., or about 93; of the span. The arch rests upon the masonry
through steel rollers placed in steel coussinets, which in turn rest upon cast-iron beds that distribute
the pressure over the masonry. The lower platform is divided into five bays by suspension-rods. It
is composed of simple lattice girders 29:} ft. apart and 10:} ft. between chords. The floor-beams are
10 ft. apart, and five rows of longitudinals receive the plates of the roadway.
Lifting Bridge, at Taranto, Italy (Fig. 581 D).—This structure spans the Strait of Taranto, and‘con-
sists of two half-arcs meeting above the middle of the strait. Each half is moved by machinery




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driven by two turbines of 14 horse-power. The halves are raised and rotated, the lifting motion being
given by four nats worked by an endless screw, and the rotation effected through large wheels at the
end of the abutment. The distance between the axes of rotation is nearly 220 ft. Total weight of
iron work, 526 tons; distance between abutments, 188 ft. .
The Niagara Cantilever Bridge (Fig. 581 E).--This is a double-track railroad bridge over Niagara
River, and is constructed on the cantilever principle. It has two steel towers 132% ft. high, rest-
ing on stone piers 59 ft. high. The cantilevers are each 395 ft. in length. The total length of the
bridge is 910 ft. between the centres of the anchorage piers. The clear span between the towers is
470 ft. The height of the bridge is 239 ft. from the surface of the river to the rail. The canti-
levers are composed of two trusses 28 ft. apart, having a depth of 56 ft. at the towers, 26 ft. at the
extremities of the river-arms, and 21 ft. at the shore ends. The materials used are steel and wrought-
iron.
The lVashington Bridge, over the Harlem River, New York City, is represented in Figs. 581 F and
581 G. The structure is combined masonry, steel, and wrought-iron, carrying roadway and footways.
The approaches are each 660 ft. long, and the remaining 1,060 ft.-—-the bridge proper—consists of two
steel arches and a central stone pier. The carriage-way is 50 ft. wide, with a 15-ft. sidewalk on each
side. The intrados of the arch is 133 ft. above the river.
One of the most interesting engineering features of the structure is the bearing of the arch-ribs, as
illustrated in Fig. 581 G. At the end of each rib the top and bottom chords converge, and a second hearing
or bed is formed, which receives the projecting surface of the pin, a free space being left between the
skew-back bearing and terminal of the rib. Thus a sort of hinge-joint is formed that secures a true
thrust, undisturbed by varying load or by changes of temperature. As the rib can oscillate freely in
such a bearing, no destructive strain is possible. Each rib thus ends, constructionally speaking, in a
sort of point. With an extreme range of temperature, a rise and fall of the crown of the arch through
a space of 3 in. may occur, and many times this amount is provided for by the pivotal bearing.
Each arch consists of six ribs thus constructed and supported. They are spaced laterally 14 ft.
from centre to centre. Their rise is 90 ft. They are connected by bracing that has two distinct
functions, namely, wind-bracing, in the line of upper and lower flanges or chords of the ribs; and

BRIDGES.
257
581 E.

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258 BRIDGES.

sway-bracing, which extends from rib to rib at each junction of the voussoirs or panels. From the
upper surfaces of the arch rise vertical columns, upon which rest the cross floor-beams. These columns
. are 15 ft. from centre to centre, and
, >> _ ~. . r 1e . — ,. ' they determine the varying length
‘,=_l'-‘ ' 1 ' i V of the rib-panels, already alluded
' ' to, as each column starts from the
termination of a joint between the
voussoirs. The two main arches,
one spanning the river, the other
the railroads, streets, and low ground
on the east bank, are identical in
construction. They contain about
7,500 tons of iron and steel.
The Garabit Viaduct (Fig. 581 H)
is a French railway bridge notable
for its great central arch. Its height
from bed of river to rail is 413 ft. ;
length 1,880 ft.
The Viaur Viaduct. -- Another
important French viaduct is that
over the Viaur River. This con-
sists of two trusses connected by a
central joint. The extremities of
the trusses support a span, the other
extremity of which rests on one of
the masonry abutments which form
the approach. The total length of
the Viaur viaduct is 1,508 ft., and
the height of rail above the bottom
of the valley 383 ft.
The Loa Viaduct is the highest
railway viaduct in the world. It is
placed at an altitude of 10,000 ft.
above the sea-level. The Antofa-
gasta Railway in Bolivia crosses the
higher Andes in its necessarily cir-
cuitous route from the coast to the
interior. The cafion spanned by this
structure is the bed of the river Loa,
and was probably formed by the
joint action of volcanic forces and
ice. The sides are precipitous, and
all the iron-work had to be deliv-
ered at the crest of the western
abutment and lowered into the
cafion.
The iron-work was all prepared
in England, and so carefully were
the calculations made that no read-
justment was necessary when the
columns were erected. The struct-
ure rests on seven piers, each con-
sisting of four hollow iron columns,
cross-braced in sections of uniform
height, and spreading at the base
like the letter A. There is, there-
fore, nothing intrinsically remarka-
ble about the plan of construction.
In the absence of trustworthy data,
it was necessary to take extraordi-
nary precautions against wind-force.
The calculations were therefore made
to resist pressure that would blow
a train of empty trucks from the
track, the estimated condition of
least stability being when a bridge
is loaded with an empty train. The
calculations, it should be noted,
took into account the weight of the
atmosphere, which is only about
two thirds that at the sea-level. No temporary staging was used. A wire-rope tramway stretched
from side to side of the cafion was used to transport and place the different partswhere they were
needed—a device successfully employed in many works now in progress in this country.




581 F.
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BRIDGES. 259

This tramway was also used to carry a locomotive piecemeal across the cafion—a service which was
successfully performed, but which, when the boiler was sent across, strained the ropes to an alarming
' degree. The girders were put together on the
abutment and transported to their places com-
plete with the aid of the tramway and a crane.
The iron columns were tested before shipment
from England, and endured a longitudinal press-
ure of 600 tons without measurable deflection.
The labor was all done by men, mostly sailors,
unskilled in this kind of work, superintended,
of course, by trained engineers. The principal
dimensions of the viaduct are: Length between
abutments, 800 ft.; height from water to rail-
level, 336 ft. 6 in; length of longest column,
314 ft. 2 in; length of principal spans, 80 ft.;
length of pier-spans, 32 ft. ; width of platform
over all, 13 ft. ; width of centre to centre, main
girders, 8 ft. 10 in.; depth of main girders,
I . .centres of booms, 7 ft. 11 in. ; batter of outer
l-I-I- . columns, 1 1n 6; battertof piers, 1 m 3; gauge of railway, 2 ft. 6 1n. ;_we1ght of
I---- iron-work, 1,115 tons; rolling load per foot, 1,} ton. The viaduct, exclusive of the
,- I-I masonry foundations, was put together in a few days more than nine months, and
II. a without loss of life or serious accident.
Foot-Bridge, River Ouse—The city of Bedford, England, lies on the north side of
III- the river Ouse, about 45 miles from its mouth. The corporation of the city acquired
land on the south side of the stream for a public recreation-ground, and it became
necessary to span the river with a foot-bridge of such construction that it would not obstruct the
view, for public gardens already existed on the north side of the stream. It was deemed necessary
also to insist upon a clear water-way of 15 ft. in mid-channel. There was practically no place for
abutments. The condi-








tions were met by means _ ,__ __>__________ _ ________ H _____ _7_ _ “M
of the double arch shown QEZWE‘MEZ'H . . g 1‘ AL AR; .,
1n Fig. 581 I, the upper , ,2,
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lower arch bearing the
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The clear span is 100 §3 i; ft.,, and the footway is “=1 'v’
7 ft. wide. __ >15 -
Pontoon Bridge at Ne-
braslea City. —Pontoon WK ' ' ' - ‘\“~\\ bridges are generally -u
used for temporary. pur- “' "
poses, but there are some
notable exceptions. At
Nebraska City the Mis- _ souri River has two arms, .~: _, fi , are: \» "
and the main branch has - ‘
a very swift current, often bearing large quantities of drift-wood. The lesser arm is crossed by a
permanent crib-work 1,050 ft. long. The pontoon section is 1,074 ft. long. A central span of 528
ft. is closed by two swinging sections, which form a V-shaped junction, with the angle pointing down-




















581 I.
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an . ~. .. ~ . _ ~. ... 1\~ .a\-\ . \Es
\. ‘_..,)__,',/‘_‘.'_.~ 7' ____ ,r _.___._..__ __ .___ __ _\ ‘ ..,\_“_\\.\v._., . \\\_ .
/ I. J / A, ...! ~ > :h'jd'rlllufrhb-g,’ .: -\ . l‘ . \ ‘__,tf_~ ‘2‘“ \A \_ ‘ \\-\ 8. \.
stream. When it is desired to open the draw, the fasts at the apex are cast oif, and the two halves
at once swing apart, the current doing all the work. The operation of closing is also aided by the
current, and the whole, it is said, can be effected by one man.
Works forRqferenee.—“ Les Constructeurs des Ponts du Moyen Age ” (Descriptions of Remarkable
Bridges of the Twelfth and Thirteenth Centuries, Brouquier-Rouie, Paris, no date; “ (Euvres,” Perro-
260 BROACH.

_—_
net, 1788; “A Treatise on Bridge Architecture,” Pope, 1811 ; “Traite des Ponts,” Gauthey, Liege,
1816; “On Vaults and Bridges,” Ware, 1822; “Les Ponts Suspendus,” Navier, Paris, 1830; “Theory,
Practice, and Architecture of Bridges,” I-Iann and IIoskens, 1843—50; “The Theory, Practice, and
Architecture of Bridges,” Weale, London, 18:13; “On Bracing,” Bow, London, 1851; “Suspension
Bridge across the Danube” (Pesth), W. T. Clark, London, 1852; “Des Ponts Suspendus,” Boudsot,
Paris, 1853 ; “ Military Bridges,” Douglas, London, 1853 ; “ Sur l’Etablissemcnt des Arches de
Pent,” Yvon Villarccau, Paris, 1853; “ General Theory of Bridge Construction,” I-Iaupt, New York,
1853; “On Iron Bridges and Girders,” Humber, 1857 ; “ Traité théorique et pratique de la Construc-
tion des Ponts Métalliques,” Molinos and Pronnier, Paris, 1857; “Des Ponts et Viaducts en Ma-
connerie,” Roy, 1857 ; “On the Construction of Iron Bridges,” Latham, 1858; “Construction of the
Great Victoria Bridge, Canada,” London, 1860; “ Sammlung eiscrner Briicken-Constructionen,” Von
Klein, Stuttgart, 1862 ; “On Iron Bridge Construction,” IIumber, 1864-; “Military Bridges,” Haupt,
New York, 1864; “De divers Systemes de Ponts en Fer,” Gaudard, Paris, 1865; “On Strains in
Girders,” Stoney, London, 1866-’69; “ Berechnung eiscrner Bogenln-iicken,” Frankel, Hanover, 1867 ;
“Theory of Strains in Girders,” Shields, 1867 ; “On Long_span Railway Bridges,” Baker, Philadel-
phia, 1867—’7 0 ; “On Wrought-iron Bridges and Roofs,” Unwin, 1869 ; “Long and Short Span Bail-
way Bridges,” Roebling, New York, 1869; “Strains in Girdcrs,” IIumber, 1869; “Iron Railway
Bridge at Quincy, Ill.,” Clarke, New York, 1869; “ The Kansas City Bridge,” Chanute and Morison,
New York, 1870; “International Bridge constructed across Niagara River,” Gzowski, Toronto, 1873 ;
“An Elementary and Practical Treatise on Bridge-Building,” Whipple, New York, 1873; “On the
Strength of Bridges and Roofs,” Shreve, New York, 1873; “\Vorks in Iron,” Matheson, London,
1873; “Proportions of Pins used in Bridges,” Bender, New York, 1873; “ Manuel de l’Ingenieur
des Ponts et Chaussees,” De Bauve, Paris, 1873; “Bridge and Tunnel Centres,” McMaster, New
York, 1875; “Continuous Revolving Bridges,” Herschel, Boston, 1875; “Iron Truss Bridges for
tailroads,” Merrill, New York, 1875 ; “Graphical Method for Analysis of Bridge Trusses,” Greene,
New York, 1875; “Theory and Calculation of Continuous Bridges,” Merriman, New York, 1876;
“Properties of Continuous Bridges,” Bender, New York, 1876; “Iron Highway Bridges,” Boller,
New York, 1876; “A Treatise on the Construction of Bridges and Roofs,” Wood, New York, 1876 ;
“ Les Ponts de l’Ame'rique du Nord,” Conrolle, Paris, 1878; “Bridges: an Elementary Treatise on ‘
Construction,” Jcnken, Elinburgh, 1878. See also numerous papers in the “Transactions” of the
American Society of Civil Engineers, Institute of Civil Engineers (British), Society of Engineers
(British), and Institute of Mechanical Engineers (British), and in the Annalee dcs Ponts ct Clams-secs ,'
also articles on bridges in the “Encyclopaadia Britannica,” 9th edition, Spon’s “Dictionary of Engi-
neering,” Appletons’ “American Cyclopaedia,” and Van Nostrand’s Eclectic Elwinccring jifagazz'nc ,-
also the works on civil engineering of Moseley, Malian, Rankine, and others. W. II. P
BROACII. A tool formed as shown in Fig. 582, and employed to cut out mortises or slots with
great accuracy and expedition. The work is chucked to the table of a press, and a succession 01‘ the
breaches of increasing width and thickness are forced through the work. In the centre of the head
of each breach is a conical recess, and similarly located in the bottom of each is a conical projection,
so that each successive breach may be guided centrally by the projection of the one following fitting
583.




into its recess. The head of
each breach is formed of rcc- F
tangular shape and tapered to
{it into a rectangular recess pro-
vided in the end of the rain of
the press to receive it. If the
mortises are of large dimen-
sions, the breaches are made
first to operate on the sides
only. Other breaches are sub-
sequently forced through to cut out the ends and the corners of ' ' ' M the mortises. J. R. """
is
BROOMS are usually made from broom-corn, which is a
species of doura or sorghum. Fig. 583 is a machine for pressing a bunch of broom-corn into shape
for a broom, and sewing it in its flattened form. The broom is placed between jaws a a, closed by


BRUSH-MAKIN G. 261

an eccentric c operated by lever 12. The machine being set in motion by the rotation of the cam-wheel
A, the cam-groove of the latter, actuating the lever f, forces forward the needle-bar 0, thus driving
the needle with its thread through the broom, above the twine wound around the latter. , The shuttle
U, operated by lever B, acting on the opposite side of the broom in conjunction with the needle,
forms the stitch. This being done, the reverse movement of the needle-bar withdraws the needle;
the eccentric h lifts the jaws a a, so that the next stroke of the needle carries the stitch below the
binding twine, the jaws being meanwhile moved along the guides a: a: by means of a pawl, operated by
a cam 01. on a supplemental shaft moved by gears h j, the pawl gearing with a ratchet formed at the
under side of the outermost of the jaws aa. The next outward movement of the needle, the jaws
being of course again lowered, carries the stitch above the binding twine. In this manner the stitches
are formed alternately above and below the binding twine, the distance apart of the stitches corre-
sponding to the intermittent feed given, as just described, to the jaws a a upon their supporting
guides x a:. The needle is supplied from the spool E, which has a tension-spring g.
BRUSH-MAKIN G. Bristles, as they come off the hog’s back, are covered with dirt and a sort of
gummy substance, that make them very unpleasant to handle. To rid them of these, and also of
























oii’ensive odors, they are first thoroughly washed, and, after becoming dry, are sorted. Each color is
placed by itself, and these grades are known to the operative as black, gray, yellow, white, and lilies;
the last are a kind almost transparently white, and of exceedingly fine texture. The sorting process
262 BRUSH—M AKIN G.

‘
also includes the distribution of the bristles in such a way that the collection shall be of equal
length. Besides, the" root-ends of the bristles must be kept together. The next process is to comb
them. By this means they are rendered elastic, and receive a beautiful polish. After being again
washed, they are ready for the use of the brush-maker.
Brushes are. divided into two general classes, known as single brushes and compound brushes.
The former are distinguished by one tuft or bundle of bristles. But a hair-brush belongs to the
second order, because of its collection of bristle bundles.
Brushes are also made of the soft hair of animals, such as the sable, badger, and squirrel. Of
such are the small paint-brushes used for water-colors. Other kinds of brushes are made of the roots
and fibres of certain tropical plants, of horse and goat hair, old rope, coeoanut fibre, broom-corn, the
fibre of whalcbone, and even of spun glass.
Small paint-brushes are manufactured as follows: The hairs are first cleaned in alum-water, and
subsequently soaked in warm water, dried, combed, and assorted. The brush-maker takes sufficient
of the prepared hair to fill a small groove which holds them tight; while thus placed the root-ends
are wound tightly with thread. The soft hairs are then arranged so as to form a point, without leav-
ing a blunt or scraggy end when the brush is wet. This part of the business is generally performed
by women or boys, as it requires a very delicate touch to arrange them properly. The handles are
made from quills, which are soaked in hot water to expand them sufficiently. When the brush is
ready the hairs are inserted, point first, in the large end of the quill. Then, by a eontrivance peculiar
to the trade, the brush is drawn through until the tied part is brought down to the small end of the
quill. This completes the process, and when the quill gets cold it contracts to its original dimensions,
and thus secures the brush part very tightly. The quills used for handles are of various sizes, and
are obtained from geese, turkeys, ducks, pigeons, and even smaller birds, such as quails, larks, etc.
The size of the handle is always proportioned to the size of the brush, and the purposes for which it
is made. When the quantity of hair or bristies is larger than can be used to advantage with quills,
the bunch of material is put into tin tubes with wooden handles. Even these, when too large,are_
placed in other handles made of wood, with perforated holes. Bundles of bristles designed for this
purpose are secured with strong cord, which has been dipped in glue. A scrubbing-brush is a com-
pound brush, and has holes bored in rows along its entire length. Into these holes bristles are in~
sorted, after first having been dipped at one end into melted pitch. When properly secured, they
remain there in spite of hard usage and hot water. Some brushes are very costly, while others are
sold at a mere trifle. Of the former are elaborately carved hat-brushes, hair-brushes, velvet-brushes,
clothes-brushes, tooth-brushes, nail-brushes, etc. Besides these we have the more common kinds of
shoe brushes, scrubbing-brushes, shavingbrushes, and other varieties, by far too numerous to mention.
I'Iair-brushes are of the most complicated manufacture. Holes large enough to admit the bunches
of bristles are bored all over the back of the brush part way through, while much smaller ones are
bored clear through. A tuft of bristles is doubled over a piece of fine wire. After being thus prop-
erly secured, the workman puts the wire through the small hole, and draws the bristles up as far as
possible in the big hole. The wire is then carried on to the next hole, until the whole surface is cov-
ered over with connecting lines of wire and tufts of bristles. When thus far completed, the bristles
are cut ofi evenly, and a fancy back is glued on to hide the wire, and give the brush a more finished
appearance. Tooth and nail brushes are made in a similar way, but the holes where the wire is
secured are made on the
585. ' side, and corked up with
MT 58‘; 537_ small plugs of ivory or
bone. Some brushes
have handles of per-
fumed wood, and are
ornamented considera-
bly, at heavy expense.
Brushes made of spun
glass are used in acids,
which will destroy ordi-
nary brushes.
Brushes are some-
times backcd with a
hard rubber composi-
! t_..___/ tion, which is made in





a die composed of two
parts, the cover and the
base. In the cover there
is cut whatever device or ornament the back of the brush is intended to receive. In the base there
are holes of a depth to correspond with the length of the tufts which are exposed after the brush
is finished. The process begins by filling the holes with bristles, which have been cut by a gauge
as much longer than the depth of the holes as it is desired to have them penetrate the back of the
brush. The upper part of the die is then covered with a sufficient quantity of plastic rubber compo-
sition; then it is adjusted to its fellow, and the die is placed in a screw-press and subjected to great
pressure. After hardening, which takes place in a fewminutes, the brush is removed.
In Figs. 584., 585, 586, and 587 is represented Woodbury’s machine for inserting bristles in brush~
backs. The first operation is the filling of the comb A with bristles. The comb is inserted in guide-
ways, and is actuated by an intermittent traverse motion, which, whenever the bristles are all removed
from one of the spaces, moves the comb along the distance of one tooth and one space to bring
another filled space into position. Whenever one comb is emptied another is made to follow it in
BUCKET. 263

'_._
the same guideways, the empty one being taken out at the opposite end of the guideways from that
in which it was inserted. As the comb is actuated in the manner described, each space is brought
successively to correspond with and form a part of a twisted way or channel B, Fig. 584. An ingeni-
ous combination of devices then forces the bristles, as they are wanted, down through this twisted
channel, holding them all the time at the middle, and bringing them at last into a horizontal position
as shown in 584. At the end of the channel the plate which forms the upper wall is bifurcated,
the ends of the bifurcations being turned up as shown. Between these bifurcations reciprocates
vertically a device consisting of a body 0, which tapers off in front to a point D, and is slotted
obliquely and vertically, the oblique portion of the slot terminating at E, and the vertical por-
tion at F. The lower portion of this piece is a hollow cylinder, the end of which, descending, comes
just flush, but does not enter the hole in the brush-back where the bunch of bristles is to be inserted,
one bunch being put in at every descent of this part of the machine, which, from its resemblance to
a hook, we shall call by that name as we proceed. As the hook rises, it forces its point between
the proper quantity of bristles for a bunch, and these, being obliged to move along the inclined por-
tion E of the slot in the hook, arrive at the bottom of the vertical portion F. Here they are acted
upon by the plunger G, Fig. 585, the end of which has two slots crossing each other at right
angles when viewed endwise. One of these slots receives the bunch of bristles as shown in Fig. 585.
The other slot, H, is of a width only to allow the passage of a wire which is destined to bind the
bunch together and secure it in the block. The plunger is caused by ingenious mechanism to de-
scend till it doubles the bristles into a loop in the middle. Other mechanism then unwinds the
binding wire I from a reel, straightens it, and passes the proper length through the slot H. The
wire is then cut. The plunger descends, receiving a rotary motion on its vertical axis, which winds
the wire spirally by forcing it into the thread of a nut contained in the lower end of the hollow
cylinder, fastening it around the doubled end of the bunch of bristles. This spirally wound wire is
destined to be a screw-thread for the bunch of bristles as the latter is screwed into the hole J. The
lower end of the wire acts as a tap cutting a female screw in the block, and the upper end serves
as a pawl to prevent the removal of the bunch by unscrewing. The hunch is thus held with great
strength. The machine inserts bristle, hair, tampico, or other material used for brushes, in wood,
leather, rubber, bone, ivory, and even glass. Its capacity is about 600 brushes of 60 knots each per
day. The \Voodbury Brothers, inventors of the apparatus, have also devised a machine which fills
the combs with bristles; another which, by the rotation of a cylinder having curved knife-blades,
forces the ends of the bunches in the finished brush against a stationary blade, and so trims all to
an even length; and a boring machine which uses a two-spurred bit, and makes the holes for the
bunches with great rapidity. (See Scientific American, xxxriii., 351.)
BUCKET. See Minn APPLIANCES.
BUDDLE. See Coxcnnrnarme MACHINERY.
BUI-IL-WORK, or BOOL-WORK. These terms appear to be corrupted from Boule, the name of
the original inventor, and now refer to any two materials of contrasted colors inlaid with the saw. In
France this kind of inlaid work is called margucterie. It consists in representing flowers, animals,
landscapes, and other objects, in their proper tints, by inlaying. It also includes geometrical pat-
terns composcd of angular pieces laid down in succession, as in ordinary veneering, and is chiefly
used in ornamenting cabinet work. In buhl-work the patterns generally consist of continuous lines,
as in the honeysuckle ornament. Two pieces of veneer of equal size, such as ebony and holly, are
scraped evenly on both sides, and glued together, with a piece of paper between. Another piece of
paper is also glued outside one of the veneers, and on this the pattern is drawn. A small hole is
then grade for the introduction of the saw, a spot being chosen where the puncture will not be
notice .
The saws used in buhl--work are of peculiar construction, and of different sizes. The frames are
of wood or metal; three pieces of wood halved and glued together constitute the three sides of a
rectangle; two pieces are then glued upon each side, each at an angle of 45° across the corners; the
whole when thoroughly dry is then cut round to the desired curve. Screws for giving tension to the
blade are commonly added, but seldom used, as the frame is only sprung together at the moment of
fixing the saw, and by its reaction stitfens the blade. A handle is attached to the saw-frame at the
bottom. In the piercing saw of metal the height from the blade to the frame is usually eight inches,
andl in the ordinary buhl-saw of wood from twelve to twenty inches, to avoid the angles of large
WOI‘i.
The buhl-cutter sits astride a horse or long narrow stool ; the work, held in the left hand, is placed
in a vise at one extremity of the horse, having a flexible jaw under the control of the foot; the saw,
which has been previously inserted into the hole in the veneers, and fixed in its frame, is grasped in
the right hand, with the forefinger extended, to support and guide the frame. “ The several lines of
the work are now followed by short, quick strokes of the saw, the blade of which is always horizon-
tal; but the frame and work are rapidly twisted about at all angles, to place the saw in the direction
of the several lines. Considerable art is required in designing and sawing these ornaments, so that
the saw may continue to ramble uninterruptcdly through the pattern, while the position of the work
is as constantly shifted about in the vise, with that which appears to be a strange and perplexing
restlessness. When the sawing is completed, the several parts are laid flat on a table, and any re-
moved pieces are replaced. The entire work is then pressed down with the hand, the holly is stripped
ed in one layer with a painter’s palette-knife, which splits the paper, and the layer of holly is laid
on the table with the paper downward, or without being inverted. The honeysuckle is now pushed
out of the ebony with the end of the scriher, and any mimne pieces are picked out with the moist.
ened finger; these are all laid aside ; the cavity thus produced in the ebony is now entirely filled up
with the honeysuckle of holly, and a piece of paper smeared with thick glue is then rubbed on the
two to retain them in contact. They are immediately turned over, and the toothings or fine dust of
264 BULLET—MAKING.

the ebony are rubbed in to fill up the interstices; a little thick glue is then applied, and rubbed in,
first with the finger, and then with the pane of the hammer, after which the work is laid aside to
dry.” When dry it is scraped at the bottom, and is then ready to be glued on the box or furniture
to be ornamented, as in ordinary veneeriug; it is afterward scraped and polished. An ebony honey-
suckle may be inserted in a ground of holly in the same manner; and these form the counter or
countm'part buhl, in which the pattern is the same, but the color reversed.
Three thicknesses of wood may be glued together, as rosewood, mahogany, and satinwcod, which
when out through split asunder, and recombined would produce three pieces of buhl-work, the
grounds of which would be of either kind, with the honeysuckle and centre of the two other colors
respectively. These are called “works in three woods,” and constitute the general limit of the thick-
nesses. Buhl-works of brass and wood are also sometimes made by stamping instead of sawing.
BULLET-MAKIN G. See CARTRIDGE-MAKING MACHINERY.
BUOY. A floating beacon serving to indicate a navigable channel, or to mark the position of
sunken rocks, wrecks, sand-banks, or other obstructions to navigation. Buoys are also used as life-
preservers, and it has been proposed to employ them as foundations for breakwaters and piers.
The essential requirements which a well-constructed buoy should fulfill are: 1, that it should be
conspicuous in all states of the weather; 2, that it should be stable; 3, that it should be so made
and moored that the most violent storms may not cause it to break adrift. .
Of the ordinary forms of buoys, those most commonly used are the “nun,” “ can reversed,” “can,”
“ egg-bottom,” “convex bottom,” “ flat bottom,” “hollow bottom,” “spherical,” and “conical.” The
“nun ” buoy, in its original form of two paraboloids joined at their bases, is represented in Fig. 588.
This shape is sometimes modified to that of two cones similarly joined; or one cone is suppressed in
favor of an “ egg-bottom.” In this case the cone which forms the superstructure is made of sheet-
iron and the egg-bottom of malleable or cast-iron. In smooth water this buoy is conspicuous, and it
has the further advantage of simplicity; but in a tideway or under the influence of the wind it
carecns over, rolls and pitches violently, and so becomes an indifferent sea-mark. In order to gain ,_
rigidity, buoys formed of a cone resting on a shallow cylinder have been used ; but these, owing. to
their light draught of water, are not suitable for a seaway, although they have been found advantage-
ous in rivers. Small nun buoys are commonly used to mark the location of a vessel’s anchor when
down. The “ can” buoy is conical, frusto-conical, or conoidal in shape, and floats upon its side
when moored. The buoys said to be the best for strong tideways are the can, cylindrical, and flat-
bottom ; for exposed channels and coasts, the English prefer the “ egg-bottom.”
The English Flat-bottom Buoy is, as are some of the others, water—ballasted ; i. e., it has a cross
diaphragm at a proper distance from the bottom, and the water is allowed to flow in and out of the
lower compartment thus made through 8 holes an inch in diameter placed at equal distance around
its sides. The water cannot be discharged unless the buoy is careened for some time, and it is there-
fore as completely ballasted as if the water had no means of exit. \Vhen these buoys are required
for deep water, where the weight of the mooring chain is sufficient for
ballast, water-ballast is not used, and the holes are plugged with hard
wood. \Vith the increased buoyancy thus obtained, the same line of
flotation as in shoal water is approximately attained.


589.

Stoney’s Keel-Buoy, Fig. 589, is an English invention which has been found of practical value. The
sides are prolonged below the bottom so as to form a circular keel, within which a large body of
water is retained, so that a buoy 6 feet in diameter with a keel of 18 inches contains within the lat-
ter a body of water exceeding a ton in weight. This allows of erecting a superstructure 25 per cent.
higher than other buoys of equal diameter, and affords a very large increase of stability.
Herbert’s Buoy, represented in Fig. 590, has also been found of value. The theory of the action
of this buoy is, that the air confined in the bottom forms an elastic spring upon which the buoy re-
bounds in gentle and easy motions, causing but moderate friction to the mooring chain, little or no
pull upon the sinker, and a corresponding relief from agitation or friction to the globe and stafi above.
BUOY. 265
7' A —'

Bells and whistles are often arranged in connection with buoys, so that the navigator is warned
of the position of the latter during thick and foggy weather, when their discernment from a ves-
sel is impossible even at moderate distances. Fig. 591 represents the bell-buoy which marks the
Rund‘lestcnc off the point of Land’s End, England. 'It is a water-ballast buoy, a being the outer
592.





















k ‘1/ // /}"/,////1/ /
.////
water-tight compartment, 6 the inner water-tight compartment; and at d are India-rubber springs.
The oscillations of the buoy cause the clapper to strike against and so sound the bell.
Oom'tonay’s Whistling Buoy, Fig. 592, is an exceedingly ingenious device, the efficiency of which
has been well demonstrated. Its operation depends upon the fact that the agitation of water due to
the existence of waves extends downward beneath the surface only to a distance equal to that meas-
ured between the trough and crest of the undulations. In other words, the agitation of the surface
due to a wave 10 feet high would practically extend only to 10 feet
below the level. It follows that if a long, hollow cylinder A is im- 594‘
mersed to a depth exceeding in measurement the height of the waves,
the water entering will not rise and fall with the varying level of the
waves as they pass, but will remain at a uniform height, which will be
that of the middle line between the highest and low-est point of waves,
or at average sea-level, B, Fig. 592. Let the cylinder be attached to
the lower portion of a float O, which rests on the surface, and hence
rises and falls with each undulation. We have therefore a moving
cylinder inclosing a motionless column of water, or, in other terms, a
moving cylinder and a fixed piston by means of which air may be com-
pressed in proportion to the power of the waves. It will be observed
that from the diaphragm D extend upward two tubes E. These are
open at the top, and are provided with valves so arranged that while
air may pass down them, it cannot be forced back. The middle tube
F has no such valve, but terminates above in a whistle. Suppose that
the apparatus is carried from the position represented, in which the
diaphragm .D is just above average level, to the summit of a wave.
Then the space between the constant level B and the diaphragm will
be largely augmented, and air will be drawn in through the tubes E.
As the buoy descends this space will be diminished, and the water-
piston will compress the air and drive it out forcibly through the only
outlet, which is the tube F. The air thus sounds the whistle. It is
obvious that any modification of the water-surface will produce a simi-
lar effect. With waves 8 feet high, running at the rate of 8 per minute,
that number of sounds in the same interval will be caused. With waves
20 feet high running at 4 per minute, 4 sounds would be produced. The force of the whistle blast,
however, is always the same, as this depends only on the weight of the buoy and the length of the
tube. Several of these buoys have been located near harbors cf'the United States, one of consider-
able power being in operation near Sandy Hook, New York.



266 BUOY.

The Pumping Buo,y.—+-Anothei' utilization of wave-power through the medium of a buoy is shown
in the pumping buoy represented in Fig. 593, taken from drawings exhibited in the Paris Exposition
of 1878. The buoy A carries a double-acting pump D at the end of the vertical stem 0. It is
anchored to the bottom by means of a cable, which is shortened as the tide falls, elongates when the
tide rises, and maintains the float B always in the same position with relation to the line of average
level X Y. The aspiration-tube of the pump plunges into the water, and the emission-tube E (of
rubber) is led to a reservoir from which a head of water sulflcient to drive a water-wheel is obtained.
The movement of the pump-piston is caused by the elevation and lowering of the float B, according
as the wave rises or falls. The buoy A always draws on the cable. It rises at high tide, when the
water from the reservoir is admitted by valves controlled by clockwork above the piston F, and falls
at low tide, when the water is admitted below the piston.
Buoy Foundationa—Mr. Thomas Morris, of London, has suggested the anchoring of buoys in water
beyond the depth of the deepest wave, and using them as foundations upon which to rear structures
supported by uprights which shall expose but small sectional area to the action of the waves. Fig.
594 shows two of these buoys as applied to support a pier or jetty, where the upright posts, horizon-
tal bearers, platform, and parapet, being well connected and braced, would, it is claimed, give firm-
ness and the requisite rigidity. A similar arrangement has been proposed as a support for break-
waters (which see).
Buoy [Moor/ings are usually single chains measuring in length three times the depth of the water,
and mushroom anchors or screw-piles, which last are easily driven into the sand.
Buoy Altamira—Buoys are usually painted some distinctly visible color, or are checkered or striped
so as to be easily recognized. The object of this is to enable the navigator to determine whether
the buoy is to be avoided or approached, and to know on which side of it to conduct his vessel in
entering a channel. Spar-buoys, consisting simply of spars of proper length, painted some particular
color, are employed to mark channels in rivers and less exposed situations. Each maritime nation
has its own system of marking and placing buoys, for the details of which the reader is referred to
the “Sailor’s Pocket-Book,” Captain Bedford, R. N., Portsmouth, 1877. See also “European
Lighthouse Systems,” Major Elliot, U. S. A., New York, 187 5; and for the use of buoys on vessels,
the respective works on “Seamanship” of Captain Luce, U. S. N ., and Captains N arcs and Alston, R. N.
Buoys lighted. by Compressed Gas—During the past few years numerous applications of com-
pressed gas lighting and electric lighting have been made to maritime apparatus, such as buoys and
beacons. When the former is employed, the gas prepared at the works must first be carried to the
place where it is to be used. This is done by means of receivers provided with pressure-gauges, and
in which the gas is compressed to 1,450 lbs. to the sq. in. In order to make the manoeuvring easier,
reservoirs having a capacity of but ’70 or 100'cub. ft. are generally used. If the gas is destined for
a work situated out at sea, the reservoirs are stowed away upon a boat. When there are quite a
number of buoys, etc., to be supplied, it is preferable to select a special boat for the service. The
reservoirs are then installed permanently, and connected by piping with a distributor that permits the
superintendent of the service, at the mo-
ment of filling the reservoir of the buoy
or floating light, to take gas from the
accumulator, which is under the proper
~ '—' "'“p' a" pressure.
‘ In the buoy the shell serves as a float
and as a reservoir for the compressed
gas. This shell is of welded iron plate
and without rivets save in spherical
buoys. In this way perfect tightness is
obtained.
The plates, which are first stamped to
the desired form, are connected with each
other by means of small temporary rivets
spaced 20 or 24 in. apart. The parts thus
put together are placed over a fire, and the
welding is begun. The welding is done
iron to iron without the interposition of
any foreign material. In this way per-
fectly tight buoys can be made; it merely
suffices to form a half-inch aperture for
the escape of the gases produced under
the influence of the heat.
Conical buoys, a specimen of which is
represented in Fig. 594 A, are to be pre-
ferred when the depth of the water per-
mits of their use. The tail, which termi-
nates in a very heavy counterpoise, has
the same effect as the keel of the ship, and secures stability. On another hand, as the part that
emerges is conical, it oifers but little purchase to waves and the wind. The oscillations when the
sea is rough are consequently much reduced, and the visibility of the light remains more constant.
All buoys of large dimensions are of this type. The largest conical buoys that have so far been
constructed have a capacity of 595 cub. ft., a draught of 23 ft., and a height of flame of 22 ft. above
the water-line. -
Cylindrical buoys have also a tail, but the part that emerges is cylindrical instead of conical. They








_-.________-_..n.w...___, .


BUTTON-MAKING MACHINERY. 267

possess the same qualities as the preceding, but to a less degree. They have the advantage of being
more easily constructed, and, consequently, of costing less. Double-case buoys, held either by a bal-
ance or by a collar fixed above the counterpoise, may be anchored in shallow water without danger of
sometimes touching bottom. Spherical or re-entrant bottom buoys (Fig. 594 B) can be grounded
without inconvenience. The Suez Company has adopted them for the beaconing of its canal. They
can be placed high and dry upon the banks or upon the sand-bars that they are designed to give
warning against.
The buoy lanterns have glasses of 8-in. or 12-in. focus. The buoys may be characterized by the
color of the flame or by making the latter flash. This is effected by means of an apparatus that acts
automatically through the pressure of the gas upon its exit from the regulator. Finally, there is
nothing to prevent the buoy from being made sonorous as well as luminous.
Floating Lights—Here, reservoirs arranged in the hold of a pontoon furnish the gas necessary to
supply the burner. These floating lights can thus be established without a crew. They possess the
two following advantages over those lighted with oil : 1, They give a greater intensity of light; and 2,
being much lighter apparatus than the oil ones, they can be kept at their normal height during stormy
weather and thus have a constant range. Moreover, in most cases a floating light can be advan-
tageously replaced with two large buoys.
Electric buoys are still in an experimental stage, and in this country the only attempt at their em~
ployment has been in marking Gedney’s Channel, New York harbor entrance. There are six of them,
three red on one side of the channel and three white on the other side. The electric-light generator
is at Sandy Hook, and the current is sent out by two main cables, which are at their outer ends di-
vided into three smaller cables, one for each buoy. Thus far the system has worked admirably both
in winter and in summer, but as at present employed the expense is far greater than that of any other
system.
BUTTON—MAKING MACHINERY. Buttons may be divided into two general classes—those with
shanks, or loops of metal, for the purpose of attaching them to garments, and those without shanks;
and each class is manufactured from a great variety of materials, and by a variety of methods. ()f
buttons with shanks, the greater number are composed of metal, although glass and mother-of-pearl
are also employed. Metal buttons are formed in two ways, the blanks or bases of the buttons
being either cast in a mould or stamped out of a sheet of metal; the former method is generally
employed for making white metal buttons, and the latter for plated and gilt buttons. To cast
buttons, a great number of impressions of the pattern of the button are taken in sand, and in the
centre of each impression is inserted a shank, the ends of which project a little above the surface of
the sand, and fused metal is poured over the mould. When cool, the buttons are taken from the
moulds, and, after being cleansed from sand by brushing, are placed in lathes; the edges are turned,
the face and back smoothed, and the projecting part of the shank also turned. The buttons are
then polished by rubbing the faces upon a board spread with rottenstone of different degrees of
fineness, and afterward by being held against a revolving board covered with leather, upon which is
spread a very fine powder of the same material; finally, they are arranged on a sieve or grating of
wire, and immersed in a boiling solution of granulated tin and cream of tartar, by which means their
surfaces become covered with a thin layer or wash of the metal, which improves their whiteness
without injuring their polish. The blanks of plated buttons are cut by a fly-press out of copperplate,
coated on one side with silver. They are then annealed in a furnace, and afterward stamped by the
descent of a weight, as in a pile-driving machine, the die being fixed in the lower surface of the
weight. The soldering of the shank is performed on each button separately, by the flame of a lamp
and a blowpipe. The edges of plain buttons are next filed smooth in a lathe, and the buttons are
afterward boiled in a solution of cream of tartar and silver; they are then placed in a lathe, and the
backs brushed, and afterward burnished with blood-stone. The metal used for gilt buttons is an
alloy of copper and zinc. This metal is rolled out into sheets, and the blanks stamped out, which
are then planished, if intended for plain buttons; but if for figured buttons, the impression is now
given. The shanks are next attached, which is effected as follows: Each blank is furnished with a
pair of small spring tweezers, which hold the shank down upon it in the proper place, and a small
quantity of solder and resin is applied to each. They are then exposed upon an iron plate to a heat.
sufficient to melt the solder, by which the shank becomes fixed to the button; and while still warm
they are plunged into nitric acid, to remove the oxide formed on the surface by the heat employed
in soldering the shanks. They are. then placed in a lathe, the edges rounded, and the surfaces rough-
burnished, which renders them ready for gliding. Five grains of gold are fixed by act of parliament,
in England, as the least quantity to be employed in gilding a gross of buttons of one inch in diameter.
An amalgam is formed of gold and mercury, and the buttons are placed in an earthen vessel along
with the amalgam, together with as much aquafortis as will moisten the whole, and the mixture is
stirred with a brush until the buttons are completely whitened. To dissipate the quicksilver, the but-
tons are shaken in an iron pan, placed over a fire until the quicksilver begins to melt, when they are
thrown into a felt cap, and stirred with a brush, to spread the amalgam equally over their surfaces ;
after which they are returned “to the pan, and the mercury volatilized completely by the increased
heat, leaving the gold evenly spread in a thin film over the surface of the buttons; they are then
burnished in a lathe, which completes the operation. The better sort of buttons undergo the gilding
process twice or thrice, and are distinguished accordingly as “ double ” or “treble gilt.” Glass hut-
tons are formed of glass compressed, while in the fluid state, in moulds, in which the shank is in-
serted; and when the glass becomes cold, the shank is firmly retained in its place. In mother-of-
pearl buttons the method of inserting the shank is extremely ingenious: a hole is drilled at the
back, and undercut—that is, larger at the bottom than at top; and the shank being driven in by a
steady stroke, its extremity expands; on striking against the bottom of the hole, it becomes firmly
riveted into the button, forming a kind of dovetail joint.
268 BUTTON —M AKIN G MACHINERY.

Button shanks are made by hand from brass or iron wire, bent and cut in the following manner ,
The wire is lapped spirally round a piece of steel bar. The steel is turned round by screwing it into
the end of the spindle of a lathe, and the wire by this means lapped close round it till it is covered.
The coil of wire thus formed is slipped ofi, and a wire fork~ or staple with parallel legs put into it.
It is now laid upon an anvil, and by a punch the coil of wire is struck down between the two prongs
of the fork, so as to form a figure 8, a little open in the middle. The punch has an edge which marks
the middle of the 8, and the coil is cut open by a pair of shears along this mark, dividing each
turn of the coil into two perfect button shanks or eyes.
Buttons without shanks are of two kinds. The first are simply disks of horn, bone, wood, or other
material, with four holes drilled through the face, for the purpose of sewing them to the garment.
Horn buttons of this description are made from cow-hoofs by pressing them into heated moulds. The
hoofs, having been boiled in water until they are soft, are first cut into plates of requisite thickness,
and then into squares of the size of the diameter of the button, and afterward reduced to an octag~
onal form by cutting off the corners. They are then dyed black by immersing them in a caldron of
logwood and copperas mixed. A quantity of moulds somewhat resembling bullet-moulds, and each
furnished with a number of steel dies, are then heated a little above the point of boiling water, and _
one of the octagonal - ‘
pieces of horn is placed
between each pair of
dies, and the mould
being shut is com~
pressed in a small
screw-press, and in a
few minutes the horn,
becoming softened by
the heat, receives the
impression of the die ;
then the edges are
clipped off by shears,
and rounded in a lathe. ‘
The holes in buttons of this description are drilled by means of a lathe represented in Fig. 596.
Four spindles, of which two only, aa, can be seen, supported in bearings at b, and by the cen-
tre points cc, are made to revolve with great velocity by means of two bands 01 cl passing over pul-
leys ee fixed upon each of the spindles, each band driving two spindles, and receiving motion from
a wheel worked by a treadle. At the end of each of the spindles a a is a hook uniting them to four
other spindles ff by similar
hooks at one end, the other end
of the spindles passing through
four small holes in the plate g,
and the projecting points be-
ing formed into small drills.
The button is placed in a con-
cave rest it, and pushed for-
ward against the drills by a
piece of wood. The standard
9 can be exchanged for another
with holes more or less apart,
and'the rest It can be set at
any height to suit different-
sized buttons. As the spindle-
holes in the plate 9 are nearer
together than the holes in the
standard 6, the spindles ff converge; the hooks in the spindles are therefore necessary to form a
universal joint.
The second description of buttons without shanks consists of thin disks of wood or bone, called
moulds, covered with silk, cloth, or other similar material. The bone for the moulds is prepared
from refuse chips sawed into thin flakes, and brought into a circular form by two operations, illus_
trated by Fig. 597. On one end of the spindle a, which revolves in bearings at'b b, is screwed a
tool c, and on the other are two collars d d, between which a forked lever e embraces the shaft,
the fulcrum of which is at f. The spindle a is put in rapid motion by a band 9 passing over
the pulley h, and over a band-wheel worked by a treadle; and the workman, holding the mate-
rial i for the mould in his right hand, against a piece of wood is firmly held down in the iron
standard Z by two screws, by means of the lever held in his left hand, advances the tool c
against the material 71 of the mould; the central pin of the tool drills a hole through the centre of
the intended mould, while the other two points describe a deep circle cutting half through the
thickness of the material, and the flat surface is cut smooth by the intermediate parts of the tool.
The tool is then drawn back a little by the lever e, and the material shifted to bring a fresh portion
of the surface opposite the tool ; and when as many moulds as the plate of the material will afford
are thus half out through, the other side is presented to the tool, and, the central point of it being
inserted in the hole made in the first part of the operation, the other two teeth out another deep
circle exactly opposite the former one through the remaining substance of the material, and the mould
is left sticking on the tool. By drawing back the lever e the tool recedes, and the mould, meeting a
fixed iron plate, is pushed off the tool, and falls into a small box m. .


























CA AM. 269


Covered buttons having come into very general use, various improvements have been introduced
in the manufacture of them, and patents for this purpose have been granted to various parties. The
following is Mr. Sanders’s method of making covered buttons: A piece of the material With which the
' mould is to be covered is cut of a. circular shape, somewhat
larger than the intended button; upon this is placed a disk of
card of the exact size of the button, and next a disk of paper
coated with an adhesive composition, which will become soft
and sticky by heat; and upon these is laid a button-mould e,
having four holes, through which threads or strings have been
passed to form the flexible shank. These circular disks, being
put together, are then laid over a cylindrical hole in a metal
block a a, Fig. 598; this hole being exactly the size of the in-
tended button, and the covering of the button being larger than
the hole, when the disks are pushed down into the hole, the ma
terial of the covering will wrinkle up on the edges round the
other disks. The tube 6 b is then introduced into the cylindri-
cal hole, and its lower edge, being beveled inward, will, as it is pressed down. gather the plaits of
the cloth on the edge of the button; toward the centre is a metal ring or collar, 0, having teeth
round its edge, somewhat like a crown-saw, which is now passed down the tube 6, and driven with
considerable force by the punch cl; and the block a a having been previously heated, the adhesive mat-
ter will be softened, and cause the several disks to stick together, which, when taken out and become
cold, will be very firm and retain its shape.
The following is the common process of making covered buttons: Thin sheets of metal, known as
“tagger’s iron” (thickness No. 36 to No. 38, and quality according to the more or less fine grade
~ of button to be made), are carried by hand rapidly
under a descending punch. This punch is double,
the-outer portion cutting out a circular blank of the
proper size, while an inner punch descends and forces
the blank into a die, so that its periphery is turned
upward, or so that the entire blank is rendered hemi-
spherical in shape. These two forms of shells are
shown in Fig. 599. One machine, driven by steam-
power, will easily form 50 gross of shells per hour.
The shells are next annealed in an ordinary fur-
nace, and then are conveyed to a horizontal revolv-
ing barrel, where they are tumbled with sawdust
until they are thoroughly cleaned from all dust and
grease. The other part of the skeleton of the button
is known as the collet. Inasmuch as the under side
of this is exposed, one face of the iron plate is ja-
; I _ _ panned. The piece, by a somewhat similar arrange-
- ment of punches to that already described, is first
if % cut out in the form of a circle, and then its inner
\.
i» ' m part is punched out, leaving it in annular shape.
6mg: M ' There are still three more portions, namely: the cloth
ill-i " 1”
"ill! '
598.


cover; the canvas tuft-piece, which rests above the
collet, and a portion of which protrudes through the
central opening in the latter, to furnish a tuft by
which the button is sewed on the garment; and the
inner filling. The last is made of specially prepared pasteboard, and in common with the other
portions mentioned is simply punched into shape.
The grouping together of these various parts is effected in two operations. By the first, the collet
and tuft-piece are fastened. The tuft-piece is laid in the collet under a press, which, descending,
forces the fabric, as already stated, through the aperture in the metal, producing the nipple of cloth
in the rear. - The paper filling is then inserted, and the button is then ready for the final assembling.
The machine for this purpose is represented in Fig. 599. A is a fixed mandrel. Bis a sleeve there-
on, supported by a spring, 0. On the upper mandrel, D, is another sleeve, E, which is sustained by
the catch F. The lower face of the mandrel D is hollowed, and a projecting annular portion of
the upper sleeve enters a corresponding portion of the lower one, B. In using the machine, a shell
is placed over the lower mandrel, and above it is laid the covering fabric. The operator then causes
the upper mandrel to descend. The cloth is thus pressed downaround the shell, and on the return
upward movement both cloth and shell are carried up inside the sleeve E. The operator now inserts
the annular piece G, in which there is a suitable cavity to receive the combined collet, tuft-piece, and
filler, the last being uppermost. The upper mandrel is again brought down, and the shell is thus
forced upon the collet, filler, etc., the cloth cover being at the same time turned under. Reference to
the section of the finished button will make this clear. ‘Nothing further remains but to attach the
buttons by dozens to cards, or make them up for the market in any desired attractive way.


CAAM. The weaver’s reed. Setting the reed by arranging the warp-threads is termed “ caaming.”
OAISSON. See FOUNDATIONS.
OALGINATION. The chemical process of subjecting metallic bodies to heat with access of air,
whereby they are converted into a pulvcrulent matter, somewhat like lime in appearance. The term
calcined is, however, now applied to any substance which has been exposed to a roasting heat.
270 CALCULATING M A CHIN ES.

CALCULATING MACHINES. Machines of this kind are designed to produce arithmetical and
other tables which shall be rigorously correct. In navigation and the higher branches of astronomy
the use of tables is very great, and, being constructed by human heads and hands, they all con-
tain errors of greater or less magnitude. The principle upon which these machines are constructed
may be described as follows : In the manner in which quantities are combined in the common system
of numeration, the value of each figure is ten times greater than it would be if it occupied a position
one place to the right. Thus, in the number 1879, although 9 is greater than 7, yet the 7 in this
position represents a larger sum than the 9, because it occupies a place to the left of the 9. The
quantities really expressed by the figures 1879 are 1,000, 800, 70, 9; but in practice we omit the
ciphers, and place the significant figures side by side, preserving their proper position from the right
hand. If a wheel be constructed on whose axis is a pinion with leaves or teeth, if these teeth work
into another set of teeth or cogs on the periphery of another wheel, and if the teeth on the latter
wheel are just ten times as numerous as those on the pinion, this system being made to revolve, the
pinioned wheel will revolve just ten times as fast as the other. This produces a kind of analogy
between the decimal notation and the working of the wheels ; for it takes 10 units to make up one
figure or unit in the second place in common numeration, and it requires 10 revolutions of the
pinioned wheel to impart one revolution to the larger wheel. This is the fundamental principle in cal-
culating machines. In such machines there are a number of dial-faces, each marked with figures from
1 to 10; these dial-faces are fixed upon wheels, the teeth of which work into the pinions of other
wheels, on which are similarly divided faces or disks, so that, while one face indicates units, another
indicates tens, a third hundreds, and so on. These wheels and dial-faces may be difierently arranged
in different machines, but the principle is the same in all. ’
A calculating machine, called the difierence engine, was constructed by Mr. Babbage for the Eng-
lish government at an expense of £20,000, to be used in preparing logarithmical and trigonometrical
tables. A valuable feature introduced into this machine is the power of printing the tables as fast
as it calculates them. Another machine, called the analytical engine, was invented by the same
gentleman, of greater power than the first. This contains a hundred variables, or numbers suscep-
tible of changing, and each of these numbers may consist of twenty~five figures. The distinctive
characteristic of this machine is the introduction into it of the principle which Jacquard devised for
regulating, by means of punched cards, the complicated patterns of brocaded stuff.
The machine in the Dudley Observatory, Albany, was invented by G. and E. Seheutz, of Stockholm,
Sweden, who sought to attain the same ends that Mr. Babbage had attained, but with simpler means.
Their engine proceeds by the method of difierences, calculating to the 15th place of decimals, and
stamping the eight left-hand
places in lead, so as to make a 600-
stereotvpe mould, from which __ _ j, ,,=.. ‘
$55!; - v E! 5 Q




plates can be taken by either


* 1 t t E ‘ £73;
a stereotype or e co ro ype [Efflflgygygflg‘
process, ready for the print- gflgfigflg
ing-press. It can express num- 3%Q\j\gg\g\g
bers either decimally or sexa- iza gesimally, and prints by the 9 (
side of the table the corre-
sponding series of numbers
or arguments for which the
table is calculated.
Fig. 600 represents a sim-
ple form of calculating ma-
chine devised by Mr. George
B. Grant. There is an upper
cylinder, which is turned by
the crank, and which itself
drives a smaller shaft under-
neath. A slide, that can be set in eight different positions on the cylinder, carries eight figured rmgs
that can be set to represent eight or any smaller number of decimal places. Each turn of the crank
adds the number set up on the rings to the number represented on the ten recording wheels carried
by the lower shaft. The multiplication process will best be understood by an example. To multiply
347 by 492, the three upper rings are set at 3, 4, and 7, respectively. The cylinder is then turned
twice to multiply by the units figure of the multiplier. If new the slide is carried along one notch,
where each ring will act on the next higher recording wheel, and turned 9 times, 347 will be multi-
plied by 90, and the product at the same time will be added to the product already scored. Another
shift of the slide and four turns will complete the operation, and show the result, 170724 2 (347 x
2) + (347 x 90) + (347 x 400), upon the recording wheels. A half-turn of the crank backward erases
this result, bringing all the wheels to 0, ready for the next operation.
Division is the reverse of multiplication. The dividend is set up on the wheels, the divisor on the
rings, and the quotient records itself on the upper recording wheels. The machine of the size illus-
trated will use numbers of eight or less figures, and show the result in full, if not over ten figures,
and its upper figures if more than ten places are necessary.
Snelgrove’s Oountcr.—Fig. 600A has several interesting features in its design. The spindle may
revolve in any direction, or move with a to-and-fro motion, so that it can be connected with a cross-
head. In its motion it turns a cam 0 working in a stirrup I) placed immediately inside the ends
of the counter. This stirrup is pivoted on the front rod shown in the perspective view, and in
its up-and-down motion rocks the framework, to which the pawls E are attached with springs to force








CALCULATING MACHINES. 271

them into the notches on the ratchet-wheels. To each dial there is a ratchetwheel A with 10 teeth,
and a wheel B with a single notch. The unitdial is worked by its ratchet separately, while all the
other ratchets ride idly, until the notch in the wheel B is reached, when the ratchet drops into the
600A.






notch, and being sufficiently wide to cover also the ratchet-wheel on the ten-dial, it turns it one revo-
lution, and similarly with the hundred and thousand dials. The interesting part- of the mechanism is
in the method of carrying on to the next wheel when the hundred or the thousand is about to be
registered. The pawl for the hundred-wheel is provided with an arm which bears against the back
of the ten-pawl, and similar arrangement for the thousand, as shown. Even although the hundred-
pawl is opposite its notch, it is kept from engaging by this arm until the ten-pawl has dropped into
its notch. \Ve have already stated that the axis of the counter may be turned with a to-and-fro
motion. Tne ratchets are prevented from going backward by pawls F, placed under the dials and
held to the wheel by a spring. The counter is fitted with the usual covering.
Troncet’s Aflthmograpli.—Fig. 600 B is in the shape of a pocket-book, with the mechanism on the
right and a black-coated sheet upon the left side. The latter serves as a cover to a multiplication-
table from 1 to 999. A small slate-pencil hav-
ing a metallic point accompanies the apparatus
The instructions show that it is possible to per-
form the four elementary operations of addition,
subtraction, multiplication, and division. A fixed
plate of metal is provided with a series of slots,
7 in number, curved at the top. At the side of
each of these slots is inscribed the series of num-
bers from 0 to 9. Under this fixed part there
is a movable one (see right of figure), which
consists of strips of metal carrying two times
in inverse order the series of the first ten num-
bers. They are provided with ' teeth on each
side, those corresponding to the upper series be-
ing painted black, and the others white. It is
these teeth that alone appear under the slots of
the fixed part. As for the figures, they are not
visible until they pass before a little round win-'
dow over each movable strip. In the normal
state, as may be seen from the engraving, it is
the 9 that appears at the top window and the O
at the bottom one. It is the latter that is designed for addition. In the state of rest we have 0
everywhere. If we introduce the point that tips our slate-pencil into the extreme right column, for
example, opposite the figure 1 inscribed against the slot, and make it slide toward the bottom until it
abuts against the fixed part, it will carry along the movable part so as to bring the corresponding
figure 1 opposite the window, at the place where the 0 was ; but the result of this operation will have
been to displace, by one teeth, the entire movable part of this column, and the figures inscribed upon
the fixed part not having moved, those that are opposite upon the movable part consequently become
higher by one unit. _
They would have been so by 2, 3, 4, or more units if, instead of lowering the cipher 1, we had
lowered ciphers 2, 3, 4, etc. It will be understood that if we operate in the same way for afterward
adding another unit, for example, when we place our point opposite the 1 of the fixed part, it is really
opposite I + the unit previously added that it will be placed. Let us continue thus up to 9, and we
shall see at this moment that, if we wish to continue, the teeth between which our points fall are
black, instead of being white. In this case it is necessary to move the point upward and to proceed
to the end of the slot—-that is to say, through the curved portion. It will be seen, in fact, that the
object of this is to act with the point upon the preceding column and to do the carrying forward, and
at the same time to bring back the column of units to O. The operation for one column evidently
applies to all the others, and the apparatus permits of adding up to ten million.
600 B.






272 CALCULATING MACHINES.

Felt’s Compiograph.—In this device (Fig. 600 0) there is a set of keys like those of a typewriter,
having figured knobs. The touching of any one of these knobs adds the corresponding number to
the total shown by the indicating wheels. A is a perspective view of the machine shown by the key-
board. Each knob, it will be seen, is lettered with two letters, one set being used in subtracting and
the other in adding. B shows a. section through one row of keys, of which it should be observed
there are only nine, the cipher being omitted. These keys depress to a. greater or less extent a long
lever a which is L-shaped in section, and is pivoted on a shaft running across the machine from side
to side at the back, a spring I) returning it to position when
the pressure is taken off the keys. At the end-of this lever _ 600 0'
is a segmental rack gearing into a small pinion, which rotates '
on a second horizontal shaft, and turns it to a greater or less
extent. This pinion has attached to it a disk shown in H
and I, and also at E. This disk carries a pawl c (H), which
engages with the teeth of a 10-toothed ratchet-wheel E 1 (B),
and moves it round a distance corresponding to the key
struck. The ratchet-wheel is firmly fastened to the regis-
tering-wheel, which, as shown at 'A, carries the different





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digits on its periphery, and indicates the result of any operation as an ordinary counter. Exceptional
care has been taken to insure the accuracy of the registration; the devices for this purpose we will
now describe. _ Any backward motion of the registering-wheel is prevented by a pawl d (0 and D).
But the wheel is, moreover, when at rest, locked as regards forward motion, and is only free to rotate
when the lever corresponding to it is depressed, or if a unit is to be carried over from the wheel
behind it. This locking is accomplished by a pawl e (C and D), which when at rest engages with the
teeth of the number-wheel. It carries, however, a pin which when the machine is at rest lies in the
notch cut in the rim of the disk already mentioned, and shown at H and I. When a key is depressed
this disk is rotated, and the pin attached to the pawl slides up the inclined part of the notch, and so
frees the number-wheel, which can then be rotated by the pawl c, as already described. It will be
CALENDER. 27 3

seen that there is a good deal of lost motion before this paw] engages with the teeth; this is done so
as to allow time for the stop-motion pawl a to get clear. Hence, in depressing a key, the disk is put
in rotation by the pinion E'. As'it rotates it first frees the number-wheel from the pawl which locks
it, and then moves it forward a certain distance by the pawl c. To insure that the wheel shall not be
rotated too much on depressing a key, a second mechanism is used. It will be observed that the
stalks of the keys are prolonged through the main lever a, and that below this lever is a second one
f, also pivoted at the back of the machine. The lengths of the key-spindles are arranged so that
they each give this lever f, when they strike, about the same amount of motion, thus depressing its
forward end. At this point the lever is connected by a link shown at J, with a detent, which, as
shown at C, rests normally clear of the pins on the number-wheel ; but as the lever f is carried down
by the, continued motion of the key it pulls down this detent between these pins, thus preventing any
further motion. When this is done, the wheel has then been turned through an angle corresponding
to the' number on the key struck.
We stated that the number of wheels were also unlocked for forward motion when a unit was
about to be carried forward from the wheel behind. This carrying mechanism is very ingenious. On
each number-wheel there is a cam g, as shown at Al. The carrying lever it has an arm which engages
with this cam. Suppose the wheel at zero to be moved forward step by step. The arm engaging
with the cam is then at the bottom of its path, being pressed against the cam by a spring, as shown
at F. As the wheel rotates, the cam being circular up to a point corresponding to the figure 4, no
motion of the lever takes place till this point is reached ; it then begins to move outward, till finally
it has reached its limit of motion at 9, and then, on the next unit being added, flies back down to the
bottom of the cam, as at G, and advances the next wheel a unit by a pawl m”, as shown at A. If the
machine is worked very rapidly, the spring operating this lever may not be able to keep the arm up
the cam at the carrying point, and so, to insure the carrying under these conditions, a second exterior
cam is added, as shown at M
It will be seen that this carrying arm has a pin 71 fixed to one side of it. This pin passes through an
oval hole in the stop-motion pawl e belonging to the wheel in front; and as the arm moves back under
the action of the cam, this pin engages with e and n, so that when the following wheel indicates 7
this pawl is quite free from the pins on the forward wheel, which is then free to move. As the
carrying arm flies back, however, this pawl would naturally tend to follow it, and might engage with
its wheel again before the carrying pawl had got in its work. To prevent this, a bell-crank lever is
pivoted on it, as shown at O. As‘the pawl is moved back this lever is bent back, so that the catch
shown on its end engages, as shown at L, with a bar running from side to side along the front of the
machine. The stop-motion pawl is then held back by this catch until the carrying bar has moved far
enough forward from the pin 71 to strike the other end of this bell-crank lever and free it, when the
pawl moves forward again into its locking position.
To set the machine to zero, the whole of the stop-motion pawls are lifted clear from their wheels
by depressing the knob shown to the left of the machine. By turning the knob on the right the
whole of the wheels can then be rotated in the forward direction. This knob turns the spindle on
which the wheels .ride, and in front of each wheel it has a pin projecting from it, as shown at M.
This pin, on turning the knob in the proper direction, comes in contact with the steep side of a sort of
' ratchet-tooth fixed to the wheel, as shown at I, and carries the wheel round with it. In the ordinary work-
ing of the machine this tooth does not interfere with the motion of the wheels, since it is then its
sloping side which comes in contact with the projecting pin, which depresses it against a spring, and
so allows the wheel to move forward. As all these teeth are in similar positions on their respective
wheels, the zeros are all in line when the projecting pins have engaged with every tooth. It will be
observed that a typewriting arrangement is shown attached to the machine at A. This prints auto-
matically the data and answer of any sum, and saves the time lost in copying down rows of figures.
The Adder—Fig. 600 D is a very simple device for adding mechanically any number of columns of
figures at a time. It consists of two disks, a larger and a smaller one, rotary in their casings. Around
the larger disk are a number of apertures correspond-
ing to numbers on a scale-marker inscribed on the 6001)-
edge of. its retaining case. In the case and between -
the two disks is a slot through which the indications
afiorded by numbers inscribed near the peripheries of
the disks may be seen. The method of use is simple.
Starting with the adder at zero, as it now stands, the
operating point is placed successively in the aperture
of the large disk standing by each number to be add-
ed, and to turn the disk as the arrow indicates until,
arrested by the stop on the right, the sum is seen in
the slot on the left. Thus, 48, 25, 99, 65, turning
the larger disk for each of these numbers, and 237
shows as the sum—the hundreds carrying themselves
automatically. If there be three columns only, and
the sum a small one, the third may be added in a
similar manner, either separately or simultaneously, on the smaller disk. In this way ledger accounts
may be added two columns at once, and instantaneous results had in tallying.
CALENDER. A machine to give a smooth, hard surface to paper, or to cotton and linen fabrics.
Calendering is the finishing process by which the goods are passed between cylinders or rollers, and
made of a level uniform surface. The machine consists of a number of rollers contained in a massive
framework; the rollers are connected with a long lever loaded with weights at the further extremity,
by which or by means of screws almost any amount of force may be applied, and the surface texture


18
2'74 _ CALENDER.

of the cloth varied at pleasure. With considerable pressure between smooth rollers, a soft, silky
lustre is given by equal flattening of the threads. By passing two folds at the same time between
the rollers, the threads of one make an impression on the other, and give a wiry appearance, with
hollows between the threads. The rollers are made of cast-iron, wood, paper, or calico, according to
the uses for which they are designed. The iron rollers are sometimes made hollow, for the purpose
of admitting either a hot roller of iron or steam when hot calendering is required. ,The other cylin-
ders were formerly made of wood, but it was liable to many defects. The advantage of the paper
roller consists in its being devoid of any tendency to split, crack, or warp, especially when exposed
to a considerable heat from the contact and pressure of the hot iron rollers. The paper takes a fine
polish, and, being of an elastic nature, presses into every pore of the cloth, and smooths its surface
more efieetually than any wooden cylinder, however truly turned, could possibly do. ‘
In a five-rollered machine, the cloth coming from behind, above the uppermost or lst cylinder,
passes between the lst and 2d; proceeding behind the 2d, it again comes to the front between the 2d
and 3d ; between the 3d and 4th it is once more carried behind, and lastly brought in front between
the 4th and 5th, where it is received and smOothly folded. At this time the cloth should be folded
loosely, so that no mark may appear until it is finally folded in the precise length and form into
which the piece is to be made up, which varies with the different kinds of goods, or the particular
market for which the goods are designed. When the pieces have received the proper fold, they are
pressed in a hydraulic press previous to being packed.
From the great weight of calendering machines, it is necessary that they should be fixed on the
basement floor. After the cloth has received its final gloss from these machines, it is taken to the
cloth-room to be measured preparatory to being folded and packed for sale or transportation.










I. 601. 602.
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SoALE.—1-4th inch = 1 foot.
Calender with five rollers, designed and constructed by Messrs. A. More & Son, Glasgow.——Fig. 601,
a side elevation; Fig. 602, an end view. The same letters of reference denote the same parts in each
new.
A AA, three cylinders or rollers made of paper, the construction of which will be noticed here
after. BB, two cast-iron cylinders, made hollow to allow of the introduction of hot bolts of iron
within them, or of steam, when it is required or preferred. 0 O, the two side-frames or checks,
into which are fitted the several brass bushes for the cylinders to turn upon. D 1), top guides, into
which the cross-head G- and elevating screws H H work. E'E, top-pressure levers, connected by a
strong rod of iron with the under-pressure lever F. This system of levers is connected with the
cross-head G by two strong links of iron. The elevating screws H H pass through the cross-headv
and rest upon a strong east-iron block, into which is fitted the brass bush of the top paper roller.
By means of the screws, the cross-head and levers can be raised or depressed as required; and
when the calender is working warm and requires to be stopped, the elevating screws are screwed up
for the purpose of lifting the paper rollers off the hot cylinders, to prevent their being injured by
the heat. '
The construction of the paper rollers or cylinders is as follows: Upon eaehend of an arbor of
malleable iron, of sufficient strength to withstand the necessary pressure without yielding, is fastened
a strong plate of east-iron, of the same diameter as the roller to be made: the plate is secured in its
proper place by a ring of iron, out in two, and let into a groove or check turned in the arbor. When
the roller is finished, the annular pieces are kept in their groove by a hot hoop put upon the outside
of them, and allowed to cool. A plate is fitted on the other end, of exactly the same size, and in the
same manner.
In building the rollers, one of the plates is taken off the arbor, but the other is allowed to remain
in its place. The paper sheets of which the rollers are to be made have each a circular hole cut in the
CALENDER. 27 5

centre of it, of exactly the same diameter as the arbor. The sheets are then put upon the arbor, and
pressed hard against the fixed plate. When the arbor is filled with paper, it is put into astrong
hydraulic press, and pressed together—always adding more paper to make up the deficiency caused by
the compression, until the mass can be pressed no harder. The half rings are then put in their place,
to prevent the plate from being pressed back by the elasticity of the paper. The roller is now to be
dried sufficiently in a stove, the heat of which causes the paper to contract so as to be quite loose.
The roller is then again taken to the press, and the unfixed plate being removed, more paper is added,
and the whole again compressed, until the roller is hard enough for the purpose to which it is to be
applied. It is next turned truly in the lathe-till it acquires a very smooth surface.
Fig. 603 shows the manner in which the calender is geared to make it a glazing calender. In this
cut, a marks the top cylinder of the calender, upon which is keyed a spur-wheel b; and c is the
under cylinder, upon which is also keyed a spur-wheel d. The intermediate or carrier-wheel ee,
when drawn into gear, reduces the speed of the under cylin-
der 0 one-fourth. Now, the cylinder at being the one that
gives motion to all the rollers, and revolving always at the
same speed, the cloth in its passage through all the rollers
below the cylinder a is carried through at a speed one-
fourth less than if it passed only below the cylinder a;
consequently, when it comes into contact with a, it is rubbed,
and thereby glazed, in consequence of the cylinder a moving
one-fourth quicker than the cloth, as above stated.
Fig. 604 shows the manner in which the rollers are lifted
clear of each other when the machine is stopped. In this,
e e are two rods of iron, attached to the block or seat of
' the top roller; 1) f 9, three bridges of malleable iron, capa-
ble of sliding upon the rods e e, but held fast upon the
rods when once they are adjusted to their proper places by
pinching screws. The bridge 6 is placed half an inch clear
of the bearing of the cylinder at, when all the rollers are
resting upon each other; the bridge f is placed one inch
below the bearing of the paper roller h ,- and the bridge 9
is placed one inch and a half below the bearing of the cylinder c. When the pressure screws of the
calender are lifted, the blocks of the top roller being attached to them, the rods e e are lifted also,
and along with them the diiferent rollers as the bridges successively come into contact with their
respective bearings. \
The manner of passing the cloth through the calender varies very much, according to the amount
of finish required upon it. 'I he various methods are accomplished by difierent arrangements of the
gearing, so that a calender calculated to do all the difierent kinds of finishing becomes a very com-
plicated machine, on account of the quantity of gearing required. For common finishing, the method
of passing the cloth through the calender is as follows: The cloth is passed alternately over and
under a series of rails placed in front of the machine, so as to remove any creases that may be in it,
and is then introduced between the lower roller A and cylinder B; returns between the lower cylin-
der B and the centre roller A ,' passes again between the central A and the upper B; and again re-


605. 606.














SOALE.—-1-5th inch = 1 foot.
turns between the top pair A B, where it is wound off on a small roller (hid in the drawings by the
framing of the machine), pressing against the surface of the top roller A. When this small roller
is .filled with cloth it is removed, and its place supplied by another, to be in succession filled as the
motion of the machine progresses.
2'7 6 C ALENDER.

‘llVater-Jifangle, with two copper and three wooden rollers, designed and constructed by Messrs. A.
More 81; Son—This machine, Figs. 605 and 606, differs nothing in principle, and little in general
construction, from the five-rollered calender above described, except in this—that it is intended for
wet goods. It is drawn to a scale slightly less, but the views given and the lettering of the parts
correspond to those of the preceding figures.
‘ A A A, the three wooden rollers, and B B, the two copper rollers of the mangle. These last con-.
sist of a copper cover upon a cast-iron body, through which passes a wrought-iron arbor, differing
from those of the wooden rollers in being round, whereas these are square between the bearings.
The smaller of the two copper rollers, namely, the third in order, is in this arrangement the driver,
the mangle being driven like the calender, by a system of reversing gear not shown in the drawings.
The pressure in the mangle is brought on by a system of levers, which diifer slightly from that
described. In this, indeed, there are strictly two distinct pressures: that brought on the axis of the
middle roller by the lever B, which is connected by a link with the weighted lever F; and that
transmitted through the whole system of rollers by the single-weighted lever D. The weight of this
last is regulated by means of a set-screw, which turns in a nut in the jaws of the lever D, and bears
upon the set-block which rests upon the arbor of the top roller. This pressure is thus transmitted,
downward from the top roller throughout the whole set, and at the middle roller B is added to the
pressure obtained by the lever E. By this arrangement, the pressure between the three under
rollers is greater by the pressure of E than it is between the upper pair ; but for very high press-
ure the lever D may be locked by set-pins and the set-screws turned down by the hand-wheel G,
until the requisite degree of pressure is obtained. The manner of passing the cloth through this
machine is the same as that already described in the calender, with this single exception, that
before the cloth enters between the lowest roller A and the small cylinder B, jets of water from a
pipe perforated with small holes, extending the whole width of the machine, are allowed to play
upon the cloth, so as to impart to it sufficient moisture for causing, it to receive the requisite
degree of smoothness preparatory to the starching process, and at the same time allow the cylinder
B to free it from any impurities that may be remaining in it, by forcing them back with the
expressed water.
Description of Calender, Figs. 607 and 608.-A, two cast-iron frames. B, C, D, three cylinders.
E, F, G, three cog-wheels. H, I, two force-screws. K, L, two fly-wheels with handles.
The cylinder B, which is in cast-iron, and hollow, is heated by another iron cylinder heated red-
hot. The material of the cylinder 0 is pasteboard; its axle is of wrought-iron. These three
cylinders must be perfectly round and parallel.
The wheel F forms the communication between E and G, which rest upon the cylinders B and D.
The relation of F to the circumference of the cylinders is such that, when the machine is set to work,
607.
1‘



these cylinders slide, causing friction, and thus give a gloss to the cloth. The friction is variable
according to the nature of the tissue. , >
In order to set the machine in motion, the fly-wheels K and L being turned so as to press the
screws H and 1 against the pillows of the first cylinder B, the cloth is placed between the rollers in
the direction indicated by the arrows. .
CALEN DER. 277

f
' Since the introduction of web-perfecting printing-presses, rolls for calendering paper require great
truth in their roundness and parallelism. Suppose, for instance, a pair of rolls to be the 10,000th
part of an inch out of parallel, and the paper rolled by them therefore the 20,000th part of an
inch thicker on one side than on the other. Now, suppose a roll of such paper to be 33 inches
in diameter, the mandrel upon which it is rolled being 3 inches thick, and there to be 450 thicknesses
of paper to an inch; the roll would in such case be .675 of an inch in diameter or 2.12 inches
in circumference greater at one end than at the other; and the effect of such a roll being placed
upon a modern printing-press, through which it would require to be drawn at a speed of from 15 to
20 miles an hour, would be that the whole strain due to unwinding the paper at such a great speed
would be sustained by the paper unwinding from the small diameter of the roll, causing it to tear.
To remedy this defect, Messrs. J. Morton Poole & (30., of Wilmington, Delaware, have introduced
a finishing process for rolls, which has achieved remarkable success, and which has been in con-
sequence introduced in Europe. That process is as follows: After the roll has been turned as ac-
curately as is practicable with the steel tools, it is finished in the grinding lathe or machine; and the
principle upon which this lathe
operates is as follows: If we
suppose the lower part of a
compound lathe-carriage to sup-
port the upper part so as to per-
mit to the latter a free, swing-
ing, cross-feed motion, and form
it so as to carry two revolving
oorundum-wheels, one on each
side of the roll, so that the hori-
zontal centre line of the roll will
be level with the‘centres of the
corundum-wheels, it is evident
that the two will form a pair of
grinding calipers, and will ad-
just themselves to touch the roll
equally on both sides, just the
same as the points of a pair of
calipers, held loosely, will adjust
themselves to the diameter of a
roll. It is also evident that a .
pair of wheels adjusted in this
manner, it traversed along the
roll, will come in contact with,
and operate upon, the roll in
places where the diameter of the
roll is equal to or exceeds the
nearest width between the two
corundum-wheels, while such
parts of the roll as are of a di-
ameter less than is the said dis-
tance between the wheels will
remain untouched. If, there-
fore, the wheels are adjusted in
their distance apart and operated along the roll until all the turning-marks are effaced, the roll will
be made quite parallel, except in so far as the reduction in the diameters of the grinding-wheels and
the deflection or sag of the roll may prove disturbing elements.
The latter element is of no practical moment, however, since its efiect upon an ordinary roll 8 feet
long'has been computed not to affect the diameter of the roll to more than the 200,000th part of an
inch. Referring to the first disturbing element, it is less in the process adopted by Messrs. Poole
than in any other yet known, for the following reasons: The ordinary plan is to perform the grinding
with a wheel on one side only of the roll. Now, supposing it to be practicable to move the carriage
containing the wheel so delicately as to be able to put on a cut the 100th part of an inch in depth,
the diameter of the roll will be reduced one-fiftieth of an inch, and the amount of the abrasion of
the emery-wheel will be that due to the abrading of that quantity or weight of metal; but if the
feed of one of Messrs. Poole’s corundum-whecls is moved the 100th of an inch, the reduction in the
size of the roll will be the 100th of an inch only; so that, with the same amount of feed, Messrs.
Poole take off only one-half the amount of metal, and have twice the area of grinding-wheel to do
it with. Hence the deviation from parallelism is only one-fourth as much under their process as it is
under the process usually employed. From the cross-swing motion, then, of the frame carrying the
corundum-wheels, the parallelism of a, roll is inevitable, providing that the roll runs circumferentially
true. The ordinary method of grinding a roll to run true in the lathe is to grind it up with one
emery-wheel in a fixed position; and this was the plan formerly employed by Messrs. Poole, in which
case the advantage obtained by theirprocess was that, since an emery-wheel in a fixed position will
grind a roll to run true, and the error arising from its use lies in the parallelism of the roll, it is
necessary only to finish the roll with the two wheels in position to insure both roundness and paral-
lelism. The only objection to this plan was that the grinding the roll true could be performed twice
as quickly with the two wheels as it could be with the one, and could be proceeded with simultane-
ously with the truing for parallelism. The method of accomplishing this result is as follows: By





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,


2'7 8 ' CALICO—PRIN TING.

a
placing a slight pressure upon the frame carrying the corundum-wheels, so as to offer a slight re-
sistance to its cross-swing, the high spots or places upon the roll will press more heavily upon the
respective corumlum-wbeels as it passes them, and, as a consequence, will suffer the most abrasion.
This remark applies, however, to high spots which do not extend entirely around the circumference
of the roll, and not to high places due to an increase of diameter; or, in other words, it applies to
those high spots which constitute a want of truth or roundness in the roll. If then a roll, being
out of round and out of parallel, is operated upon with the wheel-frame or carriage slightly resisted,
the truiug for both roundness and parallelism will progress jointly; then, when the roll is ground
so as to run true, the wheel-carriage is allowed to swing freely while the finishing traverses are
made. J. R.
CALICO-PRINTING is the process of impressing designs in one or more colors upon cotton
cloth. The coloring substances employed are divided into substantiates and adjectives. The former
are capable of producing permanent dyes of themselves; the latter require certain intermediate
matters.
It is often necessary to apply some substances to the cloth which shall act as a bond. of union
between it and the coloring matter. These substances are usually metallic salts called mordants,
which have an affinity for the tissue of the cloth as well as for the coloring matter when in a state
of solution, and form with the latter an insoluble compound. The usual mordahts are alum, and
several salts of alumina, peroxide of iron, peroxide of tin, protoxide of tin, and "oxide of chrome.
Mordants are useful for all vegetable and animal coloring matters which are soluble in water, but
have not a strong affinity for tissues.
To prevent the mordant or the coloring matter from spreading beyond the proper limits of the
design, t/rlc/eeners are used to bring it to the required consistence; the most useful are wheat starch
and flour, but many other materials are used. The colors, with the proper thickeners, are prepared
in vessels furnished with steam-jackets, for raising the contents to the required temperature.
There are eight different styles of calico-printing, each requiring different methods of manipula-
tion, and peculiar processes:
1. The marlder style (so called from its being chiefly practised with madder), to which the best
chintzes belong, in which the mordants are applied to the white cloth with many precautions, and
the colors are afterward brought up in the dye-bath. These constitute permanent prints. 2. The
padding style, in which the whole surface of the calico is imbued with a mordant, upon which after-
ward diiferent-colored figures may be raised by the topical application of other mordants joined to
the action of the dye-bath. 3. The resist style, where the white cloth is impressed with figures in re-
sist paste, and is afterward subjected first to a cold dye, as the indigo vat, and then to a hot dye-bath,
with the effect of producing white or colored spots upon blue ground. 4. The discharge style, in which
thickened acidulous matter, either pure or mixed with mordants, is imprinted in certain points upon
the cloth, which is afterward padded with a dark-colored mordant, and then dyed, with the effect of
showing bright figures on a dark ground. 5. China blues, a style resembling blue stone-ware, prac-
tised with indigo only. 6. The decolorz'ng style, by the topical application of chlorine or chromic acid
to dyed goods. This is sometimes called a discharge. 7. Printing by steam, a style in which a mix-
ture of dye extracts and mordants is topically applied to calico, while the chemical reaction which
fixes the colors to the fibre is produced by steam. 8. lSjoirit colors, produced by a mixture of dye
extracts and a solution of tin. These colors are brilliant but fugitive.
The processes actually required for finishing a piece of cloth in the madder style, as, for example,
in producing a red stripe upon a white ground, are numerous. The bleached cloth is submitted to
nineteen operations, as follows: 1. Printing on mordant of red liquor (a preparation of alumina),
thickened with flour, and dyeing; 2. Ageing for three days ; 3. Dunging; 4. Wincing in cold water;
5. Washing at the dash-wheel; 6. \Vincing in dung-substitute and size; 7. \Vincing in cold water;
8. Dyeing in madder; 9. Wincing in cold water; 10. \Vashing at the dash-wheel; 11. Wincing in
soap-water containing a salt of tin; 12. Washing at the dash-wheel; 13. Wincing in soap-water;
14. Winciug in a solution of bleaching powder; 15. Washing at the dash-wheel; 16. Drying by the
hydro-extractor; 17. Folding; 18. Starching; 19. Drying by steam.
By different engraved rollers, each supplying a difierent mordant, various shades and colors are
afterward brought out by one dye. Before the mordanted cloth is dyed, it is 'hung for some time in
airy chambers in order that the mordants may intimately combine with the fibre. This operation,
called ageing, is abbreviated», by a process in which the goods are passed over rollers in a room in
which a small quantity of steam is allowed to escape.
The aniline colors are largely used- for calico-printing,.and are applied topically, the only mordant
used being albumen or vegetable gluten prepared in various ways.
The printing-cylinders are of copper, and vary in length from 30 to 40 inches, according to the
width of the calico; the diameter varies from 4 to 12 inches. Each cylinder is bored through the
axis, and accurately turned from a solid piece of metal. To engrave a copper cylinder by hand, with
the multitude of minute figures which exist in many patterns, would be a very laborious and expen-
sive operation; and the invention of Jacob Perkins of Massachusetts, for transferring engravings from
onp surface to another by means of steel roller dies, has long been applied to calico-printing with
perfect success. The pattern is first drawn upon a scale of about 3 inches square, so that this size
of figure, being repeated a number of times, will cover the printing-cylinder. This pattern is next
engraved in intaglio upon a roller of softened steel, about 1 inch in diameter and 3 inches long, so
that it will exactly occupy its surface. This small roller, which is called the die, is next hardened by
heating it to redness in an iron case containing pounded bone-ash, and then plunging it into cold
water, its surface being protected by a chalk paste. This hardened roller is put into a rotary press,
and made to transfer its design to a similar roller in a soft state called the mill; the design which
was sunk in the die now appears in relief on the mill. The mill in its turn is hardened, and,
CALICO-PRIN TIN G. 27 9

being put into a rotary press, indents upon the large copper cylinder the whole of the intended
pattern.
As the use of copper in rollers constitutes a large item of expense, there have been many inven-
tions for rollers only partially of that metal or entirely of other substances. Iron has been used as
an inner cylinder for a thin copper envelope; in one case these cylinders had corresponding grooves
to prevent turning one upon the other. A seamless tube of copper has been placed upon a taper
tube of sheet-iron, and tin has been employed to coat the interior of a copper shell, which is then
soldered to an iron lining. Brass rollers have been tested, but the objection lies in the hardness and
shortness of the alloy. Various other alloys, notably of zinc, and also German silver, have been em-
ployed, not, however, with success. Rollers, either entirely of papier-maché, or of that material
covered with a half-inch tube of copper, have been tested, and numerous plans involving electric
deposition of the metal have been breached. By the latter means, instead of turning off the worn
face of the copper to expose a new surface, they were maintained at the original diameter by a new
coating of copper at a minimum expense. One of the most practical plans for utilizing old copper
rollers is that patented by Mr. T. Knowles, which dispenses with the necessity of adjusting the roller
to the mandrel whenever the cylinder requires renewing. Over the old thin roller an exterior roller
is forced, and when this is worn thin another new one is substituted. The exterior roller is held in
due position tightly by means of a nib. The etching process is resorted to in case of injury to a
roller whereby a sinking of the surface is produced, all but the sunk portion, which is covered with an
acid-resisting paint, being exposed to the action of acid until the desirable flatness has been ob-
tained. Strong aquafortis is employed to
make deep cuts on the roller, thus saving the 609,
time which the engraver would otherwise be
compelled to devote to making these cuts on
the first steel die. The parts which it is de~
sired shall not be attacked are painted by
hand with an acid-proof paint. Pentagraphy
is a system of tracing objects by means of
diamond or steel points upon a varnished roll-
er, and then submitting the roller to the etch-
ing process, the nitric acid attacking the roll-
er where the bituminous varnish has been
scraped off.
Fig. 609 represents the machine used in en
graving the copper cylinders used in machine
printing. In the printing-machine the cylin-
ders upon which the pattern is engraved, one
cylinder for each color, are mounted on a
strong frame-work, so that each cylinder re-
volves against two other cylinders, one of
which is covered with woolen cloth, and dips
into a trough containing coloring matter prop-
erly thickened, so that, as it revolves, it takes
up a coating of color and distributes it over the engraved roller. which transfers the pattern to the
cloth. The cloth to be printed passes over a large iron drum covered with several folds of woolen
cloth, so as to form a somewhat elastic printing surface: an endless web of blanket-ing is made to
pass round this drum, which serves as a sort of guide, and defence, and printing surface to the
calico which is being printed. The superfluous color is removed from the engraved roller by a
sharp-edged knife or plate, usually of steel or gun-metal, called the color-doctor, so
arranged that the color scraped off shall fall back into the trough; another plate of 610-
steel removes the fibres which the roller acquires from the calico. This arrangement
will be understood from Fig. 610, in which A is the iron drum over which passes the
blanket B; C' is the calico which passes over the engraved roller below; Dis the
color-roller, E the color, F the color-doctor, and G the lint-doctor. To realize an idea
of a 12 or 20 colored printing machine, it is only necessary to imagine a. large circle
and a plurality of repetitions of this mechanism arranged around its circumference.
In the four-color printing-machine, Fig. 611, the pressure is normal, in all the
engraved rollers, by means of the levers P. These rollers are turned by a belt
communicating with the prime mover. The regulators are adjusted by screws, to
which are attached hands, indicating upon dials the space to be run by the rollers in order to reach
the regulators: this is known without stopping the works. The engraved rollers can be brought up to
the pressing-cylinder, or withdrawn from it, without changing the places of the color-vessels or of the
scrapers; for all the different pieces, fixed against the pillows on the turning pieces of the engraved
rollers, move with these last. Finally, there is an apparatus placed behind the under cloth, the
interngcdiate cloth, and the stuff to be engraved, by which the workman governs these three pieces
at wil .
The vessels in which the rollers dip are made of copper or wood. It is necessary to keep them sup-
plied with a constant quantity of printing material, for the rollers would soon only skim over the
surface of the fluid and leave but a feeble impression; to this end a. reservoir pours a continual sup-
ply. A partition is placed in a position which enables it to clear the roller of the froth with which
its surface may be covered. .
Fig. 612 shows the construction of a machine for printing 8 colors, and Fig. 613 one for printing
20 colors. The surface-roller machine executes similar styles of work to those produced by the per-




\
280
OALIOOePRINTING.
fi
rotine described below. Here the pattern cylinder is in relief. In Fig. 612, A is the frame-work; B
the bowl or cylinder, which is hollow, and made with arms inside ; O U are the surface-rollers, sup-
plied with color by the endless web or sieve F revolving around the wooden tension rollers D D
--»-_----- --.-__..._--_---_._
_-__.__.-__-_
-__.,--_-____-_
...----_.___
-..-.-_..-______::::

611.
__--_.,,.
“—





























__ ....
A A A, framework.
B, ressing cylinder.
(E? C' engraved cylinders.
D D D , scrapers.
EE' 5' E, vessels containing the color-
ing matter: they are raised and
lowered at pleasure, by the screws
F.
G‘ G G G, endless screws, guiding the
regulators.
II [I H H11 HH; inions and wheels
which turn all t e machinery.

I '_‘
'-
1": u
..
P' - I '
. ' . . I . ‘
' l '- _
'--_ ‘ . . : ..-‘
.__-__,._...T||~__; ..‘c..."-._\,5__ . - - - . . . . . .._-j'--...._r:_,’-'_ . _ _ . . . _ _ .-
--. F:_:_"-
I, a shaft communicating with the
moving power.
K KKK, wheels adapted to the fe-
male screws LLLL. which put
the levers in communication with
the pillows of the rollers.
M, a wheel communicating with the
driving-power, whose office is to
press the rollers; it also moves the
wheel N, and the endless screws
0 0 O 0, which are engaged with
the wheels K KKK.

'l
1
. r" ..._





“'1'? El
PPP P, levers which are loaded
with weights in pro ortion with
the pressure require ; they are
situated beneath the floor.
Q, the cylinder round which the cloth
to be printed is rolled.
R, the c linder round which the in-
terme iate cloth is wound.
S, a weight which kee s the cloth
stretched on the cylin ers Q R.
7; a roller used to give an inclination
to the cloth when printed, and reg.-
ulate the speed.
CALICO—PRINTING. 281

E. The roller E is screwed down so as to press the sieves on the furnishing-roller, which revolves
in the copper color-box G. The two tension-rollers next to the surface-roller move in slides, so that,
by means of screw H,» the sieve can be pressed against the surface-roller; on leaving the furnishing-



roller, the sieve is wiped by the doctor 1: The surface-machine is well adapted for woolen fabrics,
and the colors, being laid on the top of the cloth, have a very rich appearance.
The perrotine machine executes a style of work very similar to hand-block printing. Wooden
blocks varying from 2% to 3 feet in length, according to the width of the pieces, and varying in
breadth from 2 to 5 inches, have the pattern engraved in relief on their surface. By the gas-process
illustrated in Fig. 614, the graving-tool is heated to redness by means of a small gas-burner, and de-
stroys all parts of the surface except those left in relief. Fig. 615 represents designs produced by






the gas-process. The blocks are fixed with their faces at right angles to each other, in a stout iron
frame, and can each in turn be brought down upon the front, top, and back of a four-sided iron
prism, faced with cloth and revolving upon an axis. The goods to be printed pass between the
282 CALI CO—PRINTING.
prism and the pattern-block, and receive the impressions in succession. The effect of these suc-
cessive applications in producing the different shades of a flower is represented in Figs. 615, 616,
and 617. The blocks are forced down upon the calico
614- by means of springs, so as to imitate the pressure of
the hand of the block-printer.
Fig. 613 represents an eight-color perrotine machine.
a‘ a‘2 a3 a4 a5 are the forms, fastened to iron supports,
which are carried by the pressure-bars b1 l)" b3 b4 I)".
These latter execute an interference motion, which, as
may be examined in the case of the pressure- bar 6‘, is
produced by the two crank-pins c and (l—of which 0
makes twice as many revolutions in a given time as d—
by the joint-levers e and f, and the stay or frame 9.
Through the rotation of the crank-pins c and d, the
forms are at first fully drawn back, while, by means of
a special combination of levers, all the color-plates h
‘ \ \ are placed between the forms a1 a9 a3 a4 a5, and the
,.< ' / \"\ / printing-tables £1719 2'3 2'4 2'5. The color-plates are flat
,/'/ / ' I! cast-iron plates covered with an elastic material, upon
/ /' / /// x A which color is transferred while passing the Color-rollers
/ / \ 1:1 Ir2 k3 k4 H. The printing-tables, which are also cov-
ered with an elastic material, serve as a support for
the stuff during the operation of the printing. The stufi to be printed is rolled off the beam Z, and,
passing over one stretching-roller, three stretching-bars, and a wooden guide-roller, is carried by
means of the needle-rollers m1 m2
m3 'm’i'm5 over the printing-tables,
passing out of the machine at w,
and being then led oif to a drying
apparatus. With a further rota-
tion of the crank-pins, the press-
ure-bars advance so far only that
the forms touch the color-plates,
the embossed designs of the for-
mer thus being caused to receive
color from the latter. The pres-
sure-bars b1 b2 63 b4 b” are now with-
drawn with the form covered with
color, while the color-plates pass
back in the mean time to the color-
ing apparatus, where they receive
a fresh supply. Another rotation
of the crank-pins advances the
forms close to the printing-table,
and presses the design covered with ‘ -
color upon the stuff in front of the printing-tables. After this operation the forms are drawn
back, the color-plates are again placed between the forms and the printing-tables, and the same
, operations are repeated during the following
rotations of the crank-pins.
During the time the coloring-plates are
moved up and down again, or, in other
words, during the time in which the forms
are not in contact with the stuff, the latter
advances as much as the width of the form
(length of guide), so that the next impres-
sion takes place close behind the one previ-
ously executed.
By a special eontrivance, it is rendered
possible to cause each form to strike the
stuff on one and the same place twice suc-
cessively, after having taken up color in the
intermediate time.
There are numerous machines connected
with calico-printing for descriptions of which
the reader is referred to the works of ref-
erence cited below. Among them may be
noted tne pentagraph for reproducing sev-
eral times at once the lines of an enlarged
pattern on the rollers; the color-pans and
dye-vats, washing apparatus, construction of
the ageing-room, and steaming-chests. Good
brief descriptions of many of these appear
in the article on calico-printing in the “Encyclopaedia Britannica,” 9th edition.
All the finishing procssses to which calico is subjected have one common end, namely, to fill up








CALIPERS. 283

the interstices which exist in the fabrics, and thus give them a more glossy and substantial appear-
ance. This is effected by filling the cloth with starch, to which sulphate of lime or baryta IS often
added to give factitious _ weight and solidity. The various operations are stretching (see CLOTH-FIN-
618.




















._.-. _ _ ' ' _ \W’ '1]I\ \J/r‘t': \ . y/
__ ‘


h t
\._/
\
\






ISHING MACHINERY), bleaching in a chlorine solution, which is followed by steaming, water-mangling,
and drying. In the starching machine, a roller revolves in a starch solution and carries it up to the
cloth, which passes around upper rollers, where it becomes saturated by the squeezing action pro-
duced. After starching, the goods are again dried, sprinkled, and calendered. (See Cmunxa.)
Lastly, each piece is folded. (See CLOTH-FINISHING MACHINERY.)
Wow/cs for Reference.—“ Traité Théorique et Pratique de l’Impression des Tissus,” Persoz, Paris,
1846; “APractical Treatise on Dyeing and Calico-Printing," anonymous, New York, 1846; “A
Dictionary of Calico-Printing
and Dyeing,” O’Neill, London
and Manchester, 1862 ; “ A
Practical Handbook of Dyeing
and Calico-Printing,” Crookes,
London, 1874*; “ Dyeing and
Calico-Printing,” Calvert, Lon-
don and New York, 1876. For
details of various improvements
in calico-printing and dyeing,
see files of the Textile Calm/w
Q's-t, an English monthly period-
ical published during 187 6 and
187 7.
CALIPERS. An instrument for measuring the diameter or thickness of objects
Calipers are made in a variety of forms, of which several examples are given in the
annexed engravings. Fig. 619 is a pair of inside and outside calipers combined,
the curved legs gauging the exterior of the work, as at B, and the straight legs, the
ends of which are bent, measuring the interior, as at A. Fig. 620 shows the usual
form of spring calipers, the legs being held apart by the bow-spring at the junction,
and brought together by the screw. A modification of this tool is shown in Fig. 621,
which is adapted for the measurement of keyholes. There are several kinds of registering calipers,
one form of which is represented in Fig. 622. On one leg is attached a scale, and on the other a
pointer, which indicates the amount of separation of the leg-points, and consequently the thickness

* This work contains a very complete series of bibliographical references to the literature of dyeing, and. with Dr.
Calvert‘s book, is illustrated by actual samples of calico, exhibiting the effects of various dyes and methods of printing.
284 CALTPERS.

of the object under measurement. Registering calipers for measuring standing or cut timber have
arms about 13 feet long, “between which is an arc denoting the quarter girth in feet and inches.
Calipers may be employed to mark off the centres of holes, or to try if a centre already existing
‘ is in the exact centre of the hole. Or they will mark off a face so that it will fit another face,
whether it be regular or irregular, the curved point being kept against the irregular face, and the
point describing (by moving the compass along) a similar line on the face to be fitted. They will
answer for many of the uses to which a scribing-block is put; and being lighter and more easily
handled, and, furthermore, capable of doing duty without the use of a surface or scribing-plate, they
are in such cases far preferable. The legs may be crossed so that the curved point inclines to the
straight point, in which position they will mark the centres of shafts or rods, either round, square,
or any other shape, or try such centres, when they already exist, more accurately than can be done
by any other tool. They will, in this case, mark 01f a line at the distance to which they are set
round any surface; they are employed to mark ofi keyways, or the taper of a gib when the key
and one edge of the gib are placed, and for a variety of other uses too numerous to recapitulate, being
among the most useful tools the fitter can possibly possess.
Vernier Calipers—Figs. 623 and 624 represent the sides of vernier calipers for very accurate
measurement, made by Messrs. Darling, Brown, and Sharpe. One side reads to thousandths of inches,
623. 624.
rnox'r smn. . BACK sum






o 5 10151025
‘ llmlll'lll "Ill
8] lllllllllillil 1 up
|

"'l""3(""l"j


E




the other to sixty-fourths and fiftieths of inches. Both inside and outside calipers are provided, and
also points to transfer the distance with dividers. The instruments are of steel, with tempered points
and ground jaws. The method of reading the instrument is as follows: On the bar is a line of
inches numbered 0, 1, 2, 87.0., each inch being divided into ten parts, and each tenth into four parts,
making forty divisions to the inch. On the sliding jaw is a line of division (called a vernier, from
the inventor’s name) of twenty-five parts, numbered 0, 5, 10, 20, 25. The twenty~five parts on the
vernier correspond in extreme length with twenty-four parts, or twenty-four fortieths, on the bar;
consequently each division on the vernier is smaller than each division on the bar by one thousandth
part of an inch. 1f the sliding jaw of the calipers is pushed up to the other, so that the line marked
0 on the vernier corresponds with that marked 0 on the bar, tlzcn the two next lines to the right 'will
differ from each other by one thousandth of an inch; and so the difference will continue to increase,


. i,
626.
a




one thousandth of an inch for each division, till they again correspond at the line marked 25 on the
vernier. To read the distance, with the calipers open, commence by noticing how many inches, tenths,
and parts of tenths the zero point on the vernier has been moved from the zero point on the bar;
now count upon the vernier the number of divisions, until one is found which coincides with one on
the bar, which will be the number of thousandths to be added to the distance read off on the bar.
The best way of expressing the value of the divisions on the bar is to call the tenths one hundred
thousandths (.100), and the fourths of tenths, or fortieths, twenty-five thousandths (.025). Refer-
ring to Figs. 623 and 624, it will be seen that the jaw is open two tenths and three quarters, which is
equal to two hundred and seventy-five thousandths (.275). Now suppose the vernier was moved to
the right so that the tenth division should coincide with the next one on the scale, which will make
ten thousandths (.010) more to be added to two hundred and seventy-five thousandths (.275), making
the jaws to be open two hundred and eighty-five thousandths (.285). In making inside measurements
with the vernier, two tenths or two hundred thousandths (.200) of an inch should be added to the
apparent reading for the bigness of the caliper-points. When the other side of the instrument is
used, no deduction is necessary, as there are two lines, one indicating inside and the other outside
measurement. .
In using this instrument, the set-screw at A is set up tight, while that at B is adjusted so as to
maintain B a sliding fit upon the bar. The calipers should not be forced upon the work, the measure-
CAM. 285

ment being accurate when the faces of the calipers just touch the object, an easy moving fit, so that
the instrument may be moved by the finger and thumb upon the work without any play between the
calipers and the work.
Alicrometer Calipers—This instrument, Fig. 625, forms a reliable and convenient substitute for the
vernier calipers for all measurements less than one inch. The main piece of the calipers is how-
shaped, with a projecting shank a, into which is fitted the screw 0, which is
accurately cut with a thread of 40 pitch. The shank a has a line of gradua-
tions of the same pitch as the screw 0. The hollow cap D, which is firmly
attached to the right-hand end of the screw C, fits upon the outside of the
shank a. One revolution of this cap opens the calipers twenty-five thou-
sandths of an inch. Parts of a revolution are shown on the line of gradu-
ations upon the circumference of the beveled end of the cap D, the value of
each graduation being one thousandth of an inch in the opening of the cali-
pers. Thus, three whole turns and one-fifth of a turn would equal eighty-one
thousandths of an inch, inasmuch as three turns equal twenty-five thou-
sandths, and one-fifth of a turn (or five of the circular graduations) equals
five thousandths, making altogether eighty-one thousandths of an inch.
Though graduated to read to thousandths of an inch, half and even quarter
thousandths are easily obtained, and measurements are read without the use
of a glass. It is provided with screws for adjustment and for holding it
securely at any given size. Being made wholly of steel, all the parts are
durable, the points of contact also being tempered. It is small, light, well adapted for use as a
pocket tool, and meets many special requirements of fine implement makers.
Fig. 626 represents calipers used for the measurement of shells in order to determine the thick-
ness of the metal on the great circle at right angles to the axis of the fuse. A quite handy tool
for the wood or'metal worker is the universal compass calipers represented in Fig. 627. The legs
have pivoted to them revolving caliper-ends, so that the device can be used either as a plain scriber,
scribing compass, or inside or outside calipers. J. R.
CALLIOPE. A musical instrument, consisting of a number of steam-whistles attuned to produce
different notes. The whistles are operated from a keyboard, or from a barrel rotated by mechanism,
and having suitably disposed pins which engage with devices in communication with the whistles.
CALORIC ENGINE. See ENGINE, AIR.
CALORIMETER. See ELECTRO-GALVANIC BATTERIES.
CAM. A curved plate or groove which communicates motion to another piece by action of its
curved edge. When the cam shown in Fig. 628 rotates in the direction of the arrow, the roller P at
the end of the lever A P will, be raised gradually by the curved portion a b, will be held at rest
while 6 0 passes underneath it, and finally will be allowed to fall by the action of c a. The circular
motion being uniform, the reciprocating piece may also move uniformly, or its velocity may be varied
at pleasure. Suppose that the reciprocating piece is a sliding bar, whose direction passes through the
centre of motion of the cam-plate ; take 0', Fig. 629, as this centre, let B P represent the sliding bar,
and let A be the commencement of the curve of the cam-plate. The curve A P' may be set out in the
following manner: With centre 0 and radius 0 A describe a circle, and let B P produced meet its
circumference in the point B. Divide o
A R into a number of equal arcs, A a, 628' L
'6
a b, b 0, etc. Join 0a, 06, Ce, etc., A ' s
and produce them to p, g, 7‘, etc., mak-
ing a p, b q, 0 '2', etc., respectively equal
to the desired movements of B P in
the corresponding positions of the cam-
plate; the curve A p q r. . .P will rep-
resent the curve required.
We will next examine the case where
the centre of motion of the cam-plate
lies upon one side of the direction of
the sliding bar, and we shall find that
the method of setting out the curve
changes accordingly. Suppose that the
direction of B P, Fig. 630, passes upon
one side of the centre of motion C;
draw OR perpendicular to BB pro-
duced; describe a circle of radius 0 R,
and conceive the motion to begin when
A coincides with R. As a matter of
theory such an extreme case is possi-
ble, and we will imagine it to exist in
order to obtain the equation which rep-
resents the complete curve. Practi-
cally, the cam would be more effective
in straining the bar than in moving it when the point P was near to the point B. Divide A R into
the equal intervals A a, a b, b 0, etc., but now draw a p, b g, e 1‘, etc., tangents to the circle, and equal
in length respectively to the desired movements of B P during the corresponding periods of motion
of the cam-plate. The curve A p g r. . .P will be that required.
The heart-wheel has been much used in machinery, and is formed by the union of two similar and
627.







286 - CANAL-LIFTS.

equal cams of the character discussed above. A curved plate 0, Fig 631, shaped like a heart, actu-
ates a roller P, which is placed at the end of a sliding bar, or which may be attached to a lever
P A B, centred at some point A, and connected by a rod B D to the reciprocating piece. The pecu-
liar form of the cam allows it to perform complete revolutions, and .to cause an alternate ascent
or descent of the roller P with a velocity which may be made quite uniform. Since a cam of this
kind will only drive in one direction, the follower must be pressed against the curve by the reverse
action of a weight or spring. ' I
Hitherto we have considered the cam to be a plane curve or groove ; but there is no such restric-
tion as to its form in practice. Let us examine the following very simple case, as well as the exten~





sion' of which it admits: C D, Figs. 682 and 633, is a rectangle with a slit R 8 cut through it
obliquely; a pin P fixed to the Sliding bar A B works in the slit. If the rectangle C D be moved in
the direction R 8, it will impart no motion to the bar A B; but if it be moved in any other direc-
tion, the pin P will be pushed to the right or left, and a longitudinal movement will be communicated
to the bar A B. Next let 0 D be wrapped round a cylinder; it will form a screw-thread, and the
revolution of the cylinder upon its axis will be equivalent to a motion of the rectangle at right
angles to the bar. l/Ve shall have, therefore, by the arrangement in Fig. 634, a continuous uniform
rectilinear motion of the bar A B during the revolution of the cylinder upon which the screw-thread
is traced. If the pitch of the screw be constant, the motion of P B will be uniform, and any change
A

i


/




'n ‘
\\
- - - . .14
‘ §
§
\a
)X“
,..
I H)
_.
avian-
' lo


of velocity may be introduced by a proper variation in the direction of the screw-thread. If the
screw be changed into a circular ring, A B will not move at all.
Cams are employed when it is required to effect a movement with extreme precision. Thus in the
machine of Mr. Applegath for printing newspapers, the accuracy with which the sheet is delivered
is very remarkable, and is insured by the assistance of the cam represented in Fig. 635. As O
revolves, the roller at B drops into the hollow of the plate, thereby determining the fall of the lever
A B, and by it the fall also of another roller which starts the paper upon its course to the printing-
cylinder. See “Elements of Mechanism,” Goodeve, London and New York, 1877.
CANAL-LIFTS. The great canal-lift at Les Fontenettes, on the Neuf-Fossé Canal, France, repre-
sented in Fig. 636, consists of two immense troughs of plate-iron capable of receiving boats of 300
tons. Each trough is supported on the piston of a hydraulic press cylinder, the cylinders being in
wells sunk between the towers. The presses are connected by a pipe with a sliding valve, which estab-
lishes hydrostatic balance when open. If one of the troughs is more heavily loaded than the other,
it descends and forces the other to ascend. The preponderance of lifting force may be shifted by .
suitable apparatus. The piston-stroke is about 43 ft. ; weight of trough filled, 800 tons. Supposing
the two lock-chambers to be in position, one at the upper and the other at the lower level, if the
communicating valve is opened the upper chamber will descend and the lower one will rise, and after
a few oscillations they will stop midway in equilibrium. To prevent this, the upper chamber is super-
charged with a weight of water equal to that contained in a press, so that it continues its motion
until it reaches the lower level of the canal. Thus each chamber in alternation lifts the other with
the least possible waste of water. The presses are 55 ft. high, 6% ft. in diameter, and built to resist
an internal pressure of 27 atmospheres.
CANALS. ' 287
1.
The largest canal-lift in the world is that at La Louviere, Belgium. The difierence between
the levels of the upper and lower canals—that is, the height the boats are raised—is 50 ft. 6%,- in.
The lift consists of two pontoons or troughs, each 141 ft. long by 19 ft. bread, with 8 ft. draught
of water, and are capable of holding the largest size of barge that navigates on the Belgian
broad-gauge canal system; such barges are capable of taking 400 tons of coal or other cargo, so that
‘ '1 . . nu-VV‘._ , I'
I imlmnmm‘mlmm'mm fl" ‘Illlnllnlmlxu mm. 1
_ 1_ a; Cu —. \llf'w. mv. 1“, ,I | p ‘
"~--"'~'e-~ml!lllt 1 at u lliiiiilullul \nm munymmmuu’
_ - _ p _ _ \ _


the total weight of the trough, water, and barge is not much under 1,000 tons. This immense weight
is supported on the top of a single colossal hydraulic ram of 6 ft. 62- in. diameter and 63 ft. 91} in. long,
working in a press of cast-iron, hooped continuously for greater security with weldless steel coils.
The working pressure in this press is about 470 lbs. to the sq. in. The time actually occupied in the
operation of lifting or lowering is only 2% min.
Dimensions, etc., of Important Canals. The Nicaragua CanaZ.—T.he route extends from Grey-
town on the Atlantic to Brito on the Pacific, :3. distance of 169.67 miles, divided as follows :





Free navigation canal in x
' excavation . i
a 2
Greytown to Deseado Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ‘ 12.37
Deseado Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.00 i . . . . .
From Deseado Basin to San Francisco Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 3 07
San Francisco and Maehado Basins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 .00 l 1.73
River San Juan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.00 i . . . . .
Lake Nicaragua . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 56.50 i . . . . .
From Lake Nicaragua to 'l‘ola Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : 8.22
rl‘ola Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . .. 5.28 i . . . ..
From Tola Basin to Brito . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.50
140.78 28.89



The principal dimensions of the canal in excavation are: Depth, 30 ft; width at top, maximum,
360 ft.; minimum, 80 ft.; at bottom, maximum, 120 ft ; minimum, 80 ft.
The leading engineering features, in greater detail, are: The construction of two harbors at the
termini of the canal, Greytown on the Caribbean Sea, and Brito on the Pacific Ocean; the damming
of the waters of the San Juan River, for the purpose of raising and maintaining the level of Lake
Nicaragua and the river at about 110 ft. above mean tide; the formation of artificial basins at different
levels by means of dams and embankments; and the use of locks, to pass from one level to another.
CANALS. Canals are open channels of water for the purposes of navigation, water-supply for
cities and manufactories, for drainage, for irrigation, etc. The form and size of the canal \\ ill de-
pend upon the purposes to which it is to .-
be applied; for navigation, on the size of
the boats and the amount of traffic; for
water-supply, drainage, etc., on the amount
of water to be supplied or discharged.
Navigable canals may be divided into
two classes: Class I. Canals which are on
the same level throughout their entire length, as those which are found in low level countries;
Class II. Canals which connect two points of different levels, which lie either in the same valley, or
on opposite sides of a dividing ridge. Canals of class I. are found in broken countries, in which it is
necessary to divide the entire length of the waterway into several level portions, the communication






288 CANALs.

between which is effected by some artificial means. The cross-section of this class presents usually
a waterway or channel of a trapezoidal form, with an embankment on each side, raised above the
general level of the country, and formed of the excavation for the waterway. In Fig. 636, A repre-
sents the waterway; B, tow-paths; O, bermes; D, side-drains; E, puddling of sand or clay.
II. This class will admit of two subdivisions: 1. Canals which lie throughout in the same valley;
2. Canals with a summit level.
Cross-section.—-The side formations of excavations and embankments require peculiar care, par-
ticularly the latter, as any crevices left when they are first formed, or which may take place by set-
tling, might prove destructive to the work. In most cases, a stratum of good binding earth, lining
the waterway throughout to the thickness of about 4 feet, if compactly rammed, will befound to offer
sufficient security if the substructure is of a firm character and not liable to settle. Fine sand has
been applied with success to stop the leakage in canals. The sand for this purpose is sprinkled in
small quantities at a time over the surface of
the water, and gradually fills up the outlets in
the bottom and sides of the canal. But neither
this nor paddling has been found to answer in
all cases, particularly where the substructure is
formed of fragments of rocks ofiering large
crevices to filtrations, or is of a marly nature.
in such cases it has been found necessary to
line the waterway throughout with stone laid '
in hydraulic mortar. A lining of this character, a, Fig. 637, both at the bottom and sides, formed
of flat stones about 4 inches thick, laid on a bed of hydraulic mortar 1 inch thick, and covered by
a similar coat of mortar, making the entire thickness of the lining 6 inches, has been found to answer
all the required purposes. This lining should be covered, both at bottom and on the sides, by a
layer of good earth, at least 3 feet thick, to protect'it from the shock of the boats striking either
of those parts. ,
Although, for the sake of saving expense in aqueducts and bridges, short portions of a canal may
be wide enough for the passage of one boat only, the general width ought to allow two boats to
pass each other easily. ' The depth of water and sectional area should be such as not to cause any
material increase of the resistance to the motion of the boat beyond what it would encounter in open
water. The following are the general rules which fulfill these conditions: Least breadth at bottom





W“












l
u - \
‘ \ . _ 0
°-‘ - R J 1" '
n?"
" ' H ‘ " s " ' ""


= 2 x greatest breadth of a boat. Least depth of water : 11} foot + greatest draught of boat.
Least area of waterway :: 6 x greatest midship section of a boat.
The bottom of the waterway is flat. The sides, when of earth (which is generally the case),
should not be steeper than 1% to 1. When of masonry, they may be vertical; but, in that case, about
2 feet additional width at the bottom must be given, to enable boats to clear each other; and if the
length traversed between vertical sides is great, as much more additional width as may be necessary
in order to give sufficient sectional area.
Figs. 638 and 639 represent cross-sections of the Erie Canal as enlarged—the former through level
cuttings and the latter through a city. ‘
All canal embankments should be formed and rammed in thin layers. The surface of the tow-
path is usually about 2 feet above the water-level, and is generally about 12 feet wide. It is
made to slope slightly in a direction away from the canal, in order to give a better foothold for the






horses, as they draw in an oblique direction. The slopes are to be pitched with dry stone from 6
to 9 inches thick.
The disposition to be made of watercourses intersecting the line of the canal will depend on their
size, the character of their current, and relative positions of the canal and stream. Small brooks
which lie lower than the canal may be conveyed under it through an ordinary culvert. If the level
of the canal and brook is nearly the same, it will be necessary to make the culvert in the shape of
an inverted siphon, and it is therefore termed a broken-back culvert.
Figs. 640, 611-1, and 642 are respectively top-view, longitudinal section, and crofs-section of a com-
posite culvert. Its construction may be briefly described as follows:
The foundation is composed of hemlock timber 6 inches to 12 inches thick, and covered with hem-
lock plank treenailed to the timber. The spaces between timbers are filled with fine, clean gravel,
well paddled in, or with concrete. Sheet-piling from 3 feet to 6 feet long is put down along the
upper and lower sides of the foundation.
The sides of the culvert are composed of white oak or white pine, 8 inches to 12 inches wide and
12 inches thick for culverts 2 feet high, and 10 inches to 14 inches wide and 18 inches thick for
CANALS. 289

culverts 8 feet in height. The timbers are set on edge, and connected with white-oak dovetailed
keys 2 inches thick and 4 inches wide, placed once in 5 feet: a white-oak treenail, 2 inches thick,
passes through the centre of the timbers, intermediate the keys.
The side timbers are connected with the foundation by treenails and wrought-iron bolts—the bolts
being secured at the top of the covering-plank with screw and nut. The side timbers should be not
less than 24 feet long each, and be well lapped, and so placed as to break joints with each other.
Sometimes they are grooved, and tongued with a white-oak tongue
one-half inch thick and one inch wide.
In cases where there are two or more spaces, the partitions are
made in the same manner as described for the sides.


640/
Jeri/an 67 2.
641.
‘q
The floors are lined with 1.15-inch white-pine plank, treenailed to the foundation timbers.
The top of the culvert is covered with white-pine timbers, from 4 inches to 10 inches thick: these
are grooved and tongued as above described, boxed down half an inch, and treenailcd to the tim-
bers on which they rest.
If the water of the brook is generally limpid, and its current gentle, it may in the last case be
received into the canal. The communication of the brook or feeder with the canal should be so
arranged that the water may be shut off or let in at pleasure, in any quantity desired. For this
purpose a cut is made through the side of the canal, and the sides and bottom of the cut are faced
with masonry laid in hydraulic mortar. A sliding gate, fitted into two grooves made in the side
walls, is maneeuvred by a rack and pinion, so as to regulate the quantity of water to be let in.
When the line of the canal is intersected by a wide watercourse, the communication between the
two shores must be effected either by :1 ca-
nal aqueduct or by the boats descending
from the canal into the stream.
Canal Agucdurts.—As an illustration of
an aqueduct for the conveyance of a canal
across a river, we instance the Wire Sus-
pension Aqueduct over the Alleghany River
at Pittsburg, Fig. 643, constructed under
the superintendence of John A. Roebling,
at the western termination of the Penn-
sylvania Canal. It consists of ’7 spans, of
gem-m, at A B. 160 feet each, from centre to centre of
' pier. The trunk is of wood, and 1,140 feet
long, 14 feet wide at bottom, 16% feet on top, the sides 8}; feet deep. These, as well as the bottom,
are composed of a double course of ills-inch white-pine plank laid diagonally, the two courses cross
ing each other at right angles. The bottom of the trunk rests upon transverse beams, arranged in
pairs, 4 feet apart; between these, the posts which support the sides of the trunk are let in with
dovetailed tenons, secured by bolts. The outside posts, which support the side-walk and tow-path,
incline outward, and are connected with the beams in a similar manner. Each trunk-post is held by
642.


19
290 CANALS.
J
a
two braces, 2% x 10 inches, and connected with the outside posts by a double joint of 2% x 10.
The trunk-posts are 7 inches square on top, and 7 x 14 at the heel; the transverse beams are 27
feet long and 16 x 6 inches; the space between two adjoining is 4 inches. It will be observed that
all parts of the framing are double, with the exception of the posts, so as to admit the suspension.


rods. Each pair of beams is supported on each side of the trunk by a double suspension-rod of
1%-inch round iron, bent in the shape of a stirrup, and mounted on a small cast-iron saddle, which
rests on the cable. These saddles are connected on top of the cables by links, which diminish in size
from the pier toward the centre. The sides of the trunk set solid against the bodies of masonry,
which are erected on each pier and abutment as bases for the pyramids which support the cables.
These pyramids, which are constructed of 3 blocks of a durable, coarse, hard-grained sandstone,
rise 5 feet above the level of the side-walk and tow-path, and measure 3 x 5 feet on top, and 4 x 61}-
feet at base. The ample width of the tow-path and footpath is, therefore, contracted on every pier;
but this arrangement proves no inconvenience, and was necessary for the suspension of the cables
next to the trunk.
The caps which cover the saddles and cables on the pyramids rise 3 feet above the inside or trunk
railing, and would obstruct the free passage of the tow-line; but this is obviated by an iron rod
which passes over the top of the cap, and forms a gradual slope down to the railing on each side of
the pyramid.
The wire cables, which are the main support of the structure, are suspended next to the trunk, one
on each side. Each of these two cables is exactly 7 inches in diameter, perfectly solid and compact,
and constructed in one piece from shore to shore, 1,17 5 feet long; it is composed of 1,900 wires of
one-eighth of an inch in thickness, which are laid parallel toeach other. Great care has been taken
to insure an equal tension of the wires. Oxidation is guarded against by a varnish applied to each
wire separately; their preservation, however, is further insured by a close, compact, and contin-
uous wrapping, made of annealed wire, and laid on by machinery in the most perfect manner. The
extremities of the cables do not extend below ground, but connect with anchor-chains, which, in a
curved line, pass through large masses of masonry, the last links occupying a vertical position; the
chains below ground are imbedded and completely surrounded by cement. Where the cables rest
on the saddles, their size is increased at two points by introducing short wires, and thus forming
swells, which fit into corresponding recesses of the casting. Between these swells the cable is for-
cibly pressed down by three sets of strong iron wedges, driven through openings which are cast in
the side of the saddle.
Fig. 644 is a cross-section, and Fig. 645 an elevation of a canal aqueduct. The trunk is con-
structed of white oak or white pine. The outside stringers are placed so as to embrace the side-
post tenons, and give them a firm support. The side-posts are 8 x 11% inches at the top, and 8 x
18 inches at the bottom shoulder, and placed 3 feet from centre to centre. The corner or end
posts are of white oak, and extend down 3 feet into the masonry to give firmness to the corner of


















UUUOWUUUL ‘ 0000000000
the trunk. A white-pine plate, 10 x 16 inches, is framed on top of the posts. The bottom of the
trunk and the ends of the floor-timbers in the abutments are covered with a course of 2-inch white-
pine plank of good quality, to make water-tight joints. The planks are treenailed to foundation-
timbers with treenails 6 inches long, of suitable size to fill an aperture 1 inch in diameter. The
CANALS. 291

sides are planked with 3-inch white-pine plank, tongued and grooved, and secured to side-posts with
treenails 7 inches long. The sides and bottom of the trunk are sometimes braced from recesses cut
into the masonry. The tow-path bridge is 12 feet wide, and supported on white-pine stringers. The
645.


W] U
floor is composed of 3-inch white-oak or red-beech timber, treenailed to the stringers. A timber of
hard wood, 6 x 8 inches, is placed upon the inside end of the floor to guide the tow-line, and is
fastened to the front stringer. ,
Waste-weirs must be made along the levels to let off the surplus water. The best position for
them is at points where they can discharge into natural watercourses. The best arrangement for
a waste-weir is to make a cut through the side of the canal to a level with the bottom of it, so that,
in case of necessity, the waste-weir may also serve for draining the level. The sides and bottom of
the cut must be faced with masonry, and have grooves left in them to receive a stop-plank or a slid-
ing gate, over which the surplus water is allowed to flow, which can be removed if found necessary,
either to let off a larger amount of water or to drain the level completely.
Loans—A lock is a small basin just large enough to receive a boat, in which the water is confined
by two upright walls of masonry or timber, and at the ends by two gates, which open and shut, both
for the purpose of allowing the boat to pass and to cut off the water of the upper level from the
lower, as well as from the look while the boat is in it. '
Fig. 646 represents a plan, 111, and Fig. 647 a section, N, through the axis of a single lock laid on
a béton foundation. A, lock-chamber; B, fore-bay; C, tail-bay; a a, chamber-walls; b b, recesses
y or chambers in the sidewalls for
646. upper gates; c 0, lower gate cham-
bers; of cl, lift-walls and upper
M mitre-sill; h h, tail-walls ; 0 o,
head-walls; m m, upper wing or
return-walls ; n 12, lower wing-
walls; D, body of masonry un-
der the fore-bay.
To pass a boat from one level
to the other—from the lower to
the upper, for example—the low-
er gates are opened, and, the





647.
,v \ _ boat having entered the look,
i they are shut, and water is drawn
0 " 1 ° ' f‘ ' 1 - 1 =1 b
y a a, ; a torn tie upper eve y means
' of valves, to fill the lock and



raise the boat; when the opera-
tion is finished, the upper gates
~ are opened, and the boat is passed
out. To descend from the upper level, the lock is first filled ; the upper gates are then opened, and
the boat is passed in; these gates are next shut, and the water is drawn from the look by valves
until the boat is lowered to the lower level, when the lower gates are opened and the boat is passed
out of the lock.
Form to be given to the chambers of locka—The most convenient is the parallelogram, a little wider
than the boats that require to pass, and sufficiently long to admit of the gates being moved with
facility. The thickness of straight walls which support earth should be a third of their height,
while those which resist the thrust of water should be one-half; if the walls of the chambers of
locks have a thickness relative only to the thrust of the earth, they may give way when the earth is
put in motion, which often occurs from a slight filtration behind the wall. Gauthey has a rule for
finding the thickness to be given to the wall of a basin intended to support water throughout its
whole height; and in the chambers of looks it must be remembered that the thrust of the water
against the vertical surface is equal to the product of these surfaces by half the height of the
water. Call It the height of the wall, a: :: its thickness: supposing its length to be 1 metre, the act-
ing power will be 1,000 x thi; supposing the cubic metre of water to weigh 1,000 kilogrammes,
and the centre of impression of this thrust being at a third of the height of the wall, the arm of
the lover of the acting power will be equal to 5b. The resisting power will be the wall itself
:71 :v x 2,000, supposing that the cubic metre of masonry generally weighs 2,000 kilogrammes.
The arm of the lever will be half the thickness of the wall: 51;; consequently the momentum of


292 CANALS.
"w
the acting power will be 1,000 x eh? >< ya, and that of the resisting power 2,000 x th x2; and as
in the state of equilibrium these two powers should be equal, we shall have 167 ha 2 1,00071. mi,
from whence we have a? : V0.167 h3 z 0.41 it; but, as something should always be allowed above
the equilibrium, by adding l,- we shall have .r : Hz nearly. Hence it is evident that the thickness of
a wall intended to support water should be at least equal to half the height of the water which acts
against it.
The length and width of chambers of locks must necessarily be regulated in conformity with the
boats used on the canal; these are generally longer and narrower than those on rivers, where the
shallows which occasionally occur require flatter bottoms to be given them. With regard to the
length of the chambers, it should be such as to enable the gates at the lowest ends to open and shut
easily. If the rudders of the boats cannot be unshipped, or occupy any portion of the length of the
chamber, then the chambers must be made sufficiently long to prevent them from interfering with
the opening of the gate; on which account the most proper rudders fornavigable canals are those
like broad oars, which can be taken out while passing through the locks.
648. P
l
\
\
\
\
\


Fig. 648 is a plan, Fig. 649 a longitudinal section, and Fig. 650 a cross-section of the present
enlarged form of one~half of a double lock on the Erie Canal. A lock of this description (of 11-
feet lift, for example) is constructed as follows : The lock is constructed of hydraulic stone masonry,
placed on a timber foundation; the chambers 18 feet wide at the surface of water in the lower level, '
649-


and 110 feet long between the upper and lower gate-quoins ; side-walls extend 19 feet '7 inches above
the upper gate-quoins and 13% feet below the lower gate-quoins; side-walls at the head terminate
with rectangular wing-buttresses, and at the foot with straight wings 25 feet in length, slightly
curved at their connection with main walls, spreading at the end 5 feet wider than bottom line
of look walls. Culverts '
formed of large stone, 650-
cut to one—quarter inch 115-.31:
joint, to pass the water
_ 1 1 ' W a a , V .5,%=;.7?;H
from lock to lock, aIO












constructed in the walls :7 / r r w \ z.
with proper apertures for: ~;:‘,)5'$;':.I,I ,1
valves, rods, and venti-
;////4¢////,-u;d§3gigé
.lators. The timbers un-
//A///%-Hqz,hgd

. . ‘ I I. , . . 0, -. ‘
der lower mitre-slll are
of white oak, white elm,
‘ mg-Qmumm “r/
or red beech; the other . I l L [ /






tiara. r ,1 ,1 a I
The foundation extends L 1 L l
3 feet above the face of
the main wall at the head
of the lock, and at the foot 6 inches below end of wing-walls; the length of foundation, exclu-M
sive of apron, is 1'73 feet 3 inches. The spaces between timbers are filled with concrete masonry.
Where rock does not occur, shcct~piling is driven 4- to 6 feet deep at the head of the foundation,
under each set of gates, at the lower end of the wings and at the lower end of the apron. The
sheet-piling is of 2-inch hemlock plank, lined with 1-inch pine boards.
CAN ALS. 293

The foundation-timbers are covered with a course of 21l-ineh pine or hemlock plank, except a
space 3 feet wide under the face-line of each wall, which is covered with 2Q-inch white-oak plank.
The planks are treenailed with two white-oak treenails at each end, and at every 3 feet in length.
The treenails should enter the timbers at least 5 inches, and fill a 111-inch bore. The platform for
upper gates and valves consists of a framework of timber extending across the lock, and raised to
within 2 feet 9 inches of canal bottom of upper level. In this platform the valves are inserted;
they lie horizontally when closed, and are operated by levers, rods, and shackle-bars from the side
of the lock.
The mitre-sills are of white-oak timber 9 inches thick. Each sill is bolted to the foundation or
platform timbers with 9 bolts 20 inches long and 1 inch square, ragged and headed.
The main walls, for 17 feet 6 inches in length from the wing-buttresses at the head, and 33 feet
3 inches of the lower end, are 9 feet 10 inches thick including the recesses, and for the intermediate
space 7 feet 10 inches, with 3 buttresses projecting back 2%; feet, and 9 feet long, placed at equal
distances apart, leaving spaces 16 feet between them, and having an offset of 6 inches in thickness at
5 feet below the top. The height of the walls is 20% feet. The chamber-walls each have a batter
on the face of half an inch per foot rise to the top of the wall. The quoin stones, in which the
heel-posts turn, are not less than 41} feet in length in the line of the chamber, and cut and formed to
a curve of 7 inches radius; the nose is rounded on a radius of 3,50% inches, and the heel beveled to
the rear of the recess. The quoin stones are alternately header and stretcher. The recesses for
the lower gates are 20 inches deep at the top of the wall, 12 feet long, with sub-recesses 9 inches
deep, 6 feet high, and 10 feet long, for valve-gates. The wing-buttresses at the head of the lock are
3 feet thick, extend on the bottom to the upper edge of the foundation, and are carried plumb to
the whole height of the main wall. The breast-wall commences 5%; feet below the upper end of the
foundation, and extends across from side wall to side wall; it is 5 feet wide and 11 feet high,
finished with cut-stone coping. The wing-walls, at the point where they join the main walls, are 7
feet 10 inches, and at the ends 6 feet 7 inches thick on the foundation; at 4 feet below the top of
the wall an ofiset is made. The face-stone of the masonry is laid with upper and lower beds parallel,
with joints not to exceed one-quarter of an inch.
Gates of locks are composed of two posts placed vertically, and united by horizontal rails; the
former, being supported throughout their height, are not subject to much wear, although they are
of larger scantling than the other timbers of the gate, which is necessary, as they sustain the entire
framework. The horizontal rails resist the weight, and as that weight is greater where the rails
are placed below the level of the water, it would seem natural that their dimensions should vary
in proportion to the weight. To determine these dimensions, it must be recollected that the thrust
of water against vertical surfaces is equal to the weight of a prism of water having its surface as
a base, and its height half that of the water. It must next be considered that the rails of the gate
are at least 26 inches apart and 38 inches from centre to centre, so that, on account of the casing of
plank in the first instance, 12 inches of height support 26 inches of water, and in the second 38
inches. The weight supported by each rail will be found by multiplying their length, the interval
from one to the other, the height of the water above the centre of the rail, and the whole by 62 lbs.,
the weight of a cubic foot of water; the product of these measures will he the number of pounds
which the rails ought to support throughout their whole length. '
Timbers from 4 to 5 inches square would be sufiicient for small gates, and for larger from 8 feet 6
inches to 10 feet 6 inches of fall; with a width of 17 feet between the hanging-posts, the rails would
be sufficiently strong if from 7 to 8 inches square, putting six rails in the height. They are gener-
ally from 9 to 10 inches at least, which is double the strength required; it is true that the gates are
more durable, but the weight is greater, which is sometimes injurious to the collar and the masonry
to which it is attached, requiring more repairs than lighter gates.
The frames or stiles of gates should be at least 5 inches in thickness more than the rails, and the
joint covered by a fillet, as well as the edge of the planks, which are afl‘ixed perpendicularly to the
rails, and mortised into the stiles, increasing the strength of the rails and the framework by their
greater thickness. Braces are also introduced between the rails, which aid materially in strengthen-
ing them, and by their inclined position transfer the stress to the hanging-post.
Great gates should always have a line of braces placed diagonally, and making an angle with the
lower rail ; all the braces above should have the same effect, and consequently the same inclination;
those below resting on the lower rail tend to depress it, and, even when properly framed and pinned
into the rails, their inclination toward the hanging-post renders them insufficient- to sustain the lower
rail; but they may be made useful by giving them an inclination in a contrary direction, and uniting
them by pins to the rails.
Instead of inclining the braces below the diagonals on the side of the strutting-post, a bar of iron
is sometimes placed diagonally from the collar to the lower end of the strutting-post, which is an ex-
cellent eontrivance; or the planks may be placed diagonally, inclining them from the side of the
hanging-post, and crossing them solidly, especially that of the diagonal above the hanging-post, and
at the extremity of the lower cross piece; or instead of a plank, a piece maybe let in in an opposite
direction to the cross-pieces, which must not be mortised into, or very little, that it may not be in
any way weakened; this piece united carefully to the lower cross-piece would tie it to the post, and
give more solidity to the framework ; the diagonal position of the planks gives them more strength
to resist the pressure. There is a. little loss of material, but, on the other hand, plank of difierent
kinds may be used after cutting out the knotty or defective portions.
Gates are opened by means of large timbers fixed above the posts, forming a eounterpoise to the
gate, and preventing it from grinding the collars and racking the framework; for this purpose the
tail of the balance-beam must be very large. Trees are sometimes used with their butt-ends not cut
ofi, to which it is easy to add any additional weight. The hanging-posts often allow much water to be
294 ‘ CAN ALS.

lost, in consequence of being obliged to give them sufficient play, and this could scarcely be prevented
if the pivot had not a little motion, and the collar fitted exactly; but the weight of water occasions
the gate to unite by pressing it considerably against the hanging-post; still, as this is cut circularly,
it only leans against a small portion of its surface, and
the water easily passes, notwithstanding the great pres-
/ sure. To remedy these defects, the posts should be partly
cut in a circular form, and partly beveled; the latter lean-
r": ing along its whole length upon the rebate made to receive
it, which having a corresponding bevel interrupts any filtration; the
circular part should not touch the masonry, buthave sufficient play
without affecting the ease of the motion.
Lock-gates measuring 8 feet from the centre of one heel-post to that
of the other are in some canals on a segment of a circle, the chord of
which is about the sixth of the span, or a little more; these propor-
tions not only allow of the gates being smaller, lighter, and stronger,
but also increase the pressure of the heel-post against the hollow quoins,
which renders them quite water-tight. Where canals are narrow, the
paddles of both the upper and lower gates are usually kept open by
an iron pin inserted between the teeth of a. rack and pinion which
raises them; when the paddle is required to be shut, the pin is with-
drawn, and the paddle falls by its own weight.
The lock-gates, Fig. 651, of the above-described lock are constructed
of white oak, planed; the cross-bars framed into the heel and toe posts.
Each tenon is ’7 inches long, and the width equal to the thickness of
bar, and secured with wrought-iron T’s. The heel and toe posts are framed into the balance-beam
by double tenons, and secured by a wrought-iron strap and balance-rod, from the top of the beam to
the under side of the upper bar. The lower end of the heel-posts are banded with wrought-iron
bands. The pivots, sockets, boxes, and journals are of the best quality chilled cast-iron. The gates
are planked with seasoned 2-inch white-pine plank, secured by 6-inch pressed spikes.
Hollow quoins, or upright circular grooves, are formed in the side walls, at the ends of the timber
sills, serving as the hinge for the gates; the upright post that turns within them is called the heel of
the gate, and the other the head. The former are retained in their position by a gudgeon or pivot
turning in a cup let into the foundation stones for the purpose; sometimes the pivot is fixed, and
the cup revolves upon it. The upper part of the post is retained by an iron ring or strap let into
the side wall, and made very secure; the hollow quoins should be worked with great attention;
they are usually of stone or brick, though cast-iron has been found well suited for the purpose.
The angle to be given to double lock-gates has long occupied the attention of engineers, but the
strongest position may be taken
when the angle at the base is -
35° 16' nearly, and the sally of I \
the gate is seven-twentieths, or ' ' ‘3
a trifle more than one-third, of
the breadth of the lock. .72






























Valves. — Some lock - gates
have their paddles, or valves,
made to open and shut by the
movement of a lever, the low- 1’
er end of which, being loaded, A
keeps it always over the aper-
ture in the lower part of the _
gate; when it is required to be (
moved, the upper part or han-
dle of the lever is pulled back, n
and the water, forcing its pas- ,
sage through, keeps it open 2’
"until its weight overcomes the
'power, and it is balanced back
into its original position.
The crank and pinion, work-
. ing in a toothed rack, are now
generally applied to raise the
paddle.

Q






Screws are sometimes used 3
for this purpose, formed of
wood, sliding up and down in . K -A

a rcbated frame, fixed in the
stone mouth of the conduit or
paddle-hole. The lateral pres-
sure of the water causes it to
adhere closely to the frame, so
that it is not only necessary to make it run with the grain of the wood, but also to have consider-
able power to move it; this is occasionally effected by means of a long iron lever, with 'an eye at
one end that spans the square end of the screw, and allows a suflieient force to be applied to raise











C -
CAN ALS. 295

the paddle. There are several applications of the screw, one of which, as used at the gates of Dun-
kirk, is very simple, and was for a long time adopted throughout Europe. To overcome the hydro-
static pressure and friction, at the mouth of the paddle-hole was a horizontal circular opening, within
which was inserted an open cylinder of wood or iron ground to fit it, which could be raised by a
lever; the waste water of the canal could then escape over the upper lip of the cylinder, and after-
ward pass out by the paddle-holes.
Figs. 652 and 653 represent an arrangement for the valves or sluices of a lock-gate. Fig. 652 is
an elevation; Fig. 653, a vertical section through G .
The object of this arrangement is that, while the'gate is kept close and tight by the pressure of
the water forcing it against its seat, the effort of lifting the gate shall at the same time relieve the
seat from the pressure of the water; and this is effected by means of fric-
tion-rollers kit, which, immediately upon the commencement of the lifting
of the gate, act as short inclines, thus taking the pressure from the seat, and
throwing it upon the friction-rollers or wheels, easing the lifting of the gate.
When the gate is closed, the wheels have run off the inclines, and the gate
bears against its seat with the pressure due to the head of water.
Inclined Planes on Canals—To save the time and water expended in Shift
'ing boats from one level to another by means of locks, inclined planes are
used on some canals. Their general construction is as follows: The upper
and lower reach of the canal, at the places which are to be connected by
inclined planes, are deepened sufficiently to admit of the introduction of
water-tight iron caissons, or movable tanks, under the boats. Two parallel
lines of rails start from the bottom of the lower reach, ascend an inclined
plane up to a summit a little above the water-level of the upper reach, and
then descend a short inclined plane to the bottom of the upper reach.
There are two caissons, or movable tanks, on wheels, each holding water
enough to float a boat. One of these caissons runs on each line of rails;
and they are so connected, by means of a chain or of a wire rope, running on
movable pulleys, that when one descends the other ascends. These caissons j
balance each other at all times when both are on the long incline, because K , i\
the boats, light or heavy, which they con- ,7 _ ,{f
tain, displace exactly their own weight of water. There is a short period when both
caissons are in the act of coming out of Mags“ “5?,
the water, one at the upper and the other
at the lower reach, when the balance is not maintained; and, in order to supply the power required
at that time, and to overcome friction, a steam-engine drives the main pulley, as in the case of fixed-
cngine planes on railways. On some canals vertical lifts with caissons are used instead of inclined
planes. I
Water-supply.—-With regard to the supply of water necessary for a canal, or for a level of canal,
it embraces the quantity required for the service of the navigation, that is, the number of times the
chambers of the locks will require to be used in the passage of boats, and the losses arising from
evaporation, from leak. We through the soil and through the lock-gates, the necessary first fillings of
the levels and the chance of accidents or breaches, and the emptying of the levels for repairs. In
estimating the quantity expended for the service of navigation, the problem is simple, knowing the
capacity, form, and number of locks, the size of boats, and the contemplated amount of traflic. With
regard to the other losses it must be largely a matter of conjecture. From experiments made by
Mr. J. B. Jervis on the Erie Canal, the total loss from evaporation, filtration, and leakage through the
gates is about 100 cubic feet per minute for each mile. Having determined the amount of water
required, the source of the supply must be gauged; and if the minimum flow of the stream be not
sufficient, reservoirs must be constructed to equalize the supply.
The quantities of water discharged from the upper pond at a lock or flight of locks, under various
circumstances, are shown in the tables on the next page. L denotes a loekful of water—that is, the
volume contained in the lock-chamber, between the upper and lower water-levels; B, the volume
displaced by a boat. The sign -— prefixed to a quantity of water denotes that it is displaced from
the leak into the upper pond. The letters 12. and m stand for a given number of boats or looks, and
are used simply for the purpose of generalization. Thus a “ train of n boats ” may mean a train of
2, 3, 4, 5, or as many boats as are to be considered; and the same number which n represents is
applied in the formulae under “ Water discharged.” Similarly, a “ flight of m locks" means a flight
of 2, 3, 4, 5, etc., locks.
From these calculations, it appears that single locks are more favorable to economy of water than
flights of locks; that at a single lock single boats ascending and descending alternately cause less ex-
penditure of water than equal numbers of boats in trains ;‘ and that, on the other hand, at a flight of
locks, boats in trains cause less expenditure of water than equal numbers of boats ascending and
descending alternately.
For this reason, when a long flight of locks is unavoidable, it is usual to make it double; that is,
to have two similar flights side by sidch—using one exclusively for ascending boats and the other
exclusively for descending boats.
Water may be saved at flights of locks by aid of side-ponds (sometimes called “lateral reservoirs”).
The use of a side-pond is to keep for future use a certain portion of the water discharged from a
lock, when the locks below it in the flight are full, which water would otherwise be wholly discharged
into the lower reach. Let a be the horizontal area of a lock-chamber, A that of its side-pond; then
the volume of water so saved is L A —:- (A + a).
















296 J CANALS.

Table showing. Quantities of lVater discharged from the Upper Pond at a Zack.










SINGLE LOCK. Lock found \Vater discharged. ' Lock left
One b at descnidimr . . . . . . . . . . . . . . . . . . . . . .. ' . . . . . . . . . . . . . . . — . . . . . . . . . . . ..
i b ..................... .. it}??? ............ .. ‘ZB ........... ..l war
One boat ascending . . . . . . . . . . . . . . . . . . . . . .. empty or full . . . . . . . .. L + B . . . . . . . . . . . . . .. full.
Two n boats, descending and ascending descending full..... L n L {descendingr empty.
alternately . . . . . . . . . . . . . . . . . . . . . . . . . . .. ascending empty... 5 ' ‘ ' ' ' ‘ ‘ ' ‘ ‘ ‘ ' ' ' ' ’ ' " ascending full.
Train of n boats descending . . . . . . . . . . . . . . .. empty . . . . . . . . . . . . . . . n L - n B . . . . . . . . . cm t
r “ “ .............. .. mu . . . . . . . . . . . . . . .. ('n—l)L-nB Py'
Train of n boats ascending. . . . . . . . . . . . . .. empty or full . . . . . . . . . n L + n B . . . . . . . . . .. full.
Two trains, each of n beats, the first de- fun (9% __ l L full
seending, the second ascending . . . . . . . . . ‘ ' ' ' ‘ ' ‘ ' ' ' ‘ ' ' ‘ ' ' ' ' " ) ' ‘ ‘ ' ' ' ' ' ' " '
\ Quantities discharged at a Flight of Locks.
r'uerrr or m LOCKS. Locks found W‘ater discharged. I Lock left
One boat descending . . . . . . . . . . . . . . . . . . . . . .. em t . . . . . . . . . . . . . . . L — B. . . .Y . . . . . . . . . l
“ “ . . . . . . . . . . . . . . . . . . . . . . . full? . . . . . . . . . . . . . . . — B . . . . . . . . . . . . l . empty
One boat ascendin<r . . . . . . . . . . . . . . . . . . . . . . .. empty . . . . . . . . . . . . . .. m L + B . . . . . . . . . . . 1
° ...................... .. full ................ .. L + B ......... .. 5% fun-
Two (n) boats,descending and ascending descending full... .. :v ,m n L ij descending empty.
alternately . . . . . . . . . . . . . . . . . . . . . . . . . . . . i ascending empty... ' ' ' ‘ ‘ ' ‘ ‘ ‘ ' ' ' ' ‘ ' ' y | ascending full.
Train ofn boats descending . . . . . . . . . . . . . . . . empty . . . . . . . . . . . . . . . n L - n B . . . . . . . . . . ’ em t ,
“ “ .............. .. full ................ .. (n—l)L-nB...'. . -P5-
“ “ ascending. . . .. .. . . . . . . .. empty . . . . . . . . . . . . . . (m + n — 1) L + n-B ¢_'
“ “ “ D . . . . . . . . . . . . . . . .. full . . . . . . . . . . . . . . . . .. nL + n . . . . . . .. ; f‘ln‘
Two trains, each of n beats, the first dc-
scending, the second ascending __ U l full ................ .. (m + 2n- 2) fulL





The least length that can be allowed between the locks should be such that 12 inches of depth, over
and above what a loaded boat will draw, will only lower the water 6 inches without the navigation
being interrupted; and if it be required to draw the contents ,of each lock from the interval above,
the distance for the locks must be so regulated that the quantity of water expended by one should
not lower that of the upper interval more than 6 inches at most: thus the distance should be greater
in proportion to the contents of the chambers of the locks and the width of the canal ; that is to say,
when the chambers are large and the canal is narrow, the distance between the locks should be
greater. Chambers 110 feet in length between the gates, by 17 feet in width, contain 1,870 super-
ficial feet; therefore, 11,843 cubic feet when the fall is 6 feet 4 inches, 15,859 cubic feet when it is
8 feet 6 inches, and 19,635 cubic feet when 10 feet 6 inches. If the canal be 48 feet in width at 3
feet below the ordinary level of the water, the length of the interval should be 446 feet, in order
that the expenditure of locks of 6 feet 4 inches of fall should not lower the water more than 6.
inches; this length should be 607 feet when the locks are 8 feet 6 inches of fall, and 7 55 feet when
they are 10 feet 6 inches; the distance then between the lower gate of one lock and the upper gate '
of the other should be always about 624 feet for ordinary canals. If two locks of 8 feet 6 inches
fall were only distant 160 feet, the water drawn from the interval, for the purpose of mounting the
boat, would lower it nearly 26 inches, and there would not remain sufficient to keep it afloat; con-
sequently, it would be necessary to draw a lockful from the upper interval, and then a second, to
cause it to rise, while only one would be required if the locks were at a sufficient distance.
This example will show the inconvenience of having locks too near each other, which is still further
increased when they are contiguous. It frequently happens that several boats arrive together in the
same interval, particularly where the boatmen stop or sleep; and that no water may be lost, the
interval where they step should be sufficiently long to admit more than one. If circumstances will
not permit this, a greater width must be given, that the lockful which the rising boats draw from
the interval may not cause the water to lower so considerably as to prevent their floating, or the
descending boats force in such a quantity as to make it run over the gates. If the interval has only
the ordinary width of 48 feet, it should be 6,398 feet in length, so that ten rising boats could stop,
if none were descending at the same time; otherwise a part of the water must be drawn from the
other intervals to keep them afloat. If there were as many ascending as descending boats, this need
not be so great; but this observation proves that, in forming a canal, it is necessary to have basins at
those situations where boats are required to stop any length of time. ,
Locomotion on Canals—In early times boats were drawn or pushed along by servants or slaves.
In civilized countries horses and mules have been chiefly used. In recent years many attempts have
been made to use steam-power by driving the boat like a propeller. The most successful boat of
this kind was invented by Mr. William Baxter, of Newark, N. J., and competed for the prize of
$100,000 offered by the State of New York in 1871 for an acceptable mode of applying steam for
propelling canal-boats on the canals—plans involving what is called the Belgian system being
excluded. This boat, Figs. 654 to 657, on her first trip in September, 1872, with a cargo of 201 tons,
made an average speed of 3.38 miles per hour, expending on an average 31.04 lbs. coal per boat-
mile. The power expended appeared to vary from about 23 to about 33 horses, and the coal con-
sumption was about 3%; lbs. per horse-power per hour. The apparent slip of the screw was found
to be from 124- to 33 per cent., while the actual slip varied from 23} to 25 per cent.
The Belgian system has been quite extensively used in some European countries. It consists of a
cable which passes from one end of the canal to the other, and is sunk in it. It is wound around a
wheel which is at one end of the boat. Steam-power is applied to turn the wheel; and as the friction














LM
.. Q \.



of the rope on the wheel prevents it from slipping, it will take up the cable on one side of the wheel
and let it out on the other, and thus draw the boat along. One of the objections to this plan is that it
655. \\‘ \ 656.




\ __..

















__ ... __ 2 l_.___.g*v ‘—
%\39 PM ,1 a
“:~—~"_~:‘:1:;" 4&4 ‘./////-=1


requires a large amount of slack-cable to accommodate a. large tral’fic, and every boat must draw in
all the slack every time it passes over the canal.
The machinery of a chain-towing steamer, the most perfect type of which, as worked on the Elbe,
is given in Fig. 6358, consists
657 of a pair of drums worked by
' gearing from engines of 80
horse-power. At each extrem-
ity it is furnished with long
outriggers, pivoted at one end,
the other projecting beyond
the ends of the vessel, formed
of double T-irons, holding a
series of loose pulleys and a
pair of vertical guides. Be-
tween the drums and the out-
riggers there are 16 or more
horizontal pulleys placed in a
gutter about 10 inches wide
“\\““,““““““ “v V by 8 inches deep, and four or
=4IZ;I\’<{2\IE\I\’<\IZQI&IJAQZL?£ - -~ :1- ; T more vertical guides for sup-
' ' porting and guiding the chain.
The chain is taken on at the stem, and dragged between and over the pulleys and guides to the
drums, which are massive castings of chilled cast-iron or cast-steel. The peripheries of these are
divided into grooves to prevent the triple rounds of chain in their passage over the drums from




4,


65S.
‘\
‘3- ~—
\ _











getting entangled together. Thence the chain runs along the gutter supported by-the loose pulleys,
and over the outrigger, where it is paid back again into the water. The objects of the outriggers
are: first, to allow the chain to come on or to run off the steamer without cutting into the edges of
the deck or fenders, and to clear the rudders ; and secondly, in passing round curves, to allow of its
being taken up and run out at an angle to the line of the steamer’s movement. In front and astern
of the drums there are wells for containing the slack chain, should there, from a surplus quantity of
298 CANALS.

chain, be no strain astern of the drums to haul the chain from off the vessel. This slack remains
until the tension behind draws it away again into the river.
The chain used on the Elbe is composed of l-inch, and in some places 1-,‘(,=-inch iron.
Wire-cable-towing steamers, such as are in use in various parts of Germany, have in the centre or
mid-line, raised to a sufficient height, two metal drums, the periphery or outer circumference of
which is divided into five grooves. These drums are made conical, so that the length of each groove
measured round the circumference of the drum is different, greater or less than the rest, to corre-
spond with the diiference of the strains developed by the tension of the cable; or, in other words,
by the power transmitted from the engines to the drums, and from the drums to the wire cable.
These drums, revolving upon strong shafts, are worked by double sets of gearing from the engines,
for fast or slow motion; but that their speeds, which vary under different strains, may correspond
and be regulated exactly, they are-coupled together by means of the three-toothed wheels, one of
which is a friction-wheel. A loose pulley raised or lowered by a lever is placed between the drums
below the lower line of their circumference, for the purpose of insuring the adhesion of the cable
to the drums when necessary. 7 .
The shafts carrying the drums also support the transmission-pulleys which, by means of two end-
less wire cables held at the vessel’s extremities by pulleys, transmit the necessary movement from
the engine to the taking—in and payingout apparatus termed a “truck.” This is employed for the
purpose of guiding the cable with a certain tension on to the drums, and of relaying it from the
steamer as it leaves the drums. It comprises a strong framing of angle—iron, and is furnished below
with small wheels by means of which it runs on deck, and is held down to rails of proper form
bolted to the deck-beams. ‘
The truck is furnished with four horizontal press-rolls, two above and two below, working in pairs on
two upright shafts. The lower pair of press-rolls receive and transmit the power from the engines,
and the upper pair guide and pay the cable on and draw it off from the drums, and relay it. These
press-rolls are cast_iron wheels, carrying at their periphery 60 teeth working on India-rubber rings.
These teeth are cast in metal, and their outer faces bear the impress of the strands of the cable, so
that the latter may receive or transmit power without friction or injury to either. The truck carries
in front two large hollow vertical drums for guiding the cable during the passage of curves, between
the press-rolls, and is furnished above and below with several small horizontal pulleys for support-
ing the cable horizontally.
The engines being started, the drums and the transmission-pulleys begin to revolve; and, the
transmission-cables driving the lower press-rolls of the forward and after truck, the cable is paid on
to and drawn off from the drums at the requisite tension by the revolution of the upper press-rolls.
As the cable passes from between the upper press-rolls of the fore-truck, it runs straight on to
the first groove of the forward drum. The cable revolves round the drums, and then runs to the
after-truck, where it passes between the upper press-rolls, and is paid out over the stern of the
steamer.
The wire cable generally used is seven-eighths of an inch in diameter. Messrs. Meyer and Wer-
nigh, the inventors of the above-described wire-cable—towing steamers, give as the results of their
dynamometrical trials the following
Table of lVorking Capabilities of lVire-cable-towing Steamers, in Still lVater, at clifm'ent Speeds, with
. Barges of difi'erent Draughts, empty or laden.









DIMENSIONS.
Total resistance to tractions of steamer and train Empty barge... . .L = 131’ 10”, .B =: 14’ 11”, D = 1’ 6”.
in lbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. = P. “ lighter... .L = 131' 10”, B = 14' 11”, D = _8”,
Speed in feet per second . . . . . . . . . . . . . . . . . . . . . . .. = V. Laden bargeln . . .L = 131’ 10”, B = 14’ 11”, I) = 3’ 3”.
Immersed section . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. : F. “ lightcrg. . ..L = 131’ 10”, B = 14’ 11”, D = 3’ 8”.
Resistance of vessels in lbs . . . . . . . . . . . . . . . . . . . . . . = W. ————~—
1 Load or cargo in cwts . . . . . . . . . . . . . . .. 1,571
Hp_ Z) x V 2 “ “ “ . . . . . . . . . . . . . .. 2,455
_ 550
MAXIMUM EFFECT IN NUMBER OF BARGES TOWED.
CONDITIONS- 50 H. P. Engines : V = 25 H. P. Engines : V = !25 H. P. Engines: V =
3’ 3” per second, or 6' 6” per second, or 8' 3" per second, or
9.2 miles per hour, 4.4 miles per hour, 2.9 miles per hour,
with P = 13 cwts. with P: 18 cwts with P = 36 cwts.
Empty barge . . . . . . . . . . . . .F: 21.6 sq. ft., W: 66 lbs. 125 .. . 62
“ “ . . . . . . . . . . . ..F:21.6 “ W:286 “ .2. i' 7
Empty lighter . . . . . . . . . . . .F: 9.6 “ W: 29 “ 267 . .. 144
“ “ . . . . . . . . . . . ..F: 9.6 “ W: 121 “ 17
Laden barge . . . . . . . . . . . . ..F: 48.4 “ W: 150 “ 55 . . . 27
“ lighter . . . . . . . . . . . ..F: 48.4 “ W: 605 “ . .. 3 . . .



In this table regard is had to the coefficient (.3) of the ship’s resistance, uponwhich these trials
were carried out.
The Suez Canal extends from Port Said, on the Mediterranean, at sea-level, and without locks,
across the isthmus by the most direct route, which carries it through the depressions of Lakes Men-
zallah, Ballah, and Timsah, and the Bitter Lakes, to Suez on the Red Sea, in a line nearly due
north and south. Its length is 99 miles; its width on the surface varies from 196 to 328 ft., accord-
ing to the strata through which it is excavated, but the bottom width is 72 ft. throughout. The
CANALS. 299

depth is 26 ft. Through a portion of the Bitter Lakes no excavation was necessary, and the deepest
cut, at El Guisr, was only 85 ft. to the bottom of the canal. The amount of excavation was about
98,000,000 cub. yds., mostly sand and clay, or a mixture of both, except at places south of the Bitter
Lakes, where some rock was encountered. The cost of the canal was about $100,000,000.
The Amsterdam Canal—This canal, which the circuitous route through the North Holland Canal,
and the increasing size and draught of the vessels trading to Amsterdam, forced that city to con-
struct in order to hold its own against the more favorably situated ports of Rotterdam and Antwerp,
extends due west from Amsterdam across the peninsula of Holland to the North Sea, a distance of
15% miles. Its bottom width is 8822 ft., its surface width 187 ft., and its depth 23 ft.
The St. Peters-burg Camal.—-The length of the canal is 18 miles; maximum width, 350 ft. ; general
width, 180 to 240 ft. ; depth, 22 ft. The total excavation amounted to about 63,000,000 cub. yds. of
clay, sand, and gravel, most of it used in the construction of the embankments. The cost of the
canal was about $9,000,000.
The canal starts from the mouth of the Neva, where it opens into a large basin, and trends south-
ward about two miles, with a width of 207 ft. between embankments. It then joins the canal to
Cronstadt, and at the same point branches to meet the Neva above St. Petersburg.
The Corinth Canal—This canal will cut the isthmus of the same name, uniting the waters of the
fEgean Sea and the Gulf of Lepanto, and make an island of the Morea.
The completed canal will be 4 miles long, with a surface width of about 28 metres (91.87 ft), a
bottom width of 16 metres (52.42 ft.), and a depth of 85 metres (27.89 ft). The depth of the cut at
the highest part of the isthmus will be 228 ft.
This canal will shorten the voyage of vessels going from the Adriatic Sea to Turkey and Asia
Minor by 185 miles, and those coming through the Straits of Messina by 95 miles.
The North Sea, Baltic, or Holstein Canal.——From the Elbe the canal passes through swampy land,
and then through gradually rising ground, to the “ divide,” 82 ft. above the sea; thence to the
Eider, a portion of which is utilized, thence to the Eider Lakes, and thence via the Rider Canal,
rectified and enlarged, to Holtenau, near Kiel. The length of the canal will be between 60 and 61
miles, the usual radii of curves 4,900 and 6,500 ft., with a minimum of 3,275 ft.
The chief value of the canal being in the speed with which it can be traversed, the curves will
be as easy and few as possible. The average cross-section of the canal will be 85 ft. 3 in. wide
at bottom, 197 ft. at water surface, and 27 ft. 10:} in. deep, giving 3,920 sq. ft. of prism, which
will permit the ordinary Baltic vessels to pass without trouble. The lakes and special sidings will
accommodate war-vessels. The depth will possibly be increased to 29 ft. 6 in., and the future
enlargement of the canal is provided for by the purchase of a strip of land along the south side of
the canal.
The canal is a thorough cut, with tidal locks at each end. The mean range of tides in the Bal-
tic is about 1 ft. 8 in. above and below the canal level, and in the Elbe 4 ft. 6 in. above the
same level.
Manchester Canal—This canal, now in process of construction, will make the city of Manchester,
at present 50 miles from the sea and 35 miles from the head of the tidal estuary of the Mersey, prac-
tically a seaport.
The length of the canal is a little over 35 miles from Manchester to the Mersey estuary, separated
into two divisions:
1. A tidal division from Eastham through the Mersey estuary to Runcorn, 12 miles, then inland 8
miles farther to Warrington, with a bottom width of 100 ft., and a depth of 26 ft. at low tide.
2. A canal division from Warrington to Manchester, 15% miles long, with a bottom width of 100 ft.,
a depth of 26 ft., and a surface width of 300 ft.
There are four locks, or rather series of locks, these locks being built in groups of three difier-
ent sizes, and with intermediate gates, so that any size of vessel may be passed without waste of
water. The total rise of the canal is 60 ft. The total amount of excavation is about 48,000,000
cub. yds.
The Panama Canal—The De Lesseps Company proposed to build this canal as a through cut 47 miles
long, having a bottom width 22 metres in earth and 24 metres in rock ; surface width, 50 metres in
earth and 28 metres in rock, and a depth of 8.5 and 9 metres. The original estimate of cost was
$120,000,000, and time for completion eight years. In 1887, $150,000,000 had been expended, and one
fifth of the total excavation completed. The plans were thereupon changed provisionally to a lock-
canal, with locks to be gradually lowered to sea-level after the canal was opened. The enterprise
failed in the winter of 1889-’90, after $250,000,000 had been spent, $450,000,000 in obligations as-
sumed, and about one third of the work completed.
Important Projected Canals in the United States. Delaware and Chesapeake Canal.——This is a
ship-canal intended to connect the Chesapeake and Delaware Bays. The length by the favored route
(Sassafras) is 30 miles from bay to bay, of which distance 14 miles will be obtained by deepening
and widening streams, and the remaining 16 miles will be thorough cut.
The proposed section of the canal is : Bottom width, 90 ft.; surface width, 171 ft. ; depth,
Ll ft.
No locks except tidal looks. The cost is variously estimated at from $6,500,000 to $11,500,000,
and the time for completion is put at four years.
Niagara Falls Canal—Several surveys and plans for a ship-canal from Lake Erie to Lake Ontario
have been made.
A recent project is for a canal 20 ft. deep, to accommodate vessels of 3,000 tons. The length is
about 25 miles, and the estimated cost $18,000,000. An alternative route of 18 miles would cost
about $1,000,000 more.
Florida Canal.—-The project for a ship-canal across Florida has been more or less continuously
300 CAPSTAN.

agitated. Starting from the St. John’s River, just above Jacksonville, a proposed canal would cut
across to the Suwanee River, on the Gulf coast. Its total length would be 137% miles, the deepest
cut 143 ft. for a short distance, and the proposed dimensions were a width of 230 ft. and a depth of
30 ft., sufficient to permit 3,000-ton vessels to pass without sidings. It was expected the canal could
be completed in three years, and the estimated cost was $46,000,000. The canal would enable vessels
to avoid the navigation of the Strait of Florida. _
Delaware and New York Bay Canal.--This project contemplates the enlargement of the Delaware
and Raritan Canal sufficiently to permit its use by large vessels. This canal, with the Cape Cod Canal,
the canal from the Delaware to the Chesapeake Bay, and the Dismal Swamp Canal, would form a grand
system of inland navigation, which would offer an almost aiisline route to the coasting trade between
Boston, New York, Philadelphia, Baltimore, Norfolk, and the Carolina sounds.
The locks of each set may be worked simultaneously, and consist in (1) a large lock 550 ft. by 60
ft., (2) an intermediate lock 300 ft. by 40 ft., and (3) a small lock 100 ft. by 20 ft. The canal is, in
fact, one continuous dock. Vessels will be able to navigate it at the rate of about 5 miles per hour,
so that a journey through its entire length, including the time required for passage of the locks, will
be from 8 to 10 hours. It will be illuminated by electric lights.
Works for Reference—See the files of Engineer and Engineering (London), and of Engineering
News, Engineering Jlfagazine, and Scientific American Supplement; also “Proceedings of American
Institute of Civil Engineers ”; also the works of Rankine, Moseley, Weisbach, Mahan, and others, on
civil engineering.
CANNON. See 0RDNANCE.
CAOUTCI-IOUC. See INDIA-RUBBER WORKING MACHINERY.
CAPPADINE. The waste taken from the cocoon after the silk has been reeled ell".
CAPPOT. A covered crucible used in glass-making.
CAPCTAN. A modification of the mechanical power known as the wheel and axle, consisting of
a vertical drum about which the chain or rope applied to the
weight to be lifted is wound, this drum being rotated by levers
inserted in suitable apertures in its upper portion. The levers
are called capstan-bars, and when in place radiate from the
capstan-head like the spokes of a wheel. On board ship,
where the capstan is used for lifting the anchor, several men
stand side by side along each bar and push on the same, walk-
ing continuously around, and so applying a steady pull on the
chain. In this respect the capstan differs from the windlass,
the drum of which is placed horizontally and turned by bars
which are arranged in connection with ratchet-wheels, so that
the pull on the chain ceases as each bar, on arriving at the
end of its course, is thrown back to get a fresh purchase on
the barrel or drum. The capstan is superior to the windlass
in point of expedition, but the men exert their strength more
efficiently on the windlass than at the capstan, since in the
latter case they are compelled to push horizontally, when they
exert a pressure only of about 35 lbs., whereas in the windlass
the weight of the body, averaging about four times this strain, is applied to the end 01" the lever.
Capstans on board ships are either single or double, according as there are one or two barrels
' upon the same spindle. The
(560. double capstan is revolved by
two sets of men, the barrels
/ being respectively located on
different decks. The common
j [:l [:l E] U capstan is represented on the
right of the dotted line in Fig.
659. Its parts are the spindle
on which the barrel turns, the
E drum-head A, whelps B, pawl-
659.






i]


[J {DAD



head (1, and pawl-rim D. The
\ barrel of the capstan is cov-
\ ered by the whelps, of which
\ there are usually six, which
\ are bolted to the barrel and
\ \ further retained by the drum-
‘0 head, which extends down over
them for about an inch. The
object of the pawls is to pre-
vent the capstan from flying
back when the strain ceases.
They are fastened to the pawl-
head, and fall into small cells
in the pawl-rim. Their dispo-
sition is usually such that the
‘ capstan cannot recoil for more
than half the length of one of the cells before being checked. When this form of capstan is used
on board ship, the anchor~chain is not brought directly to it, but the strain is applied to the latter
















CARPENTRY. 301

through the medium of a messenger, E. This consists of a heavy endless rope which is wound several
times around the capstan, and passes over a roller or sheave in the bow of the vessel. The chain,
which extends aftparallcl to the messen-
ger, is secured to the rcarwardly moving ' 661.
portion by nippcrs, which are grummcts of
soft rope wound around both chain and mes-
senger, and held by a lever which is re
moved, and the chain freed, as the latter
reaches the scuttle in the deck, down which
it passes to the lockers below. Capstans
have been constructed with wheelwerk be-
tween the spindle and barrel, the former
making 3 turns and the latter 1, revolving
in opposite directions, so that the power is
augmented as 3 to 1.
In more modern forms of capstans the
chain is taken directly to the barrel without
the intervention of a messenger. A cap-
stan of this description is represented on
the left of Fig. 659. This is provided with
a sprocket-wheel F, which engages the links
of the chain passed around. A better form,
and that most commonly used on board of
war-vessels, is represented in Fig. 660. Here
the chain is led around vertical rollers, as
shown in the diagram on the right, and then
around the lower ribbed portion of the cap-
stan. The construction of this part is such
that the chain is very firmly grasped.
Both capstans and windlasses on large
steam-vessels are frequently constructed to
be operated by steam-power, auxiliary en-
gines being especially arranged for this pur-
pose. Ellington’s improved form of hydraulic capstan for use on docks is represented in Fig. 661.
Motive-power is supplied by a three-cylinder engine operated by water-pressure, and geared to the
capstan as shown. This device has the merits of compactness and great power.
For the theoretical considerations relative to capstans, see Wheel and Axle, under STATICS.
CARBON. See DIAMOND.
CARBON IO ACID, as a motor. See GAS-GENERATING Macnmss.
CARBON POINTS. See “ Modern Mechanism,” vol. iii.
CARDIN G. See COTTON-SPINNING MACHINERY, and WOOL-srmxmc MACHINERY.
OARILLON. See BELLS.
CARPENTRY. The art of adapting timber to structural purposes. By some authorities it is
regarded as a distinct art from joinery, which is commonly defined as the production of fittings for
houses, patterns for casting, etc. Most of the work of fashioning timber which formerly required
the carpenter’s skill is now done by machinery. Rabbeting, grooving, tonguing, mortising, mould-
ing, tenoning, boring, gaining, planing, sawing, and carving are all done by ingenious contrivances
far more accurately and more speedily than the same can be accomplished by the best of hand-labor.
Thus the distinction between carpentry and joinery is virtually obliterated; or rather the modern
carpenter has necessarily become a joiner, his chief duty being the assemblage of parts previously
prepared by machines. The present article therefore relates more especially to joinery. The appli-
cation of the art to pattern-making will be found under PATTERN-MAKING AND MOLDING. The various
tools used by carpenters are described under AWL, AXE, Btrs AND AUGERS, CALIPERS, Canvmc Toors,
GI-IIsELs, CLAMPS, Conrnssns, DRAWING-KNIFE, Gauens, Genes, GRINDS'I‘ONE, HAMMER, LATHE (WooD-
TURNING), LATHE-TOOLS, OILS'I‘ONE, PLANES, RULE, Saws, SCREW-DRIVER, SCRIBING-BLOCK, Snare
LEVEL, Sponssnavn, SQUARE, STRAIGHT-EDGE, and VISE. See also DRILLING AND Denise MACHINES,
MOR'I‘ISING AND Tnsomne MACHINES, PLANING MACHINES (Ween), MOULDING MACHINES (Ween), and
STRENGTH or MATERIALS.
Jom'rs AND Fasrnumes.-'l‘he following are the principles which should be adhered to in designing
joints and fastenings, as laid down by Prof. Rankine:
“ 1. To cut the joints and arrange the fastenings so as to weaken the pieces of timber that. they
connect as little as possible. 2. To place each abutting surface in a joint as nearly as possible
perpendicular to the pressure which it has to transmit. 3. To proportion the area of each surface
to the pressure which it has to hear, so that the timber may be safe against injury under the heav~
iest load which occurs in practice, and to form and fit every pair of such surfaces accurately, in order
to distribute the stress uniformly. 4. To proportion the fastenings so that they may be of equal
strength with the pieces which they connect. 5. To place the fastenings in each piece of timber so
that there shall be sufficient resistance to the giving way of the joint by the fastenings shearing or
crushing their way through the timber.”
The simplest forms of joints are the best, so that the parts may be fitted with the least possible
inconvenience. Double abutments should be avoided, as they are difficult to fit ; moreover, when the
timber shrinks the whole strain may be thrown upon one of them.
Scaiy‘s are so made that the pieces fit into one another, so that the resulting beam is of the
l



302. CARPEN TRY.

same thickness throughout. The usual method of scarfing bond and wall plates is by cutting about
three-fifths through each piece, on the upper face of the one and the under face of the other,
about 6 or 8 inches from the end transversely, making what is termed a kcrf ,' and longitudinally
from the end, from two-fifths down, on the same side, so that the pieces lap together like a half
dovetail. Fig. 662 is a scarf.-
662' 665.
'



UII
ks









Notching is either square or dovetailed, and is made use of for connecting the ends of wall-plates and
bond-timbers at the angles, in letting joists down on girders, binders, purlins, or principal rafters.
(Jogging, or cocking, is a species of notch extending on one side, and having a narrow cog alone m
the bearing piece, flush with its upper face. It is principally made use of in tailing joists on wall-
lates.
p Pinning consists in inserting cylindrical pieces of wood or iron through a tenon.
l'Vedg'ing is the insertion of triangular prisms, whose converging sides are under an extremely acute
angle, into or by the end of a tenon, to make it fill the mortise so completely as to prevent its being
Withdrawn.
Tenon and mortise of the most simple kind is shown in Fig. 666, in which the two timbers united
are at right angles with each other. The tenon is on that which appears horizontal, while the mortise
is cut in the upright timber. The tenon is left one-third of the thickness of the timber, as shown in the
upper part of the figure.
The greatest strain upon the fibres of a girder is at the upper and lower parts, decreasing gradually
towards the middle of the depth, which is the best situation to make the mortise. The form to be given
to the tenon requires consideration. Some carpenters introduce it at the lowest part of the girder,
which in a great degree destroys its stiffness : being a sixth of the depth, it should be placed at one-
third of the depth from the lowest side. Horizontal timbers, intended to bear great weights, should be
always notched on their supports, in preference to being framed in between them; and this rule is
applicable to inclined timbers, as common rafters and braces. All the pressures to which they are
su jected should be brought tc act in the direction of their lengths, and the form of the joint should be
such as to convey the pressure as much as possible into the axes of the timber. When subjected to a
strain, a partial bearing is liable to very serious disadvantages, particularly in bridges.
666. 667.


7!










Where the mortise is to be made in the upright timber, and the tenon to be cut on another inclined,
as in a brace to a partition, a beveled shoulder, Fig. 668, is cut on the inclined piece, and a sinking
made in the upright post to receive it—the pin which secures it in its mortise passing through the
tenon. .
The beveled shoulder adds greatly to the strength of a mortise and tenon joint, and should never be
dispensed with: it renders the junction of the two pieces of timber more exact, and makes the abut
ments of all the fibres stronger and more capable of resistance. '
The common method of effecting such a junction does not occupy so much time or labor, but is not
so effective: it is usual to drive one or two wooden pins through holes bored for the purpose at right
angles through the timber in which the mortise is made, as well as through that which has the tenon.
Boring the hole for the pin requires to be nicely performed, in order that it may draw the tenon tight
into the mortise prepared to receive it, and make the shoulder-butt close into the joint, without running
the risk of tearing out a portion of the tenon beyond the pin. Square holes and square pins are pre-
ferred to round, as they bring more of the wood into action, and there is less liability to split.
Foxtail wedgz'ng, adopted by ship-carpenters, is made with long wooden bolts, which do not pass
completely through the timbers, but take a very fast hold: they are subject to be crippled in diawmg,
if they are too nicely fitted: this is remedied by placing a thin wedge into the hole prcvmus to the
CARPEN TRY. 303

insertion of the wooden bolt, which, when driven, is split by the wedge, and thus squeezed tight to the
sides of the hole. .
Bond-thrillers and wall-plates require to be carefully notched together at every angle and return, and
scarfcd at every longitudinal joint. ‘
670.


To make a good tie-joint requires great attention on the part of the carpenter; and, for uniting wall.
plates, the dovetail joint", Fig. 671, is sometimes adopted. If the effects that 671.
shrinking may produce be taken into consideration, the more usual system of
halving, Fig. 670, is decidedly preferable. Whenever this joint is employed, SE
a stout pin of tough oak, or an iron bolt, should be driven through to render it
secure; and, where there is the slightest tendency for one piece to slide from the other, iron straps
must be used.
Timbers which are laid upon the plates, and intended to act as ties, should be cut with a dovetail and
let into the timber it is to secure. Generally, where they cross at right angles, halving or cutting away
the moiety of each is adopted, and one is let into the channel cut in the other.
For joining two pieces of timber together, notch-ing is the most common and simple method; for,
when four angles are to be formed, the surfaces of one piece are both parallel and perpendicular to
those of the other. A notch may be cut out of one piece (Fig. 67 1) the breadth of the other, which
may be let down on the first; or the two pieces may be both notched to each other, and then secured
by an oak pin: this is the best practice w en each of the timbers is equally exposed to a strain in any
direction. When one piece has to support the other transversely, the 11 per may have a notch cut
across it, to the breadth of two-thirds the thickness of the one below, whicii must also have a similar
notch cutout on each upper edge, leaving two-thirds of the breadth of the middle entire, by which
means the strength of the supporting or lower piece is less diminished than if a notch of less depth
were cut the whole breadth. Such joints are particularly adapted for purlins, when let down upon the
principal rafters.
Lapping is performed in a variety of ways—either by simply halving the end of each timber, or by
halving and dovetailing, as in Fig. 67 2. In the latter case, the tim-

bers act as a tie, and cannot be readily pulled asunder. A 672'
In these joints the greatest attention is required to make the sev- _: _.;.’-‘ f @
eral parts abut completely on each other, as the least play or liability a ,- 3 -


Isl]
to motion at once destroys their efficacy. The butting oints, being
slightly tapered to one side of the beam, require very moderate blows
with a hammer to force them into their place: if driven too hard, the
parts will be liable to strain, and the abutments to split off. It is better, sometimes, to leave the abut-
ments open, and afterwards drive in a small wedge, which, if made of hard wood and not likely to






compress, is an excellent substitute. Iron has been said to injure the fibres of the timber, from its too
great hardness; otherwise it is well ada ted for the joggles and wedges.
Two pieces of timber may be united in such a manner that they reserve the same breadth and
depth throughout, which is of great importance in the construction of cams
for bridges or roofs of considerable span. The length to be given to the 676-
scarf must depend upon the force that will cause the fibres of - the timber to
slide upon each other; and that for oak, ash, or elm should be six times E; the de th of the timber; in fir, twelve times: but where bolts are used so __i. i i i .


much is not required in either case. The simplest method for uniting the 7% '79: '
ends of two timbers is by cutting away an equal portion of each, and letting
one down upon the other. Fig. 676.
Timbers united together by a number of such cuttings, afterwards united and bolted through or
hooped round with iron, are capable of sustaining great resistance: a stirrup-iron at each end
304 CARPEN T RY.

holds the timbers in their places, and one or more bolts are sufficient to prevent their being dmwn
asunder. '
The carpenter frequently exercises great ingenuity in joining timbers of considerable scantling, Fig.
2450; and, by the introduction of iron or small cubes of harder
wood into the joints, can prevent their being thrust or drawn
out of their position either longitudinally or laterally.
The scarji'ng of girders and beams have a great variety of
forms given them, and are sometimes bolted through, at others
strapped round with strong hoops of iron, Figs. 676 to 681.
Where bolts are dispensed with, it is perfectly clear that the
joint cannot have half the strength of an entire piece. Where
the stress is longitudinal, two irons put on each side will pre-
vent the scarf that is merely indented from pulling asunder; but such a provision will not maintain
the constant horizontal position of the timber.
When a scarf is forced to its bearings by the introduction of keys or wedges driven tight, they some-
times receive an additional strain, and it is often found advisable to omit them, and to bring the joints
679.
677.



678.



























~v\._‘

l i
to a hearing by some other means before the bolts are inserted. When. keys are made use of, they
should be of very hard wood, having a curled grain, which resists the insertion of the fibres opposed
to it.
To prevent lateral movement cogging is adopted, in addition to the ordinary method, and a small
tenon or cog is left upon a portion of the scarf, which enters into a notch prepared in the piece which is
to cover it, as shown in Figs. 67 5 to 67 9. Beams intended to resist cross-strains require to be lengthened
more frequently than any others, and, from the nature of the strain, a different form of scarf must be
made use of from that which is required for a strain in the direction of its length. When timber is
subjected to both strains, the cross-strain is that which demands the greatest attention. Where a floor
is supported, the scarfing requires to be further secured by iron bolts, made to pass through a longi-
tudinal piece laid to cover the under side of the joint. '
Bearing-posts, when used to support the floors of a magazine or warehouse, are generally formed
exactly square. Some timber will support, while that of another quality will suspend, the most;
therefore, in the selection of story-posts, we must pay attention to these peculiarities. Iron. however,
is generally used for these purposes, in consequence of its horizontal sectional area occupying less space
than timber of the same strength. ‘
When a tie-beam is mortised through to receive a king or queen post, and it is necessary to provide
for the means of holding it up, the tenon should not be pinned through, as it is not advisable to depend
entirely on the pins for the support: the tenon should be cut like a half dovetail, or in a sloping direc
tion on one side, and left straight on the other: the mortise-hole should be so cut that the lower end can
just pass. When it is in its place, a wooden key or wedge is driven tightly on the straight side, which
forces the tenon against one side of the mortise-hole, and prevents it effectually from being drawn out'
oak or iron may be added, or an iron strap may be applied.
rl‘enons may be wedged at the end ; but to do this they must be made long enough to pass entirely
1' ' 682.
Tenons.


through the mortise: two saw-cuts are then made across it, and the wedges are driven home. The
tenon sometimes splits, but not sufficiently to injure its strength. When in machinery it is not practi-
mble to cut the mortise through, the fox-tail wedging is adopted: the tenon 18 made to fit the mortise
UARPEN TRY. 305

exactly, the wedges are loosely put into the saw—cuts, as before, and the whole is driven to its place
When the wedges touch the bottom of the mortise, they cause it to spread, and thus hold the tenor
firmly in its place.
- Dovetailing in some degree resembles mortising and tenoning, and is more adapted to uniting
together the angles of framework. The feet of the rafters require the mortise and tenon to be care-
fully made, and the thrust is destroyed to a certain extent to obtain greater strength. A portion of
the rafter is tenoned into the tie-beam, and another small part is let into the upper part of it: both
rafter and tenon are cut at right angles with the inclination of the roof. In Fig. 683, the rafter has
two bearing shoulders in its depth, one behind the other, in addition to the tenon which unites them.
Struts and braces which are loaded require but little mortising to keep them from sliding out of their
places: the more flat- their ends can be cut, the more efficient will they be. The shrinking of timbers
sometimes occasions them to become loose, particularly where there is not much stress upon them.
King-posts, queens, and principal rafters, which are subject to great strains, should have iron straps
or ties when they unite with the tie-beam, as in Figs. 684 to 686 ; and an iron strap should embrace
685.
684.
5-4 F
686.





the head of the kings and queens, and unite with the principal rafters. the feet of which, in large build-
ings, sometimes have their abutment in a cast-iron shoe, which prevents the splitting off the end of the
tie-beam.
The ends of king or queen posts may have a screw-bolt passed into them, which allows the nut to be
turned at pleasure; and thus the framing may be tightened again when shrinking of the timbers ren~
ders it‘ necessary. This, in many instances, is preferable to the iron strap, and keys or screws put in
the ordinary way.
Whatever form we adopt for the butting-joint, we must be careful that all parts bear alike; for, in
the general compression, the greater surfaces will be less affected and the smaller undergo the greatest
change. When all have come to their bearing, they should exhibit an equally close joint; and as large
timbers are moved with some difficulty, the joint cannot he often put to the test of. trying whether it
fits nicely: it must, therefore, be set out with great precision, and worked, with regard to its lines, with
exactness. A very small portion of a tie-beam left at the end is sufficient to withstand the horizontal
thrust of a principal rafter, and blocks may he used at the ends where the rafters abut to give additional
strength.
Scgijfing a timber in a perpendicular direction—When the top surface is divided into nine squares, it
four are cut down, the other five serve as tenons to enter into as many vacant spaces left in the piece
of timber placed upon it, as seen in Fig. 687 ; or two may be cut away, as in the same figure, to re-
eeive a tenon left on the upper piece.
687.
Partitions and framingfo-r the outside of buildings, etc., Fig. 688, are a species of timber walls,
usually covered with lath and plaster, and formed of upright posts, mortised into a head and sill,
braced in different directions, and filled in with quarters. The posts are placed at the extremities, as
well as at the sides of all doors and openings. When a partition dividing two or more rooms has a
hearing which is perfectly solid throughout, it is better without braces: the posts or quarters have
only then to be maintained in an upright position, which is effected by driving pieces between them
horizontally, so as to strut them, and prevent their bending. Where they rest upon joists, which are
liable to shrink, and yield to a weight placed upon them, the partition should be trussed in a. manner
to throw its load on the parts able to sustain it. In most houses we find great neglect. upon this sub
ject, which occasions cracking in the cornice, inability to open and shut the doors, and many other incon~
veniences.
The thickness given to partitions which do not exceed 20 feet in length, is 4 inches. The posts are
then 4 inches square, and the other timbers 4 by 3. When they are of greater extent, they should be
increased in thickness. When it is required to make a doorway in the middle, the truss may be fflrlni-rl
__


20
806 CARPENTRY.

"by the braces, the inclination of which should be at an angle of about 40° with the horizon. When the
doors are at the sides,v the truss may be formed over the heads. The posts should all be strapped to
the truss, and the braces halved into the upright posts.
The weight of a square of quartered partition may be estimated at from 12 cwt. to 18 cwt., and every
precaution should be taken'to discharge its weight from the floor on which it is placed, to the walls,
which are its best points of support. In ancient timber houses, mills, die, the fronts or external sides
are formed of upright posts, placed at a distance equal to their scantling :‘ these are mortised and ten-
oned into a top and bottom plate, which serves also to carry the floors. The posts at the angles are or
a larger scantling; and into these, which form openings for doors and windows, are framed horizontal
pieces, which serve for heads and sills. Braces are then introduced, crossing each other, like a St.
Andrew’s cross. Above the lintholes, and beneath the sills, short quarters or punchions fill in the
space, and the whole are mortised, tenoned, and pinned together. .The framing should be placed on
brickwork, or a wall of masonry, so as to be kept quite clear of the ground.
FLoons._-—When the bearings are equal, if joists of the same width, but of different depths or thick-
nesses, are used, their strength is increased in proportion to the squares of their vertical thickness:
when the joists are but 6 inches deep, they are in strength to those of 8 inches in depth, as 36 to 64—
the square of 6 being 36, and that of S, 64. The quantity of timber in the one case to that of the
other is as 4 to 3—so that one~third more timber gives a strength double that of the other.
Where square oak joists are used, and the bearing 12 feet, their scantlings should be 6 inches, and
laid at a similar distance apart. Such a floor contains the same quantity of timber as if entirely formed
of 3-inch plank : the strength of timber being as the square of its vertical thickness, it results that the
strength in these two instances is as 2 to 1 : the floor composed of 3-inch plank is only half the strength
of the other; but had the whole been formed 6 inches thick, instead of with joists 6 inches apart, it
would have been 4 times as strong—the square of 3 being 9, and the square of 6, 36.
Naked floors are divided into singlejoz'sterl, double, and framedfloors: and it must be remarked that
unsawn timbers are considerably stronger than planks or scantlings cut out of a round tree. When a
tree is cut longitudinally, and formed into two pieces, these will support less than they would do when
united in the original tree, arising from the circular concentric rings which compose the tree being cut
through, which renders the timber more compressible on one side than on the other ; and as the texture
is less close where it has been sawn, it is also more susceptible of change from humidity on alternation
of temperature. .
Joists whose width is less than half their vertical thickness, are subject to twist and bend if not
strutted; and for this reason squared timber was usually employed by the builders in the middle ages ;
and we have numerous examples four or five hundred years old, where the timber selected has the pith
in the centre, and the concentric rings nearly entire, being in a sound and perfect condition. Experience
also teaches us that timber, whether sawn or unsawn, used for a floor of 16 feet bearing, composed of
12 joists, 8 inches square, placed at a distance of a foot apart, is much stronger than another of 24
joists, 8 by 4, placed edgeways, at a distance of 6 inches apart, although there is the same quantity or
timber in both cases.
Single-joisted floors consist of one series of joists, which ought to be let down or halved on to wall-
plates of a sufficient strength and scantling to form a tie, as well as a support to the floors. Each. joist
should be Spiked or pinned to the timbers on which it lies. Wherever fireplaces occur, and the joists
cannot get a bearing on the wall, they are let into a trimmer or piece of timber framed into the tivo
nearest joists that have a bearing: into this the other joists are mortised. As the trimming joists sup-
port a greater weight, they must be made stronger than the others, and should have an eighth, of an
inch additional thickness given to them for every joist they carry. When the bearing exceeds 8 or 9
feet the joists should be strutted, or they will have an inclination to turn sideways: the joists in use,
being generally thin and deep, require strutting on all occasions, and a rod of iron is often passed
through them, which, being screwed up after the strutting-pieces are placed, gives the entire floor great
solidity and firmness. The weight of a square of single-joisted floor varies from 10 cwt. to 1 ton, and
the joists should never extend to a greater bearing than 20 feet in ordinary cases.
689. Mortises and Tenons.


Tofind the depth of ajoz'st, when the length of bearing and breadth in inches is given: divide the
square of the length in feet between the supports by the breadth of the jorst in inches, and the cube
root of the quotient, multiplied by 22 for fir and 23 for oak, gives the depth in inches. A Slflglé-jOl dud
floor which has the same quantity of timber as a double floor, is considerably stronger, particularly if
properly strutted, than the latter. The plates, bedded on the walls, upon which the joists are to be
tailed down, should have their depth equal to half that of the joists, and their wrdth half as much
more. In many instances the plates are not bedded entirely in the wall, but have one-half resting
beyond the face on corbels let into the wall, at a distance of 6 feet apart. To form the entaille or
dovetail, great care should be used, to prevent the joist from drawing out of its place when once
pinned down. - »
C ARPEN TRY. 307

Double floors are formed of joists, binders, and ceiling-joists. The binders rest upon the plates
bedded on the walls, and serve the purpose of supports to the joists which are bridged on them,
as well as to the ceiling-joists, which are pulleys mortised into their sides. When the depth of a
binding-joist is required, the length and breadth being given, divide the square of the length in
feet by the breadth in inches, and the cube root of the quotient, multiplied by 3.42 for pine and
3.53 for oak, will give the depth in inches. When the length and depth are given, and the breadth
is required, divide the square of the length in feet by the cube of the depth in inches, and multi-
ply the quotient by 40 for pine and 44 for oak, which will give the breadth. The above rules sup-
pose the bin’ders to be placed at a distance of 6 feet from each other.
Binding-joists (Fig. 691) must be framed into the girders, and care must be taken that the bearing
parts fit the mortise made for them very accurately: the tenon should be one-sixth of the depth,
and placed at one-third of the depth, measured from the lower side. \Vhen binding-joists only
are employed to carry the ceiling, their scantlings may be found in the same manner as those of
ceiling-joists, which are small timbers, and only of a sufficient thickness to nail the laths to.
When their length and bearing are given, their depth may be found by dividing the length in feet
by the cube root of the breadth in inches, and multiplying the quotient by 0.64 for pine or 0.67 for
oak, which will give their depth in inches. Ceiling-joists are usually notched to the under sides of
the binding-joists, and nailed to them : this is better than mortising, which weakens the binder, and
gives more labor.
TIMBER-Ginnnns.'*-General Remarks, applying only to plain beams. Girders should always be
placed so as to have good supports for their extremities. Those intended to support floors should
rest, therefore, on solid walls or piers, not over the windows or other openings. To insure this, it is
sometimes necessary to lay them obliquely across the room, but an inclined position should be avoided
if possible. It is better to provide very strong templates over the openings to carry the girder and
throw the weight well upon the piers. The ends of all timber-girders should rest upon stone tem-
plates, and be perfectly clear of the masonry. Girders should be weakened as little as possible
by mortises or joints of any kind which cut into them, especially at or near the centre of their
length, where the greatest strain comes upon them.
WALL-PLATES are pieces of timber built into or upon a wall, to support the ends of joists or
other bearers. They distribute the weight thrown upon them by the joists, and give the latter a
hold upon the side-walls, so that these are
tied together. On the ground-floor the
wall-plates generally rest upon an oifset
in the 'wall, as in Fig. 692. Above, also,
they may rest on an offset, if there is a
change in the thickness of the wall; or
they may be built into the wall, as shown
in Fig. 693, great care being taken that
there is a free circulation of air round
the ends of the joists; or they may rest
on corbels provided for the purpose, as in
Fig. 694, thus preventing all danger of decay by contact with the masonry and want of air.
The joists are either simply nailed on to the wall-plates, or “ notched ” (Fig. 693) or “ cogged ”
(Fig. 694) upon them. If the joists are of unequal depths, the notches are varied in depth also, so
as to keep the upper surfaces of the joists in the same plane. Cogging gives the joists a good
hold upon the wall-plates, so as to tie the walls in, but it is seldom done. Wall-plates are some-
times dovetailed into each other where they meet at the angles of a building; but there are great
objections to dovetails, and it is better that they should be halved and bolted. \Vall-plates should
be in as long pieces as possible; and, when two or more pieces are required to extend along the
length of the wall, they should be carefully scarfed together.
Tredgold’s Rule for size of wall-plates:


For a 20-feet bearing, 4% inches by 3 inches.
(( fl 6 (( 4 (S
H U 4i 5 “
BRIDGING—JOISTS on “ Common Jorsrs.”—-These are generally laid about 12 inches apart from
centre to centre, or Suflicieiit-ly near to prevent the deflection of the floor-boards.
' Joists should not be less than 2 inches wide, or they will be split by the nails holding the board-
ing, especially at the heading-joints where four nails come together. They should never be more
than 3 inches wide if they are themselves to carry a ceiling (without the intervention of ceiling—
joists), as the lower surface of the joists causes a blank space behind the ends of the laths, which
interrupts the key for the plastering. '
STRUTTING.—-JOiStS more than 10 feet long should be stmitcd at intervals of about 7 feet, to
make them stiff, and to prevent them from turning over sideways. The struts also add greatly to the
strength of the floor by causing the pressure on the joists to be transmitted from one to the other.
Haring-bone strutting consists of small pieces, from 2 inches to 3 inches wide and 1 inch thick,
inserted diagonally and crossing one another between the joists.
PUGGING is plaster (coarse stuff) or other mixtures laid upon boards fitted in between the joists
of a floor, to prevent the passage of sound or smell from the room below.

* The remainder of this article is mainly condensed from “Notes on Building Construction, adapted to the Require-
ments of the Syllabus of the Science and Art'Department of the Committee of Council on Education, South Ken
sington.” Rivingtons, London. 1876.
308 CARPENTRY.

Slips of cork or list, along the upper edges of the joists upon which the boards are nailed, are
recommended by Tredgold as a means for reducing the passage of sound. Felt or felt-paper over
the boards and under the carpet have been used for the same purpose.
TRIMMING.——It often happens that, on account of fines, fireplaces, or from other causes, it is inad-
visable to let the ends of the joists rest on particular parts of the walls, and it is necessary that
they should be trimmed. When the joists are at right angles to the wall in which the fine or fire-
place occurs, they are stopped short of the portion of wall to be avoided, and tusk-tenoned into a
cross-beam called a “trimmer.” This trimmer is tusk-tenoned at the ends, and framed in between
the two nearest bridging-joists bearing on the wall, on each side of the portion to be avoided. The
joists carrying the trimmer are called “ trimmingjoists.” 'As they have to carry more weight than
the other bridging-joists, they are made wider. '
Tredgold’s Rule—To the width of the common joists add one-eighth of an inch for eyery joist
carried by the trimmer, and that will give the width of the trimming-joists. When the trimming-
joists are deeper than the others, they need not be so wide in proportion.
FLOOR-BOARDS are laid in several diifercnt ways.
Plaing'ointecl.—The boards are simply laid side by side, as close as possible (see Fig. 695), a nail
696. 697.
'30 8 .80 rd:
\ A I “ FI/I _ 1
A? / :3. WM‘ xi“ t-_‘ 2; " M\
k a“ \__ 02:19? — g _


or generally two being driven through the boards into each joist. The inevitable shrinkage of the
boards, as at A, will cause openings through this description of floor. ‘
Rcbatctl, of which the section, Fig. 696, explains itself. Here a considerable shrinkage may take
place, as at A, without causing an opening between the boards throughout their depth.
“Fillietered ” is another name for the joint shown in Fig. 696.
Rebated, grooved, and tongued—One board can first be nailed, as shown at b, Fig. 697, and then
the other board, upon being slipped into it, will be kept down by the form of joint. Thus the nails
are prevented from appearing on the surface of the floor, which is sometimes desirable.
Rebatecl and filleted.--A rectangular rebate is cut out along the lower edges of the boards, as in
Fig. 698, and the space filled in with a slip or “fillet,” occasionally of oak or some hard wood. It
will be seen that any opening caused by shrinkage is covered by the fillet, and the floor must be worn
down nearly through its whole thickness before the fillet is exposed.
Ploughctl and tongued—A narrow groove is cut in the side of each board, and an iron or wooden





tongue inserted (Fig. 699). It will be noticed that this shares some of the advantages of the
fillcted joint, but the tongue is sooner laid bare when the floor is much worn. The tongue should
be kept lower than the centre of the thickness of the boards, so that as much wear as possible may
be got out of them before it is exposed.
Grooved and tongued—In this joint, Fig. 700, the tongue is worked upon one board to fit the
groove cut in the other. This is not an improvement on the joint last described; the tongue is
necessarily thicker, and thus causes a thinner piece of wood to be left above the groove. This rots
and flakes away if the floor is often washed. ~
Dowelcd—Small oak dowels are fixed along the edge of one board to fit into holes in the other,
701 . 702. .. W





I


in the spaces between the joists (see Fig. '701). Dowelcd floors show no nails on the surface; only
one end of each board is nailed obliquely, the other being kept down by the dowel.
Of the joints above described, those illustrated in Figs. 695 and 696 are used chiefly l" or inferior
floors; that shown in Fig. 698 for warehouses or barracks; those in Figs. 699 and 700 for ordinary
CARPENTRY. 309


floors of a high class; and that in Fig. 701 for very superior floors. The joints in Figs. 696, 697,
and 700 necessitate the use of a larger quantity of boarding to cover a given surface than when the
other joints are adopted.
Hammers—The boards in floors are seldom long enough to go right across the room. In such a
case the joint between the end of one board and the next is called the “heading joint.” Headings
should always fall upon joists, and break joint with one another in plan. ‘
Square hearlz'ng.-In this, the ends of the boards simply butt against one another, similarly to the
side-joints in Fig. 695.
Splayecl or beveled heading—The ends of the boards are splayed to fit one another, as shown in
Fig. 702.
C,Tonguerl heading—The ends of the boards are cross-grooved, and laid with a cross-grain wood,
or a metal tongue, similar to that shown for the side-joints in Fig. 699.
Rebated and tongued heading is formed in the same way exactly as the joint shown in Fig. 697.
Forked headings—In these the ends of the boards are cut into a number of sharp salient
and reentering notches, whose ridges are parallel to the surface of the floor. These notches fit
one another, and form a tight joint. Such joints are sometimes used in oak floors, but they are
extremely troublesome and expensive to make.
The best floors are those laid with narrow boards (from batten widths down to strips of 3 inches
or 4 inches wide), as the shrinkage in each is less, and the joints can be kept tighter. Floor-boards
are generally jammed tightly together as they are laid, _ 3
by means of flooring-cramps; but in common floors ‘0“
they are sometimes. laid folding, thus: Two boards
are laid and nailed at a distance apart a little less a 4%,; I
than the width of three or four boards. These are m'k‘“'”/”’"‘ ‘““”m‘\\
then put into the space, and forced home by laying a
plank upon them, and jumping upon it (see Fig. 7 03).
The boards thus laid together are often of the same length, so that their heading-joints fall into
one line, and are not properly broken.
GENERAL REMARKS 0N Fhoons.—The timbers that carry the weight should, as a rule, be laid the
narrowest way of the room. The bearing timbers may be so arranged as to tie in the principal
walls, or, if the building forms a corner, having two or more external walls, they may be laid in
opposite directions in the alternate stories. All parts of timber built into walls should have clear
spaces round them for circulation of air. Timbers passing over several points of support, such as
joists over binders, joists or binders over party-walls, and similar cases, should be in as long lengths
as possible, by which their strength is greatly increased as compared to what it would be if they
were cut into short lengths, just sufficient to span the intervals between each pair of supports. Fix_
ing uniformly-loaded timbers rigidly at the ends increases their strength by one-half, but this can sel~
dom be done in practice. If the ends are built into the wall, they have a tendency to strain and
destroy the masonry. The want of a free circulation of air causes the timber to decay, and in any
case it soon shrinks and becomes loose. Tredgold recommends that floors should be laid with a slight
rise in the centre (about three-fourths of an inch in 20 feet), to compensate for the settlement that
will take place in the beams. All floors near the ground should be ventilated, to secure a perfect
circulation of air round all their parts. This is easily done by inserting air-bricks in the walls
For the same purpose openings should be left in the sleeper walls carrying the intermediate wail.
plates of ground-floors. The ground below the floor should be thoroughly drained, and covered with
ashes and quicklime. It is sometimes asphalted all over to prevent damp from rising.
CEILING-Jorsrs are light beams to carry the laths for the plastering of the ceiling. They are fixed
to the under side of the bearers of the floor, running at right angles to them—that is, in a single
floor to the bridging-joists, in a double or framed floor to the binding-joists. They should be 12
inches from centre to centre; if more widely placed than this, the laths are likely to give with the
weight of the plaster. Two inches is the best width for ceiling-joists; this is sufficient to nail the
laths to. If wider, the under surface of the joist interrupts the key for the plaster. The mode of
fixing ceiling-joists is generally to notch them and nail them.
PARTITIONS are used to divide rooms from one another, instead of walls, to save space and ex-
pcnse.
Quarter-ed partitions consist of framings filled in with light scantlings or “ quarterz'ngs,” upon the
sides of which laths are nailed and plastered. These may be “ framed ” or “ common.”
Bricknoggecl partitions have the intervals between the quartcring filled in with brickwork, upon
which the plastering is laid.
General Remarks (chiefly from Tredgold’s “ Carpentry ”).—Partitions containing timber should
not be used on the floor next to the ground, as the wood is affected by the damp, and decays.
Stone or brick walls are, therefore, preferable in such positions. A quartered partition sometimes
rests on the party-wall of the ground-floor. This is not a good arrangement, as the partition becomes
cracked in consequence of its being unable to settle together with the main walls to which it is fixed.
Nor should the weight of the partition be allowed to rest on the floor below it, as it bears heavily
upon the joists, cracks the ceilings below, and also settles and tears away from the ceiling above it.
A better arrangement is to suspend the partition from the floor or roof above; this prevents the
cracking of the cornice above the partition. Of course, if the weight of the partition be thrown
upon either of the floors or the roof, these latter must be strengthened accordingly. By far the best
plan, however, is to make the partition self-supporting, depending only on the main walls carrying
its'ends, and forming, in fact, a very deep truss. If the trussed partition be supported by two
walls of very unequal height, they may settle unequally, and, if so, will cause it to crack. If the
walls are of equal height and well founded, they will settle equally, and the partition moving with

310 CARPEN TRY.

them will sustain no injury. The framing of the truss should be so arranged as to throw the
weight upon the points of support in the walls at the end of the truss.
Framed, partition with ordinary dom‘wag in the contra—A truss of queen-post form may be used,
as in Fig. 704, which "is taken from Tredgold’s “ Carpentry.” _ ,
The braces b 6 correspond to the principal rafters, and Tredgold recommends that they should be
inclined at an angle of about 40° with the sill S S. The door-bead fulfills the part of the straining-
beam, while the bottom plate
or sill S 8' corresponds to
the tie-beam, and may pass
between the joists under the
floor-boards. The ends of
the top plate or “ head ” H
of the truss are received by
,,-_ the walls which support the
,’ .3232", . partition, but they should
not rest upon the walls un-
less the studs are secured
by straps to the head. The
filling-in pieces, “studs,”
“ quarterings ” or “ quar-
ters,” st, should be of light
scantling, just so thick—
about 2 inches—that the
laths can be nailed to them. They are tenoned to the top and bottom plates, butted and nailed on
to the braces. They should be stifiened at vertical intervals of 3 or 4 feet by short struts called
“ nogging-pieces,” or by continuous rails, 12. it, notched on to the uprights and nailed to them.
The studs D on each side of the doors are called the “ door-studs,” “ principal posts,” “uprights,”
or “double quarterings.” To avoid the waste of material caused by checking these out to form
shoulders, as shown in Fig. 704, the heads of the braces may be housed and tenoned into them.
The studs should be placed at such a distance apart as will suit the length of the laths. These
are usually 3 or 4 feet long, and the studs may be at 12 inches central intervals, so that the ends of
the laths may fall upon every third or fourth stud.
Tredgold states that when a partition rests on a floor, or'is otherwise supported thrOughout its
length, it is better without struts or braces, the quartering being simply steadied by horizontal pieces
between them. He also recommends that when extra strong and sound-proof partitions are re-
quired, the studs should not be filled in between the framing, but nailed on the outside as battens,
and then plastered. Partitions should be made of very well-seasoned timber, and the joints carefully
fitted. The whole should be allowed to stand for some time before being lathed, so that the timber
may take its bearings, and twisted timbers may be put right before plastering. W'rought-iron tie-
rods, also cast-iron sockets and shoes, are often used (for the same purposes as in roofs) in parti-
tions of large size, or those which have to bear a great weight. -
The weight of a square of partitioning may be taken at from 1,480 to 2,000 lbs. per square; the
weight of a square of single-joisted flooring, without counter-flooring, 1,260 to 2,000 lbs.; the weight
of a square of framed flooring, with counter-flooring, 2,500 to 4,000 lbs. Scantlings for the princi-
pal timbers of a partition bearing its own weight only : 4 x 3 inches for bearing not exceeding 26
feet; 4 x 39; inches for bearing not exceeding 30 feet; 6 x 4 inches for bearing not exceeding 40
feet. If the partition has to sustain the weight of a floor or roof, the sizes of the timbers must be
increased to meet the additional strain that will come upon them. The filling-in pieces should be just
thick enough to nail laths to, about 2 inches. Any timbers more than 3 inches wide on the face, to
which the laths are nailed, should have the corners taken ofi so as not to interrupt the key for the plaster.
J OINERY BEADS are narrow, convex, plain mouldings, in section generally parts of a circle. When
the head is formed upon a board, in the substance of the wood itself, its upper surface being flush,
or nearly so, with that of the board, it is said to be “ stuck” (see Figs. 705, 706, 707). If the bead
_ is formed in a separate
708- 709- strip, and nailed or brad-
' ded to the board, it is de-
scribed as “laid in” or
“planted” (see Fig. 708).
//
/ A nosing or rozmclal
4 edge is formed by round-
/
704.


a;
0,
ep.
2’1.
14.













































\
705.
% ing the edge of a piece
// of stuff, as shown in Fig.
/
, /
///
709. It is frequently used
for finishing off the edge of a projecting board, such as the tread of a step, a windOW-board, etc.
Quirlcecl bead—In Fig. 706 the circular portion is the section of the bead, and the indentation
at the side is called a “ quirk.”
A cloubZe-quz'rkccl bead is one with a quirk on each side, as in Fig. 707. It is also known as a
“flush bead,” because it is flush with the surface of the wood. . .
A staff cr angle bead is a double-quirked bead formed upon an .ngle, as shown in Fig. 708. It
is sometimes called a “ return bead.” .
A cocked bead is one which projects above the surface of the board. In order to avoid redu-
cing the whole surface of the board, the bead may be made in a separate strip, and planted upon
it, or laid in a shallow groove, as in Fig. 708.


CARPENTRY. 311

’—
A cocked bead and fillet is one resting upon a flat strip or fillet slightly wider than itself, and
planted on to the surface of the board.
Reading consists of parallel beads placed close together.
The torus is a very large bead, surmounted by a flat strip or fillet. The distinction between a
torus and a bead is, that the former is always surmounted by a fillet.
Shooting is simply making the edge of a board straight and smooth by planing off a shaving. A
board is said to have its “edges shot” when both edges have been made smooth and true with a
lane. '
p Seribing is cutting the edge of a board to fit an irregular surface.
Chamfer'ing is taking off the “ arris ” or sharp edge, so as to form a flat, narrow surface down
an angle. This is frequently done for ornament, and also to render the angle less liable to in-
jury. (Jhamfers are also often used for the same purpose as beads, especially on the edges of
boards forming a close joint, so as not only to form an ornament, but also to hide the opening
caused by shrinkage
V-joz'nt is the angle formed by the meeting ofchamfers on two adjacent edges.
Slop-ehamfer is one in which the chamfer is not carried to the extremity of the arris, but
stopped and sloped, or curved up at the end till it dies away again into the square angle.
Housing consists in letting the whole end of one piece of timber for a short distance into another.
Fantasia—Frames in joinery consist of narrow pieces of wood connected by mortise and tenon
joints, and grooved on the inside to receive boards, which fill up the openings in the framing.
In every frame the vertical pieces are called “stiles,” S S (Fig. 710), the horizontal pieces “rails,”
R R. These constitute the framing itself,
and in the example shown are filled in 710-

with panels, PP. {s
The pieces of wood forming a frame '
as little as possible by shrinking under
atmospheric influence. The inner edges 5
of the stiles and rails are grooved to the
depth of about half an inch to receive a
the panels, which should fit so tightly as
not to rattle, and yet should be free to
contract.
PANELING.——Tl16 boarding which fills in each opening of any piece of framing is called a “ panel.”
There are several forms of panels, known by technical names, depending upon the manner in which
they are respectively constructed and ornamented. .
Square and flat panels are those in which the boards are of the same thickness throughout,
thinner than the frame, sunk below its surface, and not ornamented by beads or mouldings. \Vhen
the edge of the panel, close to the framing, is ornamented by a moulding, either “planted” or
“stuck” on to the inner edge of the frame, it is designated as “moulded,” or “moulded and
flat.”
Flash panels have their surface “flush,” or in the same plane with the surface of the frame.
Doons.—Internal doors should be at least 2 feet 9 inches wide and 6 feet 6 inches high. A usual
opening is 3 feet, or 3 feet 6 inches. Very large rooms sometimes have doors 8 feet or more in
width, and 8 feet to 10 feet high. Entrance-doors vary in width from 3 feet 6 inches to 5 feet.
When a door is more than 3 feet 6 inches wide, it should be hung in two halves (“ hung folding”),
by which arrangement it requires less space into which to open, and the leaves are lighter. Doors
should, as a rule, open inward, from a person entering the room. The hinges should generally be on
his right, but this is sometimes altered by peculiarities of the position.
Solid panels are those in which the panel is in one piece, of the same thickness as the frame, and
flush on both sides with its surface.
Bead-flash panels have a bead all round close to the inner edge of the framing.
A ledged door is the simplest kind of door made, and is used only for temporary or inferior build-
ings. The very commonest consist of vertical boards butted against one another, and connected by
two or three horizontal pieces called “ ledges” nailed across the back. In ledged doors of a better
class, the boards are grooved or ploughed and tongued together, sometimes united by rebated joints,
and nearly always beaded or chamfered.
A ledged and braced door has braces diagonally across the back in addition to the horizontal ledges,
and generally housed into them.
A framed and braced door consists of a frame strengthened by a middle or lock rail and diagonal
braces, the edges of which are stop-chamfered, to give them a light appearance.
Paneled doors consist of a framework of narrow pieces of equal thickness put together with mortise
and tenon joints, and grooved on the inside edges to receive the panels. Fig. 711 is a six-paneled
door. The mode in which this is put together is shown in Fig. 712.
Fig. 712 shows one stile of the door detached; the other is in position, and supposed to be trans-
parent, in order to show the construction of the tenons which fit into it. The rails and stiles are
continuous throughout their length ; but the munting is divided into three parts tenoned in between
the rails. A portion of the door is broken away to show the construction of the munting between
the bottom panels. It will be noticed that the stiles are longer than the height of the door, having
projecting “horns” H H, which extend above and below the bottom rails. These horns are left
until the door is wedged up, in order that there may be sufficient substance to resist the pressure of
the wedges, which would otherwise, pressing in the direction of the grain, force out the wood beyond
the mortise in the stile, and destroy the joint. These horns are, of course, removed when the door
should be narrow, so as to be affected I ]






312 CARPENTRY.


fl
is finished and cleaned oif ready for fixing. The ends of the rails are formed with tenons of differ-
ent kinds, as shown in Fig. 712. These fit into mortises in the stiles, and are then secured by wedges.
The top rail has a single haunched tenon at each end, the frieze rail a common tenon at each end,
and the bottom rail a double tenon at each end. The lock rail is provided at dt with a double tenon,
strengthened by a haunch
between them; thus the
necessity of a very large
mortise (which would cut
the stile nearly in two) is
avoided. When a mor-
tise lock is used for 'a
thick door, that end of
the rail in which the lock
711.

TOP
\FRI 52:
'B








U l
;' FR! 525 RA l L is to befixed should be
2 provided with four tenons,
o u, as shown at M ,' between
E J these there is room for
.""°° '5 “"5” t the lock, which can be in--
e g n; a,
serted without interfering
with the tenons. The con-
struction of this joint is
shown in the figure, a por-
tion of the stile having
been broken away in order
to show the tenons more
distinctly. The common
practice, however, is to
make an ordinary double
tenon in the centre of the
framing (like that at (It),
the result being that the
formation of the mortise
for the lock cuts away por-
tions of the tenons, and
weakens the joint.
The inside edges of the
' stiles, munting, and rails
are grooved down the centre about half an inch deep and for one-third of their width, to receive the
panels. The edge of the panel X is shown in dotted lines. The door, having been made, the tenons
carefully fitted to the mortises, etc., is put together without any fastening, and left until imme-
diately before it is required to be fixed, in order that it may have as long a time as possible to sea-
son. Before being fixed, the door is taken to pieces, the mortises cleared out, the tenons covered
with glue, the stiles, munting, and rails tenoned into each other, and the panels inserted. The deal
wedges w w are then dipped in glue and driven in as shown on each side of the tenons, the flat part
of the wedge being next to the tenon. In the figure the wedges securing the frieze rail are shown
as originally fixed. Those for the top and bottom rails have been cut ofi' flush with the stile ; this
is shown so for the sake of illustration, but in practice it is not done until all the parts of the deer
are put together and “wedged up.” The door should then be laid upon a flat firm surface till the
0lac is dr .
c “Tmnows.—Several rules are given by different writers for the sizes of windows as regards ap-
pearance. These need not be here entered upon. The undermentioned may be useful to regulate
the size as regards internal arrangement. ,
The area of light should = 1/ cubic contents of room (Morris). The height generally from 2
to 2% times the breadth. There should be 1 foot superficial of window space to every 100 or 125
cubic feet of contents of the room in dwelling-houses, or 1 foot superficial to 50 or 55 cubic feet in
hospitals (Galton). The window-sill should generally be about 2 feet 6 inches from the floor inside.
\Vindows should, as nearly as the construction will admit, reach to the ceiling, for the sake of ven-
tilation.
Windows consist of two parts: 1. The sash or sashes (including the bars) which hold the glass.
2. The frame carrying the sashes. The sashes may be fixed; hinged on the sides to open like a door,
either in one flap or two; hinged at the top or bottom edge; suspended by lines over pulleys, with
counter-weights to slide up and down; arranged to slide laterally; or hung on pivots near their
centres. The frames may be solid or hollow. The latter (which are called “boxed or cased frames”)
are required to receive the counter-weights when the sashes are hung over pulleys.
Sums are arrangements of steps for conveniently ascending from one level to another.
The staircase is the chamber or space which contains the stairs. This may be a room of the exact
size required, the walls of which closely surround and support the steps; or the stairs may be in a
large apartment, such as a passage or hall, openings beingleft in the upper floors so as to allow head-
way for persons on the steps, and to furnish communication between the stairs and the different
stories of the building.
Tread is the horizontal upper surface of the step upon which the foot is placed. Rise is the verti-
cal height betwecn two treads. Riser is the face or vertical portion of the step. N osing is the outer
edge of the tread. In most cases it projects beyond the face of the riser, and is rounded or ornw













‘5
QEQ LOCK RAIL
it
HANGING


MUNTING


FIOJ'TOM RAI L





AW" narmm. 1e
(5;; I /


CARPEN TRY. 313

mented by a moulding, being known, accordingly, as a “ rounded” or “ moulded” nosing. Fliers are
the ordinary steps of rectangular shape in plan. Winders are the steps of triangular or taper form
in plan, required in turning a corner or going round a curve. The small ends of winders are some-
times called the “ quoins.” A flight is a continued series of steps without a landing. A landing is
the flat resting-place at the top of any flight. A. half space is a landing extending right across the
width of the stair. A quarter space is a landing extending half across the width of the staircase.
The going of a stair is the distance from riser to riser. This term is, however, sometimes taken to
mean the width of the stair, that is, the length of the steps. The going of a flight is the distance
from the first to the last riser in the flight. The line of nosings is tangent to the nosings of the
steps, and thus parallel to the inclination of the stair. Newels are posts or columns used in some
kinds of stairs to receive the outer ends of steps. If the steps are pinned into the wall and there is
no post, the staircaée is said to have an “open newel.” The handrail is a rounded rail, parallel
' nearly throughout its length to the general inclination of the stair, and at such a height from the
steps as to be conveniently grasped by a person on the stairs. Balusters are slight posts or bars
supporting the handrail.
Dimensions of stairs—The dimensions of staircases and steps are regulated by the purposes for
which they are intended.
Length of steps—As a rule, steps should not be less than from 3 to 4 feet long, so as to allow two
persons to pass, and in superior buildings they are very much longer.
Tread and rise—The angle of ascent for a stair will depend upon the total height to be gained
between the floors, and the space that can be afiorded in plan. The wider the step the less the rise
should be, as steps which are both wide and high require a great exertion to climb. Authorities differ
slightly as to the proportion between the tread and riser.
The following rule is often adopted for steps of the dimensions ordinarily required in practice, i. e.,
those with treads from 9 inches to 14 inches wide: \Vidth of tread x height of riser : 66 inches.
Thus, with a tread of 12 inches, the riser would be 5% inches; with a riser of 6 inches, the tread
would be 11 inches.
The tread of a step should, however, never be less than 9 inches in width, even for the commonest
stair; while, for first-class houses and public buildings, the stairs may have treads from 12 to 14
inches wide. Flights should, when possible, consist of not more than 12 or 13 steps, after which
there should be a landing, so that weak people may have a. rest at short intervals. Two consecutive
flights ought not to be in the same direction. '
DIFFERENT FORMS or Sums—A straight stair is one in which all the steps are parallel to on
another and rise in the same direction; thus a person ascending moves forward in a straight line.
A dog-legged stair is so called from its being bent or crooked suddenly round in fancied resemblance
to a dog’s leg. In this form of stair the alternate flights rise in opposite directions. The ends of
the steps composing each of these alternate flights are in the same plane with those of the other
flight, so that there is no opening or well-hole between them.
A geometrical stair is one in which there is an opening or well-hole between the backward and for-
ward flights.
Circular stairs are composed of steps contained in a circular or polygonal staircase, toward the
centre of which they all converge. All the steps are necessarily winders.
PARTS or WooDEN STAIRS.—Strings are thick boards or pieces of timber placed at an inclination to
support the steps of a wooden stair. Wooden stairs of the commonest description are thus constructed:























3- {WS
715.
gas
it
"'T‘t’lt‘lwumlm'i l"
as“:éétéllllr“ i " i i i r 71°“



Two strings, S S, Fig. '713, are fixed at the slope determined upon for the stairs ; in these, rectan-
gular notches are cut, each equal in depth to the rise, and in width nearly equal to the tread of a step;
upon these, boards are nailed, forming the treads t and risers r. In stairs of a better description
314 CARPENTRY.

the outer strings are cut as above described; but the ends of the risers, instead of coming right
through and showing on the outer surface of the string, are mitred against the vertical partof the
notch in the string, as shown at a a in Fig. 714 (plan), the other end of the step being, as before,
housed into a groove‘formed in the wall string. The outer extremity of the tread is also cut and
mitred, as shown in Fig. 714, to receive a return moulding, forming the nosing of the end of the
step. The mortises for the balusters are frequently dovetailed into the treads.
Housed strings—In many common staircases the strings, instead of being notched out to receive
the steps, are left with their upper surfaces parallel to the lower, and grooves are cut into their inner
sides to receive the ends of the treads and risers ; these grooves are called “housings,” and the steps
are said to be “housed” into the strings. Fig. 715 is an elevation of the inner side of a housed
string, showing the sinkings or housings formed to receive the steps. Fig. 716 is a sectional eleva-
tion through the steps, showing the treads t and the risers r in position. These are secured by means
of wedges x g, which should be well covered with glue before insertion. The treads are sometimes
formed with two tenons at each end, which fit into mortises cut through the string.
Open strings are those, such as the cut strings, or cut and mitred strings, described above, which
are cut so as to show the outline of the steps.
Close strings have their upper and lower surfaces parallel, the steps being housed into them'as
above described (see Fig. 716). ~
lVreathed string is one formed into a continuous sweep round the well-hole of a geometrical stair.
The wall string is the string up against the wall, and plugged to it ( W S, Fig. 714).
The outer string is the string at the end of the steps farthest from the wall (0 S).
A rough string is an additional support between the former two, in stairs of more than 3 or 4 feet
in width (R 8); called also a carriage. In very wide stairs two or more rough strings are used.
Wooden steps are formed of boards, as shown in Fig. 717. The risers are united to the treads by
ssgss:
5 -






7%.?“
% 2?;4'


'




.:§
\\\s\\\\\\~s.


joints, which may be grooved and tongued, as in steps 5, 6—feathered, as in step 4—or rabbeted, as
N o. 3 ; in every case the joint is glued. 'l‘he riser often has only its upper end tongued, the lower
butt-ing upon the tread below. This is not so good a construction as that shown at 3. A common
practice is to house the lower edge of the riser into the tread below, as at 11:. The tread is some-
times tongued into the riser, but that is not a good construction.
The joint between the tread and riser is strengthened by small blocks glued into the inner angle,
as shown in steps 3 and 4; these maybe either rectangular or triangular in section. The inner ends
of the treads rest upon rough strings R S (if any), and they are frequently further supported by
rough brackets, r 6, attached to the rough strings or carriages. These brackets may be pieces nailed
alongside the string, as in steps 1, 2, 3, 4, or triangular pieces fixed to its upper surface, as in 5 and
6. The treads project over the risers, and are finished with a rounded or a moulded nosing, the pro-
jection of the nosing being generally equal to the thickness of the tread. When a moulded nosing
is adopted with an open string, the moulding is returned at the end of the step, being mitred at the
angle. The mouldings are generally planted on under the rounded nosing of the tread. The treads
should be of oak or other hard wood, and may be 1),; inch thick for steps 4 feet long—the thickness
being increased by one-eighth of an inch for every 6 inches added to the length of the step.
Works for Reference.—“ N ouvelles Inventions pour Bien Batir et a Petits Frais,” De l’Orme, Paris,
1561, 1568, 1576; “L’Art de Serrurerie et de Charpenterie,” Jousse, Paris, 1751; “Specimens of
Ancient Carpentry,” Smith, London, 1786; “Traité de l’Art du Charpentier,” Hassenfratz, Paris,
1804; “Traité de l’Art dev la Charpente,” Krafft, Paris, 1819—’22; “L’Art du Tract de Charpen-
terie,” Fourneau, Paris, 1802—’26; “Treatise on Masonry, Joinery, and Carpentry,” Robison, London,
1839; “ Traité de l’Art dc la Charpenterie,” Emy, Paris, 1836—’41 ; “ The Universal Stair-Builder,”
Cupper, New York, 1841; “Modern Stair-Builder’s Guide,” De Graff, New York, 1846; “Treatise
on the Construction of Staircases and Handrails,” Nicholson, London, 1847 ; “New Carpenter’s
Guide,” Nicholson, London and New York, no date; “ Concise Method of Handrailing,” Hall; “ Art
of Stair-Building,” Perry; “Papers on Carpentry,” Waddington, London, 1848; “Orthogonal Sys-
tem of Handrailing,” Jeays, 1850; “Treatise on Handrails and Staircases,” Ashpitel, London, 1852;
“The Carpenter’s New Guide,” Ashpitel, London; “ Sur la Charpente a Grands Portées,” Ardent.
Paris, 1853 ; “ Traité des Echafaudagcs,” Kraift, Paris, 1856; “ Handrailing Simplified,” Riddell,
Philadelphia, 1856 ; “The Scientific Stair-Builder,” Riddell, Philadelphia, 1856; “Text-Book of
Modern Carpentry,” Silloway, Boston, 1858 ; “New Guide to Carpentry,” Burn; “Les Constructions
Ornamentales en Bois,” Degen, Munich, 1858 ;_ “ The American Stair-Builder,” Esterbrook and Menck-
ton, New York, 1859; “The Timber Merchant’s Assistant,” London, 1859; “The Carpenter’s and
J oiner’s Assistant,” N ewlands, 1860; “Carpenter’s Guide in Stair-Building,” O’Neill, Richmond, 1860 ;
.“ The Practical House Carpenter,” Pain, new ed. by Brooks, 1860; “ Encycloptedia of Practical
CARTRIDGE-MAKING MACHINERY. 315

W‘,
Carpentry and Joinery,” Tarbuck, London, 1862; “Instructions in Staircasing and Handrailing,”
Banks, London, l849—’63; “ The Carpenter’s and Joiner’s Handbook,” Holly, New York, 1866; “ The
Modern Carpenter and Builder,” Riddell, Philadelphia, 1867; “The Science of Building,” Tarn,
London, 1870; “Elementary Principles of Carpentry,” Tredgold, London, 1870; “Cottage Resi-
dences,” Downing, New York, 1873; “Carpentry and Joinery,” Tredgold and Tarn, London, 1873;
“Notes on Building Construction,” London, 1875; “On Transverse Strains,” Hatfield, New York,
1878; “ The American House Carpenter,” Hatfield, 8th ed., New York, 1879.
CAR, REFRIGERATOR. See RAILROAD Cans.
CARS, RAILROAD. See RAILROAD Cass.
CARTON PIERRE. Paper pulp mixed with whiting and glue. It is pressed into any desired
shape, in sectional moulds of oiled plaster. It is largely employed for decorations in relief, to imitate
sculpture in theatres, and also for the manufacture of fancy articles, picture-frames, etc.
CARTRIDGE JIAKIN G MACHINERY. The successful invention of the self-primed metallic-case
cartridge has greatly simplified the construction of breech-loading small arms. Prior to its intro-
duction and use, the prevention of the escape of flame through the joint of the breech was of diffi-
cult if not impossible accomplishment; and the complicated arrangements of the breech mechanism
had to be resorted to, with at best unsatisfactory ,results. The metallic cartridge overcomes this
difficulty, being itself a perfect gas-check, renewed at every round, preventing foulness and also wear
of the mechanism. So important an element is it, that it may be said that, with a perfect cartridge,
the most indifferent breech arrangement can be used with safety and efficiency. Among the benefits
claimed for the metallic cartridge may be mentioned its completeness and simplicity, and the facts
of its being self-primed and of sufficient strength to withstand the roughest usage; its accuracy,
because of the coincidence of the axes of the bore and bullet; and added to these, the impossibility
of firing but one cartridge at a time.
Cartridges are made of various sizes and with differing forms of projectile, as the short round,
long conical, and taper conical swaged balls. The explosion of the cartridge is caused either by
“centre” or “rim” fire, according as the percussion composition is concentrated at the centre or rim
of the rear portion. The system adopted by the U. S. Ordnance Department and leading cartridge
manufacturers is known as the centre-fire. By concentrating the percussion composition in the centre
of the head, the quantity used is reduced to a minimum—to less than one-fourth of what is required
to prime the entire circumference in the rim-fire; and this smaller quantity is so much better protected
as not to be at all liable to accidental explosions. The central portion of the head has more elas-
ticity than the rim, and is better adapted to resist the strain upon it from the sudden action of the
fulminate, besides having the ad iitional advantage of permitting the ree'nforcing of the rim, thus
strengthening the weakest portion of the cartridge-case.
The regulation U. S. cartridge consists of the following parts: The case, the cup-anvil, half grain
of percussion composition, 70 grains of musket powder, and a lubricated leaden bullet weighing 450
rains.
g The case is the copper tube which forms the receptacle for the powder-charge, the percussion com-
position, and the bullet. Its exterior conformation is designed to facilitate its ready extraction from
the gun. Besides the rim at the closed end, which is intended primarily to assist extraction, the case
is tapered from the rear to a point where it seizes the bullet.
The cup-anvil is a small metallic cup of sufficient rigidity to resist the blow of the hammer, and
of such form as to insure the passage of the flame to the powder-charge. It is provided with a cir-
cular recess or cavity, on which the percussion composition is deposited. Two little vents at the
extremities of a diameter of this recess direct the flame to the charge. The cup when charged with
the composition is placed within the copper case, pressed snugly against its closed end, and crimped
firmly into position. Cups and shell are of copper. The bullet enters more than half its length into
the case, in order that the lubricant in its grooves may be entirely covered and protected. To render
the cartridge water-proof, the edge of the case is crimped hard against the bullet. In making the
cases for the United States army, sheet copper of No. 2 wire gauge, obtained in strips 35 inches
long, 3.3 inches wide, and from .025 to .027 inch thick, is employed, each strip giving material for
40 cases.
CARTRIDGE MANUFACTURE—Tilt? first operation is performed by a double-acting press, to which the
strips, after being straightened and oiled, are fed by hand. a small stop on the die-plate regulating
the length of feed. The first shape given to the case is that of a flat circular disk 1.? inch in diame-
ter. The punch is essentially a punch within a punch, the exterior one cutting the disk clear from
the strip, while the interior one descends and forces the blank through a tapered die, giving it a
shallow cup-shape 1.06 inch in diameter and .55 inch deep. After passing through and beyond the
tapered die, the cup expands slightly, and is stripped from the interior punch as the latter ascends.
In order to draw the cups to the dimensions of the finished cases required, they are subjected to the
action of four additional punches and dies of decreasing sizes, so as gradually to elongate them
while reducing their diameters. These draws are made by the single_action presses, each having a
single punch and die. Fig. 718 represents a single-acting punch. At the second drawing the tubes
are annealed, to restore ductility. The annealing is done by placing the tubes in a perforated iron
cylinder, heating them red-hot in a charcoal fire, revolving the cylinder to equalize the heat, then
plunging them into a solution of 1 part of sulphuric acid and 15 parts of water. They are then
thoroughly washed to remove all trace of acid. The pickle is used to remove any scale or oxide occa-
sioned by the annealing. The fourth and finishing draw having left the tubes of unequal lengths
and with ragged edges, it is necessary to have the tube trimmed, which is accomplished by the trim-
ming machine. The tubes are placed in the trough of this machine, whence they are taken up by a
revolving mandrel, against which, and just inside of a shoulder upon the same, the edge of a circular
cutter is pressed. The tube, when brought into position by the mandrel, is cut clean and even by
31 6 CARTRIDGE—MAKING M AOHINERY.

the cutter, a stripper removing the tube and scrap after each operation. This machine trims at the
rate of 80 a minute. In all the operations previous to and succeeding the annealing, lard oil of the
best quality is the lubricant used. But as the smallest particle of oil will impair the efliciency of
the fulminate, it is of importance that all vestiges of it be removed. To accomplish this, the tubes
are placed in a potash solution.
The head or rim of the case is next formed
by the heading machine, Fig. 719. This ma-
chine consists of a horizontal die, countersunk
at one end for shaping the head, a feed-punch
to insert the tubes into the die, and a heading-
punch to flatten the closed end of the tubes
into the countersink. The tubes, which are a
little longer than the headed cases, are fed into
the inclined trough of the heading machine,
whence they are taken up on the feed-punch.
A shoulder on this punch, at a distance from
its extremity equal to the inner depth of the
headed case, prevents it from extending to the
full depth of the tube, and any surplus of metal
is thereby left at the closed end of the tube
for the formation of the head. The feed-punch
inserts the tube into the die, and holds it there
while the heading-punch moves forward by a
powerful cam, and presses and folds the unsup-
ported projecting portion of the tube into the
countersink of the die, forming and accurately
shaping the head or rim. The headed case, be-
ing left in the die as the feed-punch recedes, is
pushed out by the succeeding tube and thrown
by a flipper into the receptacle below. This
machine is fed at the rate of 65 cases a minute.
The tubes are now subjected to a temperature
of 125° to remove all moisture.
This portion of the shell being ready, the
“cup-anvil” is made. It is punched out by
the double-action press, of unannealed copper
in strips 20 inches long, 3.125 wide, and 0.48
thick. The cups are formed at the rate of 75
a minute. They now go to the (nip-cutting and
trimming machine, which consists of a revolv-
ing rose-cutter, made of a number of small cut-
tcrs that can be changed and sharpened at pleasure. They afterward pass to the twp-renting
machine, where the vents are punched in the trimmed cups by a two-pointed punch and correspond-
ing dies. The cups are fed by a revolving plate at the rate of '70 per minute. The circular depres-
sion in the bottom of the cup which serves as a receptacle for the fulminate is formed by the cup-
impression machine. to which the cups'are fed through a vertical trough at the rate of 80 per min-
ute. The trough has a flat pan at the top, into which the cups in quantities are emptied, and where
they are arranged so as to present
71,, the proper end to the punch in
passing through the machine. The
cups are now washed.
The next operation is the prim-
ing of the cup, which is done by
the priming machine. The per-
cussion composition which is used
consists of fulminate of mercury,
by weight, 35 parts; chlorate of
potash, 16; glass dust, 45; gum
arabic, 2; and gum tragaeanth, 2.
This composition, which is 01‘ the
consistence of a thick paste, is de-
posited in the recess of the cup
by the cup-priming machine, Fig.
720, of which the principal parts
are: 1, the central revolving spin-
dle A, with four tubular feeders
at its head, which deposits the per-
cussion composition in the cups; 2, the magazine B, on the right; and 3, the circular plate 0, on
the left, on which the unprimed cups are fed to the machine. The four tubular composition-feeders
at the head of the spindle consist each of a small depending stem, down which a closely-fitting tube
is made to slide, the lower edge projecting a little below the end of the stem. By the revolving
motion of the spindle these tubular feeders are brought successively over the magazine and over the
cups to be primed. At the moment a feeder is presented over the magazine (which is a shallow dish








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CARTRIDGE—MAKING MACHINERY. . 317

containing the composition), the latter rises until its bottom is in contact with the tube, a slight
shaking motion of the magazine during its progress serving to deposit compactly into the open
projecting end of the tube a sufficient quantity of composition for the priming of a cup. The maga-
zine then rccedes, while the revolving spindle carries the charged feeder to the circular plate C on
the left, which presents the cup for priming. The motion of this plate is from left to right, while




720. 721
5 1, '23: *
gl‘ \.._1‘, I g ' g
_ Jf/l “5‘ = 5
gm. seam ‘ -; >
a. =" ".1.- '
' s


,
-'_. F;~
ll llllllllm .

1|
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Thimnm
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;
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\. 1””, fl ‘
iiig}§%\§§,u".ilitli( U I \
‘1 “it ', .. tilt: alert
that of the spindle is from right to left, whereby the feeders and cups are made to meet and leave
each other in opposite directions. The plate is provided with eight upright movable stems, on which
the unprimed cups are fed. As the cups and feeders are brought by the revolutions of the plate
and spindle in a vertical line with each other, the cups are raised by their stems so as to receive
the composition exactly in their circular recesses from the tubes of the feeders. The tube at the
moment of contact with the cup slides up
its depending stem, and frees the compo-
sition from its end, which is pressed by
the upward motion of the cup snugly. into
the circular recess. A specific quantity
of composition is thus deposited at each
operation. This machine primes at the
rate of 35 cartridges a minute.
While the composition is still moist in
the circular recesses of the cups, the lat-
ter are put into the headed cases and
crimped into position, the cases being ta-
pered at the same time. This operation
is performed by the tapering machine,
.Fig. 721, which consists of four vertical
tapered dies 0 0, with stems projecting
from their centres, on which the cases
and cups are fed; the crimpers, which
work from the sides of the dies; and the
descending punch D, which forces the
cases into the dies. The primed cups are
placed on the ends of the stems project,
ing from the dies, and the cases are placed
over them. By the revolution of the hori-
zontal plate on which the dies are placed,
each die is in succession brought under
the descending punch, which forces the
cases into the dies and presses their heads
hard against the primed cups, while the
crimpers move forward from the side and bite the cups snugly and firmly into place. The central
stem rises out of the die as the latter leaves the punch, and the case is removed by a spring.
BULLET-MAKING.——The bullets used are generally of the elongated variety, and are made either by
compression, swaging, or casting. Compressed bullets are considered the best, as they are uniform
in size and weight, more homogeneous and more accurate, and give better results, than the cast and
swaged varieties. The lead used should be pure and soft, of a specific gravity 11.35, increased by


318 CARTRIDGE-MAKING MACHINERY.

pressure to about 11.45, and which melts at 600° F. and volatilizes at red heat. The lead is first
cast into cylindrical bars .59 of an inch in diameter and 20 inches long. They are then rolled,
having a diameter of .42 of an inch and 36 inches long. These bars are fed to the bulletybimiwg
7'23.
machine, Fig. 722, through a vertical
. tube above a horizontal cutter, which
cuts at each stroke sufficient metal
to form a bullet, and transfers it
to the die, in which by means of a
vertical punch the bullet with its
grooves is formed. The surplus
lead is forced out at the junction
of the dies, in the direction of the
longer axis of the bullet, and at the
junction of the punch and dies at
its head. The dies and punches for
this machine are made of the finest
cast-steel. The dies are cut out to
the form and dimensions of the bul-
let, and have as hard and smooth
a surface as it is possible to give
them. They are hardened in cold
water, and the temper drawn to a
light straw-color. They are made
in such a manner that only small
portions of their faces, just surrounding the base of the bullet, maybe in contact while the bullet
is being formed. A bullet machine makes 30,000 bullets in ten hours. The operation of trimming
the bullets is performed by the bullet-[rimming machine, Fig. 723. The bullets are fed by handinto
a revolving perforated circular plate, whence they are forced
724- by a punch through trimmers, which open from the point
It to the base of the bullet and conform to its shape, a cut-
’ ter at the same time passing over the base. After this they
are forced by the punch through a gauge under the trim-
mer. The bullet being finished, the next step is to lubricate
it, for which purpose the following is considered the best
lubricant: bayberry tallow, by weight, 8 parts; graphite, 1
part. The lubrication of the bullet is done by the lubricat-
ing machine. The lubricant is moulded into cylinders of
about 10 inches in length. These cylinders are fed to the
machine through a vertical tube, pressure being applied to
keep the supply constant. The bullets are placed by hand
in a perforated plaie revolving vertically, and are forced by
a punch through the sizing gauge fixed in the bottom of
the tube, which is pierced with small holes. The lubricant
is forced through the holes into the grooves of the bullet.
' The cases are now loaded with powder by means of the
loading machine, Fig. 724, which consists of a revolving cir-
cular plate with holes and a. hopper and powder measure.
The cases and. bullets are fed upon revolving plates, 35 a
minute. The former are lifted into the holes or receivers,
passed under the hopper and measure for a charge of pow-
der, and then under the bullet-feeder for a lubricated bullet.
In order to insure a full charge of powder in each cartridge,
the machine is provided with a bell, which gives notice to
the operative of any failure in this particular. The edge of
the case is then crimped on the bullet. The receivers are
smaller at the top, where the bullet enters, than at the bot-
tom, wherc the case is received, the diameter of the former
being only equal to that of the interior of the open end of
the latter. After the bullet has been pressed into the case
the cartridge is lifted, so that the edge of the case is forced
into the conical surface of 'the receiver, between its larger
and smaller diameters. The powder is placed in a large paste-
board hopper about 2 feet above the machine, and is fed to
the cases through a paper tube 1 inch in diameter. The hopper and tube stand inside of a large con-
ical shield of boiler iron. After loading, the cartridges are wiped clean and packed in wooden boxes.
hfaehinery for making Large CartridgeCases—One of the demands created by the introduction
and adoption of quick-firing guns—ammunition—is that for machinery of far greater power than
hitherto used for the manufacture of the metallic cases, which, together with the projectiles and ex-
plosives, compose the main parts of the complete cartridges.
The machines employed and the operations performed by them are briefly described as follows: The
blank or disk is punched from a strip of brass (previously cast and rolled to the required thickness)
by a cutting-out press; this machine is of sufficient power to punch out one disk at each stroke, 7 in.
in diameter by :5-111. thick. The blank is next formed into a “cup,” and is then gradually drawn







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CARTRIDGE-MAKING MACHINERY. 319

into the shape of a cylinder. The partially formed cases are then transferred to the extending
machine (Fig. 724 A). Each of these machines is double-ended, but one attendant is able to keep
both ends fully employed. The machine is arranged with a variable stroke, readily adjusted, to
economize time when engaged on short cases, or the earlier operations. Before the case has been
extended to its full length it undergoes, in a specially constructed press, the operation of indenting,
to prepare it for the subsequent formation of the head. After being returned to the extending
724A.




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machines and lengthened, the head of the case is stamped out by the heading-machine (Fig. 724 n),
which combines with a steam-stamp sundry important additions and devices to accomplish the accu-
rate and rapid execution of the work.
The final shaping of the body of the case is efi’ected in the tapering-machine, after which the head
is turned, faced, bored, and recessed at one chucking in a suitable lathe. The trimming of the cases
to length at the earlier as well as the final stages is also done on a lathe of suitable construction.
This machinery is of a very powerful description, as compared with that used for the production of
small-arm cartridges.
Automatic S/wZl-Fecd.—Among the new machinery employed in the manufacturing of cartridges of
the smaller calibres, the automatic shell-feed (Fig. 72-4 e) deserves mention. It is designed for feeding
shells or caps automatically from a hopper or box, and presenting them properly under the punch. It
is best adapted for work of one uniform size, or where a press can be used continuously upon one size
of work.
An Automatic Shell-Trimmer has been found very useful for trimming the shells of cartridges of
from 22 to 38 calibres. Inclined guides at the front of the machine are used to receive the car-
tridges as they are fed from other machines. From here they are automatically carried to a chuck,
where the ends are cut off. When this operation is completed, the cartridges are true and of exact
standard length.
lVad-Outtz'ng Press—During the past few years considerable attention has been bestowed upon the
subject of wad-cutting. The latest press that has been designed for this purpose is what is known as
the openside pillar press, and is arranged with double roll-feed, designed especially for the purpose
of feeding the felt for cutting into gun-wads. It is made of the open-side pattern, to admit of the
removal of the tools without disturbing the feed-rolls. See “ Yearly Reports of Chief of Ordnance,

U. S. A.”
Reloading Cartridges. Cartridges which can be reloaded are now used as a matter of economy by
sportsmen. Concerning these the Winchester Repeating Arms 00., of New Haven, furnishes the
following practical information :
For reloading purposes the shells of centre—lire cartridges are made of extra thickness. Rim-fire
cartridges cannot be reloaded. All shells, as soon as possible after being fired, should be cleaned and
washed out carefully with strong soap-suds or soda-water and dried thoroughly, otherwise the deposit
of burned powder left on them after tiring causes them to oxidize rapidly, and they are soon destroyed.
Care should be taken to set the primer well down. The pocket in the shell is always made deep
enough to allow the primer to be set below the surface of the head of the shell. Premature explo-
sions and misiires are often caused by failing to attend to this particular.
For powder in rifle~cartridges containing more than 40 grains, the following brands and sizes of
grains are recommended as giving the best results : American Powder Mills’ “ Rifle Cartridge,
N o. 3 ”; Hazard Powder Co’s “Kentucky Rifle, F. G.”; E. I. DuPont (Jo’s “ DuPont Rifle, F. F.


320 - ' OARVING TOOLS.

G.” ; Laflin 82 Rand Powder Co.’s “Orange Rifle Extra, F. F. G.” In rifle cartridges containing from
25 to 40 grains, use one size smaller of the same brands.
The American Powder Mills have put a new brand of powder on the market, called “Rifle Oar-
tridge Powder,” especially for use in rifle cartridges. In such cartridges none of the high grades of
powder should be used which owe
724 B. _ their quick-burning properties to
their peculiar manufacture. They
are not hard-pressed powders, and,
when compressed in a cartridge
shell, they cake behind the bullet
more than the harder pressed
brands, and give high initial press-
ure and very irregular shooting,
without greatly increased veloc-
ity.
In casting bullets, keep the
mould and lead very hot, and use
the proportions of lead and tin
given by the makers for each bul-
let. If using naked bullets, see
that the grooves are filled with
lubricating material; beef tallow
or Japan wax is best for this pur-





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pose. Wipe oif all surplus grease before loading. When patched bullets are used, place a lubri—
eating disk of wax with a cardboard wad both above and below it, between the ball and the powder.
Special forms of reloading tools are manufactured. The form made by the above-named corporation
removes the exploded primer, straightens the shell at the mouth, inserts the new primer, and fastens
the ball in the shell.
Cartridges with Divided Bullets—Cartridges in which the bullet is divided into four equal. por-
tions have been tested by the Ordnance Department, U. S. A. The parts after division were pressed
together in a mould, and arranged with a suitable charge in an ordinary shell. The results were
altogether unsatisfactory, the testingofficers finding that the chances of a hit at even 40 yards’
range were remote, and “ the accuracy so slight that it would hardly be wise to entertain any expecta-
tion of hitting an enem .”
OARVING TOOLS. In Figs. 725 to 739 are represented the various tools used in hand-carving
in wood. The chisel, Fig. 725, is of various widths, from one-eighth of an inch to an inch, has a
straight edge, and is used for plane surfaces which are square, removing superfluous wood and
grounding. It is the mostknecessary tool of the set. The gouge, Fio'. 726, has a curved edge of
various sweeps, according to the depth to be cut. It ranges from almost flat to the exact half of a
circle, about eight different sweeps. The skew-chisel, Fig. 727, is a variation of Fig. 725, the edge
CASTING. 321

,____i
being ground back from either corner, being right or left hand. It is useful for working out the
inside corners of angles, where the edge of Fig. 725 would be too wide. The parting tool, Fig. 728,
is a sort of gouge with an angular edge. Its cut is V-shaped, and it is quite essential for various
purposes of cutting angular grooves. ‘ ’ ‘ _
They are made either straight or 795~Cflrvmg @1180]-
bent. Fig. 734 is only a variation - -‘ - a
of the parting tool, quite narrow, '
and used to engrave the veins of
leaves and similar work. The part-
ing tool is often used for the same
purpose. Figs. 730 to 737 are sim-
ple variations of the tools already
mentioned. Their peculiar shape
adapts them for use in confined 727-—Skew Carving Chisel-
spaces, where the shanks of the r - t other tools could not be carried
back far enough to make a clear
cut, the relief of the carving being in
the way. Fig. 738 is a scraper, and
Fig. 739 a riffling tool for finishing.
For machine-carving, see MOULD-
me Maenmns, Woon-wonxme.
CASTING. The forming of met-
als and other substances by pouring
them while in a liquid or melted state
into moulds, and allowing them to
solidify by setting or cooling. (See
MOULDING, ORDNANCE, MANUFACTURE
OF, LADLE, Furnaces, BLAST, and
IRON-MAKING MACHINERY.) The term,
when applied to the casting of met-
als, is used synonymously with found-
ing, and the place where the work is
done is called a foundry.
For melting the metal to be cast,
the cupola furnace is most commonly
used. This will be found described
under FURNACE, CUPOLA. The re-
verberatory furnace (see IRON-MAK-
ING MACHINERY) is sometimes em-
ployed, and has the advantage of
making strong, close, and safe east-
ings. The circumstances under which
this form of furnace may be used in
preference to the cupola are as fol-
lows: when there are no means for
obtaining sufficient blast for a eu-
pola; when it is necessary to melt
down such large masses of metal as
cannot be managed in the cupola;
when it is required to bring a given
pig iron by deoxidation to its highest
point of tensile resistance, as in gun-
founding; or when it is necessary to
erect a foundry under circumstances
where a cupola with blast could not
be built or worked. Under most oth-
er circumstances the cupola is to be
preferred, as the reverberatory is
neither economical in metal nor fuel,
except where the operations are con-
stantly going on from day to day on
a very large scale, and where good
bituminous coal is cheap.
Arrangcnumt of a Foundry—A
well-appointed foundry, in addition
to the room required for the ac- _
tual work of moulding and casting, should have rooms for storing and preparing the materials
of the moulds, such as grinding and sifting the sand, loam, coal, coke, pluinbago, or charcoal.
There should also be a workshop for making the patterns which are to be used in the formation of
the moulds. The moulding-room embraces an .area of greater or less extent, but even in moderate
establishments it is necessarily of considerable size. Where heavy articles are founded there are
huge cranes for lifting and moving moulds and castings from one place to another. The floors of




v15


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- 21
322 CASTING.


such foundries are also covered or rather filled with moulding-sand to a considerable depth, varying
from 5 to 10 feet. Fig. 740 represents the interior of a foundry for heavy castings. The principal
parts are as follows: an, cupola furnaces; bb, tuyeres; a, crane; d, ovens for baking moulds; r,
cope of a greensand mould, made in the floor-bed; ff, temporary furnaces for forcing heat through
the pipes gg into a large mould; h, mould of a steam-cylinder, placed in a .pit and in process of
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completion. In one part of the room, usually at one side, and sometimes adjoining another room for
making light castings, stands the furnace for melting the metal.
Consumption of libel—According to the experiments of Dulong, 1 lb. of carbon, combining with
the necessary' quantity of oxygen to form carbonic acid, develops 12,906 units of heat. The specific
heat of cast-iron being about 13°, the melting-point 2190°, and coke containing 82 per cent. of carbon,
then to heat a ton of cast-iron of a temperature of say 40° to a temperature of 2190° would require
I-Ieat. Iron. Sp. heat.
2150 x 2240 x 13
12906 x .82.
This is supposing that the whole of the carbon is converted into carbonic acid; but if by any means
carbonic oxide is formed, a very dill'erent result is obtained, 1 lb. of carbon burning to carbonic
oxide then evolving only 4,453 units of heat. If, however, by admitting air above the zone where
the oxide is formed, we recover 4,478 units, this + 4,453 gives 8,931, which is a little over two-thirds
of the available heat to be got out of 1 lb. 01' carbon, allowing 10 per cent. for moisture in the coke,
10 per cent. for radiation, and 20 per cent. for loss of heat passing off at the top of the cupola, or
40 per cent. in all. Mr. N. E. Spretson concludes that the amount of coke per ton of metal should
not exceed 112 lbs., although the actual consumption is, as has been shown, usually much higher.
Mr. Edward Kirk states that “ the percentage of fuel actually required to melt a ton of iron will
vary according to the quality of the fuel used, the construction of the cupola, the pressure of the
blast, the way in' which the iron is charged, the way in which the bed is burned, and the amount of
iron melted. A larger percentage of fuel is required to run off a small heat than would be required
for a large heat in the same cupola.” The same authority gives as examples of the most economical
melting in a cupola the following: “ 7 lbs. of iron to 1 lb. of coal; 8 lbs. of iron to 1 lb. of Con-
nellsville coke; 4 lbs. of iron to 1 lb. of gas-house coke made from I’ittsburg coal.” Average melt-
ing in foundries he states to be “ about 4 lbs. of iron to 1 of coal, 5 lbs. of iron to 1 of Connells-
ville coke, and 3 lbs. of iron to 1 01‘ gas-house coke.”
2190 - 40 : : 59.1 lbs. coke.
Table showing Percentages of Fuel and Uaslings in seven large Slow Foundries in Albany and Troy,
1V. Y., for 187 6. (Compilcdfrom [fir/M “ Founding of dicta/8.”)
1 2 3 4 5 6 \ 7




Lbs Tonal Lbs. Tons. Lbs. .Tons. Lbs 'l‘onn. Lbs. Tons. Lbs. ‘Tons. Lbs.

Tens.





Gross amount ofiron melted... 2,059;1,0s7 2,s17;1,420 1.81s 930' 1,009? 41'!) 3,828, 6,695 1,191 2,009 gar.
' Amount of stock melted... . . . . 3 1,300l 1,860 1,842i1,$71i 1,123 42; 661! 702 2,118 521 4,276 1,042 1350' 1.460}
: Amount oi'cleaned castings. net 1.344! 919 1,9601 S80 1,12,Q 1,407 664, 707 2,216 987 4,488 975 1,294 3191
I’m-pentage. of cleaned castings a r ,. H 1‘ r r of
produced to totaliron melted. { 07‘“) 62'12 0‘) 42 08-62 56-30 53.41 5~JO
,Pereentagc 01 coal used in $15.55 14.51 15'” 1722 “3'12 15.08 18.10
( melting. . . . . . . . . . . . . . . . . . ..
\ _ . . . _ . ‘ ._.. a . .

CASTING. ’ 323

m.
Loss of Iron in Melling.--Mr. Kirk gives the average loss as follows : “ In stove-plate foundries,
from 2 to 8 per cent. ; in machinery foundries, with the average iron, from 4 to 10 per cent; on old
stove-plate and shot iron, from 20 to 30 per cent. ; on burnt iron, from 25 to 60 per cent., according
to how badly the iron is burnt.”
The same author gives the following data of a test-heat made in the foundry of the Jackson 8:
Woodin Manufacturing Company, to ascertain the wastage of iron:
Heat melted March 24, 1876: Lump coal, 2,002 lbs.; N0. 2 pig iron, 6,069 lbs.; limestone, 160
lbs.; castings, 5,029 lbs.; gates and scrap, 469 lbs. ; cinder scrap, 287 lbs. Total iron put into the
cupola, 6,069 lbs.; total iron out of the cupola, 5,785 lbs.; lost in melting, 284 lbs., or say 4.7 per
cent., or 105 lbs. per 2,240 lbs.
Heat melted March 25, 1876: Lump coal, 2,002 lbs.; No. 2 pig iron, 6,069 lbs.; Kirk’s chemical
flux used; castings, 4,3801bs.; gates and scrap, 1,036 lbs.; cinder scrap, 504 lbs. Total iron put
into the cupola, 6,069 lbs.; total iron out of the cupola, 5,920 lbs.; lost in melting, 149 lbs., or say
2% per cent., or 56 lbs. per 2,240 lbs.
Charging the Cupola, and C'astz'ng.*——Supposing the cupola to be cool, but in good working order
as to lining, tuyeres, etc., the falling iron door at the bottom, if the cupola is provided with one,
must be closed, securely fastened in its place, and well covered with sand. Moulding sand is used
when only, a small quantity of iron is to be melted; if a large quantity of melted metal is required,
a more refractory sand is desirable. A wood fire is then lit in the cupola, upon which coke, coal, or
charcoal is placed, the tap-hole being left open to supply air to support the combustion, the tuyeres
being also left open. The cupola is then filled with fuel, which is kept in brisk combustion. It
requires several hours to heat the furnace for blast, which is not laid on until the flame appears on
the top of the fuel. When the furnace is thoroughly heated, the nozzles are put in, and the fan or
blower is put to work. Before putting on the blast, however, the large tap-hole must be closed with
moulding sand, or good fire-proof clay and sand mixed, leaving a small hole at the bottom, which
serves as the tap-hole for the iron. This should be about 2 inches diameter, and is formed by placing
a tapered iron bar in the place where the hole is to be, ramming the sand tightly around it, and re-
moving it as soon as the hole is properly and securely moulded. When the blast is put on it will
drive a flame through the tap-hole, as well as out of the top of the cupola. The tap-hole is left open
to dry the fresh loam and sand, and also so that its sides may be glazed or vitrified by the heat, so
as to resist the friction of the tapping-bar; the heat also serves to glaze the lining of the cupola in
those parts which have been mended with fire-clay since the last melting. When the cupola is
intended to hold a' large quantity of iron, the large tapping-hole should be covered with an iron
plate, securely fastened to the iron casing, leaving only the small tap-hole open.
Commence charging iron as soon as the lower parts of the furnace show a white heat, which is
best known by the color of the flame issuing from the tap-hole, it being at first a light blue, but
afterward becoming of a whitish color. About ten minutes after charging the iron, the melted metal
appears at the tap-hole, which must then be closed by a stopper made of loam, which has been
worked by hand to a proper consistence; a round ball of this is placed on a disk of iron at the end
of a wooden rod, and is forced into the tap-hole; this is also done when it is wished to stop a tap-
ping out with the bott or bod stick, as it is called, but is then a more difficult operation, as the mol-
ten iron frequently squirts out past the bott stick while the men are trying to apply the plug. Pig
iron is broken into pieces of from 10 to 15 inches in length before it is charged into the cupola.
This is a very laborious operation, especially in the case of tough pig iron. The first breaking is
generally accomplished by throwing the pig down heavily upon a piece of old iron fixed in the ground,
after which it is broken up still smaller with a sledge-hammer. This work is now very often per-
formed by an adaptation of Blake’s or some other stone-crusher. From 10 to 12 lbs. of fuel are
charged for every 100~lbs. of iron, but this quantity varies, depending much upon the nature of the
fuel, of the iron to be melted, and upon the size and construction of the cupola. Along with the
coke and iron, limestone must be put in, broken up into pieces about 2 inches cube, or oyster shells,
in quantities varying from 2 to 5 per cent. according to the nature of the fuel and iron. Too much
limestone. as well as too little, causes the iron to become white and lose some of its carbon, and in
many cases its strength and softness are greatly impaired. rThe limestone, when used, is commonly
introduced into the cupola after the first charge of metal. It is intended to act as a flux, and com-
bine with any earthy matters that may be present in the metal and coke. \Vith these it forms a
glassy compound, and by this means the iron is freed from such impurities as it falls to the bottom.
The slag, as it is termed, floats on the surface of the iron collected at the bottom, and frequently
makes its appearance at the tuyeres in a solid state. The cupola should be kept full while in blast, or
at least so long as iron is melted, by alternate charges of iron, fuel, and limestone. Fuel is gener-
ally put on first, then iron, and lastly the limestone, and the charging continued without intermission
until all the iron required at that time is melted, when the charges are stopped. The blast is, how-
ever, kept on until all the iron has been tapped. As a matter of experience it has been found that
the interior form of furnaces greatly affects the condition of the metal, and thus influences its appli-
cability to certain uses. Thus cupolas which are larger in diameter at the bottom than at the top
work better than those with parallel sides, and also last longer, as the melted iron, which is apt to
cut the fire-brick, then sinks more through the materials in the body of the cupola than it does in
cupolas with parallel sides. The amount of taper to be give to the lining depends upon the size of
the cupola: a large one will bear more taper than a narrow one. If it is intended to melt different
qualities of iron in the same heat, a thick layer of fuel should be placed between the various brands,
so as to allow of the extraction of all the iron which was first charged before the second appears at
the bottom. In such cases it is preferable first to melt the gray iron, or that iron which is to make
A
'F From “A Practical Treatise on Casting and Founding,“ by N. E. Spretson.
324 OASTIN G.

soft castings, and white or hard iron afterward. When as much iron is melted as is required, the
clay plug of the tap-hole is pierced by a sharp steel-pointed bar, or iron rod driven by a hammer,
and the metal run into pots, or it is run directly into the mould by means of gutters moulded in the
sand of the floor. After each successive tapping of the iron the tap-hole is closed, and more iron is
allowed to accumulate in the bottom of the cupola. '
When the work of the cupola is over, the workmen begin to clear it out. To this end they break
down the temporary clay-work that narrows up the tapping-door to one small hole. Having cleared
this away, a plate-iron fence is set up opposite the door, behind which the workman stands, and over
which he shoots a long red, kneed at the end, into the furnace, to loosen the contents, consisting of
refuse coke and clay, and drag them out while yet hot; for, if suffered to remain until cold, they
would be congealed into a compact mass. This operation is much more easily performed in cases
where the cupola is built with a movable bottom.
Charging the Reverbwatorg/ Furnace, and Casting—When a cast is to be made at a certain time,
the reverberatory is heated for some hours previously by a brisk fire. When the furnace is white—
hot the charging-door is opened, and the pig iron is placed in its proper position on the sole, due care
being taken in stacking the metal as will be described, the most easily fusible portions being first
charged and put at the bottom of the heap. The whole quantity of iron which it is desired to melt
at one heat must be charged at the same time, as it is not considered advisable to add cold iron to
that which is already melted. All the iron contained in a liquid form in the basin is to be tapped
before any fresh pig can be charged. 'When all the iron contained in the furnace is melted, the tap-
hole is opened with a sharp crowbar, and the liquid iron is either led into pots or directly intothe
mould. The tap-hole is stopped with damped sand, or a mixture of loam and coal-dust. When the
furnace is charged with iron, all the openings and joints at the door and in the brickwork are to be
cautiously stopped with moist loam, to prevent the access of any air upon the hearth. The fire-grate
must also be well attended to, and kept well filled with coal, but not too high, so as to impair the
draught of air through the fuel. The grate should be kept free from elinkers, and the formation of
holes where unburnt air could enter the furnace must be prevented. The charging-door is generally
a fire-block hung in an iron frame, which is raised and lowered by a lever, having a balance weight.
All joints through which any cold air could enter the furnace must be covered with fire-clay or loam.
The metal to be melted should be broken to a uniform size as far as possible; and on placing it in
the furnace, the smallest pieces should be piled lowest, the larger ones on the top, as the heat of the
flame is there more intense, which is what is required for the larger lumps of metal; and a similar
plan must be adopted with regard to the melting of various qualities of metal, the most easily fusi-
ble being placed lowest in the furnace. Fuel should be fed in frequently, and it must be done quick-
ly. When sufficient molten metal has accumulated in the pool of , the furnace, it is tapped off. The
chimney damper is first closed; the metal is then run into a ladle, or is run along plate-iron shoots
covered with loam to the mould, being skimmed by the dam-plate and by men as it flows along, or
into a pool in front of the furnace, the slag being removed before the metal passes into the moulds.
The furnace is then cleared out, and any necessary repairs are executed before it is again charged.
If the repairs have been considerable, it will be necessary to make the furnace white-hot before again
charging it for use.
The reverberatory furnace is not only used for melting iron, but also for the melting of large
quantities of brass, bronze, tin, lead, and other alloys and metals. Large bells, statues, machine
frames, and similar objects, are cast from the reverberatory furnace. All metals, except very gray
fusible iron, which may be cast from a pot, are to be run in dry sand ditches directly from the fur-
nace into the mould. Furnaces for melting bronze should have a rather shorter flame-bed than is
used for melting cast-iron.
lllalleable C’astz'n_r/s.--’I‘lie manufacture of what are known as malleable castings consists in obtain-
ing a tough, soft, flexible material resembling wrought-iron, from white brittle castings, by the cemen-
tation process. The pig iron is melted in and run from clay crucibles into green or dry sand moulds,
and where the articles are small snap-flasks are much used. The castings are removed from the
moulds, and cleared from sand by brushing, by shaking in a rattle-barrel, or by similar means, and
are then placed in cast-iron “ sag-gels,” with alternate layers of powdered red hematite ore, or with
fine iron scales from the rolling-mills. The saggers are then placed in the annealing furnace, where
they are exposed to a gradually increasing degree of heat until a full red heat is attained, after which
they are allowed to cool down. The articles are then removed from the saggers, cleaned from the
hematite powder, and, so far as rendering them “malleable” is concerned, the process is completed.
The pig iron employed is almost invariably hematite; for large castings white hematite pig is select-
ed, for small articles mottled pig. The best brands of cold-blast charcoal mottled irons, Nos. 4 and
5 Baltimore, or 5 and 6 Chicago, are preferable. It is essential that the pig shall be white or met-
tled, not gray; and it is not uncommon to melt up a quantity of scrap, such as wasters, gates, and
fins of white iron.
Compressed Uastz'ngs.—Stecl is subjected to high pressure during casting by Whitworth’s process.
In casting hollow forms, rams are arranged to give a pressure to the melted metal in the mould.
After this pressure has been applied for some time, and when the mass has become solidified, the
core is withdrawn, and the metal is allowed to contract freely in cooling. In making articles of con-
siderable length, the pressure is applied to the outer surface of the mould, and the latter is made in
sections, between which dried loam or sand is placed, so as to allow the air to escape, and to admit
of the sections being brought closer together. The pressure applied is about 2,500 tons. The
moulds are strengthened by steel hoops, and the compressed steel is thus given a strength and.
homogeneousncss unequaled by any other known metal.
In Bessemer’s process the metal is poured into a revolving cylinder, whose rapid rotation causes it
to collect on the inside of the same, when it is allowed to cool. It is then split open and rolled flat.
CASTING. 325

WARPING 0F Canines—Castings often warp during the cooling process, but in what direction this
warping will take place depends in a great measure on the form of the casting, and the part of the
mould at which the metal is run in. When a moulder knows from experience what part of a cast-
ing will warp, he can in many cases counteract it in the cooling process. For example: Suppose
that, having cast a number of plates, such as shown in Fig. 741, he finds that the points of the
tongues, A and B, always curl up in the mould to about a quarter -
of an inch too high. He will then pene the pattern so that the 41-
7
tongues stand a quarter of an inch too low, and thus save a great
deal, if not all, of the pening- Another plan adopted by moulders :1
°F


E
O
to straighten castings is to uncover the parts that are apt to sink in
the sand. If any part of a casting has the sand removed from its
upper surface while it is still red~hot, that part cools the quickest
and lifts up; and of this fact the moulder takes advantage, uncov-
ering the part which experience has shown him requires to be lifted.
The cause of the cooled part lifting appears to be as follows: The part cooled contracts the quick-
est; and to sink in the mould, it would require to compress the bed sand or else to raise the other
part of the casting. The whole weight of the sand in the cope, as the top part of the mould is
called, tends to keep the casting down; and when that weight is removed at any part by removing
the sand, the contracted part naturally rises, because there is less resistance offered to its rising than
there would be to its falling. In many cases this cooling process is aided by the application of water,
which much increases its effect; and it is astonishing, under skillful manipulation, how much a plate
or casting can be shaped at will, by water judiciously employed, without causing it to crack.
It is obvious that this method of straightening by uncovering a casting is applicable mainly to
thin or light castings. The uncovering of a casting while yet red-hot and resting in the mould is
often resorted to to prevent the casting from cracking during the cooling process from the strains
induced by the casting cooling in one part quicker than in another, the thick parts being uncovered
to hasten the cooling, and thus equalize to some extent the contraction of the metal.
Iron poured into a mould, on changing from a liquid to a solid state, becomes a mass of crys-
tals. These crystals are more or less irregular, but the form toward which they tend, and which
they would assume if circumstances did not prevent, is that of a regular octahedron. This is an
eight-sided figure, and may be imagined to have been formed out of two quadrilateral pyramids
having their bases together. At 1, Fig. 742, is a group of crystals from a pig of iron, among



in,
I
i
i
~\ 1" .
lil “i I ltll
H, :31tlfl‘tiil’fi‘;lilllllll
t
i
illni ,


which one has, by the aid of favorable circumstances, succeeded in attaining its natural form. In
a perfect crystal of iron all the lines joining the opposite angles are of equal lengths, and at right
angles to each other. These lines are called the axes of the crystals. The crystals assemble or
group themselves in certain lines, in the direction in which the least pressure is exerted. When we
define the direction of these lines as the direction of least pressure, we deal with pressure due to
the mass itself. l-Ieat leaves a mass of iron according to the same law ; and therefore the lines of
assemblage will be in the direction in which the heat leaves the body. This direction is always per-
pendicular to the cooling surface. \Ve may then briefly state the law thus: The lines about which the
crystals assemble are perpendicular to the surface of the casting as it lies in the mould. In Fig. 742,
at 2, is a view of the end of a casting. This shows the assemblage lines, though the individual crys-
tals are too small to be visible, the lines being perpendicular to the bounding surfaces. The
attention should be particularly directed to the behavior of these lines at the corners of the cast-
ings. When two surfaces, as in this example, lie at an angle to each other, the systems of per-
pendiculars must meet in a plane diagonal to those surfaces. Some of the lines of each group run
into the lines of the opposite group, so that in the diagonal plane the lines interlock, breaking up
the natural order, and making very poor connection. lVe shall find in every such case that the diag-
onal is the weakest part, and that the casting will bear less strain there than through a part where
the lines lie parallel to each other. In the figure which we are considering each corner has its weak
line, meeting at the centre of the casting. In 3 we have a drawing of a flat bar, and in it we see
the same diagonal lines of weakness. The pair of diagonals joining the corners nearest to each
other are joined by a long line parallel to the two long surfaces. This line is also a line of weak-
ness, as the lines in which the crystals assemble, in the systems belonging to each surface, begin at
326 CASTING.


the surface, and as the casting cools elongate toward the centre. When they meet in the middle
they do not form continuous lines through from one surface to the other.
We see from the foregoing remarks that the. strength of a casting is greatly impaired by the lines
of weakness caused by angles; and now let us look for a means of remedy. Referring again to 2,
and comparing it with 3 and 4, we see that by making the angles into curves the lines in which the
crystals form themselves are all nearly parallel to each other; and the absence of abrupt changes of
surface also avoids changes in crystalline arrangement, which will materially afiect the strength of
the casting. Comparing 7 with 5, it will be seen that there is much more metal through A B in 7
than there is through A O in 5; and yet the strength at the two places is nearly the same, and of
course their change of form produces a corresponding derangement of crystalline structure ; but the
defect which in 7 was concentrated in the line A B is in '5 spread out between the points 0 and D,
so that no single point is much weaker than a similar point beyond 0 or D.
SHRINKAGE STRAINS IN CASTINesf‘i—General Laws regarding Shrinkagea—All castings will alter
more or less in form if the surface is removed or cut away. This is partly due to the tension on the
whole exterior of the casting during the process of cooling, and partly to the excess of tension upon
those parts of the casting which take the most time to cool. The difference in the time required to
cool the different parts of a casting depends upon their relative thicknesses, the freedom of access
to the air, and the position in which the casting lies while losing its heat ; nor is it practicable to so
cool a casting as to make its surface-tension equal all over. If a casting is allowed to cool off in the
mould, its surface-tension will be less than if extracted from the mould. and cooled in the open air;
‘ while if, after the casting has become cold, it is reheated to a low red heat, the surface-tension will
be considerably reduced, because in the first process of cooling the exterior metal, by cooling most
rapidly, also attains its strength the soonest. It therefore ofiers a resistance to the set of the in-
terior, and the latter conforms itself to some extent to the former. In reheating the casting, how-
ever, this condition is reversed, the exterior becoming heated, and therefore weakened in advance,
so that the internal crystals are given more liberty to arrange themselves in their natural order.
The thickest part of a mass of molten metal always shrinks last; hence, if a casting be composed
of irregular thickness, it will be liable to be broken by the forces contained within itself. It is,
therefore, especially necessary that columns and castings, supporting or resisting great pressures,
should be so designed as to prevent this great error. Mouldings 011 columns are often so badly
designed with regard to this matter, that the columns are excessively weak where they should be the
strongest. As a rule, mouldings should seldom be cast on a column, but rather bolted on. Much
of the irregularity of flat castings and those of irregular shapes could be remedied by a proper
attention to cooling the castings while in the mould. To be sure this is done to a certain extent,
though few moulders know why they do so. They know that by removing the sand too soon from
a particular casting it will straighten in the shrinking. This is but the result of experience, not of
thought or any attempt to know why it so acts. It is useful to know, also, that all shrinkage takes
place while the casting is changing from a red to a black heat. _
Solid Cylinders.--In the case of a shaft, or other solid cylinder, it will be noticed that the surface
of the casting at the ends will be slightly depressed. This is occasioned by the surface of the cylin-
der being cooled by the walls of the mould first, and setting, while the central portion yet remains
fluid or soft. In a few moments more the central portion cools, and in shrinking draws in the ends
of the cylinder, the outer crust acting as a prop or stay to the atoms of metal adjacent to it. If
this theory be correct, the depression should take the form of an inverted cone, owing to the gradual
checking of the shrinkage as it approaches the outer crust. In practice this will be found the case,
the obtuseness of the angle being greater or less, according to the nature of the iron to shrink.
Globes.-—The shrinkage strains within hollow, spherical shell-castings are similar to those in rings,
they being no more in fact than rings continued about a central axis. In the case of solid globular
castings, the heart or central point within will usually be found hollow or porous, owing to the fol-
lowing causes: The walls of the mould, cooling ofi the outer surface, cause it to set immediately;
the interior, cooling from the exterior inward, endeavors to shrink away from the outer crust, which
resists its so doing; hence, the interior is kept to a greater diameter than is natural, and, there
being but so much metal in the entire mass, the atoms are drawn away from the central point toward
all directions to supply the demand made by the metal in shrinking.
Disks.--In the case of flat, round disks or plates, they will usually be found hollow on the top
side, although in some cases the hollow is on the bottom side. This is owing to the following causes :
The top and bottom faces, together with the outside edge, become set first through contact with the
mould, leaving the centre yet soft. When the centre shrinks a severe strain is put on the plate by
an effort to reduce its diameter, which the outer edge resists. Now, if the cope be thin, the heat
will radiate rapidly in that direction, causing the outer or top side to set first; the under side, set-
ting later, will drag the top side over with it, causing it to round up on top and dish in the bottom.
01', if the pattern be not perfectly true in every direction, the strains first spoken of will cause any
curved portion to become more exaggerated. If the pattern be perfectly true, cope and drag of the
same thickness, and both rammed evenly, there is no reason why the plate should not come out per~
fectly true, the strains being all self-contained in the same plane and balanced. If the plate, how-
ever, have an ogee mouldir g projecting downward around the edge, it will likely be depressed on the
top surface when cast. This is due to all the surfaces being set alike and at the same instant, ex-
cepting the metal within the corners, which, containing the most metal in a mass, will shrink last of
all. When this does shrink, its tendency is to pull over the top side of the moulding toward the
plate, which, being soft, although set, will be forced downward at the edges, giving a chance for the
strains within the plate, as above described, to aid in the distortion.

* By Mr. Alfred E. Watkins.
CASTING. 327

Round and Square Bars—These strains are similar in both, and are already treated of under
solid cylinders. There is another feature, not before spoken of, which is rather curious. If two
bars of the same dimensions and mixture of iron be heated to the same temperature, and the one
allowed to cool in the mould, the other plunged while hot into water, the latter will be found to
have shrunk the most. This is due to the particles above the surface having been enabled, by the
softness of the interior metal, to get closer to each other than they could have done if the material
had cooled slowly.
Rectangular Tubes—These are usually cast with a core, which has a tendency to retain the shape
of the casting; still the flat sides will show a tendency to bulge up slightly at the middle. This is
due to much of the same causes as explained in the plate with the ogee mouldings: the outer sur~
face is cooled instantly by the walls of the mould, and is set; the inner surface is not cooled quite
so rapidly, owing to the core being of harder material and not so good a conductor of heat; when
this does cool it will pull inward the outer skin of the casting, forming a slight curve; each side,
acting for itself, will produce the same effects.
Gutter or U-shapecl Uastings.-—Thcse are usually made thinner at the edges than at the middle,
because the pattern has been made with draught. When castings of this shape are taken from the
mould, they will be found rounded over in the direction of their length, the legs being on the curved
side. This is explained by the mould cooling and setting the legs first; then when the back or
round shrinks, it pulls upward the two ends of the casting.
Wedge-shaped Castings.—In parallel castings of any length, having a cross-section similar to a
wedge, or similar to a knife in papenmill work, the thick side will invariably be found concave and
the thin edge curved. This is due to the same causes as explained above. The thin edge is set as
soon as cast; the thick edge, cooling later, shrinks and draws the ends of the casting upward, and
with them the thin edge, which acts as a pillar to resist further shrinkage.
Ribs on Plates—All ribs have a tendency to curve a plate if they be thicker or of the same thickness
as the plate, owing to the fact that whatever shrinkage strain they possess is below the general plane
of the shrinkage of the plate itself. If the ribs be thinner than the plate, they will cool first, and
by resisting the shrinkage of the bottom of the plate cause it to curve upward, or “ dish” on top.
Table showing Shrinkage of Castings.
In locomotive cylinders. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : 3%; inch in a lineal foot.
In pipes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : ~§ “ “
Girders, beams, etc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : ~§ in 15 inches.
Engine-beams, connecting-rods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : Q,» in 16 inches.
In large cylinders, say '70 inches diameter, 10 feet stroke, the con-
traction of diameter.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : 3 at top.
Ditto.. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. : {1: at bottom.
Ditto inlength. . . . . . . . . . . . . . . . . . . . . . . . . . .. z ‘5 in 16 inches.
In thin brass .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : {v in 9 inches.
In thick brass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : % in 10 inches.
In zinc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : 15'6- in a foot.
In lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . from i; to 157,- in a feet.
In copper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : 11,,- in a foot.
In bismuth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . .. = “
In tin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . from 11; to ,1, in a foot.
The following is an easy rule to find ap-
proximate weight of castings: Thickness
in §~ in. x width in 3; in. x length in ft. 2
lbs. weight cast-iron. For lead, add one-
half to the result; for brass, one-seventh;
for copper, one-fifth.
Smith’s Improved Moulding .Machine
(Fig. 742 A).---ThiS is an appliance for
moulding in loam or sand, by the aid of
striking-boards, cylindrical, elliptical, or
irregular forms, from 18 in. to 20 ft. di~
ameter. The apparatus is well suited for
moulding fly-wheels, drums, and rope-pul-
leys, in two or more parts. A particular-
shaped cam, in the case of an irregular-
shaped casting, is fixed inside the box as
shown. A pin with a revolving runner is
secured to the arm or striekle, and as the
latter revolves the pin is caused to follow
the shape of a. cam, so as to produce the
desired form of mould. If a circular ob-
ject is being moulded in two parts, it is
made with flattened sides, to allow, when
put together, for the removal of the thin
dividing cores shown in the general view.
It will be understood from the above that various~shaped castings can be made by this apparatus
by altering the shape of the cam.




328 CASTING.

A Steam ilfoulding zlfach'i-ne made by the Taber Manufacturing (10., of New York, is shown in‘ Fig.
74-2 B. To the piston-rod is attached the principal part of the mechanism, consisting of a table with lugs
projecting upward, and supporting the pattern-frame, upon which rest the patterns; the stripping-
plate frame is directly over the pattern-frame, and
rests on it, to which the stripping-plate is attached ;
the stool-plate suspended to the striliiping-plate
frame and moving with it; side levers and tum-
bling shaft for tripping after the pattern is drawn.
The pattern-frame has an annular passage which
is connected to the cylinder by a small pipe,
the object of this being to admit “some steam to
the pattern-plate at each movement of the piston,
this steam serving to keep the patterns moderate
ly warm, preventing“sweating” or accumulation
of moisture from the atmosphere, and making them
draw from the sand more freely and smoothly.
The stripping-plate frame is guided by two bored
sockets, one at the front and the other at the back
of the machine, there being air-holes below the pis-
tons, by which any desired amount of cushion can
be obtained for the drop of the stripping-plate
frame. The stool-plate really part of the strip-
ping-plate frame placed below the pattern-frame,
and its object is to support stools or internal parts
of the stripping-plate used in holding green sand-
cores, or heavy bodies of hanging sand, while the
pattern is being drawn. The side levers are pivot-
ed at one end to the table, and are connected at
the middle by links to the stripping-plate frame,
the outer end being free. The tumbling or trip-
ping shaft is in front of the machine, near the
floor, and has arms projecting upward along the
line of travel, followed by the free ends of the
side levers; on these arms are steps which engage
with the free ends of the levers on the downward
motion, to draw the pattern.
The ramming-head is carried by the wrought rods seen at either side of the machine, these being
attached to a horizontal shaft at the bottom of the cylinder, which allows them to be swung forward
and back as shown, a spiral spring being used to counterbalance the weight. The ramming-head is
usually of wood, roughly cut out over the pattern, to avoid too hard ramming on the high places.
This block may be readily changed to suit any flask within the capacity of the machine. The steps
on the stripping-plate can be also changed to suit any pattern within the range of the machine. The
steam-pipe enters the cylinder at the bottom, and from the throttle-valve to the cylinder serves also
as an exhaust-pipe, the throttle-valve being a two-way cock, by which steam is either admitted or ex-
hausted from the cylinder.
The operation of the machine is as follows: The half flask is put on the stripping-plate, with the
sand-box to hold the sand which is to be compressed, and both are filled with sand. The ramming-
head is then swung forward over the flask against steps which define its position, and the throttle-
valve opened. The upward motion of the piston and attached parts carries the flask and sand up to
the ramming-head, where it is rammed instantly, and, upon the throttle-valve lever being moved again,
steam is cut off, and at the same time exhausted, allowing the flask to descend; the stops then on-
gaging the free ends of side levers, and arresting the downward motion of the stripping-plate a. a
point about midway; the pattern, continuing to descend, is drawn from the mould, and when the
piston has returned to its lowest position the sand is struck off the flask, which is then taken from the
machine. As the man removes it he presses the tripping-treadle with his foot to release the strip-
ping-plate frame, which then falls to its proper position with respect to the pattern, and the machine
is then ready for another mould. Water or compressed air may be used instead of steam if desired,
but steam is usually preferred, as being most convenient.
The Rollet P‘Occss for producing Purified Castings—This process is intended to be auxiliary to the
manufacture of special qualities of steel, its object being to eliminate sulphur, phosphorus, and sili-
con from the castings. It consists in melting castings or pig, or maintaining them at a very high
temperature under a double action, slightly reducing and slightly oxidizing, in the presence of a slag
obtained by admixtures of limestone or lime, iron-ores, and finer-spar, in proportions depending on the
quality of the pig or castings employed.
The apparatus (Fig. 742 e) is a blast-furnace or modified cupola, using coke and hot blast. The
burdens are introduced in the same way as in blast-furnaces and cupola-s. It consists of a part A, an
independent shaft (1, several rows of tuyeres F FF, a siphon arrangement S S for separating metal
from slag, and a front chamber 1). Externally, it is composed of sheet-ironand steel; internally, at
the bottom it is lined with any suitable refractory material, preferably with magnesia. It is cosled
externally at all parts liable to injury by currents of cold water. The tuyeres are arranged in several
rows, above one another. They are water tuyeres, and project into the furnace. The hearth is sit-
uated as near as possible to the lower rows of tuyeres. A single hole serves for tapping both the
metal and the slag. In tapping, the metal is separated from the slag by means of the siphon S S,
742 B.


CASTING. 329
......v

which is so arranged in relation to the hole as to prevent tl e blast from blowing through. The metal
flows out at O, and the slag at S.
The tuyeres are arranged in several rows, to facilitate the melting of all the substances charged. They
are arranged one above the other, so as to raise the temperature along a line passing in front of their
nozzles, and so insure good working. They project inwardly, so that their ends may not get clogged
by the colder and more decar-
burized matters which descend 7420-
along the walls. The approxi- '
mation of the lower row of
tuyeres to the hearth is intend-
ed to prolong the action of the
blast upon the slag, which at
that point is light and frothy,
and upon the metal which flows
down through it, so as to in-
sure a greater elimination of
phosphorus. The separation of
metal‘from slag, as soon as both
are removed from the action
of the blast, is carried out so
as to prevent the phosphorus
already eliminated from going
back into the metal—a result
which would be produced by
the reduction of the phosphoric
acid of the slag by the action
of the coke and the metal. An-
other object of the separation
is to prevent too great a recar-
burization 0f the metal. The
temperature of the blast is as
high as possible—viz., 400° at
least—so as to insure the good
action of the tuyeres. These
would otherwise get clogged by
the slag, which is always very
refractory and stiff, or by the
decarburized metal which forms at their ends. The furnace being in operation, metallic iron is
formed, by the action of the blast and the iron-ore upon the cast-iron or pig, on the bottom part
of the walls, where it adheres, thus forming, after working 24 to 36 hours, a substitute for the
original lining. The furnace may thus be run for an indefinite period of time. But it will be prefer~
able, after two or three months working, to reline the upper portion, as the bricks will then be worn
out by attrition. The production is from 50 to '75 tons per day of 24 hours.
CASTING IN PLAS'I‘ER.——-In producing a statue or bust in plaster, the first step is the making of the
sketch model. From this there is built up a full-sized skeleton, a work requiring great precision and
mechanical skill. On this the mould is made. This is an art by itself, the main problem being how
to construct the mould so that the original form may be removed, and, at the same time, to make it
in as few parts as possible. The plaster is applied in liquid state, and when hardened is cut away
from the model.
In making a cast of a clay model of a bust, two methods may be pursued. The entire
model may be covered over with the plaster mixture, by throwing it on in a creamy state with
a cup or spoon, and lastly by spreading it on with the hands, until the proper thickness is attained
to give sufficient strength; and then, after setting, the mould may be cut into sections with a
very thin saw and carefully removed. The process more usually preferred is to apply the plaster
in sections by the method of parting. A common way is to make only two sections, the smaller one
embracing merely the crown of the head. This plan requires that the frame on which the bust was
modeled shall be so constructed that it may be taken apart and removed by the hand, after the
plaster is well set. After the mould has been carefully cleaned with water and a soft brush, the
parts are put together and bound by a strong cord or rope, and the seams stopped on the external
surface with cream of plaster. After this is set the mould is saturated with water. The bust is
then cast by turning into the cavity successive batches of cream of plaster, at the same time turning
the mould about in such a manner as to cause the plaster to run into all the lines and furrows, and to
be deposited in sufficient thickness all over the interior surface. In this way a hollow cast is made
without the use of a core. After the plaster is well set, the bust may be placed upon a table and
the mould chipped off with a chisel and mallet. This is an operation which requires great care, and
can only be done by an experienced hand, and by none so well as by the artist himself. The casting
of a bust is rendered much easier by swinging the mould in a pair of strong, concentric iron rings,
Fig. 743. This device allows it to be turned with ease in any position, greatly facilitates the opera-
tion, and diminishes the chances of making a defective cast. The plaster bust is used as a model
by the marble-cutter in reproducing the work of the artist. When several copies in plaster are
desired, it is used as a model on which to form a piece-mould, which may serve in producing an indefi-
nite number of copies. A statue in plaster may be cast in a variety of ways, depending upon the
purposefor which it is intended: whether to be preserved as a plaster statue, or copied in marble,

"0 ......“ x
.‘

-Mwfl










3
-.~"....."_-.'_-








330 CENTRE-PUNCH.


or to be used as a model from which to make a bronze cast. If it is to be preserved as a statue, it
will be cast as nearly as may be in one piece; but if to be used as a model or pattern by the
bronze-founder, it may either be taken in as
many pieces as are to be made of the bronze
casting, or it may be cast in one piece, or in as
few as possible and then joined together, leaving
the bronze-founder to make his selection of sec-
tions in which to take his loam mould.
CASTING or BRONZE STA'l‘UES.—-B1‘OIIZ€ contain-
ing 10 per cent. of tin requires a heat of about
2,000° F. to bring it to the proper degree of flu-
idity. It is considered rather a refractory metal,
liable to fly, and requires skill and experience for
its mastery. The pouring is done in the same
manner as for bell-casting, and the same cruci-
bles and furnaces are used. After the metal has
cooled, the flask is removed, the loam knocked
off, and the branches of metal which fill the
spaces of the air-holes as well as those for pour-
ing are cut off. When the statue is east in sec-
tions, the edges are made somewhat thicker than
the other parts, and lips are also provided, to
meet in the interior so that they may be bolted
together. The thickness of the edges is for supplying material for hammering them together
till the seams are obliterated. The parts are usually immersed for a few hours in a weak pickle
of aeidulated water, for the purpose of loosening and aiding in the removal of silicious matter which
has become incorporated with the surface of the bronze. All the sections are then bolted together,
the edges smoothly hammered till the joints are '
perfect, all roughnesses filed away, and the whole
surface 'ehased with appropriate tools.
CENTERING MACHINE. An apparatus, Fig. '
744, used to centre, centre-drill, and countersink,
at one and the same operation, bolts, spindles,
shafts, etc., which are to be turned in the lathe.
It is a great labor-saving tool, doing ten times as
much work as can be done by hand. The chuck is a
universal one, so. that the work requires no setting.
The combined drill and countersink is fed by the
handle at the end of the running head. The drill should be run at about 300 revolutions per minute, _
and for use on wrought-iron and steel should, while cutting, be supplied freely with oil. . R.
CENTRE-PUNCH. A tool employed to make the conical indentations necessary to reeelve the
lathe-centres. The position for the indentation being marked, the centre-punch is placed as shown







7 46.
1,, I .5;
.
2 tall}?
.\ ..
.\ ,
_ I
i
I .4
v‘ I "Irii‘i \\\\.
’ [My . Ii \.\.‘,
\ ' a, r“ ' -,‘I -\ \“
\ 1;} 1 __ - in" a "I, \ § 9.
‘ ‘ \\ 3- 'l 1 [I '\‘-_ : \'\
\-\‘\.\ 1 / \ - \


Z
/ 4 ll”, ///
/,
" -///4
>4”,
I







in Fig. 745, and its head is struck with a hammer. If the position of the indentation requires correet-
ing, the centre-punch is canted to one side, as shown in Fig. 746, and then struck as before. In Fig.
747 the punch is shown partly encased in a device for use upon the ends of cylindrical work, and
CHAIN. 331

designed to save marking the location for the indentation. The device consists of a round steel
centre-punch, which slides freely in the stem of an inverted funnel or centering cone. To whatever
distance the circular end of the work may enter this cone, the point of the punch will be always at
its centre, which spot can be marked by giving the top of the punch alight blow with a hammer. J .R.
CENTRIFUGAL AND CENTRIPETAL FORCES. See DYNAMICS.
CENTRIFUGAL MACHINE. See SUGAR-MAKING MACHINES.
CENTRIFUGAL PUMP. See Pours.
CHAIN. Chain cables are constructed either with open links, Figs. 748-750, or with stud-links,
750.
@-
@ @ @
Figs. 751-753. The standard proportions of the links of chains, in terms of the diameter of the
bar iron from which they are made, are as follows:

Extreme Length. Extreme Width.
Stud-link . . . . . . . . . . . . . . . . . . 6 diameters . . . . . . . . . . . . . . . 3.6 diameters.
Close link . . . . . . . . . . . . .. 5 “ . . . . . . . . .. 3.5 “
Open link . . . . . . . . . . . . . . . . . . 6 I “ . . . . . . . . . . . . . . . . 3.5 “
Middle link . . . . . . . . . . . . . . .. 5.5 “ . . . . . . . . . . . . . . . . 3.5 “
End links........ . . . . . . . .. 6.5 “ . . . . . . . . . . . . . . .. 4.1 “
End links are the links which terminate each 15-fathom length of chain; they are made of thicker
iron, generally 1.2 diameter of the common links. Fig. 748 is a circular link; 749, an oval link;
750, an oval stud-link with pointed stud; 751, an oval stud-link with broad-headed stud; 752, an
obtuse-angled stud-link; 753, a parallel-sided stud-link.
The Admiralty test for the tensile strength of ordinary 'stud-link cables is at the rate of 630 lbs.
per circular lg—inch section of one side of a link; equivalent to 22.92 tons per square inch of one
side or to 11.46 tons per square inch of both sides taken together—just within the elastic limit. The
weight of a link in similar cables increases as the cube of any lineal dimension, say the thickness;
and the weight per yard increases as the square of the thickness of the chain. Hence the rule that the
weight per yard of common stud-link chain cable equals in round numbers 27 times the square of the
diameter. The weight of a bar of iron a yard long is 10 lbs. per square inch of section or 7.854
lbs. per circular inch; that is, a 1-inch round bar weighs 7.85 lbs. per yard, while a stud-chain cable
of 1-inch iron weighs 26.9 lbs. per yard, or 3.42 times as much as a bar of the same size and length.
Very extended and elaborate investigations on the subject of the strength of chain cables were
conducted (1878) by the U. S. Board Appointed to Test Iron, Steel, etc., the results of which show
that, as applied to cables made from American bar iron, the Admiralty standard above noted is faulty
in two important respects : 1. The stress prescribed by it for every size of cable is too great. 2. The
stresses for the different sizes are unequal in their proportion to the strength of the links. It is
pointed out that the stress for all sizes is based upon the assumption that the cable-bolts of all diam-
eters'possess a strength equal to 60,000 lbs. per square inch. Few bars of American iron are
equal to this strength, and when they are, their cost precludes their use as cable iron; and, although
this strength may be found in the small bars, it is not found in the large sizes of the same iron.
Furthermore, it is urged that if the bars of all sizes did possess this strength, the “ proof ” is still
too great, for it probably exceeds by a considerable amount the elastic limit of the links. The Board
consequently undertook the preparation of a table by which cables could be proved without sustain—
ing injury, basing this table on the principles that a proof-strain should not greatly exceed the elastic
limit, and that the strength of a cable is equal only to that of its weakest link. In the preparation
of this table it was first necessary to establish within reasonable limits the probable maximum and
minimum strength of cables of various sizes, and the elastic limit of the links. Primarily, it was
considered that the value of an iron for chain manufacture is not to be measured by the strength of
the links, unless this strength is found to be uniformly maintained throughout a series of tests;
for it was found that those irons which furnished the strongest links in nearly every case furnished
also the weakest, their welding properties being generally defective; for, although the portions of the
links which have not been subjected to forging are very strong, in each link there is a probable very
weak spot caused by a defective weld. Comparative records were obtained of 210 sections of cables
broken by tension, which were made of 15 different irons. Assuming that the utmost strength
which can be found in a link is equal to 200 per cent. of that of the bar from which it was made, it
was determined that bars of fairly good chain iron will produce links whose strength will be not less
than 1.55 per cent. and not over 170 per cent., and that by a series of tests an average of not less
than 163 per cent., made up of fairly uniform factors, should be expected. The Board therefore
332 CHAIN.

adopted for a standard of strength and welding qualities combined 170 per cent. of the strength of
the bar for amaximum,‘ 163 per cent. for an average, and 150 per cent. for a minimum. Experi-
ments for determining suitable strength resulted in the conclusion that an iron is suitable which, as
a 2-inch bar, has a strength of 50,000 lbs. per square inch, and that other irons whose variation from
this strength does not exceed 5 per cent. are equally so. In determining the strength for the Other
sizes, it was found that the proportional strength of bars of the same material increases as the diam-
eter decreases, and that the aggregate of the increase for the 16 sizes (measuring by sixteenths of
an inch, between 2 inches and 1 inch) is from 4,000 to 6,000 lbs., produced by steps which are
made more or less irregular by irregularities in heating the piles. 'I‘he'proving-strains, calculated
upon the principles indicated, are as follows, being equal to 45.57 per cent.‘of the strength of the
strongest and to 50 per cent. of that of the weakest links:
Table showing Proving-Strains of Chain Cables.







Size. Proving-strain. ! I b‘ize. Proving-strain. I Size. Proving-strain.
In, Pounds. Tons. In Pounds. Tons. In. Pounds. Tons.
2 121 gag-4:5 IQ $2,9§6 37361525 1i; 51,08% 22;, 7'5 1% 1(lb,0~)8 54.5 1% 7130M! 31-9545 Ifi 4g,l153 1 101,499 45.53,, 1 71,—,- 6b,l3b 29%,; 1% 11% 3 4,520 10;} {2%
I § 95,128 42.53% 1% 69,920 ‘37.???5 1 38,b40 l5aaa‘305
83,947 3935-3 11-55 50;903 24%,}

.Manufacturc of Cables—Several simple machines are used to manufacture chain cables. The
successive operations are as follows: 1. Heating the round iron bars red-hot; 2. Cutting them of
the required length, but with opposite bevels (a, Fig. 754); 3. Bending the rods around an elliptic
mandrel. One end is placed against the side of a vertical mandrel and held there by a vise attached
to the latter, and a lever provided with a projecting pin extending outside the rod is made to describe
an ellipse, carrying the hot rod around the mandrel; this lever does not turn around a pin in the
centre of the mandrel, but is attached to two slides which are forced to move in grooves occupying
the position of the two axes of the mandrel; thus the pin of the lever describes an ellipse parallel
to the periphery of the mandrel. 4. The new link (6, Fig. 754) is hooked to the last preceding link
of the chain in process of making, and
welded at a small forge. 5. While it
is still hot, the cast-iron stay is intro-
duced, and the link placed in a press,
which compresses the two sides close
upon the stay, at the same time that it
makes these sides straighter: during this
last operation an auxiliary straight rod
is placed inside the end of the link,
where the next link is to come, to pre-
vent its closing. There are sometimes
circumstances in which it is necessary
to sever or slip (as it is called) a cable, or to shorten or lengthen it ; this is done by means of a bolt
and shackle substituted for a link every 15 fathoms, the portion of the cable between the shackles
being called a length or “shot.” The shackle is represented in Fig. 755, in which a is the bolt,
secured in its place by the pin 6, which is again held in its place by having its head in a conical
chamber filled with lead. One of the links next the shackle is heavier and larger than the others,
for the purpose of receiving the shackle.
In Fig. 756 is represented a machine for making chain of li-inch iron, in the links of which the
weld is invisible. It is the invention of Mr. William Dennison, of East Cambridge, Mass.
The illustration shows the position of the chain in the machine while being manufactured. The
anvil-block is a cubical mass of iron having a square recess from top to bottom, in which fits a vise
or die-carrier. This is pivoted at the bottom, and is operated by toggle-jointed levers. This joint
is connected to the vise at the top and to a cross-head or horizontal beam at the other end, and is
elevated and depressed by the piston of a small steam~cylinder standing upright directly under the
union of the levers. Inserted in the face of the vise is a die, cut to receive the half of one link in
a vertical and the half of another in a horizontal position. A corresponding fixed half in the anvil
completes the die. When closed the latter presents on its face two holes as far apart as the width
of the link, and of a size to receive the iron to be welded. There is a channel passing between these
holes for the reception of the last welded link. A trough or leader inclined and leading from the
back of the machine, through a slot in the centre of: the die, serves to convey the studs or bridges,
and by a simple automatic movement a single one is fed to the die simultaneously with the closing
of the vise. The small cylinder, with its piston-rod attached to the upper side of the toggle-joint,
is filled with water, and serves only to steady the movement of opening and closing the vise. Rising
from the back of the anvil-block is a heavy frame, supporting above a steam-cylinder of 13 inches
diameter, with a square piston-rod, which serves as a hammer or press, the end of which is formed
to correspond with. the channel in the top of the die, and recessed to receive the link tovbe welded.
There is another attachment, not shown in the engraving, a description of which is unnecessary, as it
is merely an automatic appendage designed to turn and move the chain along as it is completed;
when attached it is operated by the segmental gear shown on the side of the anvil-block. The links
are prepared by another machine, which cuts and bends them to the form of an elongated U. The
operation of the machine is as follows:


CHA IN. 333

Convenient to the machine is a furnace, provided with more or less openings to receive the ends
of the links, which, when properly heated, are inserted into the apertures of the closed die. Steam
is then admitted, and the hammer is brought down, thus forcing, with a single blow, the link into the
die and bringing the ends together, forming a butt weld. The vise is then opened by the small
cylinder below, and the perfectly-formed
link extracted. The vise is now closed,
and the last-made link placed in the
channel between the apertures of the
closed die, when the next link is simi-
larly proceeded with.
Weldless chain is made as follows:
A hole is punched through a disk of
the diameter of the flat ring shown at
A, Fig. 757. The ring thus formed is
spun on outside rolls until it acquires
the round-bar section B, by which pro-
cess also the direction of the fibre is
modified. The ring is-then drawn out
into a long hook, which is bent to form
a link, and is afterward interlocked with
other links, as shown at C'.
Flat-linked chains are made in the
fly-press. The links are cut out in va
rious forms, some of which are shown in
Figs. 758 and 759, and in these holes
are punched through which wire rivets
or pins are inserted. Sometimes the
succession of the links of the chain is
. I
one and two links alternately, or three I
o9
and two, four and three, and so on up , 6
ll
to eight and nine links, which is some- ‘






"ii
times used. Probably the largest chain
of this description ever made is that
which secures the superstructure of the
East River Bridge, New York, to its an-
chorages. (See BRIDGES.) ‘
Chains for Watches, Necklaces, etc., _
are made in a variety of ways. When t. manufactured of steel, the slip is first 69
. . .1
perforated With rivet-holes for a num- _>
ber of links, by means of a punch in _ "'_'"“ ‘‘‘ which two steel wires are inserted. The
distance between the intended links is
obtained (somewhat as in file-cutting) by resting the burrs of the two previous holes against the
sharp edge of the bolster. The links are afterward cut out by a punch and bolster of minute size.
The punch has two pins inserted at the distance of the rivet-holes, to serve as guides, which enter
the link-holes. hVhen the links measure from a quarter to a half inch in length, the press is worked
by a screw; otherwise the punches are carried in a heavy block, in which is a square bar, struck by
a spring hammer.
Chains of precious metal are commonly formed of links punched into shape from sheet metal, or
else of wire bent into the desired forms. When the links are punched out solid, every other one is
cut by a fine saw to receive the adjacent links, after the insertion of which the slit is soldered.
If
3]!“
'1.

A




757. 759.
A


Ornamental chains, such as are usually thinly plated with gold and sold by dealers in cheap jewelry
are made of pieces of brass wire and rings and bits of metal, rolled in various fancy forms, which
are afterward brazed together.
Two ingenious machines for making fine chain were exhibited at the Paris Exposition of 1878.
The essential principles of these will be understood from Fig. '760. For producing closely woven
round chain, such as is used for necklaces (0, Fig. 760), an apparatus consisting of a series of star-
334. v CHAIN.

shaped punches is employed. On the strip of metal being fed under a punch, a piece of the desired
shape is cut out and forced down into a holder below. The holder is then so moved as to turn the
blank horizontally over a quarter revolution, as from A to B, Fig. 7 60. Meanwhile a second piece
A is stamped out and forced down upon the turned piece B, so that the arms of B thus come into
the spaces between the arms of A. The construction of the punch is such that the centres of the
blanks are depressed and the arms raised, so that when two blanks are superposed as already de-
scribed the arms interlock, those of the under blank B coming up between those of the upper blank
A. It remains to bend the arms entirely over, which is done by ingenious eontrivanees—wbich need
not here be explained—to unite the two blanks. A third blank is then placed upon A, and the
arms of the latter are brought over this; and thus the operation is continued, the result being a
chain which closely resembles a flexible bar of metal. The machine produces about 45 feet of this
chain per hour, with 6 punches in operation. -
The second machine makes twisted links of fine wire of the form shown at E, Fig. 760. The wire
is fed forward horizontally by suitable devices, and is grasped near its end between rods, the ex-
tremities of which meet at an angle. Near the ends of the rods are placed cog-wheels D, which
carry bent arms as shown. By means of a sliding carriage, these cogs are rotated after the wire is
grasped. The result of this is that each arm bends the wire on opposite sides of the holding-rods in
different directions, the wire meanwhile being cut off from the main portion by a descending blade.
This produces the link above shown. A hooked needle now descends from above and catches the
link as the rods release it. The protruding end of the wire then passes through the link thus
formed, and another link is bent as before described, the operation thus continuing indefinitely.
The Mamqfacture of Weldless Steel Chaim (Fig. 7 60 A).——Of the many advantages claimed for steel
chains, it may be prominently noted that a very important saving of weight is effectedon account of
their possessing such a high breaking strain, compared with the ordinary welded iron chains. To
illustrate this, it may be stated that a given length of the weldless steel chain is 35 to 40 per cent. less
in weight than an equiva-
lent length of iron chain,
will stand the same break-
ing strain as the latter, and
indeed, where steel of spe-
cial quality is used in mak-
ing the weldless chains, this
difference can be increased
as much as 70 to 80 per
cent. Whereas superior
iron chains break at a strain
at 17 tons per sq. in., these
weldless steel chains will
stand a strain of 28 to 30
tons, with 20 to 26 per
cent. elongation.
Again, there is greater
security in their use from
the fact that there are no
welds, and they give warn-
ing of the limit of strain to
which they can bear being
approached, by elongation,
which can be carried to a
considerable extent before
the chain breaks. More-
over, in chains made by
this process the links are
all exactly alike. Though
the life of a weldless steel
chain is said to be twice that of an ordinary one, the price per length is little more than that of best
iron chains.
They are made in lengths of from 40 to 50 ft., being compressed from a solid rolled steel bar, the
section of which is shaped like a four-pointed star. In the first place, holes are pierced at intervals
down the length of the bar, thus determining the length of the several links ; then the bar is
notched between the holes, so as to give the external form of the links; the next step is “flatten-
ing out,” which presses the links into shape on their inner side, but leaves the opening still closed by
a plate of metal. They are then stamped out so as to round them up, and the metal inside them is
punched out, and the edges “cleaned,” or trimmed off. The links are now parted from one another
and stamped again, to insure equal thickness in all parts of the chain. The only processes now to be
gone through are dressing and finishing. According to the die used, the shape of the links can be
varied to suit any required pattern. The lengths of chain thus made are joined by spiral rings made
of soft steel, the convolutions being afterward hammered together till they become solid. A ring of
this description, in. diameter, underwent a strain of 46,200 lbs—that is, 23 tons to the sq. in., its
elongation being 21 per cent.
These chains have passed satisfactorily the tests of the Bureau Veritas, and both that associa-
tion and Lloyd’s have accepted their use on the same conditions and under the same tests as ordinary ’
chains.
760A.


CHAIN. 335

In Fig. 7601; there is illustrated in detail the successive steps (A to I ) of a novel method of
making chains of this class, which has been devised by M. Hippolyte Rongier, of Birmingham,
England, and which is described by the inventor as follows: a a are one pair of diametrically
opposite webs, and a' a' the other pair of webs of the bar. The first operation illustrated in Fig.
760 B, at A, is to punch out of the edge of one of the webs a a
series of shallow notches b, at equal intervals apart, corresponding 7‘50 B-
to the pitch of the links to be formed out of that pair of webs, and ,A 7, __ ,
situated where the spaces will ultimately be formed between the j "' ends of that series of links. The notches are made with bevelled
ends, and are no deeper than is absolutely necessary (for the pur-
pose of a guide-stop in the subsequent operations, as hereinafter B
described), so as to avoid, as far as possible, weakening the bar
transversely. This operation is repeated upon one of the pairs of ' “a. J, 5
webs a’; but whereas in the first operation of notching the web , _ T T ._ .,_
the “ pitch” of the notches is determined by the feed mechanism, in this second operation of notching the notches 6, cut in the web ' ' M:
a, serve as guides to influence and compensate for any inaccuracy
of the feed mechanism, so that the second set of notches b’ shall
be intermediate of and rigorously equidistant from the first set of
notches b. This compensatiOn is effected by the notches 6 fitting
on to a beveled stop on the bed of the punching-tool by which
the notches b’ are cut, the bevelled ends of the notches b causing
the bar under the pressure of the punch to adjust itself in the
longitudinal direction (if necessary) sufficiently to rectify any inac-
curacy of feed. These notches b b’ similarly serve as guides to
insure uniformity 0f spacing in the subsequent operations of punch-
ing out the links.
The second operation, shown at B, is to punch out of the pair of
opposite webs a 0. pairs of oblong mortises—two pairs 0 c and one
pair d (1. These three pairs of mortises (which might be punched
at separate operations, but are preferably punched at one stroke of
the press) are situated as close as possible up to the faces of the
other pairs of webs a’ a’, the pairs of mortises c c being so spaced
as to correspond in position to the eyes of the links to be formed,
to which they correspond approximately in form, while the pair d
correspond in position to the notches b, and therefore to the intervals
by which the links formed out of the same pair of webs a a will be separated when completed. This
operation 1s continued along the whole length of the pair of webs a. It will be observed that a con-
siderable thickness of metal is left at a* between the notches b and the mortises d. This is of primary
importance and is one of the essential features of my method of manufacture, inasmuch as by first
punching out the mortises d the subsequent removal of the metal from between the outer ends of the
links is greatly facilitated, while by leaving the solid metal (1* the transverse strength of the webs a a
is not materially diminished, so that when the operation of punching the mortises c and d in the other
pair of webs a' is performed the bar will not be bent and crippled, as would inevitably be the case were
the whole of the metal opposite the notches b, which is ultimately to be removed, to be punched out
at so early a stage of the manufacture. The operation of punching the pairs of mortises e’ and d
having been repeated along the other pair of webs a, it will be observed that, like the notches b, the
mortises c d, in the one pair of webs, alternate with those c' d’ in the other pair of webs.
The third operation, illustrated at C, is to elongate the mortises c d, and bring the mortises c c’ more
nearly to the final form. This is performed by punches similar to but larger (in the direction of the
length of the rod) than those used in the second operation.
The third operation, which is repeated upon both pairs of webs, a a, a’ a', may be considered as a
second stage of the second operation, it being preferable to punch out the mortises in two stages in
order to remove sufficient metal without unduly straining the bar.
The fourth operation, illustrated at D, consists in roughly shaping the ends of the links exter-
nally by punching out the portions (1* of the webs a between the links lying in the same plane
or formed out of the same pair of webs. . This operation is repeated on the other pair of webs
a'. Up to this point a continuous core of metal has been left at the intersection of the two pairs
of webs. '
The fifth operation, illustrated at E, consists in punching out the portions e of the core at each
side of the cross-stay of the link, so as to separate the cross-stay from the outer ends of the adjacent
links. This operation is performed by removing a portion only of the metal of the core which in-
tervenes between the cross-stay and the outer ends of the adjacent links enchained with the link
under operation—that is to say, portions e* of the core are. temporarily left attached to the outer
ends of the links in order to avoid crippling or bending-the bar, which might occur were the whole of
this metal, which is ultimately to be removed, to be punched out at once, these portions 6* being
supported by the bed-die in the operation of punching out the spaces c, as hereinafter described.
This operation having been repeated upon both pairs of webs, it will be observed that the rod-like
form of the chain is now only maintained by the portion of the core at the points f, where the inner
side of the eye or bow of one link is united with that of the next one. The severing of these inter-
vening portions of the core and the breaking up of the rod into the constituent links of the chain
constitute the sixth operation.
The sixth operation, illustrated at F, is performed by torsion, and for this purpose one end of the


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336 CHAMFERIN G.

rod is held fixed whilethe other is twisted once or twice in opposite directions, until by fatigue of the
metal at the points f, the whole of the links are severed almost at the same instant, and a chain of
roughly formed stayed links is produced.
The seventh operation, illustrated at G, is to remove the superfluous projecting pieces of metal
both from the inside and outside of the ends of the links. For this purpose the two ends of each
ligkI art]: olperated on at the same time by two pairs of punches corresponding to the outline of the ends
0 tie in .
The eighth operation, illustrated at H, is to bring the ends of the links to their finished rounded
form. This is performed by stamping both ends of each link at the same time between pairs of
shaping-dies or swages.
The ninth operation, illustrated at I, is to bring the middle portion of each link—that is to say, the
side members and the cross-stay—to the finished rounded form, which is also performed by means of
a pair of dies or swages.
The tenth and last operation is to contract the link slightly in the lateral direction in order to cor-
rect any imperfections at the sides left by the two previous operations, and bring the link to a more
perfect and stronger form. In the case of large cables only the metal is preferably heated for the
eighth, ninth, and tenth operations. A full description of the machinery for making this chain will
be found in the Steentlfic American Supplement, N o. 819.
A new mode of welding chain-links has been devised by Mr. J. H. Baker, of Alleghany, Penn.,
in which the link being welded can be turned back and forth on the die, so that only the single link
being made is handled and moved, instead of the whole chain.
CHAMFERING. See BARREL-MAKING MACHINERY, and CARPENTRY.
CHANGE —WHEELS. See LATHE, METAL-WORKING.
CHARCOAL. The general principles of charring wood and coking coal are the same, viz.: the
expulsion by heat, without contact of air, of the volatile constituents of the fuel. These constit-
uents go ofi in part as gases, containing more or less carbon, and in part as new combinations
which are still liquid at a high temperature, as acetic acid, tar, etc. The details of these operations
may be grouped into two great classes: 1, where the carbonization is effected in a permanent, air-
exeluding oven ; 2, where it is done in clamps, or kilns, or heaps. In the general aspect of carboni-
zation, the means employed would have to be antecedently classed according as use may be made,
first, of other fuel than that to be carbonized to generate the requisite heat, or secondly, of a part
of the mass itself for the charring of the other part. The type of the first system is seen gener-
ally in all the apparatus where other products than carbon are sought to be collected, and where the
coke or charcoal is incidental to the operation; as in gas retorts, or the cylinders for pyroligneous
acid or wood vinegar. Although a system like these might in some localities, where fuel was abun-
dant or in different qualities, be advantageously introduced, there is probably no establishment where
it is resorted to for the production of charcoal alone; and the other classification, of ovens or kilns,
remains as the only one that need be discussed here.
The relative advantages of ovens and kilns can only be ascertained by a comparison of their prod-
ucts in quantity and quality. With respect to the first element, quantity, it may be assumed (though
it is not universally admitted) that ovens produce a greater quantity by weight of carbon from the
raw material. Hardly any collicr can claim a yield of more than 20 per cent. of charcoal from
heaps ; while the best ovens, with perhaps less trouble, though not less expense in individual cases,
will give about 25 per cent. Again, in the assemblage of cases, the expense for ovens is probably
less, being less exposed to accidents from weather, neglect, etc., which sometimes result in the com-
bustion of an entire kiln. With respect to quality of product, the evidence is less decisive. It
would seem in theory that the oven, producing a greater weight of carbon, ought also to produce a
heavier material per se. But such is not always, nor even generally, the case; and where the oven
charcoal or coke is of the highest specific gravity (and the economy of a high specific gravity is in
general undoubted), yet from some cause, such as a peculiar arrangement or disarrangement of
fibres, it is not found to develop so much heat as that prepared in kilns. Generally speaking, the
advantages of ovens over heaps or pits are not so great as is often supposed; and, as a rule, it may be
asserted that no charcoal made under an immovable covering is so strong as that made under a mova-
ble one. The only real advantage of the oven arises from its being less subject to the changes of
the atmosphere than the pit.
Jharring of wood is still practised in Austria after methods which seem to have originated in the
period of Roman domination, for the manufacture of the celebrated Noriean iron. These may be
761.









denominated charring in heaps (Germ. haufen) or clamps, and will be understood from the accom-
panying sketches, of which Fig. 761 shows a sidewiew, and Fig. 762' a ground-plan of the arrange-
ment. The ground for this may be either leveled or sloped. In either case,_p1p_es are sometimes,
but rarely, laid in the upper parts of the clamp, to carry off some of the liquid products. File
length of the clamp (and, of course, the number of posts) is arbitrary—generally from 4Q to fill
feet; the width depends upon the length of the logs, WhlCll, being ordinarily 4 feet, and being laid
CHARCOAL. 337

in a double row, with a very small space, to the casing of the sides, will make the width very nearly
9 feet across from post to post. In Fig. 762 the logs are given as if in but one length, which can
very well be if the sticks are light. The casing may be of plank, slabs, or split cord-wood. The
ground is well pounded,.and, if in an old burning, with charcoal and dust. The logs are then piled,
beginning from the upper part, to within a few inches of the top of the casing. Then it is covered
with chips, twigs, and leaves, and finally with sand or (better) duet, which material is also filled in
against the casing, to protect it from fire. After all this is ready, fire is put in at the lower end, and
some of the dust is removed from the upper end to make a draught. Draught-holes are also opened
at discretion in the sides of the casing. When the smoke comes out where the dust is removed, it is
necessary to throw it on again, and open elsewhere with caution. In this manner the fire is led on
till the heat has charred the whole. The peculiar advantage of this method is supposed to be that,
with a clamp say of 50 feet, charcoal may be drawn from the lower end after the fire has progressed
about 10 feet, which it will do ordinarily in twenty-four hours. This is still further helped by mak-
ing it on sloping ground. If well packed, a clamp of 50 by 9 feet, 6 feet high at the head and 3
feet at the foot, will hold about 15 cords. _
Another method, more extensively and commonly practised, is that of Kilns (Germ. mmler, Fr.
meales). These kilns are of two kinds, standing and lying, the wood standing'on its end in the one,
and lying on its side in the other, as shown in Fig. 763 and 764.
The circle to be levele'diand pounded down for a kiln of this sort will be from 40 to 50 feet in
diameter; the driest ground must be selected for the purpose, and a place sheltered from winds. The
best period for burnin in America is from the middle of May until the middle of August; and then
again in October and glovember, during the season known as the Indian summer. Wood which has
been felled, and lopped, and barked in December and January, will be sufficiently seasoned to char in
the autumn following. After the logs have been arranged, as in the figures, around the three long
stakes of ten or twelve feet in length (which are to serve as a chimney), and piled as evenly and com-
pactly as possible, the whole pile must be covered to keep out the air. A site for a coaling improves


by use, for the charcoal and loam get trodden and mixed together, forming the best material for the cor
ering. On entirely new ground use must be had of sod. When covered, fire is applied, either through
the top and suffered to fall through to the centre, where provision has been made of some light wood
to catch readily, or through a horizontal flue left along the ground, which is closed at its entrance as
soon as the fire has taken; -' For the first twelve hours the kiln must be closely watched, and, therefore,
it is usual to light at day break. At the end of that period, or a little longer, according to the kind 0i
wood, its state of seasoning, and the skill of the collier, the fire will have taken sufficiently, and the top
may be covered in with dust and loam. From that time, it is better that the operation should proceed
as gradually and slowly as possible. In three or four days the cover begins to shrink and fall in, and
fresh watchfulness is required to stop every opening time made, and even new ones are made to efiect
an equable distribution of heat. These are points that cannot be taught by talking; they are lessons of
experience and observation. When the cover sinks gradually, and the smoke grows less and less, reg-
ularly, the work is known to be going on well. Expert colliers find indications of the process in the
color of the vapor and smoke, which varies at different stages. After all smoke has ceased, the kiln is
entirely and thickly covered, and left for four or five days, less or more according to its size, to cool.
The coal is begun to be drawn from the foot, but cautiously at first. until it is found to he too cool to
re-ignite upon admission of air. If so, the drawing may be continued all round for coal that is wanted,
peeling it off, as it were, like an onion; the whole contents may be hauled off to store, or it may be left
(covered up again) to be resorted to when wanted. In proportion as the kiln is well piled, fines in
various places are. unnecessary. lt sometimes happens that the fire takes in particular parts, or does
not take at all. In this last event, the advantage of a horizontal firing fine is tested. A kiln of ordi-
nary size, of this kind, holds about 30 cords; the largest contain 50 cords.
When the circumstances are such as to render it likely that the same charring-ground will be used
for a considerable period, it is worth
while to adapt to it some permanent ' 765'
accessions, as indicated in Fig. 765 ;
which represents the section of a
basin laid in dry brick, to serve as
the ground of the kiln. This baszn . I has a pit at p, with a cast-iron cover f _ ' , A1-
~ " , ' ' 7///
c, to keep ashes out, and a gutter, y, " ' ' '
communicating with the tank t, which
receives the liquid products of carbonization. With resinous wood. these products are advantageously
removed as soon as possible from the charcoal, and are valuable when caught. The tank has a lid, i,
which must be laid over it and luted when the kiln is fired.
Midway between ovens and kilns comes the shroud or alwi of Foncauld: of which a side-view is

/v f' , "‘,,_-‘T'./' V, I
2»: /////



22
338 CHARCOAL.

shown in Fig. 766, and an orthographic one in Fig. 767. It consists, in fact, of a series of trapezial
ladders, made of light frames, and capable of enclosing a circle at the base of 30 feet, at the top of 10
768.
t‘



feet, with an elevation of S or 9 feet. The sides of these frames are furnished with mortises or lugs,
by which two adjoining strings can be keyed together with wooden bolts. The top is a flat sever of
scantling, with traps that can be opened or shut for the passage of air, and also for that of a conduit
made of three pieces of light plank, for the condensation of gaseous products. The effect of these lud-
ders is to allow of a better packing (and, as it were, thatching) of the ordinary loam covering of kilns.
Fire is applied, and air furnished at first through the door d, left in one of the ladders. The charcoal
furnished by this method is said to be of superior quality; its yield is stated at 24 per cent. of the
wood, with 20 per cent. besides in crude pyroligneous acid. This yield of charcoal is about one-fifth
more than from the kilns that have been described.
Of ovens there is a great variety of form; but as the most of them are embarrassed with apparatus
for collecting other products besides charcoal, they are more connected with distillation than carbon-
ization for the manufacture of iron. Only one, of the most simple and economical form, and yet yielding
good results, will be described. A portion of it is shown in Fig. 768, which is supposed to give a tol-
erably clear idea of the plan. The building from which this is taken is about 50 feet long, 12 feet wide
in the clear, and 12 feet high, and will hold, well packed, about 60 cords, a quantity that has been found
to present the m xximum of convenience and economy. 0 shows the chimney-hole in the centre for firing,
ff flue-holes for the draught, of which there are others on top which cannot be seen. At the ends
there is a small loor for charging and drawing. The stays are of cast-iron or wood, the horizontal
binders on top of bar-iron. Wooden scantling was first used for both these, but it is neither so safe nor
so strong. The arch which is sprung for the top is low, but yet, when the fire is in, there is considerable
thrust against the walls. These walls are 11} brick, and must be well laid and joined. As the acetous
products in the oven are apt to attack the lime, asphalt, or a bituminous cement made of coal-tar and
0am, is used instead of ordinary mortar. Coal-tar is also advantageously used for coating the outside
The wood is piled lying, as is Seen in the figure. Under the chimney-hole, a chimney (so to call it) is
left in the pile, at the bottom of which the fire is placed. The wood may be kindled through the
draught-holes or at the doors, but less economically. When the fire is first started all air-holes are shut;
when it is fairly caught the chimney may be filled up with dry wood, the hole closed, but not tightly,
and air-holes opened at the ends. This will happen in seven or eight hours; The operation must now
be watched, and by the emission of smoke and vapor through the air-holes, a judgment may be formed
as to where they should be shut and where opened. In 45 to 50 hours the whole oven will have been
heated; all openings are then closed and luted, and the concern left for three or four days to cool. On
the fourth or fifth day at latest the coal should be fit to be drawn.
To what has been said, may be added some generalities as to the choice of wood and quality of the
charcoal. The denser woods are to be preferred, because, other things equal, they afford a denser and
harder charcoal. Decayed or doted wood will not yield a good article; and charcoal from green wood ,
is more light, more fria'ble, and less calorific than from dry, besides being less economical in the manu-
facture. The trees should be felled when the sap is down, ire. in the winter,~ from December to
February. Small timber is in general, and young timber always, worse than that which has attained
a larger and more mature growth. Yet very old wood is not so good, because there is always more or
less decomposition of the fibre. Branches of trees give less and a lighter charcoal than the holes, and
the best of all is furnished by that part of the trunk and roots nearest the ground. In the ordinary
felling of trees this part is all lost. Hence it would be better for the purpose (and the land would be
left in a better state) to extract the trees at once by the roots, as is very easy, and then saw the timber
instead of cutting. Heavy charcoal produces more heat, but its reducing effect is not in every case in
proportion. There are some mines with which lighter charcoal acts better; but that it should be hard
is an important characteristic universally. Charcoal just from the kiln burns quicker and produces
less heat than that which has been kept some time in store, yet very old charcoal is admitted to be less
valuable than what has not passed over one season. To what this is owing is not clear, for the affinity
)f the material for moisture is exercised very promptly, and after the first 24 hours, in' an ordinary
atmosphere and with reasonable precautions, it does not materially increase in weight. It is better to
keep charcoal in store. than to leave it stored in the kiln. After it has grown cool enough to handle,
the sooner it is made quite cold the better; all gradual expulsion of heat, such as occurs in a kiln. is at
an expense of carbon. With ovens this caution is unnecessary, for the circumstances there always
compel removal of the charcoal as soon as manufactured. The product in charcoal ranges from 18 to
’2 per cent. in kilns, and from 20 to 25 per cent. in ovens. By volume a cord of wood, 128 cubic feet.
CHIMNEY. 339

well corded, ought to give, at a mean, 40 bushels of charcoal. The price depends, of course, upon
the value of labor in each locality, and the distance of hauling. The chopping of a cord of wood
is equivalent to about one-third of a day’s labor in the abstract, and the coaling of it in kilns or
clamps afterward to about half a day. The computations of the charcoal-burner are usually made
upon the 100 bushels of charcoal delivered. Coaling in ovens, although in fact less laborious and
demanding less experience, requires more tact, and wages there are generally higher. “ Brown char-
coal ” is charred in a close vessel by means of superheated steam. .
Works for Reference—“A Handbook for CharcoalfBurners,” Svedelius (translated by Anderson),
New York, 1875; Percy’s “Metallurgy” (“Fuel”), London, 1875. Very complete references to all
the literature on the subject will be found in the latter work.
CHASER. See LATHE T00Ls, SCREW-CUTTING.
CHEESE—MAKING. See DAIRY APPARATUS.
CHEMICAL FIRE ENGINE. See FIRE-EXTINGUISHER.
CHIMNEY. The functions of a chimney are to cause a sufficient flow of air through a furnace to
maintain combustion, and to discharge the products of the latter at such an elevation above the
ground that the adjacent atmosphere may not be rendered unfit for respiration. It is chiefly neces-
sary that a sufficient height be given to the chimney, and that an appropriate material be chosen for
its construction. If the chimney cannot be made high enough, then the necessary draught must be
produced by special means. In locomotives, the exhaust steam is therefore allowed to escape into
the stack (see Locouorrvn), and in other cases ventilators or blowers (see BLOWERS) are employed,
which either blow the air beneath the grate or suck it out of the fines.
Chimneys are constructed of masonry or of metal. In the first case bricks are preferably used, and
in the second sheet-iron is employed. The external form of brick chimneys is generally quadrangu-
lar or octangular, while metal chimneys have always the shape of a truncated cone. Usually an
exterior batter of 0.015 to 0.025 per foot height is given to chimneys, while the walls have the usual
width of the bricks (6 inches) above, and at the bottom they have a thickness of double or three
times this width. As to the height and diameter of chimneys, the one dimension depends upon the
other. The higher a chimney is built, the more draught it gives, and the smaller therefore its diam-
eter needs to be for the removal of a given quantity of smoke. Besides this, the dimensions also
depend upon the temperature of the smoke which enters the chimney; and for an equal quantity of
smoke the dimensions must be so much larger, the less the temperature of the smoke which is to
be removed. According to this, an economical use of heat requires high and wide chimneys. The
usual height of chimneys is from 60 to 120 feet ; we rarely find them 40 feet or less, and chimneys
of 300 or 400 feet are seldom constructed. It is a practical rule to give the chimney the same cross-
section as the fines. It is very necessary to place chimneys upon a solid base, as the least sinking
may cause damage or even destruction.
An exterior view and cross-section of an octagonal chimney of bricks is given in Figs. '7 69 and 770,
and an exterior view of a metal chimney is shown in Fig. 7 '7 1.°'-'* In the first, A is the foundation, B
the termination of the fines or smoke-box, Othe cast-iron cap of the chimney, and D a staircase
which leads to an opening for cleaning the fines and chimney. To prevent the current of smoke
from meeting resistance at its entrance into the chimney, the union between the fine and smoke-box
must be rounded off. In Fig. 7 ’7 1, A represents the foundation, constructed of bricks and resting on
a. solid base. ' D D are anchor-screws, which firmly connect the base of the chimney, by means of
a plate E E, with the foundation, and G is a pulley fixed below the head of the chimney F, over
which passes a chain by means of which a man can be pulled up for the purpose of cleaning and
painting the chimney. B is the termination of the smoke-box, and H the opening for cleaning. To
prevent the overturning of such a chimney in a storm, not infrequently wires, stays, or cables are
drawn in an inclined direction from the chimney to the ground and anchored.
With steam-boilers, the heat of the air in the chimney should not exceed 600°, and ordinary stock
bricks will stand that temperature well; but with reverberatory and other brick furnaces the air is
at a temperature of about 2,250°, and for such cases the chimney should be lined with fire-brick
throughout; and as the adhesion of mortar is soon destroyed with such high temperatures, there
should be wrought-iron bands round the outside at regular distances from top to bottom. In ordi-
nary chimneys hoop iron should be built into the brickwork every few courses to form a bond ; and
a lightning conductor should not be omitted.
Theory of Chimney Draught—The draught of a chimney is caused by a difference of pressure at
the base of the chimney acting in an upward direction, due to the difference between the weight of
the heated gases in the chimney and a column of the external air of equal height and cross-section.
This difference of pressure is easily found. If we take a unit of area of the cross-section—one
square foot, for example—the weight of the column of external air will be the height of the chimney
multiplied by the density of the external air, and the weight of the column of heated gases of equal
height will be equal to the height of the chimney multiplied by the density of the heated gases. If
h be the height of the chimney, y the density of the external air, and y’ the density of the smoke
column, the difference of pressure referred to will be, in algebraic symbols:
(1.) p = by — hy’ : h (3/ ——y').
This unbalanced pressure acts as a motive force to drive the heated gases through the chimney
and out at the top. In order to find what height of column of the external air would produce this
pressure, acting simply by its weight, we have to divide the pressure by the density of the external
air, and shall have (2‘) Z, : h (3, _ y!)
3/ 3/

* From Weisbach‘s “ Mechanics of Engineering,“ vol.
340 CHIMNEY.

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It is a well-known law of dynamics that the theoretical veloCity (V) with which the air would enter
the chimney if there were no resistance would be found by the equation,
__ I V2
(3.) h :_-__.
y 2.9
yl—y’
. V: v _____.
(4) Mir/h X y
The velocity7 determined from this formula is not, however, that with which the external air will
enter the chimney. Resistance is offered to the passage of the air through the grate, through the
bed of fuel, and through the fines and chimney. These resistances do not admit of theoretical dcter~
mination, and can only be found by direct experiment. They are proportional to the square of the
actual velocity, and depend on the diameter and length of the fines and chimney, the thickness of
the bed of fuel, and the state of division of the latter. Weisbach gives the formula, based partly
on the observation of Péclet:
z -t) h}?
V1120, " feet;
4‘7 30d + 0.057»
From which we have
CHIMNEY. 341

w—
in which t is the mean outer and t, the mean inner temperature, or that of the smoke; h as before
representing the height and (Z the breadth of the chimney.
The values of the velocity of access of air found by Péclet for heights of 32.8, 65.6, and 98.4 feet
were 5.1 feet, 8 feet, and 9.18 feet per second, or 18,360, 28,800, and 32,948 feet per hour. These
velocities, divided by the number of cubic feet of air required to burn one pound of fuel, will give
the quantity of fuel burned per hour for each square foot of section of chimney, the section being
supposed equal to the free surface of the grate. In the ordinary process of combustion in a grate,
it is apparent that some of the air which enters must escape contact with the fuel and enter the
chimney as air. This, according to Morin and Tresca, equals 1.75 of the amount actually required
for combustion. According to this result, the quantity of air actually drawn into the furnace for
each pound of ordinary coal burned will be about 250 cubic feet. (See BOILERS.) The consumption
of fuel per square foot of chimney will then be, for the heights above given—
Heights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.8 65.6 98.4
Pounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.4 115.1 137.8
Assuming that each square foot of section of chimney corresponds to 8 square feet of grate surface,
the above figures will give, for the rate of combustion on each square foot of grate surface, 9.2, 14.8,
and 17.2 lbs. . Table I. is taken from “Heat as a Source of Power,” by William P. Trowbridge (New
York, 1874), from which also the above discussion has mainly been extracted.
TABLE I., showing Heights of Chimneys for producing Rates of Combustion per Square Foot of Area
of Section of Chimney.



Pounds of Coal burned Pounds 0f coal burned Pounds of Coal burned POI?“ Of 00;; bumgd
per Hour, per Square Foot per our, per were out
IN P¥§t°EPSIQffiSZff° of Grate, the Ratio of Grate HEEBES IN peggf§§cii§§°$° of Grate, the Ratio of Grate
' Chimne to Section of Chimney ' Chimne to Section of Chimney
5" being as s to l. y' being as s to 1.
20 60 7 . 5 70 1 ‘26 1 5 . 8
25 68 8 . 5 T5 131 16.4-
30 76 9.5 80 135 16.9
35 84 10 . 5 S5 1 39 1 7 . 4
4O 93 11 .5 90 144 18 .0
45 99 1 2 . 4 95 148 1 S . 5
50 105 13.1 100 152 19.0
55 11] 13.8 105 156 19.5
60 116 14.5 110 160 20.0
65 121 15. 1









It appears from this table that a difference of height of 8 feet corresponds to a difference in rate of
combustion of about 1 pound per square foot of grate surface, the ratio of the grate to the chimney
section being as 8 to 1. The quantities given refer to the average condition of chimneys of steam-
generators. Professor R. H. Thurston’s approximate rule for determining the amount of coal which
will be burned per square foot of grate per hour, with good proportions, is : Subtract one from twice
the square root of the height. Thus, supposing the chimney to be 49 feet high, the amount of coal
burned will be 13 lbs. To determine the height required to give a certain rate of combustion, the
same authority gives the rule : Add one to the weight to be burned per square foot per hour; divide
by two, and square the quotient. The result is the height of the chimneyr in feet.
Dimensions of Chimneys—For the theoretical considerations governing the dimensions of chim-
neys, the reader is referred to Weisbach’s “Mechanics of Engineering: Heat, Steam, and Steam-
Eagines ” (New York, 1878). Among other conclusions there reached, it is found that the breadth
decseases as the height increases; and that, inversely, if the height is diminished the width must be
increased. Other things being the same, a chimney which gradually widens toward the top can dis-
charge more smoke than one which gradually diminishes. In order to withstand the force of the
wind, the mean outer breadth of a square chimney should be one-eighth the height; if of circular
section, the mean diameter should be one-twelfth the height.
In constructing chimneys having an internal section similar to that represented in Fig. 7 70, care
should be taken not to contract the channel at the edges to a less area than that of the outlet at the
top.
The famous chimney at St. Rollox, near Glasgow, of the height of 4551]; feet, has the following
dimensions :
Dimensions of the St. Rollosc Chimney.



DIVIgégfi NCQFKTHE Height above Ground. Outer Pimneter. Thickness of Wall. I
Feet. Feet. F set I 1161188.
435} 13%~
V- isn‘t vii 1 2
IV. 210% 24 i s ’
I i l . ‘ 11 4 i} 31‘} 1 10%
II. 54} S5 2 3
I . 0 40 2 7%





The foundation of this chimney has a depth of 20 feet and a diameter of 50 feet
The following table exhibits the dimensions of many of the largest existing chimneys in Europe:
342 I ’ CHIMNEY.

TABLE 11., showing Dimensions of various High Chimneys. (br :: length of brick.)
















. I c '
Eg-
. nx'rsnron THIOKNESS or g "' c g .n .‘e
m 'g 5 'g g mans-run. masonnv. Q 5f?» .2 Q s“
3 g s s s s 5 i 2% E
2 we ,g Q) '3 o Q Q... .2 8 H D E S E g g :3 E :5 °
Z‘ gr; '5‘“ Balow Above- Below. Above. is 3 8 £2 .9.” 5
m m d. q) 0 5:! 0 Q
Q m
Feet Feet. Feet Feet Inches.
1 468 454 32 124 7 br. 14 br 4.08 14.62 Port Dundas, near Glasgow (Scotland).
2 340 . 331 18 11% 5 ft. 1% ft 2.47 18.39 Chemical factory, Barman (Prussia).
3 347 330 29 11;- 6i} ft. 1% ft 6.36 11.38 Cast-steel works, Bochum (Prussia).
4 274 It 10% 4 ft. 1} ft. 3.4 14.82 Dye works, Hagen (Prussia).
5 225 221 17;; 'i 84 br. 7 in. 5.53 12.42 Pontasser’s chemical works (England).
6 ‘ 175 20% 7} 4;,“- br. 8} in. 9.07 8.44 Alois iron works (France).
7 173 155 17 6} 8 br. 1 br. 7.91 9.14 Hepburn‘s tannery, on the Tyne (England).
8 167 161 13 5 33- ft. 10 in. 6.08 11.93 Dye works, Barmen (Prussia).
9 162 150 1( s 1.} 44 br. 10 in. 8.0 9.0 “ Einer Graben ” chemical works, Barmen.
10 141 132 111} :4 ft. 10 in. 5.90 _ 11.5 Eisengarn factor , Barmen. .
11 133 126 9% 4?; 25 ft. 10 in. 4.54 13.86 Dye works, Och e, near Barmen.
12 128 11% 44 3,} br. 1 br. 5.45 12.43 St. Oucn, near Paris (France).
18 131 126 15% - 6} 4 br. 1 br. 8.31 8.14 White‘s factory (England).
14 136 124 11% 6‘} 3 it. 10 in. 4.82 10.81 Rolling mill, Hagen (Prussia).


The Port Dundas chimney, marked No. 1 above, is the tallest in the world. It will be seen that
the portion below ground, which contains not only the foundation proper but also the fines, with
their arches and coverings, occupies a depth of 14 feet. The fines are four in number, placed at
right angles to each other, so as to form an equilateral cross in the plan; they are of rectangular
section, about '7 feet wide and 9 feet high each, and arched both at top and bottom. The founda-
tion below these fines is built up from hard bricks, all placed on edge throughout several superposed
layers up to the sides of the fines, which are arched and lined with fire-brick. The masonry above
the fines is built with the bricks laid flat in the usual way. The internal diameter at the base is 20
feet, and it gradually contracts toward the top to 10 feet 4 inches diameter. The outline of the
whole structure is of extreme simplicity, viz., the form of a truncated cone, without any deviation.
Eject of Long and Short Flues.—
TABLE 111., showing the Power of Chimneys to Steam-Boilers having Flues 100 feet long in circuit
from Furnace to Base of Chimney. (From Box on Heat.)










SIZE 40 FEET. 60 FEET. 80 FEET. 100 FEET. 120 FEET. 150 FEET.
AT TOP
INSIDE- Round. Square. Round. Square. Round. Square. Round. Square. Round. Square. Round. Square.
Ft. In. H. P. H. P H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P. H. P.
1 3 10.9 13.9 12.8 163 1 6 16.6 21.0 19.5 24.8 21.7 27.5 1 9 23.6 30.0 27.9 34.2 31.1 40.0 2 0 31.9 41.0 37.3 47.5 42.3 53.8 45 7 58.2 2 3 49.4 62 8 55.8 70.4 CO 0 76.4 63.8 81 2
2 6 65.3 83 1 70.4 90 76 5 97.4 81 103 S5 108
2 9 78 100 88 112 94 9 121 101 128 106 135
3. 0 94 123 106 135 114 145 123 157 130 165
3 6 . . . . . 150 191 163 207 175 223 186 237
4 0 . . . . . 202 257 220 280 235 300 252 321
5 0 . . . . . . . . . . . . . . . 360 458 388 494 415 528
6 0 . . . . . . . . . . . . . . . . . . . . . . . . . 577 734 615 788








The power of chimneys in this table is three-fourths of their absolute maximum power; thus the
- 150 x 4
maximum power of a chimney 3 feet 6 inches in diameter, 80 feet high, is ~3— = 200 horse-power.
The effect of different lengths of flue is shown in table IV., in which we have taken as an example
a chimney 60 feet high and 2 feet 9 inches square, which by table 111., with an ordinary flue 100
feet long, is equal to 100 horse-power. It will be seen that with a fine of one-half the length, or
50 feet, the power is increased to 107.6 horse-power only; and that with a fine 1,000 feet long, the
power is reduced to one-half nearly. This may be applied to other cases. Say we require a chim-
ney of 150 horse-power with a flue 1,000 feet long (from furnace to chimney); this would be equal
to 150 -:- .514 : 300 horse-power in table III., and may be 120 feet high and 4 feet square.
Again, a chimney of 50 horse-power, with a flue 400 feet long, must be equal to 50+.708=70 horse-
power i-n table 111., and may be 80 feet high and either 2 feet 6 inches round or 2 feet 3 inches square.
TABLE IV., showing Power of a Chimney 60 feet high, 2 feet 9 inches square, with Flues of cliferent
Lengths. (From Box on Heat.) , _

Length of Flue in Feet. Horse-Power. | Length of Flue in Feet. l Horse-Power.

, 50 107.6 800 . 56.1
100 100 .0 1.000 . 51 .4
200 85.3 1.500 48.8
400 70.8 2,000 88.2
600 62 .5 3,000 31 .7




CHIMNEY. 343

Efi'eet of Internal Temperature in Chimneys.--The discharging power of a chimney increases with
increase of internal temperature, but not to an unlimited extent; for while the draughtpower in-
creases, so does the volume of air due to a given weight increase by expansion, and the result is that
the weight of air dischargcd'attains a maximum at a certain temperature, and an increase beyond
that point results in a diminution of effect. This temperature is 525° according to Péclet; but this
is true only for cases, such as reverberatory furnaces, where the fire escapes direct into the chimney,
and, the flue being very short, f-riction'may be neglected, and the whole power of the chimney is
expended in generating velocity. Table V. shows in column 6 that the velocity and therefore the
weight of cold air is then a maximum at 682—62:522° above the external air. But the weight of
air necessary to carry off the heat increases rapidly as the temperature is reduced, as shown by
column 8; and as a result the power of the chimney, as measured by the consumption of fuel, in-
creases with the temperature throughout column 9.
TABLE V., showing the Power with diferent Internal Temperatures of a Chimney 32 feet high with a
very short Flue, as in Reverberatorg and other Furnaces : External Air, 62°. (From Boar. on Heat.)











I VELOCITY or am In
DRAUGHT IN INCHES OF WATER. i _ , Pounds of
volume 6f Ah. é FEET PER SEC/011D. Pounds of 0081 Per
in the Chim- Temperature of I ‘ Air per I b Sq. F 001.
ney, External Air in Chimney. For Velocity Fer Extra 1 ' of Chim-
Air = l. of Cold Air Velocity of Hot Total. at H0322? at Of coal' ney per
Entry. Air on Exit. ry' ' Hour.
1 2 3 4 5 6 7 8 9
1 .25 192 .0891 .0045 .0936 19. 73 24.69 400 14
1 .5 322 .1328 .0222 .155 24.10 36 . 15 200 33
1 . 75 452 . I514 .0436 .200 25 . 72 45 . 00 133 53
2.00 562 .1570 .0790 .236 26.30 52.60 100 72
2.25 712 . 1530 .1070 .260 25.99 58.44 80 89
3.0 1,102 .1337 .1783 .312 24.18 72.50 50 133
4.0 1,622 .1030 .2130 .351 ' 21 .70 86.90 33 178
5 . 0 2,142 .0390 .2350 .374 19 .75 98 . 75 25 217




With chimneys to steam-boilers the friction of the long flues must be considered as well as the
head due to velocity, the result being that the maximum effect is attained when the volume of the
internal air is between three and four times that of the external air, as shown by column 5 of table
VI. If we admit 31} as the relative volume, the temperature would be about 1,300c ; but with such
a high temperature there would be an enormous loss of useful effect, and the power of the chimney
would be only 116+107:1.085, or 8.5 per cent. greater than with double volume, which experience
has shown to be the best in practice. The table shows, however, that a variation of 130° either
way has little influence on the power of the chimney; thus, with volume 1%, we have 100+10'7:
.9346, or .0654:6.54. percent. less, and with volume 2';, 112+107:1.047, or 4.7 per cent. greater
power than with volume 2. Column 5 of table VI. gives the ratio of power of the chimney at the
different internal temperatures, and column 6 the maximum consumption of fuel per square foot.
TABLE VI., showing the Power with diferent Internal Temperatures of a Chimney 80 feet high, 2 feet
9 inches diameter, with a Flue of the same Area 100 feet long, from Furnace to Foot of Chimney.
(From Box on Heat.)





TEMPERATURE OF
Volume of Air in the Dm M of Chimne in Ratio of the Power Pounds of Coal per
Chimney, External _ v _ . I“: h t. W be y at different Tem- Square Foot of
Air = 1. A“ m weigllgmney and External Air, 6 es 0 a 1" peratures. Chimney per Hour.
1 2 3 4 5 6
1 .25 192 62 .294 71 120
1 .5 322 62 .890 S9 150
1 . 75 452 62 . 500 100 168
2. 00 582 62 .555 107 180
2 .25 712 62 . 650 112 188
8.0 1,102 62 .780 116 195
4. 0 1,622 62 .890 116 195
5 .0 2,142 62 .926 114. 192








Straightening Tall Chimneys—It is a well-known fact that high chimneys, however carefully built,
often lose their original straightness soon after their erection and assume an inclined position or a
curved shape, so that it becomes necessary to straighten them.
The Port Dundas chimney (No. 1 in table II.) underwent during its erection one of the most in-
teresting and curious operations known in masonry practice, viz., the straightening by sawing the
mortar-joints. This operation has since been frequently resorted to in similar cases, and has always
proved very successful. The mortar in the newly~built portion of the work being still soft and
plastic, the pressure of the wind caused a lateral deflection of the column, amounting to 7 feet 9
inches from the vertical at the top. The whole structure was thereby endangered, and in order to
restore its stability it was necessary to bring it back to the vertical line. The operation of sawing,
which was then resorted to, consists in attacking the mortar-joints at the windward side, and reducing
344 CHIMNEY.

their thickness so as to compensate for the compression of the mortar-joints at the opposite side
effected by the pressure of the wind. The sawing was done by first removing a portion of the brick-
work inside the chimney, forming a groove about 14 inches wide half- around the interior surface of
the chimney. Narrow holes were then cut out by means of chisels, the workmen standing upon the
internal scaffolding, and working exclusively from the inside. A saw with a single handle—~in
reality an old carpenter’s saw—was the instrument employed. It was passed through one of the
holes cut out, so as to work through a horizontal mortar-joint, and it was then worked by hand,
removing the mortar, as it proceeded through the joint, through part of the half circle on the wind-
ward side. Generally two saws were simultaneously employed, working in opposite directions toward
each other. The mortar-joint operated upon was kept wet by a jet of water during the whole pro-
cess, and the removed brickwork in the interior was replaced by fresh bricks as the sawing pro-
ceeded. As soon as the greater portion of any one mortar-joint is sawn through, the effect produced
upon the superincumbent mass causes the latter to settle, and a considerable pressure is thereby
exerted upon the saw, making it difficult to withdraw. If the precaution is taken to commence saw-
ing at the lowest joints, and proceed in succession to the higher cuts, this difficulty is considerably
lessened. In the case of the Port Dundas chimney, sawing was commenced at the top, 128 feet be-
low the chimney cope, and 12 cuts were made at unequal distances, varying from 12 feet to 49 feet.
Mr. Townsend, who conducted this operation personally, judging by the effects produced by each in-
cision, selected the spot for the next cut, proceeding gradually downward until the last cut, 41 feet
from the ground, restored the whole chimney to a perfectly perpendicular position.
In the spring of 1868 the chimney at Barmen marked No. 2 in table II. suddenly assumed an .
inclined position toward the northeast. The deflection of the chimney was considerable at the end
of May, and seemed yet to increase, and threatened an overthrow. Some layers of bricks in the
chimney at distances of 50 feet from each other were painted black outside. The height of these
black lines above the socle being known, these lines were, by means of a theodolite, projected on a
plank situated on the socle of the chimney, to find the deviation from the vertical line at these differ-
ent heights. It was thus ascertained that the chimney at a height of 251 feet was out of line 45
inches; at 210 feet, 30 inches; at 160 feet, 16 inches; at 110 feet, 5 inches. The socle stood per-
pendicular. As the deviation was still increasing, and as it would have done too serious an injury to
the manufactures of the establishment to set the chimney temporarily out of use, it was necessary
that action should be taken in the matter. The ordinary method of straightening chimneys was
resorted to. A hole was made through the whole thickness of the masonry on that side of the chim-
ney which required lowering, 4 feet above the top of the socle. Into this hole a saw was introduced,
with which a horizonal cut through one half the chimney was attempted. But as the thickness of
the wall was considerable and the bricks were hard, and as the saw could be manipulated from one
of its extremities only, the effect of sawing after two hours’ work was scarcely perceptible. The
hole through the chimney having been made without trouble, and the difficulty experienced in saw-
ing, led to the idea to gradually remove a whole layer of bricks, replacing it by a thinner layer, thus
to produce the desired slit. Before, however, this operation was performed, the experiment was
made with an old inclined chimney 120 feet high. When the method had there proved practicable
and successful, it was concluded to treat the new chimney the same way. A layer of bricks was
broken out by means of pointed cast-steel bars from 11} to 5 feet in length, and flat shovels with
long handles were used to lay those bricks which had to be placed near the inside of the chimney.
A space of 5 inches was left each time between the newly-laid bricks and the old ones of the next
division, to break out the latter with greater facility. As soon as the operation was performed, the
chimney began to move, and by slight oscillations settled down on the new layer of bricks, and there
remained quiet.
Defects of Chimneys—Smoky chimneys have a variety of causes, such as imperfections in the flue,
too contracted dimensions, too rough an inner surface, openings which admit cold air and chill it,
and (the most common of all) too large an opening at the fireplace or throat. Count Rumford paid
much attention to the cure of smoking chimneys. Ile generally found the cause to be too large a
throat, and his usual remedy was to diminish it by building a bench of brick in the back of the fire-
place, reaching up to the throat, and to lower the fireplace somewhat. Sometimes the aperture at
the top is too large, particularly if it is below the level of some neighboring house, hill, or high trees,
from which the wind may be reflected down into the chimney, or over which it may fall, and thus
beat down the smoke. An inadequate admission of air into the room in which is the fireplace will
cause a chimney to smoke, a circulating current being thus as effectually prevented as if the fine it-
self were in great part obstructed. The opening of a door or window often shows the cause of this
trouble by at once removing it. When two chimney-fines come down into one room, or into two
rooms which connect by an open passage,.the burning of a fire in one flue may establish an upward
current, which is supplied with air drawn down the other. Any attempts to make the second chim-
ney draw could only succeed by closing the connection between them, or supplying the first with the
air it requires from some other source. When a chimney smokes in consequence of the wind beating
down', the height may be increased, or the diameter at the top contracted; but the most efficient
remedy is usually found by adjusting a bent tube to the top of the chimney, and keeping its mouth
turned in the direction of the current of air by means of a vane. The effect of the latter change is
to admit a smaller quantity of air, and this is dispersed through the large body in the flue without
being felt at the base. The worst chimneys usually draw well when a stove is substituted for the
fireplace, and the pipe is led into the chimney. This causes an increased current in the smaller
channel, being equivalent to contracting the throat of the chimney when the fireplace is used.
Rej'ereneea—For practical details relative to the construction of an iron chimney 279 feet high at
Creusot, France, see Engineering, xiii., 364. A description of the manner of taking down a large
chimney is given in Engineering, xii., 188. With reference to stability of dwelling-house chimneys,
CHISEL. 345

see Engineer, xl., 220; for concrete chimneys, Scientific American, xxix., 39. See also “A Treatise
on Heat,” Box, 2d ed., London, 1876; “Factory Chimneys and Boilers,” Wilson, London, 1877.
Also articles DAMPER and BOILERS, STEAM.
CHISEL- A wedge-shaped cutting tool more especially designed for paring and splitting. The
forms of chisel vary according to the work which they are intended to perform and the material to
be operated upon. In all cases the tool may be regarded as a wedge formed by the meeting of
two straight or of two curvilinear surfaces, or of one of each kind, at angles varying from about 20°
to 120°. Occasionally, as in the chipping chisel and the turner’s chisel for soft wood, the tool is
ground from both sides, or with two bevels or chamfers ; at other times, as in the carpenter’s chisels
and plane-irons, the tool is ground from one side only, and in such cases the general surface or
shaft of the tool constitutes the second plane of the wedge: this difference does not affect the prin-
ciple. The general principles underlying the construction of cutting tools will be found under
PLANES. Stone-workers’ chisels are described under STONE-WORKING TOOLS. For the uses of the
chisels for turning, see LATHE-TOOLS, HAND-TURNING; for carving, see OARVING TO0Ls.
Chisels for Metal.-—Ghipping chisels are employed for dressing metal surfaces. Fig. 772 repre-
sents a cross-cut or cape chisel of this type, which is usually made of hexagon steel, the cutting end
.A being tempered to a blue color. The use of the cape chisel is to cut grooves. 1n chipping large
surfaces, these grooves are made closer together than the width of the flat chisel, and are intended
to assist the operation of the latter by preventing its corners from digging in, as they are otherwise
apt to do. The flat chis-
el shown in Fig. 7'73 is
then employed to cut
ofi the ridges of metal
remaining between the
grooves. The cutting
edges of these chisels
should be firmly held
against the work. For
hollow curved surfaces
a round-nosed chisel is
used, the end being
ground after the man-
ner of a gouge, and the
angles forming the cut-
ting edge being more ob-
tuse. In Fig. 774 the
dotted line shows the
form of a side chisel used
for cutting out square
corners. Fig. 7 7 5 rep-
resents a diamond-point
chisel employed for cut-
ting out the sides of key-
ways, mortises, and oth-
er inside work.
In a rod chisel for cut-
ting hot metal, the angle
of the long taper portion
should be 10° or 12°,
and the angle of the
short beveled part for > _
cutting about 40° or 50’. \
Chisels for cold iron re-
quire the long taper part to be about 30°, and the short bevel for cutting about 80°. All rod chisels are
best when made entirely of a tough hard szeel, without any iron being added to make the head. Such
a chisel will sustain a severe hammering without much injury to the head and cutting part, if only
about half an inch is hardened and the head made as soft as possible. After the cutting end has
become too thick with hammering during ordinary use, or has become otherwise damaged, the lower
part of the taper portion is thinned to a proper shape, and only a short length of the chisel hard-
ened as at the first making. Every time a chisel is repaired by such thinning, it is advisable to
cut off about a Quarter of an inch of the thin ragged end, because this portion becomes burnt dur-
ing heating, and also contains several cracks that are not visible to an unassisted eye. In chisels
for steam-hammers the angles of the
taper parts are about the same as
those of small chisels; but the cut-
ting parts are thicker and of greater
length.
A very useful class of chisel is
that named ' trimmm', represented in
Fig“. .776. This is used for cutting
all sorts of thin bars, rods, and plates; also for removing all superfluous metal that may be at-
tached to any forging which is being shaped to the finished dimensions. To permit the free use
of a trimming chisel, its cutting edge is convex, because this form enables the smith to slide the



















4




346 CHLORINATING MACHINERY.


tool easily along a out which may be of great length, although not very deep. In arched chisels the
cutting edge is concave, as shown in Fig. 777. These chisels are useful for making a square cut
through an axle or shaft,
while it is being rotated on
a gap-bearing block, which
maintains the shaft in prop-
er position for cutting. Con-
cave chisels are sometimes
made with two handles weld-
ed to short arms extending
from the tool. The imple-
ment maythen be supported
beneath the hammer by two
men, one at each handle. To
avoid the necessity of hold-
ing a chisel on the work, it
may be keyed to the ham;
mer; and if a bottom chisel
is also to be used, this is
keyed to the anvil-block.
The forging, manufacture,
and detailed uses of metal-
working chisels are fully dis-
cussed in the “ Mechanician
and Constructor for Engi-
neers,” by Cameron Knight,
New York. 1869.
Wood Chisels—The con-
StI‘UCIiOII of these tools is de-
scribed under PLANES. There
are two types, depending up-
on form : the firmer-chisel
and the framing chisel. The
firmer is made with a tang,
which is inserted in a wooden
handle as shown in Fig. 778.
The framing chisel, used for
heavier work than the firmer,
has a socket in which the
‘ wooden handle is inserted.
Three forms of framing chisel, the oval-back, bevel-back, and corner chisel, are represented in Fig.
779. In Fig. 780 is shown a chisel with a broad edge for plaster-cutting. Figs. 781 and 782 are
calking chisels, and Fig. '7 83 is a driving chisel.
CI-ILORINATING MACHINERY. Chlorina- ' 785,
tion is a process for the extraction of gold by
exposure of the auriferous material to chlorine










llllllll llulllllIIIlllll
\ \‘q'._- 'fu—Gyra
\V
\ i-
/ ' lllLl
\ '


gas. The metallic gold is thus transformed into soluble chloride of gold, which can be dissolved in
cold water and precipitated in a metallic state by sulphate of iron, or as sulphide of gold by sulphu-
retted hydrogen gas. The precipitate may then be filtered, dried, and melted with suitable fluxes,
to obtain a regulus of malleable gold. The powdered and roasted ore is placed in leachmg vats, F 1g.
CHURNS. 347


784, which are simply wooden vats swung on gudgeons, and with a filter on the bottom made of
pieces of quartz laid under a perforated earthenware cover. Pipes in the covers connect the vats
together, so that the gas which is introduced at the bottom passes through the whole row of vats.
The ore is slightly damp-
ened, but must not be wet.
Fig. 785 shows the gas-
generator. It consists
merely of a lead chamber,
containing an agitator of
hard wood, and closed by
a cover resting in a water-
joint. The whole rests on a
sand-bath. Between the
generator and the leaching
vats is placed a wash-bowl,
where any hydrochloric
acid in the gas is removed.
When the operation is end-
ed, the soluble chloride of
I gold is extracted by warm ,
" *"" ‘__“' water, and the spent ore is
tipped into dump-cars. The solution is run to
precipitating tubs, where the gold is thrown down
by solution of sulphate of iron, oxalic acid, etc.
With proper care the process is a very perfect
one, yielding 97 per cent. of the gold, which is
very fine. .
In Fig. 786 is shown an arrangement of chlo-
rination works designed by Messrs. Riotte and
Luckhardt, of San Francisco. It includes the
use of the Bruckner roasting furnace, which is
seen at I, the starting-point of the operation.
The leaching vats are placed at A, in a row, with the gas-generator D in the centre. 6' is a rail-
car for removing the spent ore from the building, while the precipitating tubs are seen at B. At E
is seen the waste-tub, where the water runs through sawdust before being finally discharged.
GI-IUGKS. See LATHE-CHUCKS.
CI-IURNS. The churn which is most in use in this country is the original “ dash-churn,” and it is
claimed by butter-makers who have had large experience to be the best. The dash—churn is hard to
operate by hand, which is one objection to its use on a small scale; but, as all churns are worked by
machinery when many are employed, this objection is done away with. The best dash-churns are
, barrel-shaped, as represented in Figs. 790, 791, and 7 92, having a moderate bulge at the middle, and
the dasher is large enough to occupy three—quarters of the area of the horizontal section of the






W











'I-Il-I'l'lil‘ll'l-l‘li ~~\-


787. 788.





\
D 0 ‘ g
° 9 i J.-
l \k— --——--
. ' \ -
\ ~1 \ 0 o ,' "ll-‘31?
\ ’ ‘ ' ~‘ "—7-.
1' \ o o I" "—
I I
1 ~ \\
I 1









\
g.---__~
!_-_‘d"




middle of the churn. The dasher should be a complete circle, or have the form of one of the dash-
ers shown in Figs. 7 87, 788, 789. A very ingenious apparatus, called the Odell 8t Smey spring motor,
is shown in Fig. 790, for operating churns. The motive force is imparted by a well-tempered volute
spring of steel, inclosed in a barrel or drum hung in an iron frame, and connected by means of a
348 CHURNS.






































wire rope or cord with a fusee, whereby the waning strength of the spring, as it runs down, is counter-
balanced and equalized. The motor runs for about half an hour with one winding up, and it requires
about 1),; minute to rewind it. In Fig. 791 is represented the Key-
stone animal power for churns, the arrangement of which is clear
from the illustration. In Fig. 792 is represented the manner in which
a number of churns are attached to the motive-power. Usually four
churns are placed in pairs opposite, or two side by side, so as to be all
worked by the power at the same time. , 9
Several churns have lately been introduced that operate on the same
principle as the dash-churn, producing the butter by concussion.
“ Bullard’s oscillating churn” is shown in Fig. 793. This churn is sim-
ply a box, without floats or paddles, adjustable to an oscillating table,
to which are attached two balance-wheels; the motion is forward and
backward, the balance-wheel overcoming the resistance of the cream and
causing the churn to work easily. This churn is very simple in construction, and easily kept in repair.
In Fig. 794 is represented the “Howe churn.” The principle of producing the butter in this



795.









'
000°50
90°
dis 00000
0000 o



churn, when properly worked, is the same as in the dash-churn. The operator must cause the dash-
boards to strike the cream-with force similar to the blow of concussion in the dash-churn. The
797.








' ' _ n . ....


proper point for the. return swing of the churn will be apparent by the churn moving back itself,
which movement must be assisted by slightly jerking it at the beginning of its return swing, to
CLOTH-CUTTING MACHINE. 349
produce the blow of concussion. Each dash-board must make the blow on each swing. The
desired motion or. stroke is easily acquired with practice, and butter is quickly produced.
The “revolving box-churn” is shown in Fig. 795
The cover of the churn is easily adjusted, and ad-
mits of no waste of cream. It contains a revolv-
ing cream agitator, running in an opposite direction,
thereby hastening the time of churning.
“Whipple’s rectangular churn,” shown in Fig. 796,
has neither dasher, floats, nor agitators of any kind,
the cream only acting upon itself and the inner flat
surface of the churn. Suspended from diagonal cor-
ners, as the churn revolves the cream constantly falls
from corner to corner, thus giving a diversified ac-
tion, and preventing the accumulation of what is
called “dead” or half-churned cream.
The Blanchard churn is represented in Fig. 797.
Of this, and of the Union churn, Fig. 798, the con-
struction is clear from the engravings. See DAIRY
APPARATUS. H. A. M., Jr.
CH UTE. An inclined trough formtng a feeder of
materials to machines, or of water to a water-wheel.
Also an inclined plane on which logs are passed down
hill-sides.
CLAMMING MACHINE. A machine in which an
engraved and hardened die is made to rotate in con-
tact with a soft steel mill, in order to deliver a
cameo impression thereupon. The mill is used to
indent copper rollers for calico-printing. (See Ex-
eaavmo.) ~
CLAMP. A device for temporarily holding the parts of a piece of work firmly together. Fig.
799 represents the form of clamp used by jeiners to hold glued joints while the glue is hardening.
The work is placed between the jaws at A, and the screws are adjusted so that the jaws just touch














800.
._.~-- .1
_._...._-
a
l






. \llllllllllllllllllll \lltllllll
t


the object. The screw B is first tightened, and the final grip is given by the screw 0. Fig. 890
represents the usual form of clamp for holding together pieces of metal while the same are being
operated upon. J. R.
CLOCKS. See Wareuss nun CLOCKS.
CLOTH—CUTTIN G MACHINE. An apparatus for cutting cloth for tailors’ purposes. The Penno
machine, represented in Fig. 801, consists of a vertical shaft driven off a counter-shaft by a bevel-
gear wheel. Attached to a hollow standard, in which this shaft runs, is a horizontal jointed arm,
carrying at its outer extremity a small vertical shaft, which is driven by belts arranged as shown in
the illustration; this vertical shaft drives by bevel-wheels a revolving cutter 4 inches in diameter,
mounted on a small stand and furnished with a handle. The radius of the arms is 6 feet, and they
are made of brass tubes, the outer length being supported by a spring from the joint; the cutter
makes 2,000 revolutions per minute, and with it a skillful operator can cut from 20 to 80 layers of
cloth, according to the quality of the material, and can follOw any description of line, either curved
or straight. The foot-plate under the cutter preserves the table from injury, and the cutter can be
moved over the surface of the table within the radius of the arm with the greatest case. A revolv-
ing emery-wheel fixed on one corner of the table enables the cutter to be sharpened without stopping
350 CLOTH—FINISHING MAOHIN ES.

the machine. A clamp is used for holding several layers of cloth together when moving them from
one table to another, by which the old-fashioned screw clamps are dispensed with. It consists of a
small casting, the foot being flat and the stem of a triangular section; on the latter slides loosely
another flat casting, having a triangular aperture to fit the stem. The elasticity of the cloth presses
upward the outer end of the upper arm of the clamp, and by doing so increases the friction on the
801.
lliiilml‘nmnunnfimimnuiaagim
~~:|‘ - -
in, llllulmnmuuunmmm
l




llflllufllllllilllmlllfltllllllllllllll


animiinmnaaunairniaitia.
‘












Imam, (....-
Ijlinw "111m Imfl'm
:IHI;lulmmnmwm ..,‘.“.l.,"lllllllllmm é/f
" " " "it-tillElill.5dimtiliulill‘llllllllumumnM




flat side of the stem to such an extent that the arm cannot move. To release the clamp, the upper
arm has to be brought to a horizontal position, when it will slide up the stem.
Mr. Albin Warth also exhibited at the Centennial Exposition, 1876, two machines for cloth-cut-
ting. The traveling machine has an arm running on a little railway, secured to the table, and carry-
ing a revolving cutter driven by belting—the power being communicated from the counter-shaft by
an endless band which surrounds the traveling pulley attached to the arm. The standard machine
has a revolving cutter driven by machinery placed underneath the table; this cutter can revolve on
its centre, but cannot travel over the table.
CLOTH—FINISHING MACHIhT ES. (See also CALENDER, CALICO PRINTING, and FULLING MA-
eHINERY.) Cloth-finishing machines prepare the surface of woven fabrics, so as to improve their
appearance, and often in the case of inferior goods to cover the poor quality of the material. N ear-
ly all stuffs when taken from the loom contain certain impurities and dressings, such as glue, which
have been used to keep the warp together, and which are therefore of a sticky nature. To remove
these substances, washing machines are used. (See LAUNDRY MACHINES.)
Drying Machines—These are contrivances for removing the water from the stuffs and for dry-
802.


ing them. Both these classes of apparatus have the same purpose, namely, to remove from the
stuff the moisture which it has absorbed during the processes of washing and falling. This moisture
is of two kinds, one part being held mechanically by the stuff, while the presence of the other part
is due to the hygroscopic qualities of the material ; this latter portion is known to be very predomI-
CLOTHé-FI N ISHIN G MACHINES.
351
l
of the finishing mat-

nant. ~~The mechanically held moisture is now
generally removed by means of centrifugal dry-
ing machines (see SUGAR-MAKING Maemnsav),
while artificial heat is required to efl’ect the re-
mainder of the drying. Dr. Herman Grothe has
published a work on this subject, in which he
shows, by practical results obtained by the use
of centrifugal machines, that the rotary drying
of moist stuffs is only economical within certain
limits, and that the construction of the centrifu-
gal machines themselves is not yet perfected, as
most of them have to drag with them vessels
and contrivances which are much too heavy. A
well-designed centrifugal machine should repre-
sent a correct combination of mass and strength,
and shonld possess at the same time moving parts
which offer little friction, and the necessarily
rapid motion of which does not produce any loss
of power, while the machine should also be pro-
vided with arrangements for stopping the rotary
motion almost instantaneously.
The drying machines intended for removing
the more closely combined portion of the moist-
ure by means of heat are of various systems.
One of improved construction (German) is repre-
sented in Fig. 802, and is more especially adapt-
ed for calico-drying. It is arranged on the ver-
tical system, and is used for effecting the simul-
taneous drying and starching of woolen and half-
woolen stuffs, which are starched on one side
only. For this purpose the stuff passes at first
through the starching apparatus A, consisting of
the squeezers a b and the box a, which contains
the finishing or covering matter through which
the lower roller a revolves; the stuff passing
through the two rollers a b, the finishing mat-
ter is very uniformly
transferred to and im-
pressed upon the sur-
face, and the small
irregularities formed
in weaving are thus
completely covered.
From here the stuff
passes into the dry-
ing apparatus proper,
consisting of six cop-
per cylinders d d heat-
ed by steam through
the hollow frames e e.
These cylinders, which
are constructed for a
pressure of from two
to three atmospheres,
are provided with cast-
iron bottoms, the lat_
ter being fixed in such
a manner that they










may easily be remov-

ed. The guide-rollers
ff pass the stuff with
the unstarched side on
to the cylinders, so
that the breaking up
ter, the clouding of the
stuff, and the greasing
of the cylinders are
prevented, while the
drying of the matter is
well and uniformly ac-
complished. From the
last cylinder the stuff




352 CLOTH—FINISHING MAOHIN ES.

passes into the folding apparatus carried by the arm B. The water arising from the condensation '
ol' the steam is continually taken off from rollers and frame.
805.
~>\ \- \\_L.k\\\éQ\\ \ \\ \\\.\ L_\\ k\\\\\ \. k\\\\\\
.. x \





The motion of the cylinder is pro-
duced by the friction-gear g h
and the pulleys i ; and accord-
ing to the speed required for
the cylinders, the friction-pulley
h is moved along its axle either
toward the centre or the cir-
cumference of the face-plate g.
Cloth-like staffs are placed in the falling-mill in order to facilitate the closing or felting of
the materials. (See FULLING MACHINERY.) Woolen stufi' is next taken to the gig-mill.
806.






Q5. ~05, ) r H ..
n . / D
Qamai m , , Quays,»
ya; TQM; 4:
4|? “L! /
alllllh i
. '.
Ill/l" t


is:




b
.._ .2.)












\ six








‘ a l a I. h1.12._»/._ / ', ' ,z/ \
l
1
/
built by the Parks & vWoolson Machine Company, Springfield, Vt.
’11-"-
\\ \ \z‘ \\‘\
l\\ l I


The Gig-Mell.—An example
of this machine, which is used
for napping the fabric, is given
in Figs. 803 and 804. The cloth
to be napped is first wound on
the roller 0', then passed down
over the two straining rollers
d' d to the cloth-roller 0. By
means of the shaft 0, which is
mounted at each end with two
slipping clutches f f, c’ is thrown
out of gear, and the lower roller
0 thrown in. The cloth is then
drawn downward over the re-
volving drum 6, which is set
with teascls, as seen in Fig.
805, until the whole length has
passed over. The action of the
two cloth-rollers is then reversed,
0' being thrown into gear, and
the cloth passes back again over
the teasels; and this is contin-
ued until the nap is sufficiently
raised. The straining roller (1’
may be adjusted to give more or
less strain on the cloth at will.
From the gig, as described,
cloth passes to the I'VooZcn-Clolh
Shearing Jllach'ine, Fig. 806.
The example we illustrate was
The rotary brush A, revolving
in an opposite direction to that in which the cloth is moving, raises the nap which has been formed


\
Jr:-
va. '
. \ \\&§\\


Vs
a gas
by the action of the gig, so as to prepare it for the action of the helical blades of the shear B.
which acts against a ledger-blade, not seen in the drawing.
The cloth is brought up to the point
CLOTH-F1 N ISHIN G MACHINES. 353



of contact of the shear-blades by the rest-bar C, the distance of which from the shears is adjusted
by set-screws according to the thickness of the cloth to be sheared. This rest-bar is composed at
either end of small movable plates or sections, which are brought up to the proper point of con-
tact or removed from it by '
. v 808.
a system of levers, operated
by the fine-toothed wheels
shown on either end of the
list-rod D. These toothed
wheels are set at such a
distance from the cloth as
not to touch the surface of
the fabric itself, but so as
to be caught and put in op-
eration by the coarse fibres
of the thick listing, and by an internal screw on the rod operate the levers, by which the mova-
ble ends of the rest are depressed, so as to allow the listing to pass through without being brought
in contact with the shear. The Cotton-Cloth Shearing Machine, as shown in Fig. 807, has been
varied in form, though not
in principle, from the origi-
nal invention of Milton D.
Whipple of Lowell. It con-
sisted in holding the sur-
face of the cloth intended
- ,. . V . to besheared or trimmed
'5 ~ ' '-
__ of loose threads or knots
' " ' ' ' " firmly against the point of
contact of the cutting blades,
by means of fixed supports
on stationary bars, over
which the cloth passed just
before reaching and after
leaving said point of con-
tact, and a little above its
plane. In the modified ma-
chine shown, the cloth pass-
es above the cutting blades,
_ and is held down on them
#1 by the straining bars, as is
.r seen in Fig. 808, in which
A A are the rest-bars, B
the cloth, passing in the di-
rection of the arrow, C the
revolving cutter furnished
with a. series of helical
blades, and D the station-
ary or “ledger blade ” of the shear. This form of machine was intended to clean and trim thin fab-
ries, like calicoes, mousselines-de-laine, etc., in which the body of the cloth was not of sufficient
thickness or elasticity to allow of its being held by a rigid bar directly against the point of contact
of the shears; but it has since come
into very general use for all cotton
fabrics. In the machine as represent-
ed, Fi". 807, the cloth enters over the
rollers C, and is drawn tight by the
friction-rod operated by the handle D,
and passes first over the brush A,
which serves to raise the nap of the
cloth, and also takes up many of the
loose ends and threads which are left
as it comes from the loom. It then
passes over the shear-blades B, and
in the machine shown to the brush
and shear E and F, which are placed


809.-


- ~ . ‘ _ ‘
~urr.,
mun,”
m,“
m.
\ I “\.
, l| ...-
above the cloth, so as to trim both J i
sides. It is then taken by the cloth-
A a
roll G, which draws it through the -
machine, and delivered to the wind-
ing rolls H by which it is wound into " ‘ \-
a roll for the folding machine. The ' " - \"w'm" \“x
dust and lint sheared off are taken
away by the fan J, through the pipes ‘
or trunks K K. These machines are varied in construction according to the work to be per-
formed, in some cases having four sets of cutters on one side of the cloth only, in others having
cutters on both sides. The pieces of cloth are sewed together by a sewing machine, designed for the


23
354 _ OLOT H—FIN ISHING MACHINES.

purpose, before entering the shear, so that its operation may not be interrupted at the end of each
piece. - ' .
Brushing .Zlfachi-nes.-For some cotton fabrics a brushing machine is also used. This serves to clean
the cloth, and leave it with a slight nap or surface, and is employed for cottonades and goods of a
similar description. A brushing machine is
also used in the manufacture of many of the
finer woolen fabrics, the cloth being alter-
nately “napped” and sheared till the de-
sired surface is attained; and this is com-
pleted by brushing. In the machine repre-
sented in Fig. 809, the cloth, previously
moistened, is submitted to the action of the
rotary brushes A and B, being passed over
tension-rollers as shown, in such a manner
as to subject it twice to the operation of each
brush. The brush (7 serves to clean the
back of the cloth from the flocks, etc., left
by the shears and other machines. From
the brush the cloth is taken to the hot press,
which completes the finish.
Presses—Fig. 810 represents the Ilarwood
8:. Quincy continuous press, which is used for
hot or cold pressing or for steaming, with a
w ~ production of 30 yards in 8 to 10 minutes.
3‘ I," The cloth goes direct from the sheariner ma-
1 ‘-
chine to the press, where it is brushed and-
pressed simultaneously, thus saving much
time and labor. The pressure can be regu-
lated at will. The machine weighs 45 cwt.,
and takes about one horse-power to drive.
A is the framing; B B, a concave bearing
made in two'halves, one to be used cold and
the other hot; C, a roller running in the
concave bearing; E, levers with the fulcrum
at J; F, levers connected with the levers E ,-
G, a shaft which by means of the cam 0 and
the hand-lever N lifts the lever B and the
roller 0. The shaft H and its cam I lift the
levers F and J 2. F 2 is a revolving brush;
K and K 2, friction-rollers; C 1, a roller
which takes the cloth off the roller 0; P,
an arrangement for plaiting the cloth. One
half of the concave bearing B is kept cool
' by means of water carried to it through the
pipe 0 1, while the other half bearing is heated by steam through the pipe 0 2 ; the lever L, having
a handle at one end, is in connection with the lever J 2; the roller 0 is heated by a steam-pipe O 3;
811.








' -JAN'RE


812.





















the lever F is furnished with a heavy weight. The action of the machine is as follows: The cloth to
be pressed passes over the bars S Sand the friction-rollers K 2 and K, then over the upper part of
CLOTH—FINISHIN G MACHINES. 355


the brush F 2, and thence between the roller 0 and the concave bearing BB, and finally over the
roller 0 1 and the plaiter. The bearings BB are heated or not as desired. The pressure may be
brought by the lever L up to 6 tons. When no pressure is required, but the ma-
chine is to be used as a brushing frame only, the roller C is lifted from the cloth
by means of the lever 1V. For the purpose of steaming the fabric it is necessary
to heat the roller 0, and to cover it with thick felt.
The hollow-plate steam-press, Fig. 811, is used in finishing woolen and worsted
goods, which are first folded between smooth pasteboards, called “ press-boards,”
and each piece laid between a pair of hollow iron plates. These are then heated
by steam, from jointed pipes connecting each plate with an upright steam-pipe
behind the press, and the whole closed up, either by screws or by hydraulic pres-
sure, till the desired pressure and finish are obtained. A uniform heat is secured
in this manner, and all the dirt and danger of fire from the old system of furnaces
for heating the plates are entirely avoided.
Among other machines used in finishing cotton goods, not above mentioned,
is the “napper,” used for cotton fiannels, which is very similar in its operation
to the “gig” used for napping woolen cloths, except that wire card-teeth are used
instead of teasels.
Singeing 1Ffd€hifl68.——FOP the expeditious removal of the floeky and fibrous
projections from the surface of cotton stuffs, singcing machines are employed, by
the aid of which the flock, etc., is burned ofi". In Fig. 812 is representeda ma-
chine of this description, constructed by the Zittauer )Iaschinenfabrik und Eisen-
giesserei of Zittau, Germany. This consists of the hearth A (above which the
singc-plate l is placed in a cast-iron frame), and of the brushing and winding
apparatus D and E, driven by the two small steam-engines B and C. By means
of suitable clutches the singeing apparatus may be put out of work without
stopping the engine. The stuff passes from the cloth-beam 6 over the rollers 9,
against the brush 2', and, going over the adjustable knife h, passes over the
heated plate 1, whence it finds its way over the corresponding parts of the other machine. If a
further singeing is required, the machines are reversed, and the manipulations are repeated, but in
the opposite direction. The brushi serves to raise the fibres of the stufi before arriving at the
813.



814.



singeing plate, so that they may be more quickly caught by the heated surface. The cover 122. is
placed over the platel as soon as the machine is stopped; this is done in order to prevent the
356 CLOTH—FINISHING MACHINES.

___
air from coming into contact with the heated plate I. The speed with which the stuff passes over
the plate varies according to the thickness and condition of the stuff and the temperature in the room.
Fig. 813 represents the burner used in an improved gas singeing machine devised by M. Blanche.
D is thegas-pipe and B the gas-burner. E is the air-pipe and U the air-tube. The gas and air
mingle in the conical tube shown, and are ignited at its orifice, the flame impinging on the cloth as
it passes around the roller A.
77w Beading ll!achz'ne.—An improved form of this apparatus, of English construction (Patterson’s
patent), and exhibited at the Paris Exposition of 1878, is represented in Fig. 814. Its peculiarity
consiSts in its bringing to bear on the cloth a number of hammers or fallers worked at a high speed,
these hammers being worked by eccentrics on a shaft which extends across the top of the machine,
and there being interposed between the eccentric rods and the hammers a spring connection which
relieves the working parts from the recoil of the blows, and materially reduces wear and tear. The
spring connection is made by suspending each hammer from a leather belt attached to a semicircular
Steel spring, as shown. In the old-fashioned beetling machines the hammers or “fallers” were
lifted by cams, and allowed to fall by gravity, while the utmost speed at which they could be run
was about 60 blows per minute. In the machine here represented the hammers give 420 blows each
per minute, while the striking effect of each blow is the same as in the old machine. The hardness
of the blow can, however, be varied by altering the speed. The cloth being operated upon is carried
by one of three rollers which revolve in bearings carried by disks, as shown, these disks being
. themselves capable of revolving. The three cloth-rollers can thus be brought successively under
the action of the hammers, and the operation of the machine is thereby rendered continuous, the
filling and stripping of the rolls not interfering with the beetling.
Cray/rang Machine—Cotton, linen, and half-woolen stuffs are usually soaked with a finishing fluid,
in order to procure a certain stiffness, smoothness to the touch, and often lustre. In order to do






this in a suitable and uniform manner, special machines are used. Starching machines, which may
either be fixed to the cylinder drying machines, or may be used as independent machines, belong to
this class. Craping machines are generally used for effecting a continued washing, boiling, and
rinsing of woolen or half-woolen stuffs in an alkaline solution, for the purpose of finishing, or as a
necessary preparation for the process of drying, or to provide the stuffs after being cleaned with
finishing matter. This machine is an important element in the finishing process. As will be seen
from Fig. 815, it is provided with three boxes, a, b, and c, which contain the different fluids to be
used for the finishing of the stufi or for the removal of impurities, such as fat or grease, from it.
Three rollers, carried in strong frames, and running against a series of pressing or squeezing rollers
d' e’ f’, project partly into these three boxes a b 0. These rollers and boxes may be used in various
ways, according to the quality of the stufi; thus the latter is either wound round the rollers, which
are 'fixed in such a manner that the stufi is saturated by the fluid, while the rollers rotate and the
squeezers partly press the fluid into the material, and partly squeeze it out of it, or the stuff is placed
in the fluid, and is simply passed through the squeezers. By means of the wheel-gear g It at the
top of the frames, the upper rollers or squeezers d’ e’ f ' can be lifted, in order to afford space for the
winding of the stuff around the lower rollers. The shafts of wheels 9 g g are provided with sectors
7.: la la, over which a chain is passed carrying at its end the rod and hook i, from which weights of
various sizes, according to the requirements of the case, are suspended in order to press the rollers
01’ e’f' firmly against the lower rollers. The material, which may be passed in or out of the machine
from either side, is, after coming from the squeezing rollers, wound upon copper steam-rollers by
means of the friction-gear Zm, which allows the speed of the steam-rollers to be exactly regulated
as required, by moving the disk to the necessary distance from the centre of the disk I. By means
of the foot-boards n, the rods 0, and the levers p, the workman at the machine can instantaneously
stop the winding up of the stuff by throwing the friction-disks out of gear. Motion is transferred
CLOTH-FINISHING MACHINES. ' 357
—v
to the rollers by the bevel-wheels g g' g", and each pair of rollers can be worked or put out of gear
independently of the other rollers by means of suitably arranged couplings 1'. By means of the
wooden rails s the stuff is guided into the machine without any folds; it are guiderollers, and 'v 'v
and u u are stretching rods for the different boxes.
The fileasuring and Winding .Machine, Fig. 816, from the Parks 8: Woolson Machine Company, is
of a kind generally used for putting up a large class of narrow woolen and worsted fabrics, which

4F
1
mum " H
l
\ll

I


are “rolled ” or wound on boards. The cloth passes through
proper guides to the measuring roller A, having a cloth sur-
face, a worm-gear on the end of which operates the gear of
the index-shaft B, and records the revolutions of the measur-
._ing roller, in yards and fractions, at the index-dial D. Pass-
" ‘ ing partly around the measuring roll, so as to give it motion,
the cloth is led around the tension-rolls E and F to the winding
' jaws 0', which inclose between them the board or slat on which
the cloth is to be wound. One of these jaws or clamps is
movable, and is operated by a screw connected with the hand-
wheel shown, so as to clasp and release the board at pleasure. After each piece is rolled and meas-
ured, the index-plate is thrown out of gear, and reset at zero for the next piece.




The Cloth-Folder, Fig. 817, is widely used for cotton cloths, prints, and other light fabrics. The
crank-disk A, on the main shaft, gives motion to the two parallel levers B B, supported on a stud, and
connected at the top by a funnel-shaped mouth-piece at 0, through which the cloth is brought from
ass CLOTH-FINISHING MACHINES.

the delivery roll F. This mouth-piece is inclined alternately to the right and left by the motion of
the bars B B, so that the lower edges of it insertthe cloth between the stationary bars D D, the under
faces of which are covered with card-teeth, and the floating table E supported by springs, which yield
sufficiently to admit of the entrance of the edge of the mouth-piece with a thickness of cloth at each
vibration of the same, and retain the fold as the mouth-piece is withdrawn. When the piece is
folded, and at the same time measured, a pressure of the foot on the lever H drops the table E,
and admits of the removal of the cloth. Another form of folding machine, of German construction,
is represented in Fig. 818. It consists of a frame about 14 feet high, carrying at the bottom the
cloth-beam a, from which the stufi passes half folded to the roller 6, and thence to the rollers e and
d. The stuff is pressed against the cylinder (Z by the roller f, while the laying down into the trolley
h is effected by the lever g worked from the shaft carrying the pulley i.
Stretching 1Vachine.-—l)uring the process of drying the maintenance of the stuff at its correct
width is of great importance, and always has been a difficult matter on account of the shrinkage
which takes place. Side and front elevations of a machine devised by J. Ducommun & Co. of Mul~
house are given in Figs. 819 A and 819 B. It consists of fixed and solid frames A carrying the main
shaft I with the pulleys K and the spur-wheel M, which transfers the motion by means of 'the
wheel Z to the roller 1V, the latter being geared to the second roller a by the pinions C and B.
These stretching rollers appear cylindrical externally, as shown in the engravings, but they consist
of an India-rubber tube drawn over a grooved core, as shown at Y in Fig. 819 B. These cores of the
two stretching rollers are arranged in such a manner that the grooves of the one correspond in
position and shape with the projections of the other roller; this cannot be seen, however, unless the
819 A.





..-_ -.__
,l
.;-.., , . i
r ,. . .
v .,-,, _
' " ' " ‘ ‘ ~ ' i . .
‘ -.-.- ' ‘ .-__._ -/ ,, . ..\
l-Izi'i "" -' - ‘ 1., .. .. . c I v- .-. --. - ,"l',
. ~ ~ I ,
' I \-_ '
'- ‘-.- a“ ., -
" ' I 2“.



[‘1' m:
L
.9'
3|
pin:
#37:". gll
H .
grasartafium
,Ifflmu m. 1:
two rollers are pressed together by means of the screws E, worked by the shaft F, when the
grooves are shown through the India-rubber tube. The stuff R is unrolled from the roller Q, and
passes over 0, under P, and over the elliptical roller T; it is taken up either by the laying or dis-
tributing apparatus X, or by the roller V, in which latter case it has to pass the table U, and is
stretched during winding up by the roller W. Even a superficial examination of the rollers a and
N will show that the stuff passing between them must be stretched. The machine also effects
the breaking up of the finishing matter, and makes even very strongly finished stuff soft to the
hand. (See Engineering, xv.) . S. W. (in part).
The Davis at Furber Steam-Gig, manufactured by the Davis 8t Furber Machine 00., of North
Andover, Massachusetts, is provided with two 7-in. diameter copper cylinders, thickly perforated with
small holes for steaming the goods, steam being admitted to the cylinders through the journals.
The main cylinders are 38 in. in diameter, and are covered with 20 hard-wood lags; every other lag
is designed to be filled with bristles in the usual manner for brush cylinders. These machines have
all the essential parts for winding the cloth from one roll to the other, means being provided for
reversing the movement of the rolls. The driven pulleys make from 130 to 160 revolutions per min.,
according to width of machines. Up-and-down wet and dry gigs in general construction are similar
to the above-described gig, the steam feature and brush-slats being omitted, and the main cylinders
being fitted to receive the usual gig-slat for holding the teasels. The cylinders are 40 in. in diame-
ter, have a vibrating movement, and are fitted with either hooks, buttons, or springs, holding the
24 teasel-slats. The wet gig has the usual arrangement for beaming off the cloth which is thrown
in and out of engagement at the will of the operator. A regulating device is provided for giving
the cloth any desired tension and amount of contact surface on the teasels. The driven pulleys run
from 150 to 250 revolutions per min. I .
Cropping-Machine.——A new quadruple cropping machine of English construction is represented in
CLOTH-FINISHING MACHINES.
359

Fig. 819 c. The cropping or shearing apparatus consists of a circular bar having a number of steel
blades wound spirally round it, and the edges of which project about 1 in. from the
819 o.
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. _ _ _ , \'_ a,“ ’ ,
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body of the bar.


These steel edges revolve against a stationary flat blade, the edge of which is placed exactly under or
over the centre of the spiral knife, and which is hollowed out to the radius of the circular cutters,
so that the latter work in perfect contact with it—in fact, are
ground into a perfect bearing surface with the edge of this
flat blade. The action, therefore, of the revolving spiral knives
against the edge of the fixed blade is identical with that of a
pair of scissors; and as these knives revolve at a speed' of o
from 1,000 to 1,500 revolutions per min., this action is con- _ ,
tinuous, so that no projecting thread or fibre can escape being > cut as the cloth slowly passes under and in contact with the f
edge of the fixed blade. There may be one, two, three, or P »
four of these cutters, according to the nature of the goods
being cropped. The tension apparatus consists of two round
bars fixed to disks at either end. The cloth passes between
these bars, which, being turned round, more or less vary the \
strain upon the cloth. From this the cloth passes over two
iron rails, which tend further to tighten it up, and the edges
of which take out any folds or creases which might occur.
The knives are made so as to be raised from the cloth or
819 D.





lowered into contact with it at pleasure while the machine is

in motion, and the amount of pressure which they will exert
upon its surface is regulated and kept uniform by means of
screws, the points of which bear down upon the frames of
the machine when the knives are in position to cut. The
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pieces of cloth to be cropped are sewed end to end, so as to
be drawn continuously through the machine, and as the sewed
part approacheseach revolving spiral, the attendant, by means
of a simple eontrivance, raises it with its corresponding blade
so as to allow the projecting sewed part to pass without being
cut or injured.
CLO'I‘II-PnI-ISSING MACHINES. The Husscy Leac/mzan alfa-
chine.—-A novel form of cloth-pressing machine is represented
in Fig. 819 D. It is a combined steam and hydraulic arrange-
ment. The cloth to be operated upon is passed through heat-
er plates, which rise and fall to give the required pressure,
and is wound on the rollers seen above the machine. It will
be evident that the winding on the rollers cannot proceed
l2
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while the cloth is being pressed between the plates, and an intermittent action is therefore re-
quired.
A is the steam cylindei taking steam only on the lower side of the piston, by means
360 , CLOTH—FINISHING MACHINES.

of a slide-valve, which is worked by the lever B, in turn actuated by the cam 0. The hydraulic
pump Pis thus worked. When steam is being admitted the runner E is clear of the cam at the
point F, so that the weight G can press the'valve on to the valve-face at H, leaving a free pas~
sage from the pump P into the pipe I and closing the pipe Q. For lifting the pressing-plates there
is a compound ram, a smaller one within a larger. The former is sufficiently powerful to bring the
large ram and the plates up to the work, at which time the full power is put on to give the pressure
required to treat the cloth. The pipe Q previously referred to leads to the. larger ram, and the
branch I to the smaller ram. As the larger ram is being lifted (during the first part of its upward
stroke) by the smaller ram it is necessary to fill the space it leaves in its cylinder, and this is done by
means of the valve M', which opens communication between an elevated tank and the big cylinder.
The cam continues its revolution until the elevation 0 comes in contact with the runner E, which
is pressed upward, and thus, by means of the valve H, opens communication between the hydraulic
pump cylinder and the pipe Q leading to the large ram ; at the same time the valve M is closed by
the superiority of pressure in the pump over that due to the elevation of the tank. It is at this time
that the full pressure is exerted on the cloth. During these operations the full pressure has been ad-
mitted to the steam-cylinder, but the cam now opens the exhaust by means of the lever B.
It is now necessary to release the water-pressure so as to let the presser-plates fall, and allow the
winding of the cloth on the rollers to proceed. This is effected by means of the projection R on the
cam. This lifts the runner E, and by means of the spindle shown raises the valve 111', thus opening
an exhaust passage. The mechanism by which the cloth is wound on the rollers and is thus drawn
through the press is very simple. There is a stop on the bottom heater-plate K, which sets the
actuating gear at work and throws it out of action intermittently, so as to synchronize with the press_
ing and releasing of the cloth between the plates.
A pressure of 350 to 500 tons is put on at every stroke, and the cloth is drawn the width of the
plate each stroke, and receives five nips in all. Two pieces can be done at once, the rate being 480
yds. per hour of wide width, or double that length of narrow widths. ,
The Gessner Cloth-Pressing Machine, invented and constructed by Mr. David Gessner, of Worcester,
Massachusetts, is illustrated in section in Fig. 819 E. The novel features here embodied are the con~
struction whereby vibration when running at high speed is avoided, and whereby extreme pressure
819 a.


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and great pressing surfaces are obtained. Another important advantage is the arrangement of the
parts so that the heavy portions may all be placed in position before the lighter ones are mounted.
The general construction of the machine is, briefly, as follows:
There is a central fixed hollow cylinder and two so-called bed-plates, the inner surfaces of which
are concave, so as to fit closely against the cylinder periphery. The cylinder and bed-plates are hollow,
and are heated by steam admitted into them when in use. The cloth passes between the cylinder
and the bed-plates, and is thus pressed.
Referring to the engraving, A represents one of the metal and frames, of which there are two,
bound together by longitudinal tie-rods. In these frames is journalled the central cylinder 0. Sup-
CLUTCH. 361

ported by tongue and groove slide-rests E on the main frame A are carriages D. B and B’ are the
circular bed-plates, which extend between the bed~plate carriages D, and are journalled in these car-
riagcs. The connections between each bed-plate and its two carriages are such that the bed-plate
tends to fall by its own gravity, and in this way normally to bear upon the cylinder. At the same
time this downward tendency of the bed-plate on the delivery side of the machine prevents any possi-
bility of the plate being raised by the action of the cloth. Mounted on each journal of the cylinder
0 is a three-armed lever F. The long arms of the lever F are fastened to togglejoints H, which are
secured to a fixed bearing at the base of the machine. The toggle mechanism is adjustable by nuts
K’, and between the two toggle-arms H, and extending longitudinally the machine, there is a threaded
shaft K, on which is mounted the hand-wheel L. The short arms of the lever F are connected by
adjustable rods G to the protecting journals of the bed-plates.
It will be observed that there is a short lever-arm having pivotal connection with each carriage of
each bed-plate, and that these two short arms are supported on a single fulcrum, and are connected
to the long arms F, which arms F communicate with the toggle mechanism. When the hand-wheel
L, therefore, is turned, the toggle-arms H are moved nearer together or farther apart on the shaft K.
The long arms F are moved down or raised, as the case may be, thus turning the whole three-armed lever
on its fulcrum. The short arms of the lever F, then drawing upon the rods G, move the carriages
I) in one direction or the other upon the slide-rests, and in this manner the bed-plates B and B' are
forced into close contact or moved away from the periphery of the cylinder C. The cloth enters the
machine at the left of the engraving, passes over one bar and under another, and then comes in con-
tact with a brush-wheel c, by means of which one side of the cloth is cleansed.
After passing over other supports, the cloth meets a second brush-wheel F, which acts upon the
other side of it. Thence it passes over a guide-roller H to a stretching—roller K, and from that roller it
passes over the cylinder 0 and bed-plate B, and so receives its first pressing. Thence it passes over
a series of rolls, 1 m n p, so thatit forms a loop, and in this loop is located a steamer 0. The cloth then
goes back to the cylinder 0, passes between that cylinder and the bed-plate B', receiving its final
pressure, after which it passes over the roll Q, the steamer R, and thence to the various guide-
rollers, and finally to the folder W
If it is not desired to give the cloth this second steaming, it may be carried directly to the last
roller and folder, as indicated in the dotted lines. It will readily be seen that by disconnecting the
toggle-joints and removing the cylinder-caps, top slides, and lever F, the bed-plates B’ may be slid
back on their rests, thus making the inner surfaces of the bed-plates and the periphery of the cylinder
easily accessible.
It will also be observed that the power applied to the single hand-wheel L is distributed to each
end of the bed-plates, each of which encloses nearly a semi-circumference of the cylinder. This power
is multiplied first by the screw surface on the rod K, then by the toggle mechanism, and finally by the
leverage of the long lever-arms F.
The bed-plates may be set in four positions: 1, simply to relieve the pressure; 2, to prevent the
contact between bed-plate and cloth, so as to leave sufficient air-space to avoid press-marks when the
machine is stopped, and also to permit of cooling of the parts; 3, to allow of access to the thin
plates of metal or jackets with which the plates are lined in order to draw-file or remove them;
and, 4, to permit removal of the cylinder by lifting it upward from its bearings. This is a very
important improvement over earlier machines, in which it was impossible to remove the cylinder
without dismembering the entire structure. A cylinder in general use needs turning down at times,
because of the cutting of its surface by foreign substances, the grinding out of its bearings, and
warping due to frequent heating and cooling. It will also be noticed that in this machine the
length of the connecting members of the operating mechanism remains unchanged throughout the
various operations, so that readjustments are not necessary every time the bed-plates are opened to
allow of access to the cylinder surface. The construction is also such that the power of the pressing
mechanism increases to a maximum as the bed-plates advance, and that a more rapid movement of
the bed-plates is effected than in earlier machines. The special importance of such improve-
ments as above noted is also due to the fact that pressing is the last operation which cloth
undergoes, and, if the press has to be stopped frequently for adjustment or repair, the whole out-
put of the mill is arrested. With older types of machine the production of finished goods was
from 3% to 4 yards per minute. With the present machine an increase of from 20 to 25 per cent.
is effected. It is adapted to the pressing of all sorts of cloth, and is now in extensive use through-
out the United States.
CLUTCH. See Courmnes AND CLurcnns.
COAL. See Bornnns, STEAM.
COAL-BREAKER. See BREAKER or Causnnn.
COAL-CUTTING MACHINES. Apparatus used for effecting mechanicallv the separation of the
coal from the enclosing rocks. The value of machinery for this purpose over manual labor consists
in the greater rapidity with which the work is executed, and the smaller waste that is made in the
operation, so that the production of a given quantity is obtained at a much less cost than by hand.
The coal itself is also brought down in much larger pieces, while the danger incident to “ holing ” by
hand is altogether removed. One of the principal drawbacks, however, appears to be the cost in the
first instance of conducting the motive-power, which is derived from compressed air, from the surface
to the workings below.
Gladhill’s machine (English) acts on the coal by means of an endless chain armed with teeth or
blades, revolving around a shive or solid plate secured over the coal. The apparatus is driven by
compressed air brought from the surface through pipes, under a pressure of from 35 to 40 lbs. per
sq. in. The chain consists of flat links, each link being enlarged at one end for the purpose
of holding the blades. The chain is made of cast-steel, and the width of each cutter is 2% in.
362 COAL—CUTTING MACHINES.

The machine advances automatically in proportion to the clearing of the coal by means of capstans,
placed at both the forward and after ends of the frame, so as to work both ways. The inventors
claim that it will advance 300 to 350 feet with a depth of 3 feet in 8 to 10 hours, producing ’75 to
90 tons of coal, assuming the vein to be 21‘; feet thick. The movements of this machine are not,
however, adapted to the undulations and irregularities found in most coal-mines.
Holmes 82 Payton’s machine (English) has for its cutting tool a strong steel blade, which is
attached to two eccentrics in order to give it rigidity; the teeth are inserted in the plate and oper-
ate like picks, each tooth advancing on the same plane and describing circles according to the im-
pulse of the eccentrics. The length of the plate is 3 feet. The teeth of the cutting blade act by
blows, as do the picks used in hand labor. About 300 blows per minute are struck, and the open-
ing of the cut is from three-fourths of an inch to one inch to a depth of 3 feet. The inventors
claim an advance of 8 to 12 inches per minute, according to the hardness of the rock or coal.
For complete descriptions of this and the foregoing machine, see “ Reports of Judges of Group 1,
Centennial Exposition, Coal-Mininrr Machinery,” by A. Jottrand.
Firth’s machine, used in the mines of the “fest Aidsley Coal and Iron Company, near Leeds,
England, consists of a pick worked by a bell-crank lever, the action being exactly the same as that
of a miner when engaged in undercutting.
There are also various forms of rotary machines. In I-Iurd’s machine a number of steel cutters
or teeth are placed on an endless chain or band, moving longitudinally around a long arm. These
cutters form a groove in the coal. This apparatus is reported to have worked in a 20-inch seam,
making a semicircular sweep of 6 feet 6 inches in 4 minutes, with only 25 lbs. pressure on a 6-inch
cylinder with 6 inches stroke, cutting a groove of 1% inch. The Monitor coal-cutter, Fig. 820, is one
820.


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of the latest forms of this type of machine. A shows the inner and supporting part of the cutter-
arm ; this is joined to the frame D by means of a pivot-hinge that holds the arm horizontally, but
allows it to be raised or depressed on either edge, by means of which the cutter can be made to lead
up or down in the coal, to follow the irregularities of the bottom, to avoid interlaminated strata of
rocks, etc. The arm can also be raised or lowered without otherwise changing its relative position
to the machine. B is the outer portion of the cutter-arm, and is geared to A in such a manner that
it can be thrown out or in to lengthen or shorten the arm as required. Attached to B is the wheel
that acts as a carrying wheel for the chain E at the outer extremity of the arm ; at the other end
of the arm, and attached to a shaft, is a similar wheel that acts as a driver for the cutter-chain.
Fis a double-cylinder verticaLtrunk engine, 8-inch bore and 7-inch stroke. The whole is attached
to the framework J. This, in turn, is supported by the wheels G, H, etc. The wheels are all plain
flanged wheels, as shown by G. While working, the machine requires but one rail of the common
T iron, 9 lbs. per yard. The forward wheel is kept on the rail by means of the second flange G,
which is slipped on and held by means of thumb-screws. The other two wheels are rimmed into the
broad flanges H, made in two more sections, which run directly on the bottom. When in shape for
moving, the wheels G H are drawn to the end of the frame J by the screw K, and the cutter-arm
swings under the frame J by means of the screw-shaft D, which engages the teeth of the segmental
COIN IN G—MACHIN ERY. 363

gear attached to the frame J. The machine is fed forward by means of a power windlass, operated
by air. The windlass consists of an upright drum, driven by a small rotary engine, so geared that
it will wind slowly enough for the lightest feed, or fast enough to pull the machine up the grade from
the gangway very rapidly. The feed can be varied instantly by the throttle-valve to suit the varying
strata that are being cut—a useful advantage, as in many places in the same breast one yard can be
cut in half the time with the same power that it would require to cut the next yard. The capacity of
the machine, of course, varies greatly with the nature of the material cut. The following will show
what the machine is stated to have accomplished in what is about the average hardness of splint
coal: Weight of machine, 8,800 lbs. ; depth of cut (extreme), 4 feet; depth of cut (average), 3 feet
6 inches ; thickness cut out, 2 feet 6 inches ; pressure used per square inch, 25 lbs. ; cut along face
(average) per hour, 20 yards; space between props and coal, 42 inches ; gauge of track, 29 inches.
Exceptional work, 15 yards in 20 minutes ; 30 yards in 55 minutes ; 5 yards in 4!; minutes.
The essential features of the Lechner coal-cutting machine, Fig. 821, are the cutter-bar and the
modes of driving it. The cutters in this case revolve in a vertical plane. The form of the axle is
square, and motion is communicated to it by a couple of pitch chains, which not only drive by con-
tact with the axle itself, but also by engaging a set of narrow cutters, which enter the open portions
of the chain. In this manner only thin films of coal are left uncut where the chains work, and get
broken off quite imperceptibly by coming into contact with the links of the chain. In addition to
the wrought-iron bars which form the framing to which the cutter-bar and the driving gear are
__ j'_'_‘_,_ __ “N.,-.2;


attached, another set of similar bars at the side of them form the stationary framing on which the
whole machine slides. The forward motion is given by means of a stationary screw, round which a
nut revolves, and this motion is arrested by moving a handle which separates the two halves of the
nut in a similar way as the screw and nut are disconnected in most screw-cutting lathes. To bring
the machine back again, a bolt attached to the stationary framing is, by means of a handle, thrown
into gear with one of the pitch chains, which are kept revolving to clear away the dust. Either
steam or compressed air can be used for driving, motion being communicated by suitable means
from the pair of cylinders to the pitch chains. The machine weighs 750 lbs., and can be handled
by two men. The cut which it makes is 6 feet deep, 3 feet wide, and 4 inches high.
COFFE R-DAM. See FOUNDATIONS.
COGGIN G. See CARPENTRY.
COG-WHEELS. See GEARING.
COINING MACHINERY. Gold and silver in their pure state, on account of their softness, are
unadaptcd for coin; consequently, each metal is alloyed with a certain quantity of some baser metal,
to give it greater hardness and durability. In this country, silver in the manufacture of silver coin
is alloyed with copper, the proportion in 1,000 being 900 parts silver and 100 parts copper ; and in
gold coin 1,000 parts, 900 being pure gold, 100 alloy of silver and copper, of which not more than
50 parts is allowed by law to be pure alloy. In United States mints the following is the process of
manufacture: By means of powerful but accurately constructed rollers driven by steam, the ingots
(which are bars sharpened at one end like the blade of a chisel, and about 1 foot long, three-quarters
of an inch to 24.} inches broad, and three-sixteenths of an inch thick) are rolled into thin strips for
the coin to be made. Fig. 822 shows the rollers in perspective, and a sectional view is given in
Fig. 823. The rollers a a, of chilled east-steel, are set in a strong cast-iron frame I) b, and are
capable of very minute adjustment by means of the wedges c d, actuated by the double screw 9
through a worm f and wheel p. They are driven in opposite directions by pulleys e c. As the
effect of rolling is to harden the strips, they are packed in bundles in copper boxes and placed in
an annealing furnace. \Vhen red-hot, the boxes are withdrawn and their contents emptied into
cold water. A pair of cast-steel finishing rollers next reduce the strips to their required thick-
ness, when the jagged ends are cut off by shears and returned to the melting-rooms. After a sec-
364 COINING MACHINERY.

ond annealing, the strips are pointed by slipping them between rollers a a, Figs. 824 and 825, while a
passage is formed by one of the depressions e e on the lower roller. The face f reduces the thick-
ness of the strip end about one-fifth. When a strip is too heavy after rolling, it is reduced to its
standard between the dies of the draw-bench, Fig. 826. The previously pointed end of the strip is





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slipped between the dies at a. The operator then places his hand upon the carriage 0', which is at
I), close to the die, and by stepping upon the treadle 0 causes the hook It to grasp the moving end~
less chain d, whereby the jaws e grasp the projecting end of the strip and draw it through the dies.
As soon as the strip has passed the die, the jaws open, the hook h releases the chain, and the car-
824. 825.
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riage is run back to b by a counterweight. The dies consist of two pieces of polished steel, adjust-
able in the head-block a. The lubricants used for the strips are wax for gold and tallow for silver.
Blanks or plant-hats are next cut from the strip by means of the cutting-presses shown in Figs. 827
and 828. A vertical steel punch, working accurately into a matrix or round hole in a steel plate of


—A_ _K'_

COINING MACHINERY. 365

the size of the planchet required, is operated rapidly by an eccentric, under which the strips are fed
by hand. In Fig. 828, a is the punch, b the bolster, c the detaching ring, and d the discharge tube.
The punch-frame g is raised and depressed by the crank-shaft, which makes from 140 to 220 revo-
lutions per minute. The first blank from every strip is weighed, and if found too light is condemned,
while the succeeding blanks from the same strip receive greater weight by being made slightly cup-
shaped by a peculiar adjustment of the punch. Blanks and strips are cleaned by dipping in an acid
bath, hot-water bath,‘and soap-water bath. Blanks receive a final cleansing by shaking with sawdust
in a hand-riddle. Blanks for silver dimes and half dimes are cleansed in a revolving steam-riddle.
The blanks are now placed in the milling machine, Figs. 829 and 830, by which, as rapidly as they





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can be fed by hand into a vertical tube, they are caught one by one'edgewise, and caused to rotate in
a horizontal plane in a channel formed on one side by a revolving wheel, and on the other by a fixed
segment of corresponding curve, but slightly nearer the wheel at one end than at the other. The
effect is that each piece in passing through this narrowing channel has its edge evenly crowded up






























J
into a border or rim. The details of this ingenious machine are shown in Fig. 830. a is the revolv-
ing plate, which reduces the blanks to uniform size by rolling them along one of the dies e e, at the
same time raising their edges. By this means much power is saved in the subsequent operation of
coining. c is the feed-tube, f the header. The blanks drop out at 9 into a box placed beneath.
After milling, the blanks are reduced to the exact standard weight by women, whose delicacy of
touch fits them admirably for this service. Seated at a long table, each one has a balance before
her and a flat file in her hand, and the gold planchets are successively tried against a counterweight.



5‘ if,” v1": J - _ H . ~ l e.
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366
COIN IN G MACHINERY.

Those that are too light are thrown aside to be re-
melted, and those that are too heavy are brought
to the proper weight by moving the file lightly
round the edge.
The coining press, Figs. 831 and 832, in use in
all the mints of the United States, is constructed
after the plan of the French lever press invent-
ed by Thonnelier. The pressure upon the die is
effected by a lever moved by a crank and oper-
ating a toggle-joint. The planehets being fed by
hand into a tube or hopper a in front of the ma-
chine, the lowcr piece in the tube is seized by
steel feeders and carried forward and lodged in
the collar between the upper and lower dies 9.
At the same moment the lever is descending, and
by the time the planehet is in position the toggle-
joint, brought into a vertical position, imparts to
the piece a pressure which, within the narrow lim-
its of its motion, is very great. The immediate
relaxation of the joint causes the upper die to be
lifted, when the feeders, coming up with a second
planehet, push away the one already coined. The
planehet before being struck is slightly less in
diameter than the steel ring into which it drops;
but the pressure upon the dies causes the piece to
expand into the collar and take from it the reed-
ing or fluting of its edge. The toggle-centres d d
are made of tempered steel. 0 is the main lever,
e the toggle-post, f the crank-shaft, and m the
connecting-rod. The coins, after being carefully
inspected to eliminate defective pieces, are put up
in bags and delivered to the mint superintendent.
In European mints the ingots are passed first
through roughing and afterward through finishing
rolls, which latter reduce the fillets to their exact
thickness. Generally the finishing rolls are of a
830.
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I uniform thickness.
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diameter smaller than the break-
ing-down rolls; in Brussels, how-
ever, the latter are only 6 inches
in diameter, and the former are 9
inches. At Stockholm, in' redu-
cing silver into fillets, the bars are
placed hot in the rolls, which are
made hollow, and kept cold by
streams of water passed through
them. The subsequent process of
fine rolling is performed when the
metal is cold. At all theEuropean
mints an accurate mechanical ar-
rangement for adjusting the space
between the rolls is employed, con-
sisting of screws with finely grad-
uated index-plates, and in some
cases of a combination of them
with a wedge adjustment. In most
cases the rolls are driven with
toothed gearing. At Vienna and
Brussels, however, they are actu-
ated by belting to avoid the irreg-
ular motion sometimes imparted -
by the toothed gearing, and which
affects the accuracy of the fillet.
Before being stamped into blanks,
the fillets undergo in most of the
mints a further process whereby
they are brought to a perfectly
The final ad-
justment is obtained by drawing
the fillets between smooth parallel
jaws, placed at an exact distance
apart by means of a gauge. Ex-
cept at Brussels, the fillets hard-
COIN IN G MACHINERY. _ 367
Q

ened by the rolling process are annealed more
or less frequently for the purpose of softening
them. In England they are placed in copper
tubes, covered and lated with clay, inserted in a
reverberatory furnace, and then rapidly cooled.
Fig. 833 represents the English annealing fur-
nace, with the copper cells resting on their car-
riage. In most mints a reverberatory furnace
is employed, the fillets being laid on the floor,
which may be slowly revolved so as to submit
the whole charge to equal heat, the flame pasc-
ing through an opening into the chamber where
the fillets are laid.
Except at the English and Danish mints, screw-
presses for stamping the fillets into planehets
are not employed. These are arranged in a cir-
cle around a large wheel, in the periphery of
which cams are placed to actuate the presses, in
connection with vacuum cylinders provided for
each press. The crank-presses in general use on
the Continent consist of a vertical frame, with a
crank-shaft overhead which drives a connecting-
rod that is attached to the punch-slide, and to
which it imparts a reciprocating motion. The
fillets are for the most part led forward into the
press by a self-acting feed. On the Continent
the blanks are all weighed. The weighing ma-
chines at St. Petersburg consist each of 10 bal-
ances with feeding tubes for supplying the blanks.
Through these the blanks are laid upon the scales,
which are depressed in proportion to the weight upon them; and from the scale they are ejected
by an automatic arrangement into one of three openings ranged one above the other, for the
reception of the too light, the too heavy, and the correct blanks. In Stockholm and Copenhagen an
882.





_‘__-








ingenious arrangement is in use. The counterpoise of the balance consists of a horizontal ring 4
inches in diameter, which rises and falls freely in a tube, and over which is stretched a diaphragm
of gauze; when the blanks are weighed and the counterpoise raised, the resistance oficred by the
368 COMPASSES.

air to the fabric-covered ring causes the beam to dip more or less, the angle being registered by an
index and graduated scale. .
Standard and Least Current Weighta—The standard weights and least current weights of gold
coin are as follows : . ~
20 dollar piece—standard, 516 grains ; least current weight, 513.42
6‘ u " H
10 “ 258 “ “ 256.71
5 “ “ 129 “ “ ‘.‘ 128.36
H (l H H (t
Any decrease in weight below the latter figures subjects the holder to a loss equivalent to the dif-
ference.
Counterfeit and Spurious Coins—The most extensive fraud perpetrated on gold coinage is “ split-
ting.” The operator uses a fine saw to split the coin neatly in two. Then he gouges the gold out
of the centre until only a thin outside shell is left, and substitutes a silver and platinum alloy for
the metal thus abstracted. The two parts are then joined
with gold solder, and the edge is remilled. In this way
gold to the value of $15.50 has been taken from a single
piece. The operation, however, generally destroys the ring
or tone of the coin, leaving it, besides, either too light or
too thick. Boring into the edge is another method. The
holes whence the gold is taken are refilled with silver, cov-
ered with gold solder, and the edges are neatly finished;
but the light weight reveals the theft. From 5 to 7% del-
lars’ worth of gold has thus been taken from one coin, and
the pieces have every appearance of being genuine. Real
counterfeits—that is, coins wholly spurious because made of
base metal—are almost invariably below weight. An excep-
tion to this, however, exists in a 35 piece which is of the ex-
act standard weight of 129 grains. It is composed of an al-
loy of gold and silver, and is worth from $2.70 to $3.40. Its
appearance and tone are excellent, but it is thicker than the
genuine coin, and hence may be detected by the gauge.
A silver piece passes current so long as the imprint is
not badly defaced or weight greatly reduced. A hole through
the coin, however, condemns it. The counterfeiter of sil-
ver coins either makes a mould in plaster from the real
coin and casts from it, or he stamps his imitation in dies.
As this last process is the same as that in use in the mints, the counterfeits thus produced are more
difficult to detect, because, besides being more accurately finished, the compression which the alloy
receives brings it nearer to the standard weight. A large number of counterfeit silver coins are made
chiefly of type metal. A very dangerous half dollar is composed of silver, copper, and zinc, and is
worth about 17 cents. It is from7 to 10 grains too light. Spurious half dollars have appeared
which constantly deceive bank tellers and other experts because they are of full weight. They are
made of a compound similar to German silver, and are so well plated with genuine silver that the
acid does not affect them. They are, however, too thick, and the gauge, as usual where the balance
fails, shows the fact. Counterfeits of the quarter dollar, though very plenty, are less dangerous
than those of larger pieces. They are composed of antimony, tin, and lead, and are both too light
and too thick, although they have a good ring. A peculiar composition has been employed, to
which powdered glass is added to give a clear sound; but this is but a clumsy expedient, as the
coin is far below proper weight, a fact easily appreciable by mere handling.
An ingenious mechanical device for detecting counterfeit coin has been invented by Mr. P. Doherty,
and has been adopted in various Government offices. It consists of a balance-lever working on a
knife-edged steel pivot similar to a scale-beam. The operating arm of the lever is provided with
gauges and adjusting stops, formed and placed in such a manner that by a single movement or appli-
cation of the coin the three essential tests of weight, diameter, and thickness are made instantly.
The gauge has the form of an open slot made just large enough to admit good coin. The size of
the coin is tested by the gauge as it enters, and when the coin touches the stop it is tested in weight
by the lever. A counterfeit of the proper weight will not enter the gauge. A counterfeit that
does enter will not move the lever. The form and position of the step are of such convenience that
it does double duty: holding the coin at a certain point on the lever while being weighed, and afford-
ing a remarkably quick and easy means of accurately adjusting the instrument. This adjustment is
so fine that the gold test is sensitive to the fifth part of a grain.
COMPASSES. An instrument consisting of a pair of arms jointed together, and therefore adjust-
able at any angle. It is used for, purposes of measurement, and for describing arcs, circles, or, with
the aid of an attachment, scrolls. Fig. 834 represents the ordinary form of compass, and Figs. 835
and 836 compass dividers. The distinction between the terms “compasses” and “ dividers,” which
are often indifferently applied to the same instrument, rests upon the fact that the true use of com-
passes is to describe arcs, etc., while that of dividers is to divide lines into equal parts. Whenever it
is nccdful to lay off numerous arcs or to measure without special accuracy being required, an ordi-
nary compass is the proper instrument for the work, because compass legs can be separated and
closed together in less time than is required for the shifting of divider legs; but to measure a
length easily and precisely, spring dividers, such as are shown in Fig. 836, having fine points, are
best adapted. The mode of adjusting a dividing compass to a length on a rule or other measure
838.















COMPOUND ENGINE. 369

consists in rotating the thumb-nut until the two dividing points are at nearly the required distance
from each other ; and this is effected by putting the points near the rule, but not touching it. After
this the final adjustment is performed by softly placing one point upon or into one of the marks on
the rule; and while this point is held in the mark with one hand, the other leg is screwed in or out
837.



by gently working the nut until both points are seen to be in the marks. To avoid wearing the
divider screw and nut to a needless extent, when the legs require shifting a great distance the two
legs should be squeezed toward each other in one hand, while the other hand is used to rotate the
thumb-nut during the time it is not in contact with the divider leg.
Compasses are sometimes provided with a detachable conical foot, which may be inserted in the
mouth of a hole or recess in order to enable the pointed leg to describe arcs or circles around the
same. An ingenious attachment by means of which compasses can be used to describe scrolls,
ogees, or other irregular curves with accuracy, is represented in Fig. 837. It consists simply of a
supporting holder, in one end of which is pivoted a cogged and in the other a thin-edged wheel.
This holder has a sleeve or clamp by which it is attached to one of the compass legs. In operation
the leg not carrying the device is held still, while the other leg is swept around, and at the same
time moved inward toward the fixed point, thus forming an irregular curve. The wheel leaves the
necessary mark on the metal or wood—a full line if the thin-edged roller is used, or a dotted one
if the corrugated wheel is employed. In laying off patterns by this device on paper or wood, black-
ened manifold paper may be used for transferring the design, in dark lines.
COMPOUND ENGINE. See ENGINES, STEAM, MARINE.
COMPRESSOR. See AIR-COMPRESSORS.
CON CENTRATING AND SEPARATING MACHINERY. Apparatus for the separation of com-
minuted ore according to the gravity of its particles. Concentrating machines are of two classes,
according as the separation is effected through the agency of water or the air-blast.
Concnsraarnve Macnmss usnve WATER.--Jigs.-—The idea of a jig was originally derived from the
treatment by hand of ore on a sieve under water. By plunging the sieve down suddenly in the
water, and allowing the particles to come again to rest upon it, a separation is effected; and if the
stuff has been sized, and the operation has been sufficiently often repeated, the denser particles are
“found in strata under the less dense. If the mass on the sieve is then divided into horizontal layers,
'ore and gangue may be separated. Much attention has been directed to the construction of auto-
matic or continuously working jigs, by which the stuff to be washed enters in a constant stream, and,
after being washed and concentrated, is delivered in two separate portions without stopping or requir-
ing manipulation. In such machines the sieves, instead of being alternately plunged into and raised
out of a vessel of water, are made stationary, and the water is made to rise and fall so as to pass in
a strong current through the meshes of the sieve and the layer of ore above it. This motion of the
water is produced by means of plungers or pistons acting below the sieve, either vertically or hori-
zontally, or by elastic diaphragms which are. alternately pushed out and in. One of the best jigs of
the continuously working class is the invention of Itittinger. It is represented in Fig. 838, and is
characterized by the inclination of the grates and the lowness of the front partition, over which the
poor and lighter stuff falls continuously and with very little water, while the heavier and richer
portions fall through the opening or slit 0 at the base of the partition. This partition is the seg-
'ment of a cylinder, and is supported upon the lever or arm d, so as to be movable back and forth in
such a manner that the opening or slit 0 may be increased or diminished at pleasure. The heavy
stuff, passing through the opening, falls into the box K, from which it is removed as required. The
inclination of the grate in this machine is from 5° to 8°. It is fed through the hopper B, which
plunges below the surface of the stuff accumulated on the grate. The loss of water which occurs
at each stroke of the piston is replaced from a reservoir, W, at the back of the apparatus. Accord-
ing to Rittinger, experience has shown that the duty of sell-acting machines of this kind is gener-
ally three times as great as that from the ordinary intermittent working apparatus.
Rittinger gives the following general dimensions, derived from practical experience, as the best
for the construction of jigs: 1. The opening of the feed-hopper should be of from 2% to 3 inches
area, and about 4 inches above the sieve. 2. The length of the sieve should be at least 24, and
better '30 inches, and its inclination about half an inch to the foot, in order to facilitate the dis-
charge. 3. The height of the material resting on the sieve should not be over 4 inches at the
lower end. 24:
370 CDNCENTRATING AND SEPARATING MACHINERY.

Hendy’s Concentrator, Fig. 839, consists of a shallow iron pan, 5 or 6 feet in diameter, supported
by a vertical shaft in the centre, and made to oscillate back and forth by means of cranks on a. shaft
at one side, and joined by connecting-rods to the periphery of the pan. The pan turns upon its
vertical axis back and forth, for a short distance, at every revolution of the crank-shaft. The figure
gives a sectional elevation of the machine. It is made wholly of iron ; therefore there is no framing
of timbers to be done when it is









set up, and no shrinking and leak- $88.
ing after the machine has been al- . \\
lowed to stand idle for a time. A <— frame gives support to the central , .....
pin and the crank-shaft, and also ,1" ‘i.
to arched arms H, which .rise over lfil l
the an and sustain theu er end / / \.
of the vertical shaft B. IThe bot- / ‘E if tom of the pan is raised in the I." ' /’ v ‘“
centre around the shaft nearly to - ,-" l/
the height of the rim, and from ' s .’
this it descends toward the periph- ,." , t
cry in a parabolic curve, by which ' I," ,9" \ I
the movement of the particles from 5





the centre toward the circumfer- ' ,
ence is facilitated, and their pas- .' _ I
sage in the other direction ob- I "
structed. The stuff to be concen~
trated is delivered, together with
the water, by the trough N to the
hopper 0, from which it is fed
through the pipe K and distribu-
tor D into the pan near its outer
edge. This feeding is not confined
to one point, but is made to ex-
tend around all parts of the cir-
cumference, by causing the dis-
tributor D to rotate around the
vertical shaft. This is accom- .
.plished by the movement of the pan. The upper edge of the pan is a continuous ratchet, into which
two pawls connected with D drop during the motion of the pan from the distributor, and in the
return motion give a velocity to the distributor equal to that of the pan. Continued impulses in this
way keep the distributor in regular rotation around the shaft. Rake-like arms are bolted to a flange
on the bottom of the hopper G, and are also carried around with the distributor, serving to separate
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the compact mass of sand and sulphurets as it settles, and also breaking the scum that gathers on
the surface. The accumulated sulphurets are discharged at the gate E. Each machine will receive
and concentrate 5 tons of stuff every 24 hours.
The Water-Column Separation—Various forms of apparatus have been devised to effect the sepa-
ration of the grains of either coarse or fine stamp-stuff, having nearly the same volume but differ-
ing in density, by allowing them to fall through a column of water either at rest or in motion. _ Such
machines may be regarded as modifications of the jig; a greater length of fall of the materials in
water being substituted for a succession of short falls, the result of the repeated shocks or jerks
CONCENTRATING AND SEPARATING MACHINERY. 371

given to the sieve. Apparatus of this kind forms a connecting link between jigs and the slime sepa-
rators. These machines depend for their operation upon the difference in the time required for par-
ticles to fall through a given height of column of water, which, for particles of equal size, is in the
order of their specific gravities. As the time required is modified by the bulk of the particles, a
careful sizing is an essential prerequisite to the success of this form of concentrating apparatus.
One of the simplest forms is a stationary cylinder, designed by Messrs. Huet & Geyler of Paris. It
consists of two stationary concentric cylinders, kept full of water by means of a supply-pipe,
while a portion of the water escapes through the opening in the conical bottom and the excess over-
flows around the top. Directly below the aperture in the bottom of this cylindrical vesse1 a receiv-
ing tub is placed, so as to receive the water and ore that fall through. This tub is divided into
compartments and rotates around a central vertical axis. The stuff to be concentrated is supplied
at intervals at the top of the cylinder. In falling through the three feet of water, the particles
separate according to their specific gravity, and the heaviest arrive first at the outlet and are caught
in one of the compartments of the tub. As the next grade of ore reaches the outlet, the tub has
turned so as to bring another compartment under the orifice, and the stuff is thus classified.
Hundt’s settling-tub operates similarly, but differs in this, that the receiving tub is fixed and the
water column is made to rotate.
Conical separators consist of a series of five or six cones arranged in succession one below the
other. Each part consists of two cones, one inserted in the other, so as to leave an annular space in
which water flows upward from a reservoir or chamber at the lower or pointed end. The stuff to
be concentrated is conveyed by a launder into the upper cone, and, passing through holes, encoun-
ters the upward current. The lighter portions are at once carried upward and over the upper edge of
the inner cone, and fall with the escape-water into an annular trough, by which they are conducted
away to the next lower cone, while the particles of sufficient weight to resist the current fall through
it, and accumulate in a small inverted cone in the chamber below, from which they are allowed to
drop through a small aperture at the apex.
Sizing and Concentration in Slate-es and Rockne—All concentrating machines work to better
advantage when the sands are of uniform size. For sizing, pointed boxes, such as that represented
in Fig. 840, are simpleand efficient eontrivances. The box is of wood and wedge-shaped. Its length
840. 841.







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depends on the size of the grain desired for the concentrating machine. The shorter the box, the
larger the size of the grain (breadth and grade of the sluices or the velocity of the sluice current
being the same). The sands settling in the box are discharged by a 2-inch iron pipe communicating
with the interior of the box at the bottom, reaching to the top of the water-level in the sluice, and
provided on the side with l-ij-inch plug-holes from 4 to 6 inches apart from centre to centre. The
proportion of water to sands is regulated by opening the plug-holes at different depths below the
water-level, the lowest hole naturally discharging the greater quantity of water with the sands de~
posited in the box. The sands afterward flow through wooden sluice-boxes of a rectangular section,
provided at the lower end with a self~raising gate acting as a riffle, in which the heavier portions of
the sands, consisting of sulphurets, etc., form a deposit near the head, while the lighter particles
escape over the gate. For every two boxes or two sets of boxes there is one riflic-gate. When the
sluice-sands are subjected to a further concentration, they are discharged into a tank by lowering the
rillle-gate.
The rocker represented isometrically in S41 consists of a wooden table of 2-ineh pine plank,
20 inches wide and 10 feet long, supported at both ends by wooden rockers, representing a section
of a width of 20 inches and depth of about 3 inches. The table has a grade of about 1 inch to the
feet, which can be increased when coarser sands are worked. The concentrated sluice-sands are
introduced at the head of the rocker, and a stream of water is turned on them. The rocker is set
‘ in motion by the left hand of the workman, giving it about 60 strokes of 8 inches :1 minute. For
coarser sands a greater number of strokes is required. The lighter sands gradually work down,
while the sulphurets remain nearer the head.
Buddies are oblong inclined vats in which stamped ore is exposed to the action of running water,
in order that the lighter portions may be washed away while the heavier are retained. The concave
huddle of Paine 82 Stevens is shown in Fig. 842. There are generally two buddles, one for the coarser
sluice-concentrates, and the other for the finer. They are of an exterior diameter of 18 to 20 feet,
and interior of 21} feet. The vertical shaft is supported by the wooden block m, carrying the jour-
nal-box. Attached to the shafts are: 1, the self-raising riffie-pulley g, which is raised by means of a
372 CON GEN TRATIN G AND SEPARATING MACHINERY.

rod 1), receiving its upward or downward motion from the endless screw b and pinion-wheel; 2, the
arms ff, carrying the brusher; and 3, the sand-distributing troughs e e. The clear-water box 2'. is
suspended by the wheels '0 v on an annular fiat ring. It is supplied by the stationary wooden box 1',
and discharges the water by means of the iron pipe k into the sieve-boxes y and z. The box s s is
















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fed by the trough h from the mixing-trough y and sieve-box z. The vertical shaft receives its motion
by the pulley a and bevel-gearing d d.
The tossing or final cleaning of sulphurets from auriferous sands is usually performed on the bud-
dle-headings if they are intended to be treated by the chlorination process. This is done in a tossing
tub of the following construction, Fig. 843. Through the axis of the tub, which is conical in form,
passes the hollow cast-iron cone 0. A shaft passing through this cone and resting on a journal
underneath carries a yoke to which the horizontal stirrers of flat iron are riveted. Revolution is
communicated to the shaft by bevel-gearing. The hammers are set in motion by the pins attached
to the vertical bevel-gear. When ready for tossing, the tub is filled to nearly half its height with
water, the stirrers are set in motion, making 48 revolutions a minute, and the ore is shoveled in near
the periphery of the tub
When nearly full, the 843' 844-
yoke is lifted out by 8561'“
means of a rope and pul-
ley overhead, and the
sands are allowed to set-
tle while the hammers are
set in motion, making 96
strokes each a minute to
facilitate the rapid tset-
tling of the sulphurets
and sands. When the
sands have settled, the
water is drawn off by an
iron siphon, and the skim-
mings are removed to a
depth of 2 inches and
thrown out as waste. The
upper half of the sands
remaining are retossed, and the resulting sands
above the sulphurets washed again in the buddle
during doubling. The lower half, of about 5 to
6 inches, consisting of sulphurets sufficiently con-
centrated, is delivered at the chlorination works
to be further treated for gold. (See CHLORINA- I,
TING MACHINERY.)
CONGENTRATING ,Mnenmss Usme AIR-BLAST.—
Krom’s Dry Ore Concentrator—A sectional view
of Krom’s dry concentrator is given in Fig. 844.
The machine is composed essentially of the following parts : a receiver H, to hold the crushed ore ;
an ore-bed 0, on which the ore is submitted to the action of the air; the two gates G, one to regu-
late the flow of ore from the receiver H, the other to determine the depth of ore on the ore-bed;
a passage 0, in which the concentrated ore descends, and roller F, to effect and regulate the dis-



















\ll
SECTION OF ORE BED
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EW OF ORE BED

CONCRETES AND CEMEN TS. 373

charge of the same; a fan B, to give the puffs of air; a trip-wheel lever and spring, to operate the
fan ; and a ratchet-wheel and pawl, to impart revolution to the roller E
The mode of operating the machine is as follows: Ore is placed in the receiver H, and the driving-
pullcy set in motion. The trip-wheel, fixed on the opposite end of the pulley-shaft, works by its
cam-shaped teeth against the lever; and by the alternate action of this wheel, forcing the lever in
one direction, and of the spring, which at once and suddenly carries it back again, the fan B is made
to swing on the shaft 1, sending at each upward movement a quick and sharp puff of air through
the ore-bed, and lifting slightly the ore lying on it. As there are six projections upon the trip-wheel,
it follows that the moderate speed of 70 to 80 revolutions of this per minute will give 420 to 480
upward movements of the fan in the same time, and consequently a corresponding number of puffs
of air to agitate the ore; this rate is sufficient to secure steady motion of the heavy balance-pulley,
and yet not so fast as to produce any unpleasant jar or noise. The ore-bed is composed of wire-
gauze tubes, placed at distances from'each other of 136, , g, and J; of an inch, according to the grade
of ore to be concentrated—the finer requiring that the tubes be set nearer together, while the coarser
allow of their being farther apart. The ore-bed, situated in front of the fan, as plainly shown in
the sectional view, is formed by these tubes, their ends next to the fan being open; and the air from
the bellows, entering these, escapes through the top and sides of the tubes, agitating the ore that
lies on them, and also that between them near the surface. The ore between the tubes rests on that
immediately underneath, in the passage 0, and sinks as fast as the roller F, at the bottom, effects
its discharge. The tubes being open on the lower side, any fine ore passing through the meshes of
wire gauze simply descends with the main body 0, thus preventing any liability of the tubes to filling
up. In discharging the concentrated ore C, the roller R is operated (as mentioned above) by means
of the ratchet-wheel and pawl, and, the latter being carried by a crank on the trip-wheel, it follows
that its speed is governed by the speed of this wheel, which also gives motion to the fan B; by this
connection the fan, which effects the concentration, and the roller, which discharges the concentrated
ore, are made to act in concert with each other. .
CONCRETES AND CEMENTS. The term concrete is applied to a mortar of finely-pulverized
quicklime, sand, and gravel, which materials are first mixed dry, made to the consistence of mortar
with water, and thoroughly worked. The most approved proportions are those in which the lime
and sand are in the proper proportions to form a good mortar, and the gravel is twice the bulk of
the sand. The bulk of a mass of concrete when first made is found to be about one-fifth less than
the total bulk of the dry materials; but as the lime slakes, the mass expands about three-eighths of
an inch in height for every foot of the mass in depth. The use of concrete is now mostly restricted
to the forming of solid beds in bad. soils for foundations, for blocks of artificial stone, and for walls
of edifices. ‘
“ Béton ” is the term applied by French engineers to any mixture of hydraulic mortar with frag-
ments of brick, stone, or gravel. It is generally used in the same sense. The smallest amount of mor-
tar that can be used will be that which will be just equal in volume to the void spaces in any given
bulk of the broken stone or gravel. The best and most economical béton is made of a mixture of
broken stone or brick in fragments not larger than a hen’s egg, and of coarse and fine gravel mixed
in suitable proportions. The mortar is first prepared and then incorporated with the finer gravel;
the resulting mixture is spread out into a cake about 6 inches thick, over which the coarse gravel
and broken stones are uniformly strewed and pressed down, the whole mass being finally brought to
a homogeneous state with the hoe and shovel.
The terms “ béton ” and “concrete,” while not originally synonymous, have become almost strictly
so by usage. The matrix of béton possesses hydraulic energy, while that of concrete does not; and
herein is the accurate distinction.
For mixing concrete, a boiler-iron box, placed diagonally on a shaft and rotated, is commonly em-
ployed, as shown in Fig. 845. The ingredients are thrown into the hopper above, and thence pass




845.
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through the open door into the box. The latter is then revolved, and when the materials are then
oughly compounded it is emptied into a suitable receptacle placed beneath. Wheelbarrows are gen_
erally used for conveying the concrete from where it is mixed to wherever it is needed; but when
large quantities are prepared by machinery which is not portable, a sling-cart maybe advantageously
used. The box should be of stout planks, and about 51} feet long, 31.} feet wide, and 9 to 10 inches
deep, and so arranged that it can be readily slung up underneath the cart by means of a windlass.
3'74 CONGRETES AND CEMENTS.

For erecting concrete walls, the apparatus devised by Mr. E. E. Clarke, Fig. 846, is often employed.
It consists of a wooden clamp, the vertical parallel arms of which can be readily adjusted by means
of traverse screws to any thickness of wall. These arms support the planking which determines the
thickness of the structure, and are attached—one fixed and the other movable—to a horizontal brace.
\Vhen in use the entire apparatus is kept in position by securing this brace to some fixed point of
support. The illustration represents the apparatus in position for laying a hollow concrete wall, not
intended to be furred inside. The hollow is secured by means of a
movable plank, called a core, a trifle thinner on the lower than on 846-
the upper edge, so that it can be moved after the concrete is rammed
around it. The ties between the inner and outer walls may be com-
mon bricks, and these are placed under the core, in each of its posi-
tions, as the building progresses. The core is notched on the lower
edge, so as to fit down upon the ties flush with their lower beds.
A more simple apparatus for making concrete walls consists merely
of a boxing of planks kept in place by upright posts on the exterior
at suitable distances apart, say 4 or 5 feet. The lower ends of the
posts are mortised and keyed into horizontal cross-pieces called fut-
tocks, which reach entirely through the wall, and are withdrawn and
the holes filled up after the box is filled with concrete and a new
course is to be commenced. The upper ends of the posts may be
kept in position by similar cross-pieces, but the more common prac-
tice is to confine them by lashings of rope or cord, tightened or 100s-
ened at pleasure by a stick used as a lever.
Fence or railing posts, of the minimum size consistent with the
requisite degree of strength, may be firmly set and retained perma-
nently in their upright position by inserting them in concrete foun-
dations. The mortar for this purpose need not be very rich in cement,
and in quantity might barely exceed the volume of voids in the coarse
material.
Concrete floors are frequently used in fire-proof buildings. The
concrete is in some cases packed in between the iron beams, and in
others is used in the form of slabs or plates.
The quick-setting varieties of hydraulic cement are quite exten-
sively used for the manufacture of drain and sewer pipes. The mortar, composed of 2 to 21} meas-
ures of clean coarse sand to 1 measure of the cement powder, mixed with a small quantity of water,
is moulded by special machinery into pipe in sections of suitable length. These sections, when joined
together with cement-mortar, form a continuous water-tight tube.
Bébn, blocks for building purposes are of great value in regions where stone of large size or skilled
labor to cut the same is scarce. Such blocks have been employed in the construction of the new
piers and decks of New York. The materials employed were: 1. Portland cement of two brands,
tested to withstand a tensile strain per square inch of not less than 200 lbs. in the first and 250 lbs.
in the second case. 2. Seashore sand, sharp, clean, and rather coarse than fine, used without any
preparation. 3. Broken stone (trap rock), not too large to pass through a ring 2 inches in diameter,
and not less than a quarter of an inch in smallest dimensions. The formulas were: 1 volume of
cement, 2 of sand, and 5 of, stone; and 1 of cement, 23, of sand, and 51} of stone; the unit of measure
being a cement barrel. In mixing, 2%; barrels of sand were spread on the mortar-bed to the depth of
3 inches. Cement was then evenly distributed over the sand, and both materials were mixed with
hoes; 18 gallons of water was then added, which produced a stiff but plastic mortar. In the mean
time 5 or 5.} barrels of stone were spread to a depth of 6 inches on a turning platform, and on this
the mortar was evenly shoveled. Thorough mixing with shovels followed, and finally the béton was
carried to the moulds. The mass was then evenly and partially rammed, a 36-lb. rammer, falling 6
or 8 inches by its own weight, giving good results. The moulds, ranging in capacity from 1 to about
2 34; cubic yards, were made of 2-ineh spruce plank, tongued, grooved, and dressed to 1% inch thickness
by 4!; inches in width, .nailed with 30-penny nails to pine pieces 5 x 6 inches, placed 28 inches apart,
and capped by a pine plate 5 x 8 inches, into which the uprights were mortised. When the uprights
were arranged to enter into mortises in the platform, allowance was made for a tenon of the‘ width
of the upright, 1%} inch thick and 2} inches long. Tenons, however, were successfully dispensed
with, by screwing strips to the platform with £=inch lag-screws. The ends of the moulds were dadoed
into the side-pieces and secured firmly with a fi-ineh ircn rod, ending with a crank-handle nut to
draw the sides closely to the end pieces.
The béton made as above, when a year old, weighed per average of 10 blocks 156 lbs. per cubic
foot; or the weight of a cubic yard might safely be taken as 4,200 lbs. When immersed in water as
soon as it could be handled sa'felv, at 45 days old it yielded to a crushing force of 420 lbs. to the
square inch, or say 30 tons to the square foot; and under the same conditions, at a year old, it
yielded to a crushing force of 1,520 lbs. to the square inch, or say 110 tons to the square feet. When
dried in air it yielded to a crushing force of 1,620 lbs. per square inch, or say 116 tons to the square
foot. Béton made by the same formula, wherein “lime of Teil ” was substituted for Portland cement,
after 45 days’ immersion yielded to a pressure of 256 lbs. per square inch, or say 181} tons per
square feet; after a year’s immersion it yielded to a pressure of 1,079 lbs. per square inch, say 79
tons per square foct ; and at a year old in air it yielded to a pressure of 1,087 lbs. per square inch,
or say about 78 tons per square foot. These blocks could not be safely handled unless at least a
month old, and then the corners were very liable to injur ; while blocks made with Portland cement,
weighing nearly 53% tens, when only 8 days old, were easily lifted by the derrick. The cost of


CON CRETES AND CEMEN TS.
37 5
wv

materials ranged from about $7.88 to $8.88 per cubic yard; and of manual labor, including carpen-
ters repairing moulds, etc., about $5 per cubic yard.
Béton‘Ooz'gnat, so called from its inventor, is composed of clean river-sand 4 or 5 parts by vol-
ume, hydraulic or common lime 1 part, hydraulic or artificial Portland cement one-quarter to three-
quarters part, and water enough to moisten the materials. The compound is put into the moulds
in successive layers from 1 to 3 inches in thickness, and is packed by hand. One of the most impor-
tant structures of this material is the monolithic arch of St. Denis, France, represented in Fig. 847.
This was erected for the purpose of testing the béton. The span is 196 feet 10 inches ; elevation of
847.
(3 w,"-
u'll, B a
“j .‘64 '-‘
it ;
Q . ‘ ‘L-(z
; \J x '
“9+ .. . __
mu """mnmmnlmn . '.
lmumnmnuummut""""""""""" wills, ;, a
...... ._ llllllll mu mm -
arch, 19 feet 8 inches; cross-section at X, 3 feet 11 inches by 3 feet 3 inches; at C, 6 feet 6 inches
by 6 feet 6 inches. The composition of the concrete in the arch consists of river-sand 4 parts,
hydraulic lime 1 part, and Portland cement one-half part. The French aqueduct of La Vanne is
built from blocks of béton Coignet. '
Ransome’s artificial stone consists of clean river-sand, the grains of which are cemented by sili-
cate of lime. This stone is extremely hard, and some specimens have offered as great a resistance
to rupture by compression as the best sandstone and marbles.
For concrete foundations, see FOUNDATIONS and BREAKWA'I'ERS.
Roman Cement—The materials employed in the manufacture of this cement are the nodules, of
an ovoidal or globular form, which are found in the London clay, and known by the name of
Septam'a. They are calcined in perpetual lime-kilns with coal, in which a very moderate and well-
regulated heat is carefully preserved. After calcination the stones are ground under heavy edge-
stones to a very fine powder, which is sifted, and then packed in easks for sale. These nodules are
found in many localities in this country.
Roman cement is one of the most powerful hydraulic mortars, and is exceedingly valuable, not
only on account of the rapidity with which it hardens (and this is effected in a very few minutes),
but because when hardened in considerable masses it is not liable to crack.
All artificial or natural hydraulic limestones are soluble (before as well as after calcination) in
muriatic acid, with the separation of silica, except when sand or some similar substance has been
added to them.
The hydraulic limestones, when they do not contain a sufficient quantity of lime to be capable
of slaking with water, must be very finely pulverized; it is only by this high state of division that
a proper action can ensue. A thorough penetration of the silicious portion by the lime is never en-
tirely effected, but a certain proportion remains inclosed and removed from the sphere of action.
LTORTARr—A mixture of slaked lime in the state of paste with sand. possesses the property, when
spread in thin layers between bricks, of gradually hardeningr to the consistence of limestone, and thus
cementing the bricks together. In order to understand the principles upon which mortar is mixed,
it is necessary to become acquainted with certain facts which here exert the greatest influence.
Conditions of Hart."lening.—-Qi1nple lime, in the state of paste, likewise hardens, but only to form
a loose mass, of too slight consistence to bind the parts of a wall or building firmly together. It is
only when the layer of lime forms a very thin stratum, as between two polished stones, that a firm
and solid cement is produced. The lime must be prevented from forming masses of any consider-
able thickness, as these always possess a'very slight degree of cohesion. The lime attaches itself
firmly only to the surface of the building-stones, which differ from it in character, and this surface
should be extended, as it were, by mixing a granular powder with the lime. This leads directly to
the object and use of sand in the mortar, which is only intended to bring about more intimate con-
tact between the surfaces of the stones and the lime. The shape of the bricks and hewn stones is
so irregular that crevices of a line at least, and in hewn stones often of an inch in width, are left
between them when laid one upon another. Lime alone placed between the stones would, conse-
quently, be in layers of a line to an inch in thickness, and in such masses would never bind. If,
however, a sandy powder of any kind of stone is mixed with it, the mass of lime is thus divided
into a great‘number of thin layers, or, as it were, fills up the interstices between the sand, and, find-
ing everywhere points of attachment, binds the grains of sand together, and extends this binding
action to the stones themselves.
It is further known that even the best mortar, when quickly dried, as for instance on the stove,
does not harden, but remains friable and porous. Although, therefore, mortar placed under water
remains porous and will not bind, yet the action of moisture is essential to make it harden in the
air. LaStly, the free access of air is also absolutely necessary to the setting of mortar.
Pr'oporzfz'om of Jlfz'atura—When these facts are borne in mind, the rules to be observed in mixing
mortar will be olwious._ Although many kinds of stone in the form of coarse sand are applicable
for making mortar, as limestone, for instance, yet quartz-sand is always most easily obtained. The
grain of the sand, however, is a matter of some importance. Very fine sand renders the mortar too
dense, and impedes the free access of air; sand in grains of the size of hayseed, particularly if it
is angular or sharp, is very good ; the interstices become too large to be entirely filled with lime if
very coarse sand is employed. It is then advantageous, particularly when irregularly shaped build-

876 eouennrns AND CEMENTS.
l

ing-stones are used, to mix two kinds of sand together, coarse and fine. Fine sand can only be
mixed with the lime when the mortar is intended for a thin coating upon the surface of walls, etc.
The more irregular the sand is, the better. The proper proportion of sand and lime is a most impor-
tant point in preparing mortar; and the good quality and solidity of the mortar are more influenced
by it than by anything else. Errors committed in the mixing can never be subsequently corrected.
As a general rule, the lime should be sufliciently fine to cement all the grains of sand together,
but should form at the same time the thinnest possible stratum between them. The surfaces of the
grains of sand, or the interstices between them, should therefore be only just covered with the lime
in a half-liquid state, and no more. The rule might be laid down in the following terms: Let as
much lime be mixed with the sand as it will take up without having its volume increased. Practi-
cally, about 3 to 4 cubic feet of sand (or six times the weight) are added to 1 cubic foot of half-
liquid lime, provided the lime be fat, or very fat; poor lime, which may be viewed as already con~
taining a certain portion of sand, will not bear the addition of more than 21} cubic feet of sand to
1 cubic foot of lime. The sand should be pure; i. e., it should not contain too much iron or clay,
and, least of all, bog-earth or vegetable matter. ‘
Hardening or Setting— Time required—Although mortar sets sufficiently in a few days, or weeks,
to enable a wall to withstand pressure and the like, yet the hardening proceeds so slowly and grad-
ually that it only attains its maximum (in which case a wall appears as if constructed of one piece
of stone) after years, or even centuries. The apparent superiority of mortar in olden times over
that in the present is solely attributable to the longer time which has been allowed it to harden and
set, as no essential difference can be traced in the mixture of the ingredients. Although we see, on
the one hand, that old buildings can only be destroyed with the aid of powder, yet it must not be
forgotten, on the other, that in som buildings the direct converse is observed, and that the durable
portions only have been enabled to withstand the ravages of time, while the weaker and less dura-
ble parts have long since disappeared. In the same manner, it is probable that some buildings
erected in our own age will stand forward to posterity as patterns of solid architecture, just as those
of the middle ages and of the ages of Greece and Rome appear to us at present.
STRENGTH or Omens—Table 15* shows the tractile strength per square inch of cement mortar
42 days old, kept in open air: '










TABLE I.
I PROPORTION OF SAND FOR 1 OF CEMENT.
I CEMENT. I .
0 l 1 2 a I 4 l 5 s I 7 s I 9 I 10
: I . I |
I RESISTANCE PER SQUARE INCH, IN POUNDS.
lPortland cement.... as“ I 2841} 199;;f I 16611- 142} ‘ 12s l 116a 106g 99} I 92.} 95,1,
Inomtm eement....—~.. 142;; I 1423, 1135 I 9:} 19a 67 | 57 42; an I 25,“, o






The following conclusions were drawn from an extended series of experiments, undertaken to
ascertain the adhesion of mortar to the solid materials used in constructions :
1. That particles of unground cement exceeding one-eightieth of an inch in diameter may be
allowed in cement paste without sand to the extent of 50 per cent. of the whole, without detriment
to its adhesive or cohesive properties, while a corresponding proportion of sand injures the strength
of the mortars in these respects about 40 per cent. 2. That when these unground particles exist in
the cement paste to the extent of 66 per cent. of the whole, the adhesive strength is diminished
about 28 per cent. For a corresponding proportion of sand the diminution is 68 per cent. 3. The
addition of these siftings exercises a less injurious efiect upon the cohesive than upon the adhesive
property of cement. The converse is true when sand, instead of siftings, is used. 4. In all the
mixtures with siftings, even when the latter amounted to 66 per cent. of the whole, the cohesive
strength of the mortars exceeded its adhesion to the bricks. The same results appear to exist when
the siftings are replaced by sand, until the volume of the latter exceeds 20 per cent. of the whole,
after which the adhesion exceeds the cohesion. 5. At the age of 320 days (and perhaps considerably
within that period), the cohesive strength of pure cement mortar exceeds that of Groton front bricks.
The converse is true when the mortar contains 50 per cent. or more of sand. 6. When cement is to
be used without sand, as may be the case when grouting is resorted to, or when old walls are to be
repaired by injections of thin paste, there is no advantage in having it ground to an impalpable
powder. It has been determined that most American cements will sustain without any great loss of
strength a proportion of lime paste equal to that of the cement paste, while a quantity equal to one-
half to three-fourths the volume of cement paste may be safely added to any Rosendale cement with-
out producing any essential deterioration of the quality of the mortar. By the use of lime is secured
the double advantage of slow setting and economy.
Table II. shows the adhesion to Croton front bricks and fine-cut granite of mortars containing
different proportions of sand. The mortar was of the consistence ordinarily used fer brick-masonry,
and the bricks were used wet, and were pressed well together by hand. They were wetted with fresh
water every alternate day for 29 days, the age of the mortar when tested. Each result is the aver-
age of five trials. The right-hand column shows the ratio of the adhesive strength of the several
mortars, assuming that of pure cement to be 1.

* Tables I.. II., III.. IV., and V.. with accompanying notes. are taken by permissron from “Limes, Hydraulic Ce-
ments, and Mortars,” by General Q. A. Gillmore, U. S. A. D. Van N est-rand, publisher, New York. _
CONCRETES AND CEMENTS. an




TABLE II.
E 25; weight in Adhesion per
Pounds required» _ Ratio of
6,2 comrosrrrozv or THE 1101mm. Materials Cemented. w w m Squage 11,1121], in Adhaklm
z 2 Bricks apart. om; '
1 Pure cement paste . . . . . . . . . . . . . . . . . . . . . . . .. Croton bricks . . . . . . . . 421 30.8 1.00
2 1 volume cement powder, 1 volume sand . . . . " “ . . . . . . . . 215 15 .7 0.51
s 1 “ “ “ 2 “ . " “ ...... .. 169 12 .3 0 .40
4 1 “ "' “ 3 “ “ “ 14 6.8 0.22
5 1 “ “ “ 4 “ “ " . . . . .. 71 5.2 0.17
6 1 “ “ “ 5 “ “ “ . . . . . . . . 59 4 .3 0.14
7 1 “ “ “ 6 “ “ “ 45 0.11
8 Pure cement paste . . . . . . . . . . . . . . . . . . . . . . . . . Fine-cut granite .. . . . 444% 27 .5 1.00
9 1 volume cement powder, 1 volume sand . . . “ " ... .{ 332% 20.8 0.76
10 1 “ '“ “ 2 .. “ “ 201 12.0 0.46
11 1 “ “ “ 3 “ “ ‘ .'; LC; 9.2 0.33
12 1 “ “ “ 4 “ “ “ . .. . .i 127 7.9 0.29







Table III. shows the ultimate strength of rectangular parallelopipeds (2” x 2” x 8") of cement
paste and mixtures of cement and lime paste without sand, formed in vertical moulds under a pres-
sure of 32 lbs. per superficial inch, and broken when 95 days old, on supports 4 inches apart, by a
force applied at the middle. The'mortars were kept in sea-water from the time they were one day old.





TABLE IH.
g i P eneu‘ai‘lfinzi :18 PM“ W'eight in g Average Break-
. 5" - ‘ Pounds snp- ing “'eight of
0 no; conrosrrron on THE CEMENT. Ported before each kind 0,
z 2 1 Impact. 2 Impacts. Breaking. ‘ Mortar.
I .
1 Pure cement paste (average of two trials) . . . . . . . .i .114 .195 994 t I
2 “ " " “ . . . . . .. .112 .163 957 i p
s “ “ _“ “ ...... . . .117 .192 1,025 I 11004 lbs-
4 “ “ “ “ . . . . . . . . .107 .187 1.034
5 Cement paste, 1 volume; lime paste, i~ volume... . .155 .250 1,000
6 “ " " "' . . . . .160 .250 996 1 9.1} I,
7 “ “ “ “ .... .147 .245 992 . “
s “ “ r ._ “ 931 J
9 “ “ “ 1 volume. . . . .155 .250 863 l
10 “ “ “ r . . . . 155 .265 847 816 u
11 “ “ “ “ . . . . .150 .200 785
12 “ “ “ “ . . . . .150 .195 7 69
13 “ “ “ {L volume. . .. .120 .200 597 l
14 “ - “ “ “ . . . . .200 .300 70 ' 56:, ,,
15 “ “ *- “ ... . .180 .220 51s I t
16 $6 ‘6 65 H _._. ..-_ ..-. 17 “ “ “ 1 volume. . .. .187 .395 597
18 “ “ “ “ . . . 180 .295 574 56c, “
19 “ “ h “ 207 .325 553 4
20 “ “ “ . .. .2 0 550 J
21 “ i volume “ 1 volume. . .. .180 .300 865
22 “ “ “ “ . .. .100 .320 303 36, ,I
29 2 “ 2 “ . . _ . .1s0 .293 955 , “i
24 “ “ “ “ . . . . .1E0 .290 3'75 J
25 “ 1} volume “ “ . . .200 .300 339 I
26 “ “ “ “ . . . . .2-0 .340 316 005% a
27 “ -* 2 2 . . .. .290 .260 286 °
28 2 . “ “ “ . . .. .270 .350 250







Other mortars of light-colored Rosendale cements and lime, mixed, formed into blocks of the
same size, preserved and broken in precisely the same manner as the foregoing, gave the following
results when 95 days old. The average of four trials is given in each case.





TABLE IV.
NO. OF Breaking Weight,
MORTAR. COMPOSITION OF THE MORTAR. in Pounds.
1 Cement paste, 1 volume; lime paste, 5 volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7?
2 “ 1 “ “ l “ . . . . . . . . . . . . . . . . . . . . . . . . .. 723i-
3 “ 1 “ “ i “ If: ' ' . ' ' . . . . . . . .. 132
4 it 1 it t 1‘ “ 60s

‘1
Water-glass, while it renders common mortar hydraulic, injures its strength and its adhesive prop-
erties, and is greatly inferior to cement as a hydraulic agent in both efficiency and economy, irrespec-
tive of the degree of energy required.
Table V. shows the strength of mortars of various cements made into prisms 2" x 2" x 8” in
vertical moulds, under a pressure of 32 lbs. per square inch. and broken on supports four inches
apart, by a pressure midway between the supports. The prisms were kept in sea-water after the
first 24 hours, and were 320 days old when broken. The breaking weights given are averaged from
many trials. The cement was measured in powder.
378 ~ CONCRETES AND CEMENTS.









, TABLE V.
g BREAKING wmen'rs or MOB-TABS
‘5 4, COMPOSED or
o- 5; man or CEMENT usnn.
z 0 Cement, vol. 1, Cement, vol. 1,
2 PM“ cement" Sand, vol. 1. Sand, vol. 2.
Pounds. Pounds. Pounds.
1 English Portland (artificial) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,536 1,260 950
2 Cumberland, Maryland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954 920 558
8 Newark and Rosendale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 841 560 500
4 Delafield and Baxter (Rosendale) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 886 692 582
5 “ Hoffman ” Rosendale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849 607 . . ..
6 “ Lawrence “ Rosendale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 777 . . . .
7 Round Top, Maryland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 . . ..
8 Utica. Illinois . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 732 756 562
9 Shepherdstown, Virginia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747 618 450
10 Akron, New York . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._ 764 651 608
11 Kingston and Rosendale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720 556 500
12 Sandusky, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 554 464 . . . .
18 James River, Virginia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 628 688
14 * Roman cement, ccotland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558 . . . . 880
The following were broken when one year old :
15 Lawreneeville Manufacturing Company (Rosendalc) . . . . . . . . . . . . .. . . . . 910
16 Sandusky, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 802 . . .. . . ..
17 Kensington, Connecticut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954 709 506
18 Lawrence Cement Company (Rosendale), “ Hofi‘mau “ Brand. . . . . '75 911 . . . .
19 Round Top, Maryland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840



Crushing and Tensile Strength of the Hydraulic and other Cements at the Philadelphia Exhibition.











Crushing "Tensile
Strength. Strength.
9.5 “its
NAME or Exmm'ror. AND PLACE or MANUFACTURE. It}: ,9; 5,5 .5
a; a 8 .7, s E
o ‘3 5* 5 3 H
I 5’3 ‘5 as “a
3: 8 2 5. 8 2°
PORTLAND CEMENT. Poundm Pounds
1 Toepfi’er, Grawitz 85 00., Steftin, Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1,439 12 216 3
2 Hollick & 00., London, England . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1,330 10 216 8
3 Wouldham Cement 00., London, England . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,140 12 199 3
4 Saylor’s Portland Cement, by Coplay Cement 00., Copley, near Allentown, Pa, U. S... 1,078 8 154 2
5 Wampum Cement and Lime 00., Newcastle, Lawrence 00., Pa, United States . . . . . . . . 968 12 163 8
6 Pavin de Lafarge, Teil, canton of Viviers, department of Ardeche, France . . . . . . . . . . . . . 931 12 158 8
7 A. H. Lavers, London, England . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 926 6 192 2
8 Francis 82; 00., London, England . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 907 14 163 3
9 William McKay, Ottawa, Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 882 10 141 3
10 Borst 85 Roggencamp. Deli‘zyl, Netherlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 826 12 132 8
11 Longuety St 00., Boulogne-sur-Mer, France . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 64 12 108 8
12 Riga Cement (10., by C. X. Schmidt, Riga, Russia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 693 5 184 2
13 Scanian Cement 00., Lemma, near Malmo. Sweden . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 606 14 112 3
14 Bruno Hofi‘mark, Port Kund, Esthland, Russia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580 6 154 2
ROMAN AND OTHER CEMENTS.
15 Coplay Hydraulic Cement, b Coplay Cement 00., Coplay, near Allentown, Pa, U. S... 292 8 88 2
16 Charles Tremain, Manlius, . Y., United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 12 47 3
17 Allen Cement 00., Siegfried’s Bridge, Pa., United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 12 48 8
18 P. Gauvreau, Quebec, Canada; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 284 8 47 2
19 Riga Cement 00., by 0. X. Schmidt, Riga, Russia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 6 44 2
20 Anchor Cement, by Coplay Cement 00., Coplay, near Allentown. Pa, United States. . . . 208 12 41 8
21 Cumberland Hydraulic Cement 00.. Cumberland, Md., United States . . . . . . . . . . . . . . . . .. 196 12 41 3
22 Société Anonyme des chaux éminemment hydrauliques de l’llomme d‘Armes. pres 184 7 29 2
Montélimar, France . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. l
23 Howe‘s Cave Association, Howe‘s Cave, N. Y., United States, No. 1 . . . . . . . . . . . . . . . . . . 183 6 28 2
24 “ “ “ "‘ “ No. 2 . . . . . . . . . . . . . . . . . . . 170 10 48 2
25 “ “ “ “ “ No. 3. . . . . . . . . . . . . . . .. 170 S 81 2
26 Societa Anonima per la fabbricazione del cemente, provincia di Reggio, Emilia, Italy, L 181 12 27 3
1st quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
27 Socicta Anonima per la fabbricazione del cements, provincia di Reggio, Emilia, Italy, ) ,-
2d quality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5' 104 12 22 8
28 Thomas Gowd , of I imehouse. Ontario, Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 126 8 28 2
29 A. H. Lavers, ondon, England . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 6 24 2
scoTT’s BELENITIC CEMENT.
30 Patent Selenitic Cement 00., London, Eng. (made with Howe‘s Cave lime and plaster). 298 20 52 5
PARIAN CEMENTS.
81 Francis & 00., London, England, 1st quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,175 8 181 3,
32 “ “ “ 2d quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 696 12 169 8
83 A. H. Lavers, London, England . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 205 6 51 2


*This cement appeared to be inferior in hydraulic energy to Roman cement generally, and had probably been
injured by age and exposure.
CON CRETES AND CEMENTS. 379

All the cements exhibited at the Centennial Exposition were carefully tested before awards were
recommended, by mixing them dry in each case with an equal measure of clean sand, tempering the
mixture with water to the consistency of stiff mason’s mortar, and then moulding it into briquettes
of suitable form for obtaining the tensile strength on a sectional 'area 1% inch square, equal to 21}
square inches. The briquettes were left in the air one day to set, then immersed in water for six
days, and tested when seven days old. After thus obtaining the tensile strength in each case, the
ends of the broken specimens were ground down to lg-inch cubes, which were used the same day
for obtaining the compressive strength by crushing. The results, averaged from a number of trials
with each sample of cement, and divided by 2} in order to get the strength per square inch, are
recorded in the preceding table.
Teil Hydraulic Concrete. Stone.—The Teil stone manufactured by the Fire-proof Building Com-
pany of New York consists of artificial blocks of Teil hydraulic concrete.
_ The hydraulic lime of Teil is preéminently a hydraulic cement, containing 66 per cent. of silicate
of lime. It is mixed with sand, pebbles, broken stone, etc., and the concrete thus formed hardens
equally well under water as in the air. Its strength increases with age. The crushing strength of
Teil hydraulic mortars, according to well-authenticated experiments, is 220 lbs. per square inch at the
end of 45 days, and 614 lbs. when 2 years old. Their tensile strength is 41 lbs. per square inch at
the end of 45 days, and 164 lbs. after 2 years. In artificial blocks of stone of various compositions,
in which Teil hydraulic lime is largely used, the crushing strength varies from 2,600 to 7,500 lbs. per
square inch, and the tensile strength from 288 to 426 lbs.
Blocks of Teil hydraulic concrete 10 feet long, 6 feet wide, and 6 feet high, weighing 25 tons
each, are used in the construction of sea-walls, piers, etc. They are placed in regular courses like
masonry, and form a wall of great strength. (See BREAKWATER.)
' This material is also suitable for the construction of lighthouses, for which it can be made in sep-
arate blocks for masonry, or the building of whatever size can be built of a single mass without any
joints. The lighthouse of Port Said, Fig. 848, is built in this way of one mass of Teil concrete; it
849
r A ‘-—


_ __"'__' ' _ ____ _ ______. »- " "“ ‘ | ‘
' H“ l.___’ ..-




is 180 feet high, and rests on a Teil concrete base of 400 cubic yards. Fig. 849 represents the can
riage used for transporting the heavy concrete blocks from place to place.
CEMENTS FOR VARIOUS PURPosss.——Air and water-tight, for casks and cisterns: Melted glue
8 parts, linseed-oil 4; boil into a varnish with litharge. This hardens in 48 hours. Plumbers’:
Black resin 1 part, brick-dust 2. Melt together. For leaky boilers : Powdered litharge 2 parts, fine
sand 2, slaked lime 1. Mix with boiled linseed-oil. Apply quickly. Acid-proof : A paste of pow-
dered glass and concentrated solution of water-glass. Cutler’s: 1. Pitch 4 parts, resin 4, tallow 2,
and brick-dust 2. 2. Resin 4, beeswax 1, brick-dust 1. 3. Resin 16, hot whiting 1, wax 1. This is
used for fastening blades in handles. For ivory or mother-of-pearl: Isinglass 1 part, white glue 2,
dissolved in 30 parts hot water and evaporated to 6 parts. Add gum-mastic 5,11,- part, dissolved in
one-half part alcohol, and add 1 part zinc-white. Shake up and use warm. J eweler’s, for uniting
all substances: Gum-mastic 5 or 6 hits as large as a pea, dissolved in spirits of wine sufficient to
render all liquid. In another vessel dissolve the same amount of isinglass in rum enough to make
2 ounces of strong glue, adding 2 small pieces of gum ammoniaeum, which must be moved until dis-
solved. Heat r-and mix the whole. Keep in a closely-corked phial, and put the latter in boiling
380 CONCRETES AND CEMENTS.

water before using. Black, for bottle-corks: Pitch hardened by the addition of brick-dust and
resin. For jet: Use shellac, warming the edges before applying, and smoke the joint to make it
black. For meerschaum or china: 1. Make a dough of garlic, rub on the edges, and bind tightly
together. Boil the object for half an hour in milk. 2. Use quicklime mixed to a thick cream with
white of egg. Soft, for steam-boilers: Red or white lead in oil 4 pants, iron borings 3 parts. Gas-
fitters’: Resin parts, wax 1, Venetian red 3. Coppersmiths’: Boiled linseed-oil and red lead
made into a putty. This is used to secure joints and on washers. For emery on to wood: Equal
parts of shellac, white resin, and carbolic acid in crystals. Add the acid after the others are melted.
Iron and emery: Coat the metal with oil and white lead, and when hard apply the emery mixed with
glue. French ' putty, hard and permanent: Linseed-oil 7 parts, brown umber 4, boiled for 2
hours, one-eighth part white wax stirred in. Remove from fire and thoroughly mix in white lead 11,
and fine chalk 5% parts. India-rubber: Fill a bottle one-tenth full of native India-rubber cut into
fine shreds. Pour in benzole from coal~tar till the bottle is three-fourths full. The rubber will
swell ; and if the whole be shaken every few days, the mixture will become as thick as honey. If
too thick, add benzole; if thin, add rubber. This dries in a few minutes, and will unite backs of
books, straps, etc., very firmly. Chinese, for fancy articles, wood, glass, etc.: Finest pale-orange
shellac, broken small, 4 parts, rectified spirit 3 parts. Keep in a. corked bottle in a warm place
until dissolved. It should be as thick as molasses. Rust-joints: 1. Clean iron borings 2 parts,
flowers of sulphur 1%,, sal-ammoniac 115. 2. Finely-powdered iron borings 1 part, sal-ammoniac %,
flowers of sulphur T16. Pound together and keep dry. For use, mix 1 part with 20 of pounded iron
borings, and mix to a mortar consistence with water. For making metallic joints sound: 1. Use a.
putty of boiled linseed-oil and red lead. 2. Use a putty of equal parts of white and red lead. For
electrical and chemical apparatus: Resin 5 parts, wax 1, red ochre 1, plaster-of-Paris {a Melt at
moderate heat. For mending stone, or as mastic for brick walls: Make a paste of linseed-oil with
clean river-sand 20 parts, litharge 2, quicklime 1. For chucking work in the lathe: 1. Black
resin 8 parts, yellow wax 1; melt together. For use, cover the chuck to one-sixteenth of an inch
thick, spreading over the surface in small pieces, mixing it with one-eighth of its bulk of gutta-per-
cha in thin slices. Heat an iron to dull red, and hold it over the chuck till the mixture and gutta~
percha are melted and liquid. Stir the cement with the iron until it is smoothly mixed. Chuck the
work, lay on a weight to enforce contact, and let it rest for half an hour before using. 2. Burgundy
pitch 2 parts, resin 2, yellow wax is, dried wax 2. Melt and mix. 3. Resin 4 parts, melted with
pitch 1. While boiling add brick-dust until dropping a little on stone shows the mixture to be suf-
ficiently hard. Elastic, for leather or India-rubber: Bisulphidc of carbon 4 ounces, shredded India-
rubber 1 ounce, isinglass 2 drachms, gutta-percha 1} ounce. Dissolve, coat the parts, dry, then heat
the layer to melting, place and press the parts together. Water-tight, for wooden vessels: Lime,
clay, and oxide of iron, mixed, kept in a close vessel and compounded with water for use. For
leather, straps, etc.: Gutta-pcrcha dissolved in bisulphide of carbon. Keep tightly corked and
cool. It should be of the consistence of molasses. For marble, or for attaching glass to metal:
Plaster-of-Paris soaked in a saturated solution of alum and baked hard. Grind to powder and mix
with water for use. Can be colored to imitate any marble, and takes a fine polish. Impervious, for
corks, etc.: Zinc-white rubbed up with copal varnish. Give two coats so as to fill all the pores, and
finish with varnish alone. For cracks in wood : 1. Slaked lime 1 part, rye meal 2, and linseed-oil 2.
2. Use a. paste of sawdust and prepared chalk with glue 1 part, dissolved in water 16. 3. Oil-var-
nish thickened with equal parts of litharge, chalk, and white and red lead. For wood and glass or
metals: 1. Resin and calcined plaster, the former melted, made into a paste. Add boiled oil to con-
sistence of honey. 2. Dissolved glue and wood-ashes to consistence of varnish. Fire-proof and
water-proof : Pulvcrized zinc-white, sifted peroxide of manganese, equal parts. Make into a paste
with soluble glass. To mend iron pots and pans: Partially melt 2 parts sulphur, and add 1 part fine
black lead. Mix well, pour on stone, cool, and break in pieces. Use like solder with an iron. Lon-
don cement, for glass, wood, china, etc: Boil a piece of cheese three times in water, each time allow-
ing the water to evaporate. Mix the paste left with quicklime. For aquaria: 1. For fresh-water
aquaria: Take 4 gill gold~sizc, 2 gills red lead, 11} gill litharge, and sufficient silver sand for a thick
paste. This sets in about 2 days. 2. For fresh or salt water: Take 4 gill powdered resin, 1 gill
dry white sand, 1 gill litharge, 1 gill plaster-ofParis. Sift; and for use mix with boiled linseed-oil,
to which a little dryer has been added. Mix 15 hours before using, and allow 2 or 3 hours to dry.
For petroleum lamps, impervious to the oil : Resin 3 parts, boiled with water 5 and caustic soda 1.
Then mix with half its weight of plaster-of-Paris. This sets in three-quarters of an hour. Roman:
Green copperas 3!; lbs., slaked lime 1 bushel, fine gravel-sand 1 bushel. Dissolve the copperas in
hot water, and mix all to proper consistence. Keep stirred. Glass to glass, for sign-letters, etc.:
Melt in a water-bath liquefied glue 5 parts, copal varnish 15, drying-oil 5, oil of turpentine 2, tur-
pentine 3. Add slaked lime 10. Hydraulic: Oxide of iron 1 part, powdered clay 3, and boiled oil
to a stiff paste. Stone: Sand 20 parts, litharge 2, quicklime 1, mixed with linseed—oil. Leather
and cloth, for uniting parts of boots and shoes, seams, etc.: Gutta-percha 16 parts, India-rubber 4,
pitch 2, shellac 1, oil 2. Mix and use hot. Mahogany: Shellac melted and colored. Colorless, for
paper: Add cold water to rice-flour, mix, bring to proper consistence with boiling water, and boil one
minute. Water-proof, for cistern stones : 1. Whiting 100 parts, resin 68, sulphur 181}, tar 9. Melt
together. 2. Sand 100 parts, quicklime 8, bone ashes 14, mixed with water. Transparent: India-
rubber 75 parts, chloroform 60. Mix, and add mastic 15. Cloth to iron: Soak the cloth in a dilute
solution of galls, squeezing out the superfluous moisture, and applying the cloth, still damp, to the
surface of the iron, which has been previously heated and coated with strong glue. The cloth should
be kept firmly pressed upon the iron until the glue has dried. For cracks in stoves : Finely-pulver-
ized iron (procured at a druggist’s) made into a thick paste with water-glass. The hotter the fire,
the more the cement melts and combines, and the more completely does the crack become closed.
CON DEN SERS. 381

For china, glass, etc. : 1. Diamond cement, for glass or china, is nothing more than isinglass boiled
in water to the consistence of cream, with a small portion of rectified spirit added. It must be
warmed when used. 2. White lead rubbed up with oil. Articles mended with this must stand for a
month. For corks of benzine~bottlesz A paste of concentrated glycerine (commonest kind) and lith-
arge. This soon hardens, and is insoluble in benzine or any of the light hydrocarbon oils. For caus-
tic lye tanks: The tanks may be formed of plates of heavy spar, the joints being cemented together
by a mixture of 1 part finely-divided India-rubber dissolved in 2 parts turpentine oil, with 4 parts
powdered heavy-spar added. Colored: Soluble glass of 33° B. is to be thoroughly stirred and mixed
with fine chalk and the coloring matter well incorporated. In the course of 6 or 8 hours a hard
cement will set. The following are the coloring materials: 1. Black: well-sifted sulphide of anti-
mony. This can be polished with agate to a metallic lustre. 2. Gray-black: fine iron-dust. 3.
Gray: zinc-dust. This has a brilliant lustre, and may be used for mending zinc castings. 4. Bright
green: carbonate of copper. 5. Dark green: sesquioxide of chromium. 6. Blue: Thénard’s blue.
7. Yellow: cadmium. '8. Bright red: cinnabar. 9. Violet red: earmine. 10. Pure white: fine
chalk as above.
Works for Reference.—“ On Calcareous Cements and Quicklime,” Higgins, London, 1780; “ Mé-
moire sur les Mortiers Hydrauliques,” Treussart, Paris, 1829; “On Calcareous Mortars and Cem-
ents,” Vicat, 1837 ; “ On Limes, Calcareous Cements, Mortars,” etc., Pasley, London, 1847 ; “ Prak-
tische Anleitung zur Anwendung der Cemente,” Becker, Berlin, ISM—’68; “Practical Treatise on
Limes, Hydraulic Cements, and Mortars,” Gillmore, New York, 1863; “On Limes, Cements, and
Mortars,” Burnell, 1868; “ Die Hydraulisehen Miirtel,” Michaelis, Leipsie, 1869; “Traité sur l’Art
de faire de bons Morticrs,” Charleville, Paris ; “ On Calcareous and Hydraulic Limes and Cements,”
Austin, New York, 1871 ; “Experiments on the Strength of Cements,” Grant, London, 1875; “Port-
land Cement, its Manufacture and Uses,” Reid, London, 1877. See also “Reports of Commissioners
to Paris Exposition,” 1867.
CON DEN SERS. When the exhaust steam from an engine is to be condensed, it can be brought
into direct contact with the condensing water, or passed over surfaces which are cooled by water or
air. In the first form, or jet condenser, the exhaust steam mingles with the condensing water;
while in the surface condenser the fresh water resulting from the condensation can be used to feed
the boilers. At the present time, when steam of considerable pressure is used at sea, it is of great
importance to use fresh water in the boilers, since water deposits solid impurities much more rapidly
as its temperature is increased; and nearly all modern ocean steamers are provided with surface
condensers. With either form of condenser, as ordinarily constructed, an air-pump is required, to
remove the air and vapor; and the surface condenser is provided in addition with a circulating-
pump, to force water rapidly around the condensing surfaces. The general arrangement of a sur-
face condenser, such as is used in connection with marine engines, is shown in Figs. 850, 851, and
850. 851. S52.








852. It consists of a number of tubes within a box or case. The exhaust steam passes around the
tubes, and the water of condensation is removed by the air-pump shown in Fig. 850. Cold water is
pumped through the tubes to condense the steam by a circulating pump, Fig. 852. In practice there
,are, of course, many modifications of this general principle. Sometimes the exhaust steam passes
through the tubes and the condensing water circulates around them ; and independent air and circu-
lating pumps driven by small engines are often employed. (See ENGINES, STEAM, MARINE.)
Some interesting notes on surface condensers, descriptions of early forms, and general discus-
sions, may be found in the “Transactions of the Society of Engineers,” 1862, and “ Transactions of
the Institution of Engineers in Scotland,” vols. iv., v., and xi.
There are a number of condensers, designed principally for use in connection with land engines,
that require no air-pumps. Prominent among these are Morton’s ejector condenser and those of
the same class, which are described in the “Transactions of the Institution of Civil Engineers,”
1872, and the “Transactions of the Institution of Engineers in Scotland,” 1868, 1869. The papers
referred to contain much interesting and useful information. The minimum amount of condensing
water required in any particular case can be calculated by table I. under EXPANSION or STEAM AND
GASES. Suppose the pressure of steam when discharged into the condenser is 10 lbs. above zero, that
the initial temperature of the injection water is 70° F., and the final temperature 115°. By column 7
see CORK-CUTTING MACHINERY.

in the table referred to, each pound of steam on being condensed must be deprived of 1141 —- 83
z: 1058 units of heat, and each pound of water takes up 115 - 70 = 45 units; so that the least
05
quantity of water necessary to condense a pound of steam is = 23.5 lbs. In order to render
all the condensing water available, it should be brought into as intimate connection with the steam
as possible. To this end, in jet condensers, the condensing water is frequently introduced as spray
and falls on a scattering plate, while in surface condensers the passages are small, so that the water
shall move rapidly and be divided up into small portions, each one of which will receive heat
quickly; and if it were not for the increased resistance to the passage of the water that follows
from decreasing the area, it might be advantageously subdivided to a much greater extent than ob-
tains in practice.
The size of a jet condenser, according to ordinary practice, is about one-third of the volume of
the cylinder. In proportioning surface condensers, a very ordinary rule is to make the condensing
surface three-fourths of the boiler-heating surface ; but there are condensers in use having a much
less proportion of surface. There are examples of surface condensers condensing 10 lbs. of steam
per hour per square foot of surface ; but the more usual practice is probably between 4 and 6 lbs.
The efficiency of a condenser depends of course on the manner and velocity with which the con-
densing water passes through it, as well as upon the thickness of the condensing surfaces. In
some experiments by Mr. Joule, where each condensing tube was surrounded by another tube and
water was driven in one direction through the annular space, while steam passed through the tube,
as much as 100 lbs. of steam were condensed per hour per square foot of tube surface (Rankine’s
“ Treatise on the Steam Engine,” p. 266); and in Engineering for Dec. 10, 1875, is an account of
some experiments in which this rate of condensation was exceeded. ~
It has been proposed to use air for condensing steam, instead of water, and condensers have been
constructed on this principle. The efficiency of such a condenser obviously depends on the velocity
with which the air is brought into contact with the condensing surface; and in one form of air
condenser the condensing surface was made to revolve, after the manner of a fan. For notes on
the theory of air condensation, account of an experimental condenser, and experiments on the heat
received by air at different velocities, see Van Nostrand’s Eclectic Engineering lllagazinc, i., 527;
the Scientific American, x., 265 ; and the Engineering and illim'ng Journal, xxiv., 259. R. H. B.
CONE—PLATE. See LATHE-GHUCKS.
CON E—PULLEY. See BELTS.
CONFORMATOR. An apparatus used by hatters to obtain the shape of the head. It has the
form of a hat brim and crown, and is composed of 60 small branches of ebony held close to the
frame in which they slide by a brass spring wire. When not in use, the inner arms of these branches
together form an elliptical cavity; but when the conformator is placed on the head, every projection
thereon pushes the branches more or less outward, the wire spring yielding and the cavity assuming
an irregular shape. Upper inner arms of the branches form an elliptical-shaped aperture in the
crown of the apparatus, which assumes the same shape as that impressed upon the branches them-
selves. On these arms are steel points, upon which a piece of paper is pressed, and which thus
mark on the paper the exact conformation of the wearer’s head reduced in scale. The piece bounded
by the indented line is then cut out, and placed in a device consisting of numerous branches, which
are slid inward until they touch the edge of the paper on all sides. They are then secured in place,
and their outer surfaces form a block exactly corresponding in shape to the head measured. Over
the block the hat after being warmed is pressed, and thus caused to fit. This device was invented
by M. Allié of Paris in 1843. See Scientific American, xxxviii., 148.
CONVERTER. See STEEL.
COPE. See MOULDING.
CORK-CUTTING MACHINERY. Cork is the soft cellular interior bark of the Qucrcus subM', a
species of oak indigenous to Spain and Portugal. It is removed from the tree by making several
longitudinal clefts up and down the trunk, and then girdling the latter with horizontal incisions. The
first crop is not gathered until the tree has attained the age of 15 years, and is employed only for infe-
rior purposes. Seven years afterward the tree will have another coating of bark, which is stripped,
and a new supply is thereafter gathered about every 6 years. After the stripping the cork is in-
snected and assorted according to size and quality, that of the finest texture being most valuable.
The inferior portions are generally sorted out, their crust burned off, and sold mostly for floats, hence
receiving the name of fishing-cork. The better qualities are first boiled and scraped, and then
blackened over a coal-fire, the object being to make the surface smooth and at the same time to con-
ceal flaws. After being forwarded to the warehouse, the largest slabs are cut into pieces of about
31} feet in length, 18 inches in width, and ranging from half an inch to 3 inches in thickness. Dry-
ing and packing in bales weighing 150 lbs. each follows, and the cork is ready for exportation. ‘
In this country, after the cork is received at the factory, it undergoes another asserting, and a
thorough steaming in a chest designed for the purpose, the latter process softening the cork and
rendering it easy to cut. Various machines have been devised for cork-cutting. In one, rapidly-rem
volving circular knives are used, which cut by a drawing motion, as crushing strokes simply break
the cork or cause it to crumble. The workman, sitting in front of the machine, places a piece of
cork of suitable size in a revolving spindle, by which it is firmly held. The spindle is raised a meas-
ured distance, and the edges of the cork come in contact with the rotating knife, which smooths
them off, leaving the material in perfectly cylindrical form. Another method is to place the rough
bits of cork in grooves on the circumference of a wheel, which, working automatically, carries each
piece to a point where its ends are received by a small lathe. The cork is then revolved slowly,
while a large circular knife removes a thin shaving, thus giving it the necessary taper and a smooth
COTTER. 383

and true surface. As soon as a cork is finished by the automatic lathe, it is released and another
substituted.
Figs. 853 and 854 represent one of the latest improved machines for cork-cutting. The cork from
the bale is first passed to the machine, in which A is an iron table bolted to a wooden one by means
of the brackets D and E; B is a guide-piece, and C is a revolving disk of steel, similar to a circular
saw, but having the edge sharp, the bevel of the blade being all on the outside, so that the cork shall
not jam. The pieces of cork from the bale are laid upon the table A, and kept against the guide
or gauge B, whose distance from the knife regulates the width of the strips the cork is cut into.
The cork strips next pass to the machine shown in Fig. 854, in which A A A A represent a revolv-
ing spindle, driven by the pulley B and fitting easily, and capable of being slid or moved horizon-
tally back and forth through the bearings provided in the standards 0 6'. Upon one end of A is
the flange D, which passes down into a recess provided in the lever E, so that if the latter is
operated laterally the spindle A A A A will also be operated laterally. 1 is the cutter, which is
formed of a hollow piece of cast~steel tube, parallel in its bore, and wlth a sharp edge produced by
beveling off the outside. F represents a round spindle, which passes through the revolving spindle
A A A A, the latter being made hollow to receive the former. The spindle F protrudes into and
nearly through the cutter I. It is supported and regulated in its distance up the spindle A A A A
by the hand-screw H, which screws
it to the face of the bracket G, that
end of the spindle F being flat and
provided with a long slot. J is a
tail-stock or back-head, adjustable
by the screw-handle 17!, the upper
part of J being a block of hard
wood denoted in the drawing by K.
The gauge I. is adjustable by a nut,
as shown. The operator places a
strip of cork on the gauge L, and,
while the machine is running at a
high speed, he pulls toward him
the handle E, thus forcing the cut-
ter through the cork and up against
the wood block K. He then moves
the handle E back again, which
withdraws the cutter, carrying the
cut cork in the bore of the cutter until the cork meets the end of the stationary spindle F, which
retains it, and the cutter, passing back, leaves the cork, which falls down. After the machine is
once set, therefore, the operator has nothing to do but to feed the cork strips with one hand, and
operate back and forth the handle E with the other hand.
To taper the corks, they are fed by hand in a horizontal position down an inclined trough to a
vertically-operated plunger, having its upper end hollowed to receive a cork, which drops into this
hollow when the plunger is at the bottom of its stroke. It is then carried up by the plunger and
held for an instant horizontally level with a rapidly revolving spindle, similar to a lathe-spindle, but
having a flat and solid end; then a stationary spindle, answering to the dead centre of a lathe, ap-
proaches and forces the end of the cork against the revolving spindle, which by friction revolves the
cork. At the back of the position now held by the revolving cork, and lying in a plane inclined to
.the plane of the length of the cork, is a. large revolving steel disk, similar in form to that shown at
O. This steel blade, while revolving at a high speed, is traversed over the top of the revolving cork,
cutting it taper and of the necessary diameter from end to end at one out. As soon as the cork is
thus turned, which takes but a second, the driving mandrel recedes and releases it, the plunger falls,
carrying the cork with it, and while the cork falls below the machine the cork-cuttings are carried by
the revolving cutter to the back of the machine, as follows: from where the cutting operation is
performed for about one-third of the circumference of the disk-knife it is provided with a guard,v
which retains the cuttings upon the knife, but on leaving the guard the centrifugal force throws the
cuttings off and into a box provided to receive them. The capacity of each of these machines is
about 250 gross per day. .
An ingenious cork-cutting machine, the invention of M. A. Robert, was exhibited in the Paris Ex-
position of 187 8. The sheet of cork is first cut into square blanl's approximating the finished cork
in size. These are fed down, one at a time, between vertical guides, and descend upon a table,
where they are met by a clamp, which grasps them and pushes them forward between spindles, the
under one of which is spiked and the upper one toothed. While held in these the cork is rotated on
its vertical axis against a swiftly-moving band-saw blade about 2 inches in width. This blade is
constantly in motion, and in order to keep it sharp a horizontal grindstone is provided. The stone
is actuated at intervals by a cam-wheel driven by a worm and pinion from the main shaft, so that
at every revolution of the latter the grindstone is brought into contact with the blade and rotated
for a few seconds.
The same inventor also exhibited a small machine in which a knife was moved to and fro by
hand. Strings attached to the knife-handle, which ran on guides, rotated the spindles between which
the cork was secured.
COTTER. See GIB AND Corrsn.
COTTON-GIN. A machine for cleansing cotton and preparing it for the market or for carding.
The most simple as well as the most ancient cotton-gin is the roller-gin, which consists of fluted
rollers about five-eighths of an inch in diameter, and from 9 to 16 inches long, placed parallel in a










384 COTTON—GIN.
1
frame, which keeps them almost in contact. The rollers revolve in opposite directions; the cotton
is drawn through between the rollers, while the seeds are prevented from passing by the narrowncss
of the space. This machine is still used for the finer and longer-stapled cottons, but the operation
is tedious and expensive; and the saw-gin, invented by Eli Whitney in 1793, from its general use,
its wondrous effects on the extension of cotton cultivation, and its influence on manufactures and
commerce, may new claim distinction and consideration almost exclusively as the cotton-gin. In, its
main features this machine still continues as first invented by Whitney; but in various details and
workmanship it has been the subject of many improvements. Fig. 855 presents a perspective view
of an improved cotton-gin, and Fig. 856 is a section of the same. In the latter, a is the grate-fall
head, or end of breast; b, seed-board; c, saw-cylinder; d, saw; e, “patent detached grate;” f,

H ‘5 >_~._
W
“~-
“ We ..






“











//
/
r—x
screw or bolt on which the grate-fall rests; 9, back board, to which are attached the back grates
and “patent moter;” k, grate-fall hollow, which is hung upon hinges, and may be raised or low-
ered at pleasure; i, sliding-butt, by means of which the saw-tooth may be made to assume any de-
sired angle with the curved surface or front of the grate; j, “patent brush;” it, sliding mote-
board; Z, bottom board.
The grate-fall, or breast, into which the seed-cotton is thrown, is formed with ends or heads of
east-iron, and pear-shaped, the lower and back side being composed of cast-iron grates, screwed
firmly to the wood-work of the breast;
the saws project through the interstices
between the grates from 1 to 2 inches;
the upper and back part of the grate-
fall, called the “hollow,” is hung upon
hinges, and may be raised or lowered at
pleasure, and fastened in any desired
position by joint-bolts through the grate~
fall heads.
The seed-board makes the front part
of the breast, and stands nearly perpen~
dicular, leaving a space between it and
the grates for the discharge of the seed;
it is hung upon pivots at the top at each
end, so that the bottom may be swung
outward and the hopper emptied at any
time. When in place the bottom is fast-
ened by small slide-bolts. The position
and angle of the seed-board may be read-
ily varied and adjusted, by altering the
position of the slides upon which the
pivots rest. These slides are fixed to
' the grate-fall heads by small bolts pass-
ing through slots, having a nut outside.
The grate-fall, or breast, is hung to the
front top timber of the frame by stout
hinges above the saw-cylinder, and the
lower part rests upon two short screws in the front piece. That part of the hinge or butt which is
attached to the top timber is so fixed as to slide up or down by means of slots and an adjusting
screw, and is fastened in the desired position by bolt-nuts.
The saw-cylinder is made of wooden staves, about 2 inches thick, upon an iron shaft, and turned
in a lathe of a uniform diameter; and by the application of a small saw, when in the lathe, grooves
are formed to receive the saw-segments, which are made of the best cast-steel, and inserted and
fastened into these grooves.


/
' Y/
7
% V 1
1/ 377 h
// a?“ ”
/
////.

COTTON—GIN. 385

There is a set of wooden grates behind the saw-cylinder. and a row of hair or bristles, called the
“ meter,” to separate the false seeds, motes, and dirt from the ginned cotton.
The brush is made of about 20 inches diameter, cylindrical, having slits lengthwise between the
rows of bristles and a hole around the shaft to receive the air as the brush revolves ; and a rapid
centrifugal motion is given to the air, which is forced out with great power between the rows of
bristles.
Behind the brush is an opening, the length of the frame, into the lint-room, and beneath the
brush a sliding board, called the mote-board, which may be slid back or forward for the purpose of
regulating the draft of the gin, and properly separating the motes, dirt, and leaf from the clean
cotton.
In the saw-gin, as ordinarily constructed, the cotton is liable to collect in the spaces or interstices
between the grates, and around them above the saws, thus choking or clogging the grates, and pre-
venting the rising and free escape of the roll of seed-cotton. The patent detached grate, instead
of being attached directly to the wood part of the breast at the top, has an arm or brace extending
out behind, through which it is screwed to the wood, so that the top of the grate stands out and is
detached from the wood, and has a space behind of a quarter inch or more between it and the wood,
and also a space between it and the adjacent grates; so that there is no chance for the cotton to
collect above the saws, and the choking is entirely avoided.
Many efforts have been made to improve the saw-gin, so as to separate motes and other impurities
from the fibres of ectton. By some this has been essayed by means of rotating brushes acting on
the fibres, and carrying them from the grate to the stripping-brush, rotating in a reverse direction to
the saws. Some have used stationary brushes, through which the saws carry the fibres to be stripped
of motes and other impurities. The objection to these is that they act on the cotton only when
upon the teeth of the saws, and therefore, instead of separating the motes and other impurities from
the fibres to which they adhere, sometimes with considerable tenacity, the fibres are drawn out with
the motes, thus oeeasioning considerable loss of cotton. The object of the meter is to avoid this
loss, and to hold on to the motes or other impurities, as the fibres are stripped from the saws by
the stripping-brush, the fibres being under the operation of both brushes at the same time. The
meter also more effectually stops the current of air generated by the rotation of the stripping-brush
from acting on the fibres before they are cleaned, than if located at a greater distance from the point
of action of the stripping-brush.
The lilaecm'thy Gin is designed to clean large quantities of cotton expeditiously without oeeasioning
any injury to the staple. The cotton is drawn, by a leather roller having shallow diagonal grooves
which will not admit of the passage of a seed, between a metal plate called the “ doctor,” fixed tan-
gentially to the roller, and a blade called the beater, moving up and down in a plane immediately be-
hind and parallel to the fixed plate. While the cotton is drawn through by the roller, the seeds
are forced out by the action of the movable blade. Numerous modifications of this gin have been
made, and in some cases the movable blade or knife is made to work horizontally instead of verti-
cally. The double-action gin has a double set of knives, set so as to balance each other, each revo-
lution of the crank giving two strokes of the knife.
The Cowpm' Lock-Jaw Gin—In this machine the jaw which locks fast the cotton fibre is formed
by the nipping-blade, which is caused to approach and nip the fibre on the roller at the time it is
traveling at the same surface speed and in the same direction. While the fibre is so held, the beater
acts on and pushes away the seeds close to the nipping-blades, and separates them from the fibre
close to the seed. The nipping-blade then returns to its former position, moving in the opposite












direction to the surface of the roller. A fresh sup-
ply of cotton is then drawn in and grasped, when the
nip is repeated.
The Knife-Roller Gin—This has the same roller
as the Maearthy gin, with the steel blade or press-
ing knife pressed against its surface by springs and
screws. A knife-roller is substituted for the beater-
plate used in the Maearthy machine. It consists of
a spindle carrying oval plates of about 5 inches in
diameter. These plates are placed diagonally with
the axis on which they are fixed; and being oval,
when caused to revolve the blades or knives draw
the cotton-seed alternately right and left along the
edge of the pressing knife, while the ginning roller pulls away the fibre from the seed and it falls
through a grating. There is a guard which prevents the seed from being broken between the gin-
ning roller and the edges of the knives on the knife-roller.


25
386 COTTON —SPINN ING MACHINERY.

The Seattergoocl Needle- Grim—A notable improvement has been made in Scattergood’s “needle-
gin,” in which the teeth are needle-pointed, and set in Babbitt metal, causing less injury to the staple
than the old saws. The circles or rings of teeth are each composed of 10 sections, one of which can
be easily replaced when injured. One of these gins, of 50 rows of teeth, will gin a bale of cotton
per hour, and requires about 5 horse-power. The method of setting the teeth is shown in Fig. 857.
The bent teeth necessary to form a section are placed in a mould, and the soft metal poured around
them. The number of sections (10) required for a circle are then placed between two iron disks of
the proper diameter, which fit into a groove on the section, and an axial hole in which also fits
on the central shaft. This process is repeated until the desired length of cylinder is obtained, when
by means of a screw cut on the shaft, and its proper nut, the whole cylinder is firmly drawn to-
gether.
This gin, having two-fifths more space between the teeth than the saw-gin for the same number of
teeth, will at the same velocity clean a larger amount of cotton, while the rounded teeth will not in-
jure the staple like those of the saw. It has also a self-acting feed-motion.
The machine, 858, has a box occupying the top of the gin. An endless rotating apron of
slats forms the bottom, while an upright endless rotating apron of slats forms the front, and a rota-
ting toothed roller forms the lower front corner. The lower apron brings the seed-cotton forward
and against the toothed roller; the roller, having a slightly accelerated motion, seizes the cotton and
carries it over itself, when it drops into the hopper of the gin. The upright apron lifts the super-
fluous cotton up and away from the roller, and keeps turning the whole mass of seed-cotton in the
hopper over, thereby shaking out much of the dirt and sand and opening the cotton; by its action
all tendency of the cotton to jam and choke in the machine is avoided. An easy adjustment of the
upright apron changes the feed at the will of the operator.
Table showingelaimed Capacity of various Cotton- Gina.




r
l NAME OF cm. Size. “mm °f Cm” clenned REMARKS.
per Hour.
Whitney . . . . . . . . . . . . . . . . . . . . . . . . SO-saw. 90
Maearthy. hand machine . . . . . . . . . li—inch. S to 12
Same, single action . . . . . . . . . . . .. 4t) " 25 to 50 .
5a ne, self feeding, double action. . 4n “ 30 to 80 Maximum on long-stapled cotton.
Cowper lock-jaw, power . . . . . . . . . 30 "' 48% to 76 “ “ “
“ “ hand... . . . . . ... 14 “ 21} to 35' . “ “ “
_ Knife-roller . . . . . . . . . . . . . . . . . . . . 40 ~‘ 50 to 150 -

For an account of a trial of cotton-gins in Manchester, England, in 187 2, see Journal of the Society
of Arts, xx., 252. These experiments show advantages in favor of the roller-gins. S. W. (in part).
COTTON—PRESS. See PREss, HYDRAULIC, and STEAM-COMPRESSION or COTTON.
COTTON-SPINNING MACHINERY. Under this heading are grouped the machines which con-
vert raw cotton into yarn ready for weaving, namely: I. Openers; II. Eveners and lappers; III.
Carding-machines ; IV. Drawing-frames; V. Mules and other spinning machines ; VI. Spoolers;
VII. iVarping apparatus; VIII. Dressing apparatus. These will be successively considered.
Of late years the processes of cotton manufacture have been materially changed in some respects,
and especially in the means used for opening the cotton from the bale and preparing it for the card.
The old “willow” is now entirely superseded in the best mills by the improved “opener,” which
delivers the cotton taken from the bale in a tightly-wound “lap,” instead of in loose light masses,
which were liable to take fire if there was any gritty or gravelly matter among the cotton, as is often
the case. Such fires are very troublesome to extinguish if once ignited.
I. THE OPENER confines the cotton in an iron casing until it emerges in the sheet to be wound up












859.
t A AIL. H
C) C) 1 C3 C3 _
A _._L. ..:_. ...Lkwr
(D O J C) i C)
C 8
o
0 G A
g“ o 8
halo 0
s f—_—X






into a lap, ready to be transferred to the second machine, or lapper, where three of the opener laps
are usually drawn down in thickness, and united in one, which in its turn is taken to the card. Two
things are required to be accomplished by these machines: first, the thorough opening and loosening
of the matted cotton as taken from the bales; and second, the removal of sand, stones, and seed,
left by the gin, which are always found to a greater or less extent in the cotton as put up for market.
Fig. 859 represents an improved opener, built by the Kitson Machine Company of Lowell, Mass,
COTTON —SPINN IN G MACHINERY.
387



.0'.,


iii



\
Her.
cl .




iglfisfiil
raises
- \‘vm\_
I
‘figo‘
N
Inca-'0’..-"











Jo
I!



and used in some of the prin-
cipal cotton mills of this coun-
try. The feed-table or endless
apron A receives the cotton and
carries it to the feed-rolls B.
The rolls 0 are the pulling or
preparing rolls, and run twenty
times faster than the rolls B ,'
they consequently pull the mat-
ted bunches of cotton apart,
and drop them in a softened
condition into the gauge-box I).
The rolls F and E receive this
cotton from the gauge-box D in
a sheet of uniform thickness,
and carry it to the beater G in
the opener. By the force of
this beater it is blown through
the circles H and trunks J to
the condenser X, connected with
which is the exhaust-fan M,
which carries off the dust,
and aids in pulling the cotton
through the trunk. The entire
bottom of the trunk J is made
of hoop-iron slats standing
edgewise a short distance apart,
and the cotton, after being well
opened by the preparing-rolls C
and beater G, and blown over
this sieve-like arrangement, is
thoroughly cleaned. The roll
K and the screen L in the con-
denser X slightly compress the
cotton as it passes between them
and drops into the gauge-box
O. The ratchet-roll N acts as
a clearer for the screen L, and
at the same time throws out
the surplus cotton if the gauge-
box becomes too full. P is a
glass door by which the opera-
tor ean see the height of cot-
ton in the gauge-box. The con-
struction of this gauge-box and
its connection with the rolls 8
and screen R are such that the
cotton is measured in one uni-
form sheet to the lapper or
scutcher, through which it pass-
es and comes out in the form
of an even lap, ready for the
finisher-lapper or card. It. is
claimed for this trunk arrange-
ment of machines that the cot-
ton is cleaned in a more thor-
ough manner than by the old
process; that it will not clog
in passing through, neither is
there danger from fire; that
the cotton is measured ofi by
the gauge-box evener than it
can be spread by hand, thus
insuring an evener lap; and
that the trunk, taking out the
greater bulk of sand and grit
before it reaches the lapper,
saves the wear and tear of the
same. This machine will open
and clean 4,000 lbs. of cotton
per day, with an expenditure
of about 8 horse-power.
Another form of cotton-open-
388 COTTON —SPINN IN G MACHINERY.

er and picker, as built by Messrs. Whitehead & Athcrton of Lowell, Mass, is represented in
Figs. 860, 861, and 862. The cotton as taken from the bale is spread loosely on the feed-apron
A, which delivers it to the feed-rolls B, from which it is taken by the hinged beater or whip-
per 0, the details of which are shown in the smaller drawings on the right, Fig. 862, in which
are exhibited the heaters which strike the cotton, and which are rectangular loops of best Nor-
way iron hanging on rods, which are supported by the arms. The whole is driven by a belt-pul-
ley, and the rapid motion causes the whippers to assume a radial position, as represented in Fig.
862, and strike the cotton from the feed-rolls, with a blow which is sullicient to remove the seeds
and dirt, which fall through the gratings shown in the elevation, while the cotton is carried on
to the wire-gauze cylinders EE', from which the air is exhausted by the fan M. Passing through
between these gauze cylinders, the cotton goes to another pair of feed~rollers F, from which it is
again taken by the beater (1', and carried on as before to the gauze cylinders I and 1', the air
from which is exhausted by the fan N. The beater J again throws the cotton forward to a third
pair of gauze cylinders, exhausted by the fan 0, and from these it passes through the condensing-
rollers 11’, and is wound up in a lap or sheet at L. The leaf-extractors [) and H are large cylinders
fitted with buckets like those of an overshot wheel on their peripher , and revolving slowly in a
reverse direction to that of the cotton, as shown by the arrow. The cotton is thrown by the beater
against the edges of these buckets, and much light material which has not fallen through the “grids”
or gratings is caught in them, and dropped in their revolution into the dust-box under the machine.
The peculiar merit and novelty of this machine, which is now very extensively used, lies in the
hinged or flexible beater, which, while delivering an effectual blow on all the cotton which is fairly
loose, will yield to a hard mat or cake, such as is often found in heavily-pressed cotton, until the
successive rapid blows have so loosened it as to permit its easy separation, thus avoiding much of the
jar and wear to the machine incident in the use of the rigid beater, and also saving power. These
machines, as represented in the cuts, have been found by actual test to open and clean 4,000 to
5,000 lbs. of cotton per day, with an expenditure of less than 2 horse-power per 1,000 lbs.
The lap which is taken from these machines now passes to the second picker or lapper, when
three laps are united and drawn down into one, which is taken to the card. This operation is in-
tended to secure evenness in the thickness of the sheet delivered to the card, and this object is also
aided by the improved “ evener,” as illustrated and described below.
II. Evnnnas AND L.\rrnas.--The object of an evener, applied to a finisher-lapper, is to regulate
the supply of cotton which passes through the machine so that laps of any required weight can be
obtained, without being compelled to weigh the cotton on to the feed-apron of the breaker-lapper. rI‘o
accomplish this result, a number of different kinds of eveners have been invented, many of which
have been open to the serious and fatal objection of not being sensitive enough to produce an even
weight of laps, in consequence of the construction of the eveuer being such that the feed-rolls were
obliged to serve the double purpose of holding the cotton while being operated upon by the beater
(necessitating a great weight upon the feed-rolls to hold the cotton) and to even the supply of the
same passing through the machine.
The construction of the Whitehead & Atherton evener, represented in Figs. 863 to 865, is such
that its only office is to regulate the supply of cotton, while the feed-rolls have no direct connection
with the evener to
interfere with its
sensitiveness. In ll
Figs. 863, 864, P1)
are two feed-rolls J
for holding the O O
cotton while being
acted upon by the beater. T T are two
of eight evener-platcs, between which and
the roll V the cotton passes to the feed-
rolls. These plates are connected by means
of rods R R to the levers in the box S,
which are connected with the lever G, at-
tached to the shipper-lever J, which 0p-
erates the quadrant belt-shippers L L.
During the passage of the cotton over
the evener-plates, should an uneven sur-
face present itself, the plates immediately
under the part that is uneven operate, and
either increase or reduce the supply of the
cotton to the beater, as is required to pro-
duce a given weight of lap. The cotton,
being delivered as evenly as possible in
this manner to the lapper, passes through
two more boaters, which complete the
cleaning and prepare it for the next op-
eration.
Fig. 865 is a perspective view of the
finisher-lapper. At A, A‘, A2 are the rests
for laps from the opener. B is the beater-cylinder; O, wire-gauze condenser-cylinder; and D, the
fluted roll for joining the laps.
III. Oannmu Macnmns.—From the apparatus thus far described the cotton emerges in the form of










. . . . . . _ . . ..H
II.
.-... . ,....-1'
i 0
H620 -':".'-_':'-g-"T‘I".':r\‘g ‘1













COTTON -SPIN N IN G MACHINERY. 389

a very clean, light, downy fleece called a lap, consisting of short fibres thoroughly disentangled.
But these fibres are not parallel; they lie across each other at every imaginable angle, and any
attempt to combine them together in this state would be fruitless; they must be rendered parallel,
865.


and to efl’ect this is the object of carding. This is an important process, as regularity and perfec-
tion in carding are essential to the fineness and beauty of the cloth. Cards are formed of strips of
leather, in which are inserted small staples of wire called teeth, having the projecting ends slightly
bent in one direction. The strips of leather are fastened to flat surfaces or cylinders of wood or
metal, and the cotton is passed between two or more of these surfaces. The teeth of cards are of
various sizes, being thicker or slenderer to adapt them to coarse or fine materials. It is essential
that the teeth should be all alike, equally distributed, and equally inclined over the surface of the
leather. The teeth are implanted by pairs, and retained in it by the cross part ccl, Fig. 866, at
right angles with the teeth. The
866- leather must therefore be pierced
with twin holes at the distance
Wewwwwtw g, ett\tilwkt\tw a as iiol‘éinlifléllifi
bitiwyyiwyti c d ear/(erawag assertsass?was
erwise, the teeth would vary with
the angle of inclination, and the
card would be irregular. The leather should be of the same thickness throughout, so that all the
teeth may project an equal distance. Card-making requires a degree of precision which is hardly
possible with hand work, and cards are now manufactured exclusively by machinery.
Strict uniformity is necessary as to the size, shape, obliquity, and length of the teeth, and also in
the angle which they bear to the cylindrical surface around which they are placed. The action of
the cards will be understood from Fig. 866. If the two cards a and b on the left he moved in op-
posite directions, as indicated by the arrows, with a tangled tuft of cotton-wool between them, the
fibres will be seized by all the teeth, one card pulling them one way and the other pulling them in
the opposite direction. The fibres are thus disentangled and laid in parallel lines, each card taking
up and retaining a portion of the cotton. All the cotton may be gathered on one card by reversing
the position of the two, and placing them as shown on the right of Fig. 866. Then, by drawing the
upper card a over the lower one I), the teeth of the latter offer no resistance, but give up their cotton
to the upper card.
The following is a description of the card-making machine invented by Mr. Whittcmore. Long
sheets or fillets of leather, of suitable length, breadth, and thickness for making cards, are stretched
by winding the fillets upon a roller or drum, from which it is conducted upward between guide-rollers
to a receiving-roller at the top of the machine, where it is held by a cramp, by which means the leather
is kept stretched.
The holes are pierced in the leather to receive the wire staples or teeth of the card by means of a
sliding fork, the points of which are presented to the face of the leather, while the fork is made to
advance and recede continually by the agency of levers, operated by rotatory cams upon a revolving
main shaft. The leather fillet is shifted so as to bring diflerent parts of its surface opposite to the
points of the sliding fork, so that the holes shall be pierced at regular distances. This is done by
cams, which shift the guide-rollers and confining-drums laterally as they revolve, and consequently
move the fillet of leather at intervals to the distance. required between the holes.
The wire of which the teeth of the card are made is fed from a coil on one side of the machine,
and brought forward at intervals by a pair of sliding pinccrs, moving to and fro through the agency
of lovers, operated by rotatory cams upon the main shaft. The pincers having advanced a distance
equal to the length of wire intended to form one staple or two points, this length of wire is pressed
upon exactly in the middle by a square piece of steel, and being there confined, a cutter is brought
forward which cuts it off from that part of the wire held in the pineers. The length of wire thus
afi»-——> ‘





390 COTTON —-SPIN N IN G MACHINERY.

separated and confined is now, by a movement of the machine, bent up along the sides of the square
steel holder, and shaped to three edges of the square, that is, formed into a staple; and in the same
way the wire is cut and bent into staples as long as the'machine is in operation.
The wire staple is held with its points or ends outward in close proximity to the forked pierccr
before described, and by another movement the staple is moved forward, its points entering the two
holes previously made in the leather by the sliding fork.
While the wire staple is being thus introduced into the leather, its legs or points are to be bent,
that is, formed with a knee or angle. This is done by a bar or bed, which bears up against the
under side of the wire staple when it has been passed half way into the holes in the leather, and
another bar above it, being brought down behind the staple, bends it over the resisting bar to the
angle required, forming the knee in each leg. A pusher new acts behind the staple, and drives it
home into the leather, which completes the operation.
In this manner a sheet of card, sometimes called card-clothing, is made, of the kind usually em-
ployed for carding wool, cotton, or other fibrous materials. The wire staples are set in the leather,
sometimes in lines crossing the sheets, which is called ribbed, or in oblique lines, called twilled,
which variations are produced by the positions of the notches or steps on the periphery of the cam
or indented wheel, which shifts the guide-rollers that hold the leather fillet as described.
The carding engine consists of one or more cylinders, covered with card leather or clothing, and a
set of plane surfaces similarly covered, made to work against each other, but so that their points do
not come into absolute contact. The action of the machine is substantially similar to that of the old
hand-cards, which were simply wire brushes drawn past each other by hand in the manner already
described. For making coarse yarns one carding process only is employed; but for finer yarns the
cotton is first passed through a breaker carding engine, which performs the first rough carding; and
the slivers delivered by this are then doubled by laying together a large number of them side by side
and overlapping one another, so as to obtain sufficient thickness and breadth of material to allow of
867.


, -
- r:::_-_~_ ... r::— ' ’










1
a further carding. The lap thus formed is fed into a second or finisher carding engine. As many
as 96 slivers from a breaker card, each drawn out of a separate can, are laid together by a doubling
machine into a single thickness for the supply of the finisher, in order that the mixing of the cotton
may be more thoroughly effected, and more perfect uniformity insured in the sliver delivered by the
finisher. For the finest qualities of yarn the finisher card is itself used as a breaker, and the sliver
delivered by it is afterward combed by a combing machine. Fig. 867 shows the general arrange-
ment of the mechanism of a carding engine such as is used as a finisher. The lap E, formed of a ,
number of slivers, in this case from the breaker card, laid together into a fleece by the doubling
machine, is carried by the feed-roller G to the Zicker-z'n H. The latter draws the cotton into the
machine, so that its filaments are immediately seized by the large cylinder A, which generally rotates
at a much higher speed than the drum H. The cotton is then teased out by the teeth of a “ fancy
roller,” B, which runs in the same direction as the main cylinder. Its teeth, however, are bent for-
ward in the direction of motion, and it therefore requires to be driven at a higher velocity than the
carding cylinder, and has accordingly a surface speed of 2,000 feet per minute, that of the main
cylinder being about 1,600 feet. The cotton is thus taken from the teeth of the main cylinder and
thrown against those of the stripper C. The fibres, having thus been subjected to a preliminary
carding, are again swept off the teeth of the stripper, moving at only 400 feet per minute, by the
higher speed of the main carding cylinder. In some machines more rollers and strippers are added,
so that knots taken out by the first drums and returned to the cylinder are again caught by others.
Passing the combination of rollers, the fibres are next brought into contact with the cards of the top
flats D, which arrest knots and hold them until the entanglement is removed, or until the flat is
taken out and cleaned, which is occasionally done. The teeth of these flats are set to face those of
the carding cylinder A, and travel forward in the same direction as the surface of the cylinder, but
at a very slow rate. The flats are arranged to work at a slight inclination to the surface of the card—
COT TON ~SPIN N IN G MACHINERY. 391

ing cylinder, so that the delivering side of each flat is closer to the cylinder, and a wider space is left
at the entering side between the flat and the cylinder for the cotton to enter. The angle thus formed
is called the bevel of the flat. On quitting the carding cylinder each flat in turn is stripped of any
impurities by a vibrating comb. The flats are further cleaned by the brush 1, and their surface is
kept true by an emery-wheel, V.
The fleece of straightened fibres, which now lie in parallel rows among the teeth of the cylinder
card, is removed by the dofl’er K, which is covered by a spiral fillet of cards revolving at a much
slower rate than the cylinder, and in a different direction. From the doffer the fleece is removed by
a vertically reciprocating comb I, called the dqfi'w-knife, which has a rapid motion tangential to the
surface of the teeth. The material is then contracted into a sliver by condensing rollers, which, re-
volving at a relatively greater velocity as the sliver proceeds, slightly draw it, and tend to make the
fibres parallel. Thence the sliver is coiled down in the can 0. The coiler consists of a revolving
plate having an eccentric aperture, through which the sliver is passed from a pair of rollers above
the plate. The can is also made to revolve with a slow motion in the opposite direction to the coiler,
and the centre line of the latter is eccentric to the axis of the can, whereby the sliver delivered from
the coiler describes a succession of curves in the can, which form coils continually crossing each
other, so that when the sliver is removed its parts do not adhere together.
The breaker carding machine differs from that above described in having a series of pairs of card-
ing rollers or workers and clearing rollers or strippers, arranged around the entire upper surface of the
main cylinder. In each pair of rollers the fibre undergoes combing out and straightening. The means
for taking the cotton upon the main cylinder and delivering it in coils are similar to those already de-
tailed. Garding machines are sometimes made which are a combination of the breaker and finisher
card, having rollers and clearers on the side of the cylinder next the feeder, and flats on the side next
the doffer. The finisher carding machine was formerly constructed without the licker-in, the main
cylinder taking the fleece directly from the feeding roller. This caused the fibres to clog the cards.
For the purpose of sharpening the teeth, when a carding engine is first filled with new sheets,
fillets, etc., the cylinders are put in motion the right way, and a light emery-board, about 4 inches
bread, is traversed over the top of the cylinders with a very delicate hand ; this is called facing up
the teeth, because the points of the wires are running against the board, and is intended to cut
down any single wires that may be too long. After running the cylinders in this way about 15 min-
utes, their motions are reversed, and they are mounted on the main and doffing cylinders ; these are
denominated the fast-grinders, and, after being properly set, are caused to revolve in an opposite
direction to the card-cylinders. This operation is continued until the whole of the teeth on both
cylinders are ground down to one uniform length; but, during the process of grinding, the emery
cylinders are made to traverse a little each way, so as to grind the wires to a round point, and pre-
vent them from being hooked. The cards are then dressed up—first with a brush dusted with chalk,
and then with emery-boards, called strickles; this latter process is called sharpening, and is contin-
ued daily to the breakers, and every second day to the finishers. The fast-grinders are not applied
above once a year, or only when the cylinders on some part of the surface have become higher than
on the other parts, or, technically, “off the truth.” By this method of grinding the cards when
necessary, and sharpening them every working day, they are always in good order, and consequently


_ .
v '.v ‘23»?4 71-5\

produce more perfect work: also, when the practice of sharpening is continued daily, it can be done
in much less time; two men can easily sharpen 3O carding engines in the space of 4 hours. The
card-belts being all fitted with buckles, no time is lost in making them long or short, for the purpose
of reversing the motion of the cylinders. The tops are also brushed out and sharpened once a week.
392 COTT ON —SPIN N IN G MACHINERY.
Fig. 868 represents the carding engine ordinarily used in New England, as built by the Lowell
Machine Shop, with Wellman 8: Woodman’s improved self-stripper. The compound cam and mangle
wheel B, driven from the pulley A, traverses slowly from back to point of the card, and returns over
its path by means of the semicircular mangle-rack C', stopping in its progress at each alternate top
fiat,‘which being raised from its seat by the spring bar E, driven from a cam on the opposite side of
the card to the one shown in the drawing, the cleaner-comb D is passed under'it, and on being drawn
out removes the dirt and short cotton from the top flat, leaving it held by the curved wires shown
in the drawing, until such a quantity has accumulated as to make it necessary to remove it by hand.
This “stripper,” which was introduced in 1856, has now become of universal use, not only saving
a large amount of hand-labor, but also causing much less injury to the card-clothing than was caused
by hand-stripping, from its even and steady motion. This motion is so arranged by cams as to strip
the alternate flats, numbered 1, 3, 5, 7, etc., in its passage from back to front of the card, while on
its return it cleans those numbered 2, 4, 6, 8, etc. By the form of the different cams and gears,
the traverse motion of the stripper is arrested at each flat for the necessary length of time required
to lift the flat, strip it, and return it to its seat before moving to the next one. The same form of
card is used for both breakers and finishers, and the sliver of cotton is delivered from the dofl’er-
comb into the “ railway-box,” a long box or trunk running the length of the section of cards imme-
diately under the dofl'er, in which an endless belt, of leather or canvas coated with India-rubber,
conveys the slivers from the section of cards in a parallel state to the railway or lap head, which is
simply a set of rolls placed at the end of the section.
In the case of the breaker-railway or “lap-head,” as it is called, Fig. 869, the slivers of a large
number of cards, not often less than 64 or more than 96, are wound into a broad flat lap of the width






of the finisher-card, to which they are transferred. This lap-head is shown in perspective in the
engraving. The cards for this would usually be arranged in 4- or 6 sections of 16 each, according to
the width of the mill, and placed longitudinally in the same; while at the end of each section a
belt running transversely would receive the slivers from that section, uniting in one broad sheet at
the lap-head, which would stand in line with the last section.
The section of finisher-cards is usually not less than 8 nor more than 16 cards, and the railway-
head to the finishers consists of a set of drawing-rolls, as described in the “ drawing-frame,” usually
with a draught of from 3 or 4 to 1. At this point the sliver is delivered into cans, which are carried to
the drawing-frame. The number of cards in a section, and the draught of the railway-head, are regu-
lated by the fabric to be produced, it not being considered advisable that the railway-sliver should
weigh over 100 grains per yard. This sliver, on leaving the drawing-rolls, passes through a conical
tube or “trumpet,” accurately bored to a given size, which, by a system of levers acting on a belt in
the interior of the machine, driven by one of a pair of conical drums or pulleys, so changes the
speed of the front rolls that the sliver keeps its full size and weight when one of the cards is acci-
dentally or intentionally stopped. This apparatus is known as “Hayden’s railway evener and draw-
ing regulator,” Fig. 870. It is the invention of Newell Wyllis of Glastonbury, Conn, and D. W°
Hayden of Providence, It. I., and has been improved by George Draper of IIopedale, Mass.
Still another form of card which has given successful results under practical test, invented and
built by Messrs. Foss 8t Pevey of Lowell, Mass, is represented in Fig. 871. This, by using more
flats, aims to produce the same result at one carding which formerly required two, thus saving one-
half the room in the mill, and, as shown by the test annexed, one-third of the power and labor.
The power required to drive cards varies with the amount of cotton carded per day, varying from
one-sixth to one-third of a horse-power per card, including railway-heads, which respectively take
about 11} horse-power for the breaker lap-head, and one-half horse-power for the finisher-railway;
COTTON—SPIN N IN G MACHINERY. 393

N
and the amount of cotton to produce the above results varies from 27 lbs. per day, single carding,
to 60 lbs. per day, double carding. '
The following gives the results of a power test of the Foss & Pevey under-flat cotton card, con-
ducted at the Massachusetts Mill, Lowell, Mass, August 1, 1878: Eight top-fiat breakers (old style)
took 2.264 horse-power; eight
top-flat finishers, with railway,
2.679; allowance for lap-heads,
as by previous tests, .2264. Six—
teen top-flat cards, carding 520
lbs. cotton per day, took 5.207
horse-power; eight Foss 6t Pevey
cards, including railway, carding
520 lbs. cotton per day, took
3.277; saving in power, 1.930,
besides the saving in room and
attendance, the quality and quan-
tity of work being the same.
The “top-flat” system of card-
ing, as already described, is the
one which has been generally
adopted in the United States;
but numerous important varia-
tions have been lately introduced,
notably in the new combination
card of the Whitin Machine C0m~
pany, which adds the “worker
and stripper,” as used in wool
cards, to a part of the top flats.
In this case the cotton is taken
from the feed-rolls by a licker-
in, which delivers it to the main
cylinder, and the flats, which it
reaches first, collect the larger
part of the leaf and shells be-
fore it reaches the workers, by
which it is evenly distributed.
This form of card is intended
to work from 80 to 100 lbs. of
cotton per day, or double the
amount allowed to the flat card. A card is largely used in England, in which the positions of the
parts are exactly reversed, the cotton being leveled by the workers and strippers before going to the
top flats, which catch the dirt and waste.
Another form of English card is known as the roller card, and has no top flats at all, but uses the
workers and strippers entirely. A card of this kind has been introduced in this country by the
Messrs. Gambrill of Baltimore,
and is known as the Gambrill 871'
card. One of these cards will a
turn out from 160 to 180 lbs.
of cotton per day; it takes out
less waste and cleans the cotton
less thoroughly than the flat
card, but is very serviceable
with clean cotton or for coarse
work.
Still another form of English
card is represented in Fig. 872,
in which the top flats are at-
tached to an endless chain, which
travels slowly in the same direc-
tion as the surface of the main
cylinder, and by the operation
of which, as shown in the cut,
each card-flat is reversed in po-
sition as it leaves the cylinder
to return to the starting-point.
It is then stripped by a cleaner-
eard, which is stationary at that
place.
IV. DRAWING-FRAMES.—~Tlle cotton leaves the carding engine in the state of a delicate, flat, nar-
row strip or ribbon, called a sliver; and these slivers have now to be converted into drawings by
being elongated, narrowed, and thinned to a still more delicate condition. In the first place the sliv-
ers are collected in tall cans, from two to six in number, on one side of the “ drawing-frame,” and
are from thence carried upward to two or more pairs of rollers, the two rollers of each pair revolving





























394 COTTON-SPINN IN G MACHINERY.


in contact. Here all the slivers or cardings are collected into one group, and are drawn between the
rollers by the rotation of the latter. Now, if these rollers all revolved equally fast, the cotton
would leave them with the same united thickness as when it entered; but the last pair revolve
quicker than the first, so as to draw out the cotton into a more attenuated ribbon, because the more
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slowly revolving rollers do not supply the material fast enough for the maintenance of the original
thickness. This is perhaps the most important principle in the whole range of the cotton manufac-
ture; for it is exhibited alike in the present process and in the next two which follow. All the sliv_
ers are connected into one after leaving the rollers, and the united drawing passes through a kind of
trumpet-shaped funnel, and thence is conducted into a tall can, round the interior of which it coils
itself. One consequence of the drawing process, if properly conducted, is that the drawing is per-
jéifkiv. 8733: ;


















fectly equal in thickness in every part, and formed of parallel fibres ; and in order to insure this, the
drawing is repeated more than once, each narrow ribbon being “ doubled ” with others before each
successive drawing. '
The drawing-frame as built by the Lowell Machine Shop is represented in Fig. 873. The cans
which have received the sliver from the railway-head, which is in reality a “first drawing,” are
placed behind the frame, and the attenuated sliver is delivered at the front through the rolls A.
COTTON-SPINNING MACHINERY. 395

Two or more of these slivers are united at the trumpet B, and compressed by the condenser-rolls O',
and delivered again into cans which stand on the rotating plate D D, to which a reciprocating action
from right to left and mice verse is given by the shaft E. The drawing-frame, as now usually built,
it
874.





/ \ @D
has 4 pairs of consecutive rolls, the speed of which varies according to the quantity and quality of
the work desired. The draught or attenuation in the machine will vary, accordingly, from 3 to 44; to 1,
and the speed of the different rollers may be approximately stated as follows: first pair, 100 revolu-
tions per minute; second pair, 125 revolutions; third pair, 180 revolutions; fourth pair, 300 revolu-
tions. It will be seen by this that the draught is arranged to come between the first and second and
the third and fourth pairs of rollers, the last being the greatest, and that between the second and
third pairs barely suificient to keep the fibres in tension. The average power of the drawing-frame
may be taken at one-tenth horse-power for each delivery.
Roving-E'ames.—Two sets of drawing-frames, known as first or second drawing, are usually em-
ployed, and from the second, Fig. 874, the sliver passes to the roving-frame, where it is brought to the
state of racing. In many respects the process of roving is similar to that of drawing, inasmuch as it
draws out the cotton to a state of still greater attenuation; but as the cotton, in its now reduced
thickness, has scarcely cohesive strength enough to make the fibres hold together, the roving has a
slight twist given to it, by which it is converted into a loose kind of thread, or spongy cord.
The “ bobbin-and-fly frame ” consists of a system of vertical spindles, on each of which is placed
a reel or bobbin, and also a kind of fork called a “fly,” still farther removed than the bobbin from
the axis of the spindle. The drawing or delicate sliver of cotton is first drawn through or between
rollers, and elongated to the state of a raving; then this roving passes down a tube in one prong
of the fork or fly, and becomes twisted by the revolution of the fly round the bobbin, while at the
same time the twisted roving becomes wound with great regularity upon the bobbin. The machine
in fact performs three different and distinct operations : it first attenuates the “ drawing” to a state











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of still greater thinness and delicacy than it had before; it then gives to the roving thus produced
a slight twist, sufficient to enable the fibres to cohere ; and, lastly, it winds this twisted roving upon
a bobbin, on which it is conveniently transferred to the spinning machine. Instead of the bobbin»
396 COTTON ~SPINN IN G MACHINERY.
M

and-fly frame, in this country the specder and stretcher are more commonly used, especially on the
coarse yarns. _ The principal d-ifl’erence in the two machines is that, while in the fly frame the flyer
is like an inverted U, and is screwed to the top of the spindle, requiring to be unscrewed and replaced
each time the bobbin is dropped, in the speeder it is in the form of a flattened ellipse, as shown in
the engraving, and of double the length of the bobbin, thus permitting the removal of the latter
without disturbing the flyer. From two to four of these machines are successively employed to reduce
876.


the roving to the proper size for the yarn to be produced, doubling the roving to insure greater even-
ness before drawing at each operation.
The mechanism of the Lowell speeder, as generally adopted at present in the United States for
877.



















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coarse yarns, is essentially the same as that of the fly frame, its principal feature consisting of the
“differential motion,” so called, invented by Aza Arnold of Providence, R. I.,-in 1823, and intro-
duced by Henry llouldsworth in England in 1825. By this motion the velocity of the surface of the
bobbin, which is continually increasing in diameter with each successive layer of roving, is kept uni-
form, and takes up the roving exactly as fast as it is delivered by the pressor or finger of the fiyer.
This differential motion may be briefly described as follows, by reference to Fig. 875: A is the main,-
or driving shaft of the machine, to which power is given through the pulleys V V'. The train of
gears, B, Bl, B2, etc., transmit motion to the drawing-rolls C, 0‘, etc. ; and the small bevels a and b
carry the fiyer F, which is always driven at the same speed, the amount of twist being regulated by
the speed of the rolls 0, C", which can be varied by changing the gears B, B 1, etc. These motions
COTTON-SPINNING MACHINERY. ‘ 397
V
are positive and uniform during the operation of the machine on any given size of roving, The
roving, coming from the rolls 0, passes downward through the hollow tube of the flyer to a presser,
by means of which it is wound on the bobbin E. As this bobbin increases in size with every layer
that is wound upon it, a variable motion must be given to it to keep the surface velocity the same,
and thus avoid breaking the tender roving. This is accomplished as follows: A gear G on the shaft
A drives the bevel-gear 1 through the pinion H. 1 communicates motion through J to L, and thence
through ill, N, and U to the shaft P, which, by means of the small bevels c and d, drives the spindle
D and the bobbin E. Were the bevel-gear J stationary, the motion transmitted would be the same
as that received, only reversed in direction; but, in order to accomplish the desired result, it is given
a motion around the centre of the shaft H] by having its own axle inserted in the web of the
large gear K, which moves freely on the shaft H I, and to which motion is given by the pinion T,
which is driven from the shaft H by the gears shown at Q and the cone-pulleys if and r, and the belt b'.
Now, if the gear K be made to revolve around the shaft H I, carrying with it the fulcrum of the
bevel J, it is obvious that the motion of the bevel L and its consequent train of gears will either
be advanced or retarded, according to the direction given to the gear K. In order to retardthe
revolutions of the bobbin in proportion to its constantly increasing diameter, the gear K is there-
fore made to move in the same direction with the bevel 1; and, as each successive layer of roving is
put on to the bobbin, its velocity is increased by the shifting of the belt S from left to right on the
cone pulleys Rr by a ratchet motion not shown here, but which is operated by the same action
which lifts and lowers the bobbin for each successive layer. This is done by raising and lowering
878.
sun-z VLEW.


















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31
mm
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the rail W, in which the spindles are stepped, the spindles being splined,
and sliding up and down through the driving-gear (I. The exact propor-
tions are not given in this drawing, the object being only to explain the
motion, which is one of the most beautiful and important in its effects of any in the process of
cotton-spinning.
Fig. 876 is a rear view of the ordinary form of English roving-frame, exhibiting the general ar-
rangement of the gearing; and Fig. 877 is a front view, showing the spindles and the gears by which




398 COTTON-SPINNING MACHINERY.


they are driven. These machines are built by nearly all the principal makers of cotton machinery
in the United States, and are generally used for fine yarns.
Draper’s filling-frame, Figs. 878 and 879, the invention of Messrs. George Draper 8t Sons of
Hopedale, Mass., is designed to accomplish the object of spinning a soft-twist bobbin of weft, like
the mule “ cop,” for use in the shuttle. The great difliculty in previous attempts to accomplish this
879.
END VIEW.






























purpose has been that, when the yarn was being wound on the spindle at the extreme or “ nose ”
of the cop, the pull on the traveler was so directly radial that it reduced the size of the yarn, by
stretching it, to a finer number than when it was winding on the base of the cop, where the pull
was more tangential. This objection the Messrs. Draper seek to obviate by diminishing the speed
A of the front rolls at the time the yarn is winding on the small barrel of the bobbin, so as_to give
less draught at that time, and consequently a coarser yarn is delivered from the rolls; but it is
reduced to its proper size by the tension between the traveler and the bobbin. This is accom-
plished by the use of the cone-pulleys A B, by which the front rolls are driven independently of the
others, and the driving-belt on which, 0', is traversed from right to left by the shipper D, which
in turn is moved by the chain E, connected with the lift motion, which gives the traverse to the
ring-rail in such a manner that, when the rail is up at the top of the wind, the front rolls are re-
ceiving a slower motion than when it is down on the base of the cone. The drawings will fully
explain all the details. This frame, though a very recent invention, is being widely introduced, as it
produces a soft-twist weft, similar to that spun on the mule, with great rapidity, and occupies but
one-half the floor space of the mule in a mill, while it can be tended by a cheaper class of operatives.
COTTON ~SPINN IN G MACHINERY.
399

All previous attempts to spin weft in the frame directly upon the spindle without the use of a bobbin
have proved failures eventually. The use of the bobbin also saves 50 per cent. of the waste.
Spirming-fiiumea—The roving, having been reduced to the proper size for the intended number of





880.
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yarn, now goes to the spinning-machine, which may be a throstle or mule; the ring-throstle being
generally used in the United States for warp, and the mule for weft, though either machine is occa-
sionally employed for both purposes.
Fig. 880 shows the ring spinning-frame of the latest pattern,
as built by the Whitin Machine Company.
The principle of the ring spinning-frame is very simple.
The spindle is driven by a band from a
central cylinder, and the bobbin is held upon the spindle by a slight friction, and revolves with it,
881.






the yarn being wound upon the bob-
bin by the friction of a “traveler” or
small metal hook, which is carried by
the yarn around a ringr of hardened
iron, which is concentric to the spin-
dle, as in Fig. 881, where A represents
the plan and section of the ring, E the
ring-rail which carries it, and which
rises and falls to give the traverse to
the yarn on the bobbin B, which is
carried by the spindle C, and gives
the proper twist to the yarn. D is
the traveler, which is carried by the
thread F, and the resistance or “drag ”
of which winds the thread on the bob-
bin as fast as it is delivered by the
spinning-rolls, the operation of which
is identical with that of the rolls in
the drawing and roving processes, be-
ing the fundamental principle as in-
vented by Arkwfight.
Great improvements have been made
since 1870 in the construction of the
spindles and bobbins. The first of these
was the invention of Oliver Pearl of
Lawrence, Mass, and consisted in cut
ting ofi 21} inches from the top of the
spindle, thus lessening the tendency to
vibration, boring out the bobbin to a
thin shell, and then strengthening it
by retinforces, or bushings, at the bot-
tom, top, and centre, the centre bush-
ing being at the height of the top of
the spindle, and by its adhesion thereto,
W7




(\
Lr














"























E


A, Old spindle. C. Garsed‘s spindle.
B, Pearl’s spindle. I), Rabbeth‘s spindle.
E, Sawyer’s spindle.



A
combined with the adhesion of the bush at the, bottom, getting friction enough te be carried around
with the spindle. This reduction of weight above the bolster admitted of a much larger reduction
400 COTTON-SPINNING MACHINERY.

below, so that the weight of the spindle was reduced from 12 or 13 ounces to 5 or 6 ounces, and the
bobbin from liounee to half an ounce, saving one-third of the power required to drive the spin-
ning in a mill, or one-sixth of the whole power required in the manufacture.
A reference to Fig. 882 will show the difference from the old form of spindle, and also the forms
of the Sawyer spindle, which was patented by Jacob H. Sawyer of Lowell in 1871, the Garsed spindle,
and the Rabbeth spindle.
In the Sawyer spindle the bolster, or upper bearing, is at the top of a tube, which reaches half-way
up into the bobbin, the latter being chambered out to receive it, and supported on the spindle by two
“ bushes," or reenforces, one at the top of the bobbin, and one just above the tubular bolster. By
this arrangement the centre of gravity of the full bobbin is brought down close to the fulcrum, and
the vibration of spindle and bobbin lessened still further than by Pearl’s patent, with a somewhat
greater saving of power, the spindle being, as before, reduced to 5 or 6 ounces.
Another light spindle was introduced by Richard Garsed of .Frankford, Philadelphia, in 1872,
in which the bobbin is chambered out for half its height from the bottom, or nearly to the top of
the spindle, and a reenforce inserted at the bottom, two steel wires passing through, forming a
clutch, which engages on a squared shoulder on the spindle, just above the bolster, and driving the
bobbin by a positive motion, the pit of the bobbin at the top of the spindle not being tight enough
to cause friction.
Still another form, introduced in 1871—’72, is the “ iabbeth ” spindle, built by Fales & Jenks of
Pawtucket, R. I., in which the bobbin is similar to that of the Sawyer, but in which the spindle runs
in a tube full of oil, a sleeve carrying the driving-whorl, on its lower end, being so attached to the
spindle as to overhang the tube, and with it be introduced into the lower half of the bobbin, which
is partially supported and driven by it.
Many thousands of each of these forms of light spindle are now in operation, saving from
33 to 40 per cent. of the power formerly required, or admitting of being used at such increased
velocity as materially to increase the product of a given number of spindles with the same power as
before.
V. Memes—In these machines the rovings are delivered from a series of sets of drawing-rollers to
spindles placed upon a carriage, which travels away from the rollers while the thread is being twisted,
and returns toward the rollers while the thread is being wound. The drawing and stretching action
of the mule-spinner makes the yarn finer and of a more uniform tenuity than the mere drawing and
twisting action of the throstle. As delivered by the rollers, the thread is thicker in some parts than
in others; and the thicker portions, not being so well twisted, are softer and yield more readily to
the stretching power of the mule, by which means the twist becomes more equable throughout the
yarn. rl‘ln‘ostle-spinning is seldom employed for numbers higher than 40 or 50 hanks t0 the pound,
because smaller yarn would not have strength enough to bear the drag of the bobbin; but in mule-
spinning the yarn is built upon the spindles without subjecting it to appreciable strain. The mule-
earriage carrying the spindles recedes from the rollers with a velocity somewhat greater than the
883.
i
:v \k‘;
l 5
i;
i.
a“.
a.._ Q. _
"em
'. E
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-.a|0


rate of delivery of the reduced roving, the rapid revolution of the spindles giving a twist to the yarn
which stretches it further. Whenthe rollers cease giving out the rovings, the mule-spinner still
continues to recede, its spindles revolving, and thus the stretching is eifected. The distance to which
the spindles reeede from the rollers while both are in action is called a stretch. This is usually from
54 to 56 inches. The space over which the carriage moves in excess of the paying out of the rollers
COTTON—SPINNING MACHINERY. 401

is called the gaining of the carriage. The space traversed by the carriage after the paying-out
action of the rollers is stopped is called the second stretch ; during this, the spindles are revolved
very rapidly to save time. When the drawing, stretching, and twisting of the yarn are accomplished,
the mule disengages itself from the parts of the machine by which it has been driven, and the ear-
riage is returned to the rollers, the thread being then wound upon the spindle. The specific differ-
8M.















ence between the action of the throstle and the mule is, that the former has a continuous action upon
the roving, drawing, twisting, and winding it upon the spindle; while the mule draws and twists at
one operation as the carriage runs out, and then winds all the lengths upon the spindles as the ear-
riage runs in.*
The Mason Self-Actor little—As an example of the best form of American construction of this
885.


machine, we present in Figs. 883 to 886 views of the self-actor mule constructed by Mr. William
Mason of Taunton, Mass. Fig. 883 is a perspective view, Fig. 884 an elevation of the opposite
side, and Figs. 885 and 886 plan and elevation of carriage and drawing-rolls. This mule differs
___1-
* Knight‘s '" Mechanical Dictionary."
26
402 COTTON -SPIN N I N G MACHINERY.

from all others mainly in the manner in which all the movements appertaining specially to a self-
actor are produced. In most other varieties the carriage is run in by means of a rope being wound
upon a kind of spiral scroll-wheel, the grooves in which the rope winds commencing with a small
diameter on one side, and increasing in diameter until the carriage has arrived at the middle of its
course, and then diminishing on the other side of the scroll until the carriage reaches the end of the
stretch. The carriage is then hauled out by another rope wound on a grooved cylinder that is uni-
form in diameter. These ropes need constant adjusting, as they are liable to stretch and vary with the
changes in the weather. In the Mason mule the carriage is run in by a crank motion. A crank-pin
is fixed in a large wheel, which by a pitman or connecting-rod is attached to a rack, the rack plying
886.

._- rfl‘










into a pinion-wheel, on the shaft of which is a large wheel that gears into another pinion on another
shaft that extends the whole length of the mule on its back side near the floor. On this back shaft
are a number of small chain-wheels, carrying endless chains that pass under the carriage and around
small pulleys at the front of the machine. These chains may be two, three, or four in number,
according to the length of the carriage and number of spindles. The carriage, being attached to
the chains, is not only run in through the intervention of the trainof machinery leading back to the
crank, but is also drawn out by the same train independent of the crank, as will be described fur-
ther on. The chains also hold the carriage perfectly square and straight. Thus the crank in running
half a revolution will, through this train, run the carriage in and give it the same motion over its
course as that of the piston of a steam-engine, which is the sweetest reciprocating motion that can
be produced. The carriage eari be run in in less time with this motion than any other, and it starts
and stops at a dead point without the slightest concussion or jar. The drawing-rolls are driven from
the main shaft through a train of gear-wheels, and the band-pulleys that drive the spindles are on
the same shaft. The carriage is driven out by gearing extending from the front drawing-roll to the
same train that runs it in. Thus, when the carriage arrives out, the crank has returned to the
proper position to run it in again. The back-off motion and the depression of the faller are also
produced by a crank through the medium of the necessary devices, which enables this operation to
be performed quickly and smoothly without jerking or shaking. In the winding, a small quadrant is
employed in combination with a cam, the shape of which is so arranged as to correct the imperfec-
tions of the quadrant as it is ordinarily used. These mules work very quietly and smoothly, without
shocks or concussions, and can be run rapidly, and, it is claimed, with from 49 to 50 per cent. less
power than other varieties.
The space required for a pair of mules depends upon the number and gauge of the spindles, and
the relative position of the heads. If the latter are not set opposite to each other, a pair of mules can
be erected in a width of 16 feet from outside to outside of creel-box; 18 feet gives ample room. To
ascertain the length of a mule with any required number of spindles and gauge, multiply the number
of spindles by the gauge and add 58 inches.
The Parr- Curtis Mule—This mule, Figs. 887 to 890, is representative of the best English practice,
and is built by Messrs. Curtis, Sons & 00., Phoenix Works, Manchester. It is baSed on, and im-
proved from, the original mule of Richard Roberts. The motions are as follows: The rollers deliver
the yarn, the carriage is taken out, and the spindles are turned by bands from drums to which mo~
tion is given by the twist-pulley M The next motion is backing off the spindles to uncoil a suffi-
cient quantity of yarn to allow the faller to descend, and carry with it the yarn to the point where it
is to begin to be wound upon the spindles. The carriage is then drawn in, and the spindles receive
the yarn, so distributed as to form a cop. Fig. 887 is a side view of the headstock, with the carriage
in position of half stretch. Fig. 888 is a plan of the headstock, with a portion of the rollers on
each side, and of the carriage in the same position as in Fig. 887. Fig. 889 shows the details of the
regulator, and Fig. 890 the change-clutch mechanism.
Motion is given to the machine by the driving-pulleys O, which drive the twist-pulley M by the
rim-shaft I, which, by means of the bevel-gears A, Fig. 888, also gives motion to the roller-shaft
B, and through that, by the gears n, to the taking-out shaft K, on which a drum carries the band
L, which passes around a carrier-pulley on the front of the headstock, and returns to the front of
COTTON -SPI NN ING MACHINERY.
403















404 COTTON-SPIN N ING MACHINERY.

fl
the carriage; the other end being also fastened to the back of the carriage at a, and similar drums
at each end of the shaft being connected to the ends of the carriage. The twist-band 0 passes from
the twist-pulley 1V to the front of the headstock around the carrier-pulleys Pp, driving in its paS~
sage the pulleys k on the drum-shaft R, from which smaller bands are carried directly to the spindles
S, Fig. 887. The upright shaft T, Fig. 887, is driven by bevel-gears on the hub of one of the pul-
888.
M














_. , .
“.\‘~\-
‘ ' r
‘.“~“~__-~__-_-
-“‘-‘\‘\\\“\

“- ““_\\\‘\__















leys U, and, through another bevel-gear, gives motion to the winding-scroll U, Fig. 887, around
which the band 0 passes through the carriage, and is made fast to a take-up ratchet on the front
side, and draws in the carriage to the roller-beam, when the stretch and twist are completed. When
the belt is on one of the pulleys 0, the carriage is drawn out, and the rollers are put in revolution,
by the shafts B and K, driven by the rim-shaft I ; and when the stretch is completed, a spring
COTTON -SPINN IN G MA CHINERY. 405

shipper throws the belt upon the other pulley 0', which by the bevel-gear drives the shaft T, and by
means of the scrolls U draws back the carriage to its starting-point. While the drawing-out shaft
11’ is in operation, the shaft a, driven from it by the bevel-gears d, drives through thegears o the
cross-shaft m, a pinion, 9, Fig. 887, which works in the segment-gear g of the quadrant arm D,
raising it to a perpendicular position. Down this arm runs a screw, as seen in Fig. 887, on which
moves a nut to which is attached a chain, the other end of which passes round and is fastened to
the drum 7‘ in the carriage, which is geared to the drum R, which drives the spindles. When the
carriage is drawn in, this quadrant holds back on the chain, thereby revolving the drum 7', and
through it the drum R, giving motion to the spindles S, Fig. 887, and winding up the yarn already
produced; the change of position of the nut on the quadrant, as the latter drops over to a horizontal
position, increasing the tension of the chain, and consequently the speed of the spindles, as the yarn
is wound from the larger diameter of the cop down to the smaller one of the spindle itself. By
means of a ratchet and click the screw in this quadrant is given a rotatory motion, which carries
the nut at each stretch further toward the end of the quadrant, thus describing increased arcs, and
thereby causing the spindles to turn at each stretch more slowly at the beginning and more quickly
toward the end of each winding-on, the faller-wire beginning the winding-on each time at a higher
point on the spindle. When the double cone which forms the base of the cop is completed, the
winding-on, guided by the quadrant D, remains constant, as the nut does not move any more, while
the faller after each stretch continues to lay on the yarn successively at a higher point on the spindle.
The faller and counter-faller shafts are shown at 3;, Fig. 888, operating arms 2' z' and wires c.
Motion is given to these from the scroll b on the drum-Shaft, through the chain and lover shown.
Their operation is too well known to need further description.
On a cam-shaft, driven from the upright shaft T by the bevels and pinion, are cams (not shown)
for engaging and disengaging the clutch, which stops and starts the rolls as required, and also for
stopping and starting the drawing-out motion. The change-clutch W (see Fig. 890) on this shaft,
which effects these changes, is operated by the lever h, attached to the inside of the headstock, the
cams on each end of which are struck and moved by rollers attached to the carriage as it reaches
each end of the stretch, and which engages and disengages this clutch, one-half of which is fast to
the sleeve N, sliding on the shaft, and the motion of which shifts the belt on the pulleys C, and
efl’ects the other changes mentioned above.
The backing-ofi motion is given to the twist-pulley ill by a friction-clutch, which is put in opera-
tion for a few seconds when the belt is shifted from one pulley C to the other.
The regulator-shaft 1, with the snail 2, shown in detail in Fig. 889, is operated by a dog or finger














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4, which is attached to the carriage and connected with the counter-faller. Should the yarn be
wound too tight on the cop, the strain on the counter-faller depresses it, allowing the dog 3 to fall,
so as to engage in the snail 2, and give a rotary motion to the shaft 1, which is communicated by the
gear 3 to the screw on'the quadrant, and releases the nut 21, so as to slacken the strain a little. The
screws on the quadrant Q and the regulator-shaft 1 are run back by hand when the cop is com-
pleted. It is impossible to describe all the details of the motions without a great number of en-
gravings of parts; but it is believed that the above description will convey to a mechanic a sufficient
idea of the operations of this mule. .
VI. SPO0L1NG.—Thc yarn, having been taken from the spinning-frame, is now to be prepared for
the loom, which is accomplished by the use of three consecutive machines, forming parts of one
system, the first of which is the spoolcr, as represented in Fig. 891. This machine has a two-
fold purpose: first, to transfer the yarn from the small bobbin on which it is spun, containing from
1,200 to 1,800 yards, to a large spool, holding from 18,000 to 20,000 yards, which is done to save
labor in the next operation of warping, by putting so many yards of yarn on the spool that the
warper will not have to be stopped to piece ends; and second, by passing the yarn through a fine
slot in the guide which leads it on to the spool, to detect lumps or weak places, either of which will
break the yarn at the guide, and which being removed, and the sound thread tied with a firm and
even knot, leaves it in condition to run through the warper without breaking.
The construction of this machine is very simple, consisting of merely a main cylinder or drum, driving
from 60 to 120 strong upright spindles carrying the thread spools, with the accompanying bobbin-
406 COTTON —SP'IN N I N G MACHINERY.

holders and thread-guides. The “Wade bobbin-holder,” the invention of A. M. Wade of Lawrence,
Mass, is a recent and valuable improvement, by which a semi-cylindrical cup or trough, A, Fig. 892, is
substituted for the spindle formerly used to hold the bobbin from which the yarn is to be wound.
891.






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The bobbin is simply laid in this cup, from which it is prevented from “jumping” by a pair of bent
wires B, hung loosely from a pivot a few inches above, but allowing perfect freedom of rotation. This
permits bobbins spun on any spindle to be spooled ofi equally well in the same spooler. The loosely
hung wires close together as the bobbin is
unwound, always keeping it in its place,
but are so light as to cause less friction
than was due to its rotation on the spin-
dle formerly used. A spooler of 100 spools
will require one-quarter horse-power, and
spool off 2,000 lbs. of 30 yarn per week.
VII. “Harmon—The next machine is the
warper, which prepares the yarn for the
dresser. In the improved form of warper
made by Messrs. George Draper & Son of
Hopedale, Mass, a V-shaped frame, called
a “creel,” receives a sufficient number of
the large spools, already filled, to form from
one eighth to one-fourth of the proposed
warp, usually between 300 and 400—this
being as large a number of threads as can ~
be properly attended to at this machine. From this creel the threads are brought together into a
flat sheet between a pair of guide-bars drawn through a “reed,” which spaces them at equal dis-
tances, and then pass between a pair of light rollers over a movable or rise roll, through a second
pair of rolls, and then through what is called the warper-box, which consists of a frame carrying a
number of light hooked wires equal to the number of threads to be warped. In this machine as
described these wires are loosely hinged, in such a manner as to fall backward when not kept in a
nearly perpendicular position by the friction of the threads, over one of which each wire is hooked.
From the wires the yarn goes to the “section-beam,” so called, on which it is wound, and to which
is communicated the power to drive the machine.
So long as all the threads are unbroken, the machine once started runs smoothly; but if one thread
breaks, its wire falls backward to a horizontal position, and catches in a light “vibrating bar,” the
interruption of the motion of which, by means of a spring and lever, throws off the driving belt and
stops the machine. The “ rise-roll” now comes into operation ; and being so hung in slotted guides
at either end as to have perfect freedom of motion perpendicularly, and so balanced by weights
underneath as always to lift with gentle pressure, it at once rises sufficiently to “take up the slack”
of the yarn, which for an instant continues to be delivered by the spools, the motion of which is not
arrested by the stopping of the machine. After the broken thread is mended by the attendant, the
wire is lifted to its place, and the machine is again started. When the section-beam is filled, it is
removed and taken to the dresser.
VIII. DRESSING.—The dressing machine at present entirely superseding all others is an English in-
vention, known as the “slasher” dresser; and Fig. 893 represents the most improved form as built by
the Lowell Machine Shop, in which A A are the section-beams, as taken from the warper, B the size-
trough and “squeeze-rolls,” C' C the drying cylinders, D the lease-rods, and E the loom-beam on
which the warp as finally prepared for the loom is wound. .
The section-beams, having been filled at the warper, are taken to the “slasher,” where four or more,
as required to form the warp, are placed in their positions, and the yarn from them is then carried
through hot starch, kept so by a steam-pipe, in the size-box B; and the superfluous size being
squeezed out, while the body of the thread is by the same pressure well filled, it passes around the
large drying cylinders C 0, made of copper or galvanized iron, then through the lease-rods D,
where the threads are separated, and is finally wound on the loom-beam E. In order to form the
892.


COUPLING, OAR. 407

“lease,” so called, by which the threads are separated into two equal parts or “sheds” for the
weaver, a piece of thread or string is passed between the threads coming from the section-beams, at
the first start, so as to divide 2 from 2, or 3 from 3, as may be; after passing the drying cylinders
one of the iron lease-rods is substituted for this string, and the different threads of each half are
further subdivided by the successive ones, so that no two threads shall be stuck together by the size.
As each beam is filled a fresh lease-string is run through for the use of the weaver. Another form


of slasher, instead of drying cylinders, passes the yarn through a closed box heated by steam-pipes,
in which the air is kept in circulation by a fan. This form is by some considered preferable for fine
yarn.
Works for Reference—“Hand-Book on Cotton Manufacture,” Geldard, New York, 1867; “The
Science of Modern Cotton-Spinning,” Leigh, London, 187 6. S. W.
COUPLING, CAR. See RAILWAY CAR.
COUPLINGS AND CLUTGHES. Couplings for shafts are divided into two classes, couplings
(proper) and clutches. The chief difference between the two is, that a coupling is a permanent con-
nection, or rather one which requires some time and labor to take apart, while a clutch is a junction
that can be disconnected instantly by suitable mechanism embodied in it. Whatever the form of
coupling used, it should be of such a nature that the strength and rigidity of the line of shafts shall
be at least as great at the joints as elsewhere.
COUPLINGs.—One of the simplest forms of coupling is the flange or plate coupling. This, as shown
in Figs. 894 and 895, consists of two flanges fitted independently to the ends of the shafts to be
united, and then secured together by through bolts a a.
Some millwrights have contented themselves with fitting the flanges loosely to the shafts, and driv-
ing in a taper key or wedge to secure them in place; but this is always bad practice in either coup-
lings or pulleys, as the taper key tends not only to burst the hub, but also to confine the contact to a
single line, and thus to increase the chances for it to work loose. The plate-coupling, fitted accurate-
ly and forced on the shafts under pressure, faced up in place, and secured by closely-fitting belts in
reamed holes, is undoubtedly qualified to fulfill the requirements of strength and rigidity; but it is
open to three serious objections: it re- _
S94— 895- quires skilled labor and additional time to





fit the shaft to the coupling; it necessi-
, /, ,""' , tates the use of open-sided or hook hang
ers, which are needlessly heavy and ex-
...._ ._
. {1&1
G



pensive; and finally, it involves the use of
pulleys made in separate halves, to be bolt-
ed together upon the shaft. These disad-
vantages—all entailing increased first cost
' and constant inconvenience whenever it
becomes necessary to disconnect the shafts in order to change pulleys or for any other purpose-—
finally led to the introduction of adjustable couplings. These have almost entirely supplanted the
plate-coupling in the United States and have made large progress abroad. Numerous patterns, all
more or less successful, are now made. For description we select one of the oldest of them, and
one which is claimed to fulfill best the conditions of a perfect adjustable coupling. These may be
enumerated as follows : it must secure the shafts so that their axes will form a continuous straight
line; it must be rigid and strong, as already noted ; it must grasp each shaft-end independently, but
with the same force; it must be able to accommodate itself to slight differences in diameter, and must
do this without being thrown out of centre; it must be easily and quickly put on and taken off ; and
it must be cheaply made. The patent double-cone vise-coupling, Figs. 896 and 897, made by Messrs.
\Villiam Sellers & Co. of Philadelphia, consists of three principal parts, an outer sleeve a and two
internal sleeves b b,-Fig. 897. The external sleeve is cylindrical outside, but is bored a double taper
inside; that is, its inner surface has the form of two conical frusta meeting in the centre of the
coupling. The internal sleeves are bored to fit the shaft, and are turned outside to fit aecumtely into


408 COUPLINGS AND CLUTCHES.
the taper holes in a, but are large enough to remain say three-eighths of an inclrapart when put into
the opposite ends. Both the shell a and the cones b b are provided with slots in which may fit the
square bolts 0 cc ; and the latter have also a keyway in the centre, and are rendered elastic by slot-
ting quite through in one of the bolt grooves. If new the cones be put into the shell, the belts in-
serted, and the nuts screwed down, it will be seen at once that the cones Will be forced into the shell,
will contract in doing so, and will bind on the shaft with a force proportioned to the power exerted
to drive the cones into the shell ; and it is manifest that this acts in no way to spoil the alignment
of the shafts or to throw the coupling out of centre. The fundamental principle of the Sellers coup-
ling is the use of an external sleeve surrounding two flexible internal sleeves, which grasp the end


of each shaft independently; and this principle, first applied in this device, is that upon which all of
the better class of adjustable couplings have since been made. When coupling together shafts of
difierent sizes, it is best to reduce the larger size to the smaller, and to use a coupling of that size,
thus saving in weight and first cost (Fig. 898).
Special couplings have been devised to connect shafts whose axes do not form a continuous straight
line. For this purpose strong spiral (or helical) springs have been used; but probably the best known
device is what is known as Hooke’s universal joint, from the inventor, Dr. Robert Hooke. The ob-
ject of this coupling is to unite shafts which are inclined to each other in the line of direction, and
which do not therefore admit of being rigidly connected, as in ordinary cases. This coupling is very






897.
a 898.
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commonly employed in light machinery, as in steeple clocks, for taking off the index-motion, and is
then usually constructed by forming an are on the two extremities which it is intended to connect,


(l
and forming the joint by a central cross <b+b , the extremities of the are on the end of one shaft
(1
being jointed to the arms a a, and the extremities of the are on the other shaft to the arms 6 b, at
right angles to the former. But this simple mode of construction is not adequate to the purposes
for which the coupling is required in a line of shaft-gearing; in this case, although the principle is
not in any way changed, the construction is much more substantial. Figs. 899 A and 899 B represent
a form of it adapted to heavy strains. A is a strong disk keyed on the end of each shaft, carrying a
899 A 899 B.


pair of bearings for the reception of the gudgeons formed on the extremities of the cross. Fig. 899 n
is a face view of one of the disks, showing the cross in its place, with its alternate journals disen-
gaged. In Fig. 899A the shafts are shown at nearly the limit of the angle to which the single
joint ought to be applied. This angle ought not to exceed 15°; when a higher angle is introduced,
the rotatory motion becomes very sensibly irregular, and the friction is greatly increased. This
defect may be obviated by using a double joint.
CLU'renEs.—Of these devices there are two kinds—those which cause a positive engagement or
interlocking of the connected parts, and those which determine the junction of the latter by close
frictional contact. The weight of advantage is in favor of the latter system, through its preventing
the shock otherwise due to the sudden starting of the machinery.
In the cl uteh represented in Fig. 900, which belongs to the former class, a and b are the two parts
of the coupling, formed on the acting faces into alternate projections and recesses, such as they
COUPLINGS AND CLUTCHES. 409
correspond to, and exactly fitting into each other when in gear. The part a is, in this example,
cast on a spur-wheel, from which the motion of the shaft is supposed to be taken off. Both of the
parts a and b are to a certain extent loose on the shaft; the former being capable of moving round
on it, though deprived of longitudinal motion by washers and pins marked e, and the latter being
free to slide on the shaft, though prevented from turning on it by a sunk key, which slides in a slit
inside the clutch or sliding piece b. The mechanism is put into gear by means of the handle cl, which
terminates in a {ark with cylindrical extremities c; and it is obvious that by the contact of the flat
faces of a and , the latter will immediately carry with it the other part at the same speed as the
shaft. Supposing, now, that the motion of the wheel a is suddenly accelerated, the oblique faces of
the couplings immediately fall out of contact, and slide free of each other, leaving the couplings
clear, and the shaft free to continue in motion. In the old form of this eontrivance, known as the
sliding bayonet clutch, the part 6, instead of the tooth-like projections on the face, had two or more
prongs which laid hold of corresponding snugs cast on the face of the part aP-whieh, moreover, was
at















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\





usually a broad-belt pulley introduced with a view to modify the shock on the gearing on throwing
the clutch into action. In an older form still the pulley was made to slide end-long on the shaft. A
form analogous to this was known as the “ lock-pulley.” Instead of the end-long motion common to
the other modes, the parts were “locked ” together by a bolt fixed upon the side of the pulley, and
which, when shifted toward the axis, engaged with an arm of a cross, of which the part b, in Fig.
900, is the modern representative. The belt was worked by means of a key and stop, the turning of
the key throwing back the bolt, and thereby unlocking and disengaging the pulley.
One of the simplest forms of frictional clutches is the friction-cone clutch represented in Figs. 901 A
and 901 B. It consists of an exterior and interior cone, a b ,- a is fastened to the shaft A, while 6
slides in the usual way on the feather f of the shaft B; pressing 6 forward, its exterior surface is
brought in contact with the interior conical surface of a ; this should be done gradually; the sur-
faces of the two cones slip on each other till the friction overcomes the resistance, and motion is
transmitted comparatively gradually, and without danger to the machinery. It must be observed
410 COUPLINGS AND CLUTOHES.

that the longer the taper of the cones, the more difficult the disengagement ; but the more blunt the
cones, the more difficult to keep the surfaces in contact. The limiting angle of resistance for sur-
faces of cast-iron upon cast-iron is 8° 39', and this angle with the line of shaft will give a very good
angle for the surfaces of the cones of this material. When thrown into gear, the handle of the
lever or shipper is slipped into a notch, that it may not be thrown out by accident.
Another friction-cone clutch is represented in Fig. 902. The two parts of this coupling, 0 and d,
are arranged on the shaft b, in the same manner as in Fig. 900. a is a shaft driven by'mcans of
bevel~gear off the main shaft 1), its motion being derived from the latter shaft through the coup-
ling. c is an interior cone east upon the back of the bevel-wheel; (Z is an exterior cone having the
same taper as the cone 0, such that by means of the handle 0 it may be moved into contact with the
interior cone. The surfaces being supposed to be well fitted to each other, the cone (1 will by its
friction drive the cone 0, and thereby also the upright shaft. When either of the shafts a orb is
accidentally stopped, the cones immediately fall out of gear, and the connection is broken. They
are held in gear by means of a screw, or more commonly, and perhaps better, by a weight.
Another mode of accomplishing the same purpose in small machinery, by means of an cpicyclic
train, is represented by Fig. 903. In this the shaft AA is continuous, and supposed to be that
through which the motive power is transmitted. The wheel a is fast, but the wheels marked 1) and a
run loose on this shaft. The two pinions (l d have their bearings in the wheels 0 c, and gear with the
two opposite bevel-wheels, a and 1). (One of these pinions only is requisite to complete the motion,
the second being introduced merely to maintain the equipoise of the system.) If new motion be
given to the shaft A A, it is clear that the wheel 6, which is loose, will be made to revolve in the
contrary direction to the wheel a, which is fixed, by means of the carriers (1 cl ; but no motion of the
wheel 0, if slightly opposed, will ensue; and so long as this last remains at rest, the wheels a and b
will have the same angular velocity in opposite directions. But if the motion of the wheel 6 be
opposed by means of a friction-gland e, which can be tightened by means of the T-screw marked f
to any degree required, the teeth of that wheel will serve as fulcra to the carrier pinions d (l, which,
becoming levers of the second kind, with the resistance at their axes, will carry round the wheel 0
with half the velocity of the prime mover a, and, gearing with the wheel h, on the main spindle of
the machine to be impelled, will transfer to it the motion which itself receives. We have supposed
the wheel I) to be held absolutely still, but it is obvious that it may be brought gradually to rest by
means of the friction-gland; and as the wheel 0 can attain motion only as the motion of the wheel 11
is reduced, and can attain its full speed only when 6 is brought to rest, it is clear that the wheel h,
and consequently the machine, may be brought into action without the slightest degree of shock, and
may moreover be driven at any velocity less than the maximum that may be desired.
Another mode of obviating shock in starting machinery, which has been long in use, is represented
by Fig. 904. On the shaft B is fixed a drum or pulley, which is embraced by a friction-band a as
tightly as may be found necessary; this band is provided with projecting ears, with which the prongs
b b of a fixed cross on the driving-shaft A can be shifted into contact. This cross can be shifted
end-long on its shaft A, but is connected to it by a sunk key, so that, being thrown into gear with
908.
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the ears of the friction~band, the shaft being in motion, the band slips round on its pulley until the
friction becomes equal to the resistance, and the pulley gradually attains the motion of the clutch.
The arms and sockets c c, which are keyed firmly on the shaft A, are used to steady the prongs and
to remove the strain from the shifting part.
Among the most improved friction-clutches manufactured are that made by Messrs. Brown 8:
Sharp, in whose device friction is produced by forcing two shoes against the interior surface of a
flange by means of a combination of the lever and inclined plane, and that made by Messrs. Bur-
well & Bates, which embodies a combination of wedges and lever to draw a flexible strap around a
hub, thus operating on the shaft or pulley to be moved with less leverage than the other devices, but
dispensing with the heavy flange which the others require. Fig. 905 represents the Mason clutch,
which is manufactured by Volney W. Mason 8: Go. of Providence, R. I. A movement of the sleeve
GRAN ES AND DERRICKS. 41 l

F along the shaft A forces out or draws in the segments E, whose adhesion to the flange B makes
the required friction, which may be regulated in amount by the adjustable arms of the toggle-joint
:
a; (ll ,
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The clutch should be so placed that when in action the toggles will have passed a trifle beyond the
straight line, so that there will be no tendency for them to fly out or to produce a pressure on F or
on the shifting lever.
GRAN ES AND DERRICKS. The common lifting crane consists of an arm or jib jointed to a post.
From the outer end of this arm a tie connects with the post. A weight suspended from the end of
the jib then tends to pull the latter downward, but the tie holds it back and is thus brought into a
state of tension. The jib is at the same time pushed down-
906- ward on its joint, and is therefore a strut. Thus the down-
ward pull of the weight is by this eontrivance decomposed into
two forces, one of which is resisted by a tie, the other by a
strut. The strains on these portions are determined as fol-
lows: Through C, Fig. 906, draw 0 B parallel to the tie A B,
and P Q parallel to the strut C B; then B P is the diagonal
of the parallelogram whose sides are each equal to B C and
B Q. Let B P be considered to represent a downward-pulling
force of 20 lbs. This maybe decomposed (see STATICS) into
the forces represented by B Q and B 0. But A B is equal to
B Q, since each of them is equal to GP; also BB is equal to
A 0. Hence, the weight of 20 lbs. being represented by A C, the strain along the tie will be repre-
sented by the length A B, and that along the strut by the length B C. If we suppose A B to be
3 feet long, 0 B to be 3 feet 6 inches, and A C 1 foot, it follows that the strain along the tie A B
equals (3 x 20) 60 lbs., and along the strut (3.5 x 20) 70 lbs., when the weight of 20 lbs. is sus-
pended. In every other case the strains along the tie and strut can be determined when the sus-
pended weight is known by the proportionality to the sides of the triangle formed by the tie, the jib,
and the upright post.
Suppose, however, that in practice the engineer is called upon to erect a crane to sustain a weight
of 10 tons, according to the numerical proportions we have employed forillustration : the strain along
the tie-rod would be 30 tons, and therefore the tie must at least be strong enough to bear a pull of
that extent; but it is customary in good engineering practice to make the machine of about ten times
the strength that would just be sufficient to sustain the ordinary load. Hence the crane must be
so strong that the tie-rod would only be broken by 100 tons suspended from the chain ; that is, by a
strain of 300 tons upon the tic-rod. This large increase is necessary on account of the jerks and
other occasional great strains that arise in the raising and lowering of heavy weights. For a crane
intended to raise 10 tons, the engineer must therefore design a tie-rod which not less than 300 tons
would tear asunder; and knowing the strength of the proposed material per square inch of section,
it is easy to determine a section of tie-rod capable of withstanding the strain noted. In the same way,
the strain on the jib amounting to 35 tons, the jib should be ten times as strong as a strut which would


412 CRANES AND DERRICKS.

collapse under that strain. It is also necessary to secure the upright support very firmly to resist
the pull of the tie. The hoisting machine may of course be of any suitable form. (For a complete
graphic demonstration of the properties of cranes, etc., see “Experimental Mechanics,” Ball, New
York, 1871.)
The same considerations apply to the structures known as derricks and shears. Thus a crane
represented at 1, Fig. 907, possesses essentially a jib A, tie B, and post 0. The derrick 2 has a
907
1 2 3

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a-i—a‘ __a_
single strut F, sustained by the guy E. Shears have two struts similarly sustained. The gin, 4,
is merely a framework of three or more legs. There is still another structure forming a second class
of derrick, namely, the boom derrick or balanced derrick, 5. In this case the boom D is swung to
its mast at the middle, and the weight W is balanced by a counterpoise P. In some instances the
opposite arm to that which sustains the weight is shortened and braced by guys leading to the mast
above and below.
The distinction between the appellations crane, derrick, etc., is, however, not very minutely kept,
and in many instances is practically disregarded. Thus a hoisting apparatus traveling on an eleva-
ted railway, so as to raise loads from beneath, is known as a traveling or overhead crane, although
the essential features of the crane already noted are wholly absent.
Games—In Fairbairn’s tubular crane, the jibs are made of metal plates so arranged and com-
bined as to form a connected series of tubular or cellular compartments. Fig. 908 is a vertical
I
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section of a crane of this kind adapted to lift a weight of about 8 tons. Fig. 909 is an elevation of
the same; Figs. 910 and 911 are cross-sections on the lines a b, 0 cl ; and Fig. 912 a transverse verti-
cal section on the line ilc. A A is the jib, which in its general outline is of a crane-neck form, but
rectangular in its cross-sections, as shown in Fig. 911. The four sides are formed of metal plates
firmly riveted together. Along the edges, the connection of the plates is effected by means of pieces
of angle-iron. The connections of the plates at the cross-joints, on the convex or upper side of the
jib, are made by the riveting on of a plate which covers or overlaps the ends of the two plates to be
joined ; the rivets at this part are disposed as represented in Fig. 913 (a plan of the top plates), and
GRAN ES AND DERRICKS. 413

known as “ chain-riveting.” BB is the pillar, which is firmly secured by a base-plate p to a stone
foundation, and fits at the top into a cup-shaped hearing, which is firmly secured to the side-
plates of the jib at or near to the point where the curvature commences, and on which bearing the




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jib is free to revolve. Fig. 912 is a transverse vertical section of the lower part of the jib, showing
the manner of fitting the bearings for the chain-barrel (which is placed in the interior), and the spin-
dles and shafts of the wheel-gearing by which the power is applied thereto. D is the chain-pulley,
which is inserted in an aperture formed in the top of the jib. The chain passing over this pulley
enters the interior of the crane, and is continued down to the chain-barrel. E is a pulley or roller,
which is interposed about half-way between the chain-pulley and the chain-barrel, for the purpose
of preventing the chain from rubbing against the plates. Fig. 914 is a plan of- the lower plates.
‘ 914.
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Fig. 915 is a vertical section of another crane, constructed on the same principle as that which has
just been described, but calculated for lifting much greater weights (say 20 tons); it diflers in having
the lower or concave side A A of the jib strengthened by means of three additional plates, B, B, B,
whereby the interior is divided into one large and three smaller cells, as shown in Figs. 916 and 917,
915.


which are cross-sections on the lines a b and c d of Fig. 915. This arrangement of the cells to
strengthen the lower or concave side is advisable, in order to obtain sufficient resistance to the com-
pression exerted by the load lifted, without unnecessarily increasing the weight of the other parts.
Fig. 918 represents an elevation, and Fig. 919 a plan, of a movable crane, arranged and used for
414 GRANES AND DERRIOKS.
laying the voussoirs in the inverted arches of the United States Dry Dock at Brooklyn, New York, by
Wm. J. McAlpine. This crane has been used for hoisting stone weighing from 10,000 to 15,000 lbs.
at the extremlty of the arm, which describes a circle of 50 feet diameter. It has also been used

918.











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with an out-rigger, by which stones from 3 to 5 tons weight were hoisted 10 feet beyond the extrem-
ity of the arm.
_ A similar crane was used by the same engineer in the construction of the locks of
the enlarged Erie Canal. A‘movable sheave traversed along the arm of the crane, which was laid
919.
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Bonn—1 inch = 8 feet.
on an inclination toward the mast of 20°. By the use of the “Siamese blocks,” the stone is moved
toward or from the mast and hoisted or lowered with the accuracy requisite for setting fine-cut stone.
Fig. 920 is a side, and Fig. 921 an end elevation of a foundry crane, as constructed at the Lowell





wfi
CRANES AND DERRICKS. 415

Machine Shop. It is operated as follows: The weight is suspended from the sheave J, and is raised
by the chain passing over the pulleys H and K, and around upon the barrel 0, either by the boom A
or the pinion L, according to the weight to be raised. The pulley H is suspended from .a carriage
supported by the wheels E and F, traversing on rails at the top of the cope. Motion in or out is
920.







M
given to this carriage by means of the upright shaft and bevel-wheels
at B and P, which causes the drum .0 to revolve, and draw either at
the upper part of the chain, which, passing over the pulley G, is at-
tached to the outer extremity of the carriage, or at the lower part of
the chain, which is fastened to the inner extremity.
Fig. 922 represents a crane used at Woolwich, England, for hand-
ling heavy guns, which is capable of lifting a weight of 85 tons through
a height of 60 feet. The jib is of wrought-iron, 55 feet long, and is
attached at the bottom to a platform composed of wrought-iron gird-
ers mounted upon four pairs of cast-iron rollers, which run along the
sweep-plate or roller-path. Two of the pairs have a cogged wheel
inside,l‘worked by the hydraulic gear, for revolving the crane within
the circle of the roller-path; the other rollers are plain. Each pair

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of rollers is carried in a cast-iron roller-box, provided with gun-metal _ __ ,
bearings for the axles to work in. The roller-path is of cast-iron, and ‘ l'.
the central pivot or bed, for the crane to work on, of the same mate-
rial. The latter is bushed with a gun-metal socket for the central pin "-2,-—
of the crane, and is connected with the cast-iron summit of the 7-foot “
screw-pile beneath by four wrought-iron bolts each 3 inches in diameter.
The central pin is of wrought-iron, and about 13:1L inches in diameter. It connects the crane to the
centre pivot or bed. The platform-girders are floored on the top with timber, to which, and direct to
the girders themselves, the bed-plate of the hydraulic engine for winding the chains and revolving
the crane is bolted. The stays for the jib are of wrought-iron, and are supported from the jib by
other cross-stays, as shown in the engraving. The mainstays are of cast-iron, and trussed together
41 6 ORAN ES AND DERRICKS.

922.












by diagonal stays 'of the ordinary character. A wrought-iron platform, lightly constructed, is sus. '
pended at the extremity of the jib, for facilitating the means of access to jib-end sheaves. A wrought
iron ballast-box, capable of holding about 100 tuns of gravel or slag ballast, is attached to the plat
923.



form-girders at the back of the crane, for the purpose of counterweighting the full weight of the
load. This counterweight, together with the natural stiffness of the crane,.is sufficient to overcome
the resistance of the load. . ,
CRANES AND DERRICKS. 417
4
Hydraulic Cremcs have of late years been introduced with great advantage where water under suffi-
cient pressure is available. The form of hydraulic crane used at Sir William Armstrong’s works is
represented in Fig. 923. The jib and pillar of the crane are of wrought-iron, and revolve in top and
bottom bearings. The crane has three motions, namely, lifting, turning, and traversing, all of which
are eifected by hydraulic power. The lifting cylinder A is made of double power, that is, it will lift
slowly or quickly as desired, by a ram and piston arrangement, the highest power being equal to 20
tons; the ram is 11 inches in diameter, and the piston 15}, inches in diameter, the length of stroke
being 6 feet 8 inches. The turning cylinders B are applied in the usual manner at the foot of the
crane pillar, the rams being each 4% inches diameter, with 5 feet stroke; and both the lifting and
the turning cylinders, with their valves, are fixed in a chamber beneath the level of the floor. A
three-port slide-valve is used for the two turning cylinders, and mitre-valves for the lifting cylinder.
The chain from the lifting cylinder is carried upward through the crane pillar, bending over a sheave
C at the top of the pillar, and passes successively over the pulleys of the traveling carriage .D and
the running block E, and is finally made fast at the extremity of the jib. For the purpose of over-
hauling the ram of the lifting press, a small press is placed between the two turning presses B; and
the overhauling action is effected by a chain being attached to the sliding head of the lifting ram at
I. The pressure in the overhauling press is constant, and its action is therefore equivalent to that
of a counterweight; the ram is 4% inches diameter, with 3 feet 5 inches stroke. For effecting the
traversing motion of the load suspended at the hook, the traveling carriage D is hauled inward and
outward by two presses H fixed to the back of the crane pillar, and connected by chains with the
traveling carriage; the ram of each press is 5!; inches diameter, with a 4 foot 7 inch stroke. The
alternating action of these presses, which is precisely the same as that of the presses B used for the
turning motion, is regulated by a three-port slide-valve If attached to the front of the pillar, with a
lever at each side for working it. The wa-
924. . ter is supplied to and discharged from these
presses by two pipes which pass through
the top bearing of the pillar, and the con-
nection between the valve and these pipes
is effected in each case by a trunnion-joint
at J J.
Wall Crane—Fig. 924 shows an exam-
ple of Appleby’s hand-power wall cranes.
These cranes may be fixed on any wall, pier,
or column of the foundry or forge; and so
convenient are they that a traveler may be
arranged over them if necessaiy. In foun-
dries several of these cranes, fixed diagonal-
ly with each other, are especially useful for
the lighter branches of the work, as the
floor in the centre will by this means be
entirely free for the heavier duties of the
overhead traveler, such as lifting heavy cast-
ings or ladles. The traveler is not then
wanted for the lighter part of the work, as
this is managed by the smaller cranes per-
haps more expeditiously than with the heav-
ier ones.
Overhead Trarelers are made of various
designs, the chief points to be observed in
their construction being the making of the main girders sufficiently strong for the weight they will
be required to support; andvin those worked by hand-power, the gearing should be of especially
good construction, for it must be borne in mind that the gross weight of both traveler and load has
to be moved every time the crane is put into operation. The girders are of several forms, some hav-
ing timber beams and wroughtiron truss and tie rods, while others are of wrought-iron of various
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sections. The heavier varieties are fitted with a central or platform girder, which to a great extent
supports the weight of the lifting and working gear with its framework.
Fig. 925 shows a traveler with the main and platform girder composed of wrought-iron, rolled in
H section and trussed. This form of traveler is frequently used where lightness is required with a
418 ORANES AND DERRICKS.

long spam. The general arrangement of the crab-gearing is as follows: The lifting gear is single
and double purchase, and the power is increased by blocks or chains, the upper sheaves for which
are carried in the transom on the top of the side-frames of the crab. The chain-barrel is keyed


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into the large spur-wheel to relieve the shaft from torsion, the ratchet-wheel is cast to the flange of
the barrel, and the brake-ring is cast to the spur-wheel; the brake-strap is lined with wood, and
fitted with a hand-lever. It will be seen that the two traveling motions are on one centre; the lon-
gitudinal motion, being the heaviest work, is given by the crank-handle; the lighter work of the
CRANES AND DERRICKS. 419

transverse motion is given by the hand-wheel, and as the attendant can have one hand on it and the
other on the crank-handle, a load can be simultaneously moved transversely and longitudinally any
short distance required, a condition most favorable to some operations.
Figs. 926, 927, and 928 represent an English wire-rope crane for lifting heavy work ranging from
15 tons downward ; it has a span of 40 feet, and traverses a length of 180 feet. The three different
motions for longitudinal traverse, cross-traverse, and hoisting are all derived from one endless steel-
wire rope, three-quarters of an inch diameter, and weighing 2 lbs. per yard. This rope is driven at
a speed of 4 miles an hour, by means of a clip-pulley fixed at one end of the shop, which is driven
by belts and gearing from the engine working in the shop. The rope extends the whole length of
one side of the shop, going and returning on the same side at the level of the traveler, and passing
round a loose pulley at the further end. The rope is entirely unsupported between the two ends, and
is not strained tight, but hangs loose with only a slight tension, because the peculiar action of the
clip-pulley allows of the whole power being communicated to the rope by the grip of the pulley
through half of its circumference, even when the tail-rope is entirely slack. The clip-pulley A, Fig.
926, fixed at the end of the shop, is speeded to drive the wire rope B B at the rate of 4 miles an
hour, and lays hold of the rope with an amount of grip proportionate to the strain thrown upon the


O
rope by the load, releasing it from its grasp when the rope has passed the centre line. The construc-
tion and fixing of the movable jaws or clips round the circumference of the clip-pulley is shown in
Figs. 927 and 928. At one end of the traveling platform 0 of the crane is fixed another clip-pulley
D, of the same size and construction, round which the same wire rope passes, making three-quarters
of a turn. The rope then passes on to the further end of the shop, and round the groove-pulley B
at that end. This pulley is centred in a sliding frame provided with an adjusting screw G, for tight-
ening up the rope to any tension required. It has not been found necessary to have any sliding weight
attached to this frame, for variable tension of the rope.
The lifting gear consists of a very long cast-iron nut or screwed barrel H H, extending nearly the
whole length of the traveler, as shown in the plan, Fig. 929; and inside the“ barrel works a short
980.








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screw I, sliding on two feathers upon the long shaft J J, which is driven by a friction-clutch from the
clip-pulley D on the traveler, so that by the revolution of the shaft the screw is traversed along with
the barrel. The long driving-shaft J is supported at intermediate points of its length by the two
sliding brass steps KK, sliding along freely with the barrel H, and kept apart from each other at
420 GRAN ES AND DERRICKS.

the distance of half the length of the barrel by the rod L; by this means the shaft J is never
left unsupported for more than half its length. One end of the hoisting-chain being attached to
‘ .
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the screw-frame 1V, Fig. 929, the chain .N passes along through the inside of the barrel H, round
a pulley .P at the further end of the traveler; then over a pulley on the cross-traversing car~
riage R, Fig. 927, down to a snatch-hook, and up again over a second pulley on the carriage
R; and the end is attached to the nearest
extremity of the traveller at /T. The crane 932.
has two speeds for the lifting gear, one being
at the rate of 6 feet per minute, the other
at the rate of 3 feet per minute; and at the
latter speed the crane is calculated to lift 15
tons.
Traveling Cranes—Fig. 930 represents a
portable crane constructed by Messrs. W. Sel-
lers & Go. It is designed to accompany goods
cars, and to be used in loading and unloading
freight at way stations on railways. The chain,
passing over sprocket-wheels, is coiled in a box {mm
on the platform. This arrangement permits the use of a very much longer chain than I. _ is admissible when wound on a drum in the ordinary manner,- and diminishes the size, "l ‘i', ‘ “ “(a-1t.
parts, and amount of machinery required in
the hoisting gear. The swinging gates serve
to spread the base of the car in any re-
quired direction when the crane is in use.
These gates ordinarily lock to the side of the
:ar.
Fig. 931 represents a large 7-ton steam travel-
ing crane built by Messrs. Appleby of London.
The engines are carried on a base-plate which
rotates on friction-rollers. The boiler and ma-
chinery serve as a counterbalance to the weight
to be lifted. The work is done with a pair of


CRANES AND DERRIOKS. 421

direct-acting steam-cylinders placed slightly on the incline, one outside each side-frame, the crank-
pins being fitted into a pair of balanced disk-plates. In addition to the usual lifting and turning
motions, each crane has a neat arrangement for traveling by steam, and for altering the radius of
the jib by the same agency. The engine-shaft between the side-frames carries a bevel-wheel, made
fast or loose on the shaft by means of a toothed clutch, for driving an oblique worm-shaft gearing
into a tangent wheel on the derrick-chain barrel for raising or lowering the jib, the worm-wheel
securely locking the wheel in any position. A broad spur-wheel is geared on the crank-shaft, and
works a narrow wheel below it on a weigh-shaft, which has a small crank-pin at each end equal in
length to the stroke of the slide-valves. The narrow wheel can be moved by a hand-lever laterally
about 4 inches on a spiral feather, thus reversing the valves for running the engines in either direc-

Sonia—g inch = 16 feet.









tion. A pair of spur-wheels are placed on the left side of the crank-shaft, and gear into wheels on
the countershaft below. One pair of these wheels are of equal and the other of unequal diameters,
and either pair can be made drivers by means of a 'double-toothed clutch. Provision is made for
working the crane by hand if necessary through the shaft, which also carries a set of bevel-wheels
'422 ORANES AND DERRICKS.

984.




Maul 10’ 0‘














and double friction-cones for driving the slewing and traveling motions. As this shaft has two
speeds communicated to it from the engineshaft, it will impart two speeds to the slewin and travel-
ing motions. The motion from this set of wheels is transmitted through a train of wxeels to the
spur-wheel on the column, which is twice the depth of the pinions gearing into it. The pinions are
placed at different heights, so that the slewing pinion clears the pinion driving the traveling gear,
which is fixed. To travel the crane, the body is fixed to the carriage, and the wheel revolving on
the crane-post drives the traveling mechanism. The friction-cones are operated by an eccentric lever,
and can be thrown into contact while the engine is running, the jib being put in motion gradually.
0n the cones being reversed, they act as a brake and arrest the motion of the jib. A pinion sliding
en a feather in and out of gear, with a spur-wheel en the barrel-shaft, conveys the lifting motion
CRANES AND DERRICKS. 423

from the counter-shaft. This pinion is withdrawn for lowering, and the descent of the load is con-
trolled by a strap-brake worked from a foot-lever, which is fitted with a pawl and ratchet, so that
the load can be left suspended at any point of its descent. As the slowing motion can be put into
action through the cones while a load is being raised or lowered, considerable saving of time is
'eifected. The speeds of working arc in direct relation to the loads. As many as 60 or 70 leads
may be lifted and turned around in an hour with the quick speed.
Fig. 932 represents an overhead traveling crane as arranged for the loading of vessels along river-
fronts and decks. As constructed at the docks of Middlesborough, England, the traveling stage or
gantry of each crane has a span of 23 feet from centre to centre of the rails. The clear height is
17 feet 6 inches, and the traveling wheels are 12 feet apart. The crane and the whole of the sub-
structure is designed for a working load of 5 tons at the maximum radius of 21 feet.
DERRIGKS.——Fig. 933 represents a common form of derrick used for the setting of small stones.
The mast is supported in upright position by radial guys, made fast severally to posts set firmly in
the ground. The weight to be raised is attached to the lowest block, which is suspended by means
of another block to the end of the boom. The rope passes over the pulley or sheave in or on the
boom, and thence over another near the top of the mast; thence passing down parallel to the mast,
it is attached to a barrel or drum, and can be taken up or let out by means of a gear and pinion and
935.
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crank, thereby raising or lowering the weight. The boom can be raised or lowered by means of the
rope at the bottom of the mast, which is passed two or three times round a small fixed cylinder, and
is united to the end of the boom by a system of blocks. By the slacking of this rope, the boom
may be lowered while the weight is suspended, which enables the workmen to take up the stone at
424 CRANK.

one distance from the mast, and lay it at another more remote. The machine is swung into position
by a small rope attached to the end of the boom or to the weight itself.
Fig. 934 represents Savage’s derrick as improved by Mr. McAlpine, and used at the Brooklyn Dry
Dock for the laying of the heaviest stone. It difiers somewhat in its arrangement from the simple
emachine already described. It will be seen that the hook for the suspension of the weight is sup-
ported by two blocks. By tracing the position of the rope N o. 1, it will be seen that by it the right-
hand one of these blocks can be raised or lowered by means of the crank, pinion, gear, and barrel
N0. 1 of the crab, at the opposite end of the boom; in a similar way, the left-hand block is raised
by rope N 0. 2. Thus it will be seen that, by the winding up of rope N o. 1 on the barrel, a motion
upward and outward is given to the suspended weight, whereas by the winding up of No. 2 the
weight is raised upward and onward. Again, if rope N 0. 1 alone be slackened, the weight is lowered
outwardly. By these means the stone may be deposited at any spot within reach of the boom.
In Fig. 935 is represented the large floating derrick used for lifting blocks of béton weighing as
much as 100 tons, in the construction of the stone piers for the city of New York. The float is of
rectangular form, one side being 75 feet, the other '70 feet; its depth is 13 feet. It is stiffened by
16 trusses made similar to the well-known Howe truss. The tower which carries the ring-post and
booms is made of twelve pieces of Georgia pine, 14 by 14 inches at the lower ends, 63 feet 3 inches I
in length, and 12 by 12 inches at the upper end; these legs are stifiened by struts and braces. The
lower ends of these legs are fastened into a heavy cast-iron circle. At their upper extremities the
legs are brought close together, and are held by a casting of circular form, to which they are bolted.
This casting is made with a recess which is filled with spherical rollers, which rest against a casting
fitted to the ring-post, so that its lateral pressure where it passes the tower causes but little friction.
The front or hoisting boom of the derrick consists of two plate-iron box girders 22 inches deep by
9 j- inches wide; the upper and lower members of these girders are of channel iron three-fourths of an
inch thick; the side plates, which are riveted to them, are three-eighths of an inch thick. All the rivet-
holes are drilled. These girders are spaced 24 inches asunder, and are held in position at the ring-
post ends by being inserted in deep sockets formed in a heavy casting which encircles the post. The
boom is supported by 18 diagonal rods 24; inches in diameter, made of iron. These converge near
the top of the ring-post, and are secured to it. The following are the chief dimensions of the struc-
tures: Length of float '71 feet, breadth 66, depth 13; length of hoisting boom 60 feet 3 inches, of
back boom 50 feet 3% inches; length from end to end of boom, 110 feet 6%,. inches; height of tower,
62 feet 3 inches ; height of ring-post above tower, 49 feet 8 inches; total length of ring-post, 62 feet;
height from bottom of float to top of ring-post, 127 feet 3 inches.
CRANK. A crank is a lever or bar movable about a centre at one end, and capable of being
turned round by a force applied at the other end; in this form it has been used from the earliest
times as a handle to turn a wheel. When the crank is attached by a con-
936. necting-rod to some reciprocating piece, it furnishes a combination which is
extremely useful in machinery. .
Let 0 P, Fig. 936, represent an arm or crank centered at O, and connected
by means of a link or connecting-rod, PQ, with a point Q, which is con-
strained to move in the line (J E D. The formula 0' Q 2: a cos C +
i/b‘z — a2 sm2 0 gives the position of Q for any given position of the crank
C P; a being the length of the crank, b the length of the connecting-rod, and
O the crank-angle P O D. The space D E is called the throw of the crank.
The eccentric circle supplies a ready method of obtaining the motion given
by a crank and link. In Fig. 937, a circular plate movable about a centre of
motion at O imparts an oscillatory movement to a bar Q D, which is capable
\ of sliding between guides in a vertical line D Q, pointing toward 0. Since
P Q remains constant as the plate revolves, it is evident that Q moves up and








937. 939.
n D
I' O 9 0
LE
0 0
;
Q-- l
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o®



down in the line C .D, just as if it were actuated by the crank C' Pand the connecting-rod P Q ; the l
' length of the connecting-rod is in this case, therefore, equal to the radius of the rotating circle. It is
obvious that an arrangement of this kind would be little used, by reason of the oblique thrust on the
bar Q D. A second and more useful form is shown in Fig. 93.8, where the bar Q D terminates in a
CRANK. ' 425

half hoop which fits the circle. The form usually adopted in practice is derived at once from this.
A circular plate is completely encircled by a hoop, to which a bar is attached.
The cram/r with an injhzile h'nlc is shown in Fig. 939. Suppose the roller at Q to be replaced by a
~ cross-bar Q R, standing at right angles to D C; as the circle revolves, it will
cause the bar to reciprocate, C' P will remain constant, and P Q will always be
at right angles to R Q, and will therefore remain parallel to O D in all positions.
The crank with an infinite link also appears under the guise of a swash-plate.
Here a circular plate, EF, Fig. 940, is set obliquely upon an axis, A C, and by
its rotation causes a sliding bar P Q, whose direction is parallel to A C’, to oscil-
late continually with an up-and-down movement, the friction between the end of
the bar and the plate being relieved by a small roller.
In the reciprocating engine, which is the ordinary form of construction, the
rectilinear motion of the piston is transmitted through a connecting-rod to the
crank, and there changed into rotary motion. It is evident, therefore, that the
two ends of the connecting-rod travel different distances in the same space of
time, one end describing a path which is equivalent to the diameter of a circle in
which the other end of the connecting-rod passes through half a revolution in the same time; so
that the distances described by the two ends are as 1 to 1.5708, this being the ratio of the diameter
to the semi-circumference of a circle. Let the circle in Fig. 941 represent the path described by the
941.















centre of the crank-pin in one revolution of the engine. Suppose D F is the position of the crank,
and G F the position of the~._connecting-rod, when the piston is at the point G in the line A B, which
represents the stroke. ‘If the pressure on the piston at this point is represented by the line G H,
by drawing a perpendicular H 1 to the line A B at the point H, G I will be the effect of the given
pressure in the direction of the connecting-rod, and F K, equal to G I, will be the force transmitted
by the connecting-rod from the piston to the crank-pin. But the only part of this force which can
produce motion in the crank is that which acts tangentially to the circle at F, or in a perpendicular
direction to the crank D E To determine the magnitude of this tangential force, draw K L paral-
lel to the position of the crank, and FL, drawn perpendicular to the crank, will be the tangential
force required. In Fig. 941 the semi-circumference is divided into 10 equal parts, and the tangential








942.
E anced/(gift
2 _ .
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' IvRWARD 0° 18° 36° 9" 72° 90° 108° 1.26" 144-. ' 162° 100°.
REWAW 1:19" 162." 144? 126° /0.9° 90° 78" $4" 36" 16" 0°
943\
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inn/4.01) 0° 10' ° 9,“ 73¢ 90° A105" 126°“ P144." 1683 100°
figure/£0" In" IM° 126° 1oe° 90° 72° 54° 86 18° 0°
pressure is determined for each in the manner indicated above. If the pressures so determined are
then laid ofi on perpendiculars to a base line representing the path of the crank-pin, dividing it into
10 equal parts, the extremities of the perpendiculars can be connected by a curve, which gives the
rotative effect at every point of the revolution. This is illustrated in Figs. 942, 943, and 944, which
are diagrams of rotative effect for connecting-rods of different lengths. It will be seen that the
\
426 CRANK.

rotative effect is unevenly distributed through the two quadrants of the semi-revolution, on account
of the angularity of the connecting-rod, and that this irregularity diminishes as the connecting-rod is
lengthened. With a connecting-rod of infinite length, representing the casein which there is no
Ensure a): [2370:
l






foRWA/mo' 13° 36° 54° 72f 90° we“ .w~ IM° I °' 180°
Mir/AW /so°- 162,"; 144’ 1&6! ms" 90° 7a° '54” 66° 18° 0°
angularity of connecting-rod, as in the yoke connection, there is no irregularity in the two quadrants.
It will be seen that with any length of connecting-rod the rotative eficct at any point is generally less
than the corresponding pressure on the piston; and that at the ends of the stroke, when the crank
is“ on the centre,” the rotative efiect is zero. From these facts some have supposed that there is a
loss of power in its transmission by this form of connection; but, as has frequently been shown,
this opinion is not well founded. Power, it must be remembered, cannot be produced without
motion; and since the crank-pin travels through a larger distance than the piston, it requires a less
mean pressure to give the same power as is exerted by the piston. The reader who desires to in-
vestigate this subject more fully will find discussions in Scott Russell’s “Treatise on the Steam En-
gine ; ” in the Scientqlfic American for Aug. 22, 1874; and in the Iron Age, Sept. 25, 1873.
In the year 1849 the Society of Arts offered a prize “for the best collection of diagrams (with ex-
planations) to illustrate the action of the forces on a crank or cranks turned from a horizontal direct-
action steam cylinder or cylinders; the effect of various proportions of connecting-rods, and degrees
of expansion of steam, being shown.” The following diagrams were communicated to the Society
in accordance with their invitation, by TV. Pole, C. E., and obtained the silver Isis medal.
The varieties of expansion taken in these diagrams are three, viz. :
Steam admitted during the whole stroke (Nos. 4, 5, 6).
“ “ half the stroke (Nos. 7, 8, 9).
“ “ one-fourth the stroke (Nos. 10, 11, 12).
The varieties of length of connecting-rod have also been taken at three, viz.:
Connecting-rod indefinitely long, supposed to act always in parallel directions (Nos. 1, 4, 7, 10).
( Connecting-rod five times the length of crank, which may represent about the ordinary length
Nos. 5,8, 11).
Connecting-rod three times the length of crank, or about the shortest made (Nos. 6, 9, 12).
Diagram No. 1 is explanatory of the action of the
forces in the transmission of the power from the pis-
ton to the crank, for an indefinite length of connecting-
rod. The piston-rod is shown by the long dotted line.
The object of diagrams Nos. 4 to 12 is to exhibit the
values and variations of the forces at the beginning and
end of the engine; i. e., the pressure of steam on the
piston, and the force turning the crank round.
Each set of these diagrams contains a figure showing
the pressure on the piston at all points of the stroke,
on the plan of rectangular cofirdinates ; . the abscissa
representing the space passed over by the piston, and
the ordinate the corresponding pressure. Thus, when
the piston has moved from 0 to x, No. 7, or 11,,— of the whole stroke, the steam-pressure upon it is
represented by the line x y. The scale given under the left-hand figure, in Nos. 4, 5, 6, and which
also applies to Nos. ’7 to 12, shows the position of the crank corresponding to any given position of
the piston: thus, in N0. 6, it is seen by inspection that when the piston has passed through 1%,- of
its course, the crank has passed through about 81° from the dead point, and so on.
The right-hand figure in each diagram represents the tangential or working force acting on the
crank-pin at every point of its semi-revolution from .E to F, Nos. 1, 2, and 3. The curve of this
figure is also laid down by rectangular codrdinates ; the path of the crank-pin (reduced to a straight
line) forms the line of the abscissa, while the ordinates express the corresponding forces. Thus, in
N o. 5, when the crank-pin has moved from O to 0, or 120° from the dead point, the tangential force,
tending to turn it round, is represented by the line 0 o. The additional scale under this diagram
shows the position of the piston corresponding to any given position of the crank; thus, in No. 5,
when the crank is at 140°, the piston has moved through 196 of its stroke, and so on. The lines rep-
resenting the forces are measured by a scale, which is appended to diagram 4. The pressure of the
steam upon the piston, While the steam-valve is open, is made : 100 on the scale; and the ratio of
any other force to this pressure is therefore easily ascertained by simple measurement.
In No. 4, the connecting-rod is supposed indefinitely long; the pressure on the piston is uniform
at 100. The tangential force on the crank-pin begins at 0 when the crank is at the dead point,
increases to 100 when it arrives at 90°, and diminishes again to O in the same ratio as the increase.
The mean value of the force, throughout the semi-revolution, is = 63.6, which x the space passed



CRANK. 427

through by the crank-pin is exactly :1 the pressure on the piston x the length of its stroke; or, in
other words, the area of the figure 0 f g = the parallelogram a b c d. The result is in accordance
with the principle of “conservation of 02's viva,” by which we know that (neglecting friction) the
amount of power or work given out at the crank-pin is equal to that performed by the steam on the
iston.
p In No. 5 is seen the effect of the connecting-rod being made five times the length of the crank.
Here the tangential force, commencing at 0, arrives at a maximum value of about 102 when the
crank has passed through about 80°.




























4.
Two cranks at right angles.
b c 3 ‘ ______. -.'.--|. .. .--..
__ , —- Mean | l | .forQci-anks,
steam reassure 8 §' lI ) l in! I
W Ps'cfii 2‘ ' Mean '- - --‘-- - 'f— ' - -- forlcrank.
l “6 I miss P N i ' l
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a I ,1 13 “I ‘ t \
012345018910parts.uԤo:l Dead.-
,_ Dead
Stroke of Piston. \ I; J point e 10° 50° 90° 130° 1'70o g point.
Path ofcrank-pin.
30° 50° 100q 180°
In | l i l l ' - ' lj 1111]
Corresponding position of crank.
6 l
0 5


0 I23456789 lOpartsof
L I | i . . I ~s1roke.
Corresponding position of piston.
In No. 8, where the connecting-rod is three times the length of the crank, the tangential force
arrives at a maximum value of about 106 when the crank has passed through about 7 5°.
It will be perceived, however, that these variations make no difference in the mean force through-
out the whole figure; the effect of the connecting-rod being merely to vary in a slight degree the
distribution of the force over the path of the crank~pin, without affecting the total amount of power
conveyed to it by the machinery. The comparative merits of long and short connecting-rods, in
other points of view, involve considerations which it would be out of place to introduce here. _
The return stroke, or the other semi-revolution of the crank, does not exactly correspond with the
figures shown in diagrams 5 and 6, owing to the reversed condition of the connecting-rod. The
nature of the variation will be seen in N o. 6*, where the tangential force is shown for an entire rev-
olution of the crank. It will be observed here that the force at 10° (commencing at A') corre-
sponds with that at 350°, at 60° with 300°, and so on.





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u 500 iii O 1509






Nos. ’7, 8, 9 show the effect of cutting off the steam at half the stroke. Here the mean pressure
on the piston is : 84.6, and the mean tangential force on the crank-pin is = 54, the equality be-
tween the areas of the right- and left-hand figures being still preserved. The power of the engine is
diminished in the proportion of 1000 : 846, although the economy is much increased, as is well known.
Nos. 10, 11, 12 show the efiect of cutting off the steam at one-fourth of the stroke. Here the
mean pressure on the piston is: 59.6, the mean tangential force is = 38, and the power of the
engine is reduced from 100 to 59.6.
Nos. 9* and 12* show the values of the tangential force through an entire revolution of the crank,
in the cases above alluded to under corresponding numbers.
428 CRANK.

The combined action of two engines, with cranks fixed at right angles with each other, is shown
in six cases out of the nine previously described; namely, with three variations in the degree of ex-
pansion, and two in the length of connecting-rod. The curve of tangential forces is laid down for
10.
Steam
cut of.
Steam
cut of.












..‘._-.|_ _______-___-
. I. , _ _ l r . l I i l 50° 100° 150° 500 100° 150°



two cranks in diagrams 4, 7, 10, 6*, 9*, and 12*; in the three former for half a revolution (the
other half being precisely similar), and in the three latter for a whole revolution of the crank. It is
presumed that these figures will be understood without any further description. As an example: at
0, N o. 9*, one crank is supposed to have traveled 130° from the dead point E, No. 3, the tangen-
tial force on it being expressed by the line 0 p‘; the second crank will then have traveled 220° from
6*. , ~Te










l |
. V . l A I V _ .
0 30° 60° 90° 120° 150° 180° 210° 210° 270° 300° 3303 300°
90° 120° 150° 180° 210° 240° 270° 300° 330° 0 30° 00° 90°
AA', path of the two cranks. ‘













180° " 2400 l ' :meo
2700 3300 see 900


12*
I n? 1 1 '
1200 1800 ' '2400 ’ ' ' snub ' .3600
90° 150° 210° 270° 330° 30° 900
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F




the same point, and the combined tangential force will be represented by the line 0 p". The undula-
tions of the upper line will therefore represent the inequalities of the working power in the crank-
shaft throughout its whole revolution.
In laying down the forces in these diagrams, the following points have been assumed:
(a.) That as long as the steam-valve remains open, the pressure of the steam in the cylinder is
uniform. This is not always the case in practice, but must generally be assumed in calculation.
(6.) That after the steam-valve is closed, the steam expands according to Mariotte’s law, the pres-
sure varying inversely as the volume. This is the usual assumption. The causes of variation from
this law are treated of in works on the steam-engine, but cannot be comprised in an investigation
of the present nature. \
(a.) That no power is lost by friction in the transmission of the force through the machine.
(07.) The influence of the clearance space on the volume of the steam, in expanding, has been neg-
lected. This is but oflsmall moment, and its introduction would have interfered materially with the
simplicity and clearness of the diagrams.
CRANK. 429

(a) The moving parts are supposed to have no weight or mass, the forces being considered in a
statical point of view only.
The curves have been formed by finding the length of ordinates at convenient distances apart, and
tracing a curved line through the points thus obtained.
The methods of determining crank diagrams from the conditions of actual practice are fully de-
945.



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430 CRANK.

scribed and illustrated in Porter’s work on the “Steam-Engine Indicator,” and Rigg’s “Practical
Treatise on the Steam-Engine.” The graphical determination of the correction for acceleration and
retardation of the reciprocating parts, described below, is from the last-named work. Figs. 945,
946, and 947 give the rotativc efiect for connecting-rods 4, 5, and 6 times the length of crank re_
spectivcly, at every twentieth of the revolution of the crank, for any pressure on the piston. They
are carefully laid out from the same constructions as were made in determining Figs. 942, 943, and
944, and will be found useful in practice. The manner of constructing and using them needs but
little explanation. Suppose, in either figure, that the pressure on the piston when it is in a position
on the forward stroke corresponding to a crank-angle of 144°, or on the return stroke corresponding
to a crank-angle of 36°, is equal to the line A B. It is only necessary to set a pair of dividers to
this distance, and then move one point along the base line until the other point incloses the given
distance in a perpendicular direction between the base and the line marked “Reference Line,” when
the corresponding distance CB, which represents the rotativc pressure
0 for the given point, can be measured directly. The same method is to
be pursued, of course, for any given piston position which can be found
on the diagrams.
Suppose, in Figs. 94S and 949, that 0° A d C D and 0° C c a A repre-
sent the true indicator diagrams (as explained in the article INDICATOR)
taken from an engine, and that it is required to find the correspond-
ing diagram representing the rotativc effect upon the crank-pin. The
a, length of connecting-rod is supposed to be five times the length of
6 crank. In Fig. 950, make 0E equal to the length of either indicator
diagram, and draw a circle with this diameter, to represent the path of
the crank-pin. Divide the semi-circumference of this circle into 10
equal parts. A simple method of doing this is illustrated in the figure.
Bisect the radius D T. From G, the middle point, as a centre, draw the








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straight line G G, and from G as a centre,
with the radius G D, describe the are D H.
f From 0 as a centre, with the radius 0 H,
/ describe the are H I. Then 0 I will be
/ one-fifth of the semi-circumference, and
/ being bisected gives 0 K, the required
length. Continue the line E G, and lay off
the length of the diagram, to represent the stroke of the piston, so that its outer extremity is five
times I) G from the point 0'. Then find the points of stroke corresponding to the several crank
positions laid off in the circle, observing that the last position on the forward stroke is the first
position on the return stroke, the next to the last on the forward is the second on the return, and
so on. (The references to forward and return stroke are for direct-acting engines, the forward
stroke being that in which the piston moves from the end of the cylinder that is farthest away
from the crank. In back-acting engines, where the cylinder is between the guides and crank, the
forward stroke corresponds to the return stroke in direct-acting engines.) The points so deter-
mined on the line representing the stroke of the piston are then to be transferred to the indicator
diagrams, Figs. 948, 949, and perpendiculars erected, as shown. It will be seen from these figures
that while the crank-pin is passing over successive equal intervals, the corresponding spaces through
which the piston moves are unequal. N ow, as the crank is revolving at a practically uniform speed,
it is evident that the motion of the piston is being accelerated during one portion of the stroke, and
w
\\
\\
-\\\\
\
Ow
CRANK. 431

.... _
retarded during the other. Force is required to produce this acceleration, and is given out during
the retardation; so that the indicator diagrams, Figs. 948, 949, do not represent the true distribution
of pressure on the piston. The force absorbed by the reciprocating parts is greatest when the en-
gine is on the centre, and at this time its value, in pounds per square inch for a connecting-rod of
infinite length, is l f 2 h f '
revo utions 0 en- weig t o reciprocati radius of crank,
0‘000341 x ( gine per minute ) x ( parts, in pounds, Hg) X ( in feet,

area of piston in square inches.
If, for example, an engine has a cylinder 20 inches in diameter and 4 feet stroke, and makes 60
revolutions per minute, the weight of the reciprocating parts being 500 lbs., the foregoing expression
gives for the accelerating pressure, in pounds per square inch,
0.000341 >< time x 500 x 2 __ 3 9
314.16 " "'
Having determined the accelerating pressure at the commencement of stroke for a connecting-rod
of infinite length, in the case under consideration, make A B, Fig. 951, equal to this pressure on the

2 O









1’
scale of the indicator diagrams, Figs. 948, 94 9, and with A B
as a radius describe the circle A ED. As the connecting-
rod in this instance is five times the length of the crank,
make B 0 equal to one-fifth of A B, and draw the diameter
TE at right angles to A D. At the extremities of this diam-
eter draw lines parallel to A D, and lay off on these lines
distances TH, E C, each equal to Be. Find P, the centre
of a circle passing through the points H, c, and C, and draw
the are H c C, with Be as a radius. Divide the semi-circum-
ference A ED into 10 equal parts, and through the points of
division draw lines parallel to A D. Then A c, a b, c (1, cf,
etc., represent the pressures absorbed in accelerating the re-
ciprocating parts, and E 0, 108° 11', 126° f, etc., represent the
pressures given out during retardation for the forward stroke,
and exactly the opposite for the return stroke. These pres-
sures are then to be transferred to the diagrams, Figs. 948,
949, and added or subtracted, according as they represent
pressures absorbed or given out. In this manner the out-
lines of new diagrams, which show the true distribution of










o pressure on the piston, and which are distinguished by being
g; shaded, are produced. To transfer these pressures to the
°_ crank diagram, make A G, Fig. 952, equal to the distance
: traveled by the piston in one revolution, on the same scale
3%. as the Previous diagrams. A method of drawing a circum-
ference corresponding to a given diameter that is exceedingly
accurate is shown in the figure. A B is the given diameter.



at
war
it ,5? At the extremity A erect the perpendlcular A F; make A 0
'* o a l t lius and divide it into 5 e ual )arts. From
8 g , 3 equal to tie ru , . _ _ q 1 1
0Q "8 a , B, the other extremity of the given diameter, lay off 1) D
_ as equal to one-fifth of A C, and DE equal to two-fifths of
fig °,_ -_-:g s A 0; draw the straight lines GD, GE, make A F equal to
g s> C D, and draw F G parallel to C E; then A G will be the
k o4 °§ N circumference of the circle whose radius is A B. Divide this
‘° \ circumference into 20 equal parts, which can'be done as indi-
° °i cated by the dotted lines. From A draw a straight line A H,
cg a; and lay off from A toward H any distance 20 times. Con-
“°._._"_;§ nect the last point H With 0, and through the several pomts
\-
of division draw lines parallel to H G, which will divide A G
432 CRUCIBLES.


into 20 equal parts. Erect perpendiculars at the several points of division which correspond to the
crank positions in Fig. 950. Find from the diagram 946 the rotativc pressures corresponding
to the pressures in the shaded diagrams, Figs. 948, 949, and lay them off on the corresponding per-
pendiculars in Fig. 952. A curve drawn through the points so determined, as indicated, will rep-
resent the effective pressure on the crank-pin during a revolution; and if the area included between
‘ this curve and the base line is measured, a line representing the mean pressure can be drawn paral-
lel to the base line, including an area equal to that between the curve and the base line. This equiv-
alent area is distinguished by shading in Fig. 952, and it will be seen that it is so drawn as to add
an area equivalent to that cut off from the original crank diagram. The area of an irregular figure
similar to that in Fig. 952 can be measured with great accuracy by an instrument called the planim-
r
"\
/
952.
\\























0— ,_ - '1' ’7
..I ' J ‘ I _ ,I f I I,
I“ I > \ ' r I r. | 7 J V :6?
V V 7 '/‘//4%¢’4
A?" 18° 36" 61+ 72." 96° /0 ° °14f016z° we" 71;" 36° 4‘4! 73" 50" I08 " ' I z 180°
L w .15' ll V l
{VFW/18D R5701?”
eter, which calculates mechanically the area of a figure whose boundaries are traversed by a
pointer; or it can be computed by the aid of Simpson’s rule, which is explained in most works on
mensuration, among which may be mentioned Prof. Rankine’s “Useful Rules and Tables.”
The effect of the reciprocating parts on the distribution of pressure throughout the stroke of the
piston was first pointed out by Charles T. Porter, and the Porter-Allen engine is designed to produce
an even distribution by the application of this principle. It is easy to see that by varying the weight
of. the reciprocating parts, and the speed of the engine, almost any desired distribution of pressure
may be effected.
See SLIDE-VALVE for a table showing piston and crank positions for connecting-rods of different
lengths. The formulas by which they were computed are appended, as well as rules for the estima-
tion of rotativc effect, the latter being taken from H Tresca’s “Course in Applied Mechanics.” If
0 :ratio of length of connecting-rod to length of stroke, r : fraction of stroke completed when
crank angle = O, and a : distance from centre of cross-head to centre of shaft:
For the forward stroke-
a : c + 0.5 -— 1'
a2 + 0.25 — 09
a
° . 0
a :[02 + 0.25 —- c x cos. (180°— C'-- are sin. 8128 )]% ‘
r : c + 0.5 — a
For the return stroke-—
a : c — 0.5 + 2‘
cos. (180° -— C’) = a? + 0.25 - e?
a
a : [09 + 0.25 —- c x cos. (0— are sin. 81n' 0)]1}
cos. 0 ::



20
r = a + 0.5 -— c
If P: pressure on piston, p : corresponding rotativcv pressure on crank-pin, a: crank angle,
1 : length of connecting-rod, and 9' 2 length of crank—-
r x cos. a ]

l
(I? ~— 0‘9 x sin.2 a)r
CRAPING MACHINE. See CLOTH-FINISHING MACHINERY.
CROWN GLASS. See GLASS-MAKING.
CRUCIBLES. Vessels used for the fusion of certain metals, for assaying, and generally for many
other chemical purposes in which intense heat is employed. The principal requisites of a good cru-
cible are, that it should be capable of enduring the strongest heat without becoming soft or losing
much of its substance; that it should not crack on being exposed to sudden alternations of temper-
ature; that it should withstand the corrosive effect of the substance fused in it; and lastly, that it
should be sufficiently strong to support the weight of the molten metal when lifted from the furnace
p:PXSlI1.mX[1 PhLLB.
CRUCIBLES. 433

F.—
Crucibles which become tender at a high temperature are then liable to break or crumble when
grasped with the tongs, and are very dangerous.
Clay m'twiblcs are made of fire-clay, mixed with silica, burnt clay, or other infusible matter. In
order to counteract the tendency clay has to shrinking at high temperatures, the other substances are
mixed with it. The proportion of burnt to raw clay may be varied, but two-thirds raw clay to one-
third burnt clay is a very common proportion. It is necessary that there should be a sufficient
quantity of raw clay to produce the proper degree of plasticity for working. The unburnt fire-clay
must be ground, as must also the burnt clay, the latter generally consisting of old crucibles or glass-
pots, which have been exposed to high temperatures. The surfaces of these old pots must be
cleaned from all extraneous matter, and their vitrified coating be chipped off. Clays which contain
a maximum quantity of pure silica are best adapted for the most infusible crucibles, if in addition
they are comparatively free from such injurious admixtures as lime or iron; and the infusible proper-
ties can be strengthened by additions of burnt clay, such as we have indicated, or of powdered
coke and plumbago. The celebrated Berlin crucibles are made from 8 parts fire-clay, 4 parts black
lead, 5 parts powdered coke, 3 parts old ground crucibles. Another mixture is 2 parts fire-clay, 1
part ground gas-coke. The materials should be as free from lime as possible, well kneaded together,
and slowly dried in a kiln. When fire-clay is not easily obtainable, as a substitute for it steep com-
mon clay in hot hydrochloric acid, wash it well with hot water, and dry it.
The crucibles in most common use in Birmingham and its neighborhood, as well as in Sheffield,
England, are made of a fire-clay found near Stourbridge, which is generally mixed with some other
substance, such as powdered coke, in order to lessen its tendency to contract when strongly heated.
The following are about the average proportions: 4 parts fire-clay, 2 burnt clay cement, 1 ground
coke, 1 ground pipe-clay. These Stourbridge-clay crucibles, or casting-pots, are only carefully dried,
but not burned until required for use, when they are put into the melting—furnace first with the mouth
downward, and when red-hot are taken out, and put in again with the mouth upward. The melting-
pcts or crucibles employed by Mushet in the manufacture of cast-steel, or homogeneous metal, were
made by mixing kaolin or china clay with black or gray fire-clay from the coal measures, and pul-
verized old pots, the clays being passed through riddles having 64 to 100 meshes to the square inch.
The proportions used by Mushet are 5 parts by measure fire-clay, 5 parts kaolin, 1 part old pot, and
11} part coke-dust; the ingredients being well mixed, and then kneaded, tempered, and moulded in
the usual way.
When it is necessary to protect a crucible from the corrosive action of the material to be melted
_ in it, it can be lined with charcoal powder or black lead. In a small crucible, the powder maybe
made into a paste with a little gum-water or molasses, and rammed into the crucible, the central
cavity being afterward shaped by a small rammer of the desired form. For larger crucibles, a mix-
ture of anthracite powder, powder of gas-retort carbon, or gas-tar may be employed. To test cruci-
bles as to power to resist corrosion, protoxide of lead, or a mixture of protoxide of lead and dioxide
of copper, is melted in the crucible. If a clay crucible is not permeated or corroded by this mixture
to a sensible extent after a short time, it may be considered capable of resisting all ordinary corro-
sions in practice. As a rule, clay crucibles resist permeation and corrosion in the proportion of the
fineness and regularity of grain, but their tendency to crack is increased in the same ratio.
Cornish crucibles are principally used for assaying copper; they are made of a clay found in some
parts of Cornwall, and the smaller sizes are capable of resisting sudden alternations of temperature,
a' quality which is probably due to the large proportion of silica mixed with the clay, but they are
rapidly corroded by melted oxide of lead. Hessian crucibles were formerly employed to a much
greater extent in metallurgical operations than they are at present. They are made principally from
a clay found at Gross-Almerode, and in their composition resemble very closely the Cornish cruci-
bles. The form is triangular, and they are generally packed in nests of six, the smaller sizes fitting
into the larger. These crucibles are tolerably lasting at moderate temperatures, but are apt to fuse
when exposed to very great heat. Several kinds of French crucibles are manufactured, some of
which are of very excellent quality, especially those of Beaufay, called the m'eusets de Pam's, and
those of Dcyeux, termed creusets de Saveignics. Both kinds, however, contain a large percentage
of. oxide of iron, which renders them objectionable for some purposes. London crucibles are of a
reddish-brown tint, very close-grained, and capable of resisting the corrosive action of oxide of lead,
bnt‘liable to crack when suddenly heated. They are made of various sizes, from 2;} inches up to 81}
inches in height. For special metallurgical or chemical purposes, crucibles are sometimes composed
of platinum, lime, bone-dust, magnesia, pure carbon, and other materials.
Crucibles are made of various forms and sizes, according to the kind of work for which they are
intended; those used for assaying are scarcely larger than a lady’s thimble, while others made for
zincing shot will hold as much as 800 lbs. of molten zinc. Some are nearly cylindrical, others trian-
gular, and others skittle-shaped. A, Fig. 953, shows the pot and cover employed in melting steel,
while B is a common form of crucible for brass and the like. Small crucibles are generally kiln—
burnt before being used; larger crucibles are usually dried gradually in hot stoves. Where the
crucibles or pots, as they are familiarly termed, are made of fire-clay and upon the works, the pot
flask, or mould, and plug are commonly of the forms 0 and D. The pot mould is of cast-iron, with
two cars cast upon it to lift it by. Its inside is the shape of the outside of the pots; it is turned
smooth, and is open at the bottom as well as the top. There is a loose bot-tom made to fit, but not
so small as to pass through; this has a hole in the centre, three-quarters of an inch in diameter.
When in use it stands upon a low post firmly fixed in the ground, which also has a hole 5 or 6 inches
deep in its centre. The plug which forms the inside of the pot is of lignum vitae; it has an iron
cfintre which projects through it about 5 inches, corresponding in size with the hole at the bottom of
t e mould.
The clay for a steel-pot weighs about 24 lbs. ; it is moulded upon a strong bench into a short cylin-
28
434 CRUCIBLES.

der, and, the inside of the mould having been well oiled, the clay is dropped into it, and the plug,
also oiled, forced into the clay, while the projection finds the hole in the loose bottom in the centre
of the mould, which guides the plug. The plug is driven down 2 or 3 inches by the blows of a heavy
mallet on the top of the iron head; it is then taken out to be oiled again by putting a piece of round
iron through the hole in the iron head to lift by, giving it at the same time a screwing motion. It is


then driven by the mallet, while the clay, rising up between the plug and the mould, reaches the top.
The clay is cut even with the top of the mould by passing the knife round between it and the flask
or mould several times, holding it inclined toward its centre. The mould is now taken and set with
its loose bottom upon a small post fixed in the floor, and gently allowed to rest upon it. This
pushes up the bottom with the pot upon it; and the hole being filled with a bit of clay, the pot
is finished. When the pots are sufficiently hard to bear handling, they are placed to dry upon rows
of shelves against the fines in the furnace, where they remain from 10 to 14 days. Before use they
are annealed by being placed from 17 to 20 hours in a special annealing furnace ; and they are taken
directly from this and placed for use hot into the melting-furnace.
Crucibles are frequently made on an ordinary potter’s wheel, and special machines are also em-
ployed for the same purpose. One of these, T. V. Morgan’s machine ,for making either large or
small crucibles, is illustrated by Fig. 954. The
peculiar mechanical arrangement consists in fit- 954-
ting the former, or forming tool employed in the
apparatus, so that, in addition to being capable
of an up-and-down movement, the former is free
to be moved and adjusted horizontally as the
crucible is being moulded, and according to the
required size or thickness of the crucible. When
a crucible is to be made, the frame is pulled down
to cause the former to enter the plastic material,
which is placed in a mould, on a revolving lathe
or jigger, as uSual; and when the former reaches
the bottom of its course, a catch on one of the up-
rights secures the frame in position. The thread-
ed rod is then turned, to cause the former to
move horizontally and spread the plastic mate-
rial against the sidc of the mould. Finally, the
back end of a lever carried on the top of the
frame, and free to move backward by means of
a slot or otherwise, is inserted into a hole formed
for the purpose, and its forward end is pressed
down by hand, so that the lever bears forcibly
upon the frame, and prevents all' vibration or
movement of the former. When the crucible is
finished, the handle is turned to bring the former
to the centre of the crucible, the lever is moved
forward out of its hole, the catch released, and
the frame raised up by a balance~weight. The
operation is then repeated for the next crucible,
and so on. Fig. 954 is a section of Morgan’s ap-
paratus. a is the former, or forming tool; it is
fitted to a block b, which is, as before stated, free
to be moved horizontally in a frame a by means
of a screw (1, taking into a corrresponding thread
in a nut in the block b ,- the ends of the screw cl
work in fixed nuts on the frame 0, and the right-
hand end is provided with a handle 9, which is
turned according as the former a and block b are required to be moved. The frame a is free to
move up and down in slots formed in two uprights, and its weight is counterbalanced by weights k k,


CRUSHER. 435

“f
on the end of chains or cords passed over pulleys and connected to the frame. n is a catch on the
upright to secure the frame a in position when the former a reaches its lowest position. 0 is the
mould into which the plastic material is fed; this mould is carried on an ordinary lathe or jigger p,
to which rotary motion is imparted as usual. When the frame 0 is caught by the catch 12, and the
mould is caused to rotate, the screw (1 is turned by its handle 9, so as to cause the former a to move
horizontally, and spread the plastic material against the side of the mould; and when it has been
moved to the required distance, which is regulated by a scale on the frame, the back end of a lever
q, carried on the top of the frame and free to move backward by means of a slot, is inserted into a
hole formed in an upright, and its forward end is then pressed down by the attendant so that this
lever bears forcibly upon the frame a and prevents vibration or movement of the former. When
the crucible is finished, the handle g is turned to bring the former a to the centre of the crucible,
the lever q is moved forward out of its hole, the catch 12 is released, the frame is raised up, and the
mould is removed in the ordinary manner; all being then ready for the next operation. we is a hor-
izontal bar, under the platform and hinged at so, while its front end extends to the front of the ap-
paratus. a: is a block on the bar u, and y is a collar on the lathe-shaft. When it is required to stop
the revolution of the lathe, the attendant moves the bar at on its hinge 112, so as to bring the block 1
against the collar y. z is a horizontal bar or guide for the bar at. (The foregoing is abridged from
Spretson’s “ Casting and Founding”)
For graphite crucibles the foliated form of graphite (see GRAPHITE) is employed, and it undergoes
grinding as a preliminary process. It should not be ground so fine as to lose the appearance of
scales. With the plumbago thus prepared is mingled a small proportion of kaolin or china clay,
varying according to the use for which the crucible to be made is intended. To every 10 parts of
graphite is also added 7 parts of a gray clay which is imported from Klingenberg in Bavaria, besides
a little ground charcoal, the latter to secure porosity. These ingredients are mixed dry; water is
afterward added, and the compound passes to a huge cast-iron cylinder capable of holding about 3
tons. Here thorough stirring is done by means of arms arranged radially on a central vertical rota-
ting shaft. Each arm, bcsidcs having four vertical beveled blades, is made fiat above and beveled
below, so that the mass undergoes a kneading which secures its rapid and homogeneous mixing. The
material emerges of the consistence of thick dough, and is at once moulded into crucibles. This is
done either by hand or machinery, special forms being made in the former way.
The machine process is exactly the sameas that in common use by pottcrs for moulding plates,
teacups, etc. A plaster mould is prepared, which is placed on the rotating wheel. Into this the
ball of graphite dough is placed; and as the mouid rotates, a former is brought down into it from
above, which carries the material out against the sides and forms the inner cavity, according to
gauges previously adjusted. The mould is then taken from the lathe; and after the crucible has
become dry enough, the latter is turned out, placed upside down on the wheel, and its exterior
smoothed by hand. '
The baking process, which next ensues, does not differ from that followed by potters. Each cru-
cible is inclosed in a large fireclay vessel, known as a “ sagger,” and a number of these are heaped
up in the kiln. A “number” in crucible-making means 2 lbs. of material. When the baking is
finished the crucibles emerge hard, and varying in color from grayish white to blue-gray. The dif-
ference in hue is no criterion of quality, and is simply due to cracks or other imperfections in the
saggers.
In point of 'size, plumbago crucibles held from 2 ounces up to 600 lbs. Their average lifetime in
brass-making is from 35 to 45 heats. Clay crucibles can be used but once. For melting steel they
will run from 4 to 6 times, and longer if coated with a mixture of fire-clay, plumbago, charcoal (or
better, gas-carbon), and silica (pure fine quartz sand). Care should be taken to remove slag from the
surface after each melting. Old steel-pots are freed from slag, ground up, and rcmanul'acturcd into
crucibles. The same “meta ” used for crucible-making is also formed into plugs or valves in the
ladlcs used for conveying molten steel, made by the Bessemer process, to the moulds. Plumbago
crucibles may be generally employed, except in cases where a flux is used, as the flux would eat the
clay from the plumbago. In using them, they should be kept in a dry place, the least dampness being
fatal. It is well, for the first time of using, to put the crucible in the furnace at the time of light-
ing the fire, so that it heats up gradually with its surroundings. The pot should be placed in the
fire and not on it, and the fire should surround it to the very top.
CRUSIIER. Sec BREAKER on Caesars.
CULTIVATOR. See AGRICULTURAL Macmxnnx.
CUPEL. See ASSAYING.
CUPOLA FURNACE. See Funmcx, CtrroLa.
GURU-KNIVES Sec DAIRY Arrxuarus.
CUT-OFF. See Escmrs, Srsxn, Srxrroxxnr RECIPROCAT‘ING.
DAIRY APPARATUS. The following list comprises the apparatus and supplies necessary for
the fitting up of a dairy factory for the manufacture of cheese and butter, receiving the milk of about
450 cows:
1 steam-boiler, 4 horsepower, and fittings. ‘ 1 set hoisting-crane castings.
2 BOO-gallon steam-vats, complete. 1 curd-scoop.-
16 cheesepress screws, 20 inches long, 1'} inch 1 set stencil-plates, for dating cheeses.
diameter. 1 set stencil~plates, paste, sponge, and brush.
1 milk-conductor (can to vats). 1 wrench, No. 3.
1 curd-knife, 13 blades, 20 inches long. 1 large slate.
1 curd-knife, horizontal blades, 6 x 20 inches. 2 thermometers.
436 DAIRY APPARATUS.

1 scrubber mop. 1 siphon strainer.
1 cheese-trycr. Patent milk-pans.
1 steam-engine, 4 horse-power. Factory churns.
16 galvanized iron cheese-hoops, with follower Butter-bowls.
15 inches diameter. Butter-moulds.
1 standard scales, 600 lbs. Butter-workers.
1 standard scales, 240 lbs. Cheese-bandage.
1 weight-can, 60 gallons, large faucet. Linen strainer.
l curd-pail. Annotto.
1 best-pail. Steam-pipes, joints, valves, etc.
1 factory stencil-plate. Belting.
2 rennet jars, 15 gallons. Cooler-pails.
1 factory account-book. Pans.
1 set of milk-testing instruments. Press and cap cloths.
1 curd-mill. Renncts.
1 set casters for curd-sink. Dairy salt F.)
1 siphon, with valve and faucet.

Milk is delivered at the dairy in cans, of which there are several varieties in use. They are
made with only one seam, and the bottoms are of wrought-iron, and tinned. Their capacity is
from 15 to 50 gallons.
Ventilated milk-cans are used in order to allow the “animal odor” of the milk to escape, so that
the milk will not become tainted. Undoubtedly, if milk from cows in abnormal conditions is to be
transported, ventilation will be of great advantage; but if it is positively known that the milk is
from cows in perfect health, ventilation is entirely unnecessary, as has been practically demonstrated
by Hardin’s method of making butt-er, where every favorable condition is presented to injure the
milk if the “animal odor” possessed any such injurious properties. Still, for fear that the milk
from one cow in an abnormal condition might be mixed with the rest of the milk, ventilated cans
956./





“ 0' I \ \'
a 0‘0:\ 0}} “I; 0 | “p; \ '
‘n I". I a?!" ‘\'v\‘ 'n ‘.,'
. ‘ I



,5
are of great value, and their more general use is desirable. The
simplest ventilator is one invented by L. E. Arnold, and repre-
sented in Fig. 955. It is made by cutting a circular orifice in
the cover of a can, and soldering over the aperture a piece of
coarsely perforated tin, or of wire cloth, giving the latter a mod-
erate depression in the middle. Around the outside of the wire
cloth is soldered a flange of tin, 2 inches high, to prevent loss
of milk. '
Milk is sometimes aerated before it is put into the cans for transportation. If such be the case,
the atmosphere must be pure and sweet, and free from any injurious offensive odor. The dcocloriz-
ing strainm' and cooler, invented by Busscy, is simply a strainer-pail, raised about 2 feet above the
can, and arranged so that the milk falls in a spray into the can. Another method of aeration was
invented by Jones 8t Faulkner, and consists in forcing air into the milk. Fig. 956 shows the manner
in which this is accomplished.
Vessels for Selling illiZ/tv—The old method of setting milk in small tin pans is rapidly being limited
to the farm-house. The pans hold from 8 to 10 quarts, are light, and are easily handled. They
cool the milk readily without the use of water, and are easily cleansed; but they are not suitable
for large dairies. Another method of setting milk is in large pails, which are usually made of sheets
of tin 24 x 20 inches, and are from 19 to 22 inches high, and nearly 8 inches in diameter. These
pails are filled with milk within 4 or 5 inches of the top, and are then placed in “pools” to allow
the cream to rise. Care must be taken that the surface of the milk in the pails is not above that
of the water in the pools. '
An attempt has been made by Mr. Hardin to do away with the “pools” for setting milk, by the
introduction of a sort of refrigerator. I-lis method is shown in Fig. 957. As it is the nature of
heated air to ascend, the ice-shelf is placed in the top of the box, to secure uniform temperature. A
space of 1 inch is left open on each side of the shelf, to allow the air to pass around the ice. The
drippings from the ice are utilized to the extent of 4 inches in the bottom of the box. The cans are
made with a perforated rim on the bottom, to allow the water to pass under them. The covers of
the cans fit outside, so as to shed the water, and prevent any of the drippings from the ice getting
into the milk.
A milk-can designed to take the place of the water-pools and deep pails mentioned above is repre-
sented in Fig. 958. A complete set consists of four pans, with wooden vats containing them, and
the framework on which they stand, together with the supply water-pipe, skimmer, etc.; also all








DAIRY APPARATUS. 437
\
,.._..-
spouts necessary to operate them. The water is first passed through the centre of the milk and
near the surface, after which it surrounds the pan completely, always standing higher than the milk,
to prevent drying of the cream. The size of the milk-pans varies; some hold 8 gallons, others 90
gallons of milk at a time.






Another method of setting milk for cream is by means of shallow pans, of which there are a great
many varieties in use.
The Orange County milk-pan is shown in Fig. 959, and a section of the pan in Fig. 960, from
959.


which it will be seen that A represents the milk-pan, which is made of tin. The water-vat B is
made from galvanized sheet-iron. The patent water-regulator E is a hollow tube that can be
raised or lowered at pleasure. The situation of the top of this regulator determines the depth of
















960. 961.
1. A r [1'3 ‘-
| D i ’
1-. E
I: 8' J .c g
F .
é \
the water in the vat. The water rises in the vat around the milk-pans
to the top of the regulator, then passes down through it into the pipe ‘
F, and is conducted off. With this device the temperature is per-
fectly controlled. The bottom of the water-vat is supported by a
movable board-bottom in the rack, and between this board-bottom and the metal water-vat is put a
waterproof lining, which is a non-conductor of heat, and which prevents the atmosphere of the room
from coming in contact with the bottom of the vat, thereby leaving all the cooling properties of the
water to be used upon and to control the temperature of the milk. At each end


Q of the pan in the vat there is a space for ice to be stored, and, as it melts, the
water passes oif down through the regulator pipe. The Orange County milk-pan
i \ A 962.
l B
c n o D o
E


limp!“
\\
r“
|
\l
' it,
t
is made in double racks also, as shown in Fig. 961. When so arranged, the upper pan is reached by
By
means of a movable platform, which is kept under the rack, and, when wanted, is drawn out.
use of the double rack a set for 30 cows can be used in a room S x 10 feet.
The iron-clad pan is represented in Fig. 962. The illustration shows the pan fitted with steam
438 DAIRY APPARATUS.

apparatus, so that the temperature of the milk may be held at pleasure. If the “ scalding process”
for raising cream be adopted, the attachments to this pan render it very applicable for such object;
or if the ordinary process be employed, the cold-water pipes connected with the pan adapt it to that
system. In Fig. 962, pipes A are for the water-supply, F the waste-water pipe, G the sour-milk
964.


pipe, and opposite O on the other side is placed a thermometer for regulating the hot and cold water.
(For conversion of milk into butter, see CHURNS.)
Butter- Workers.---'l‘he common wooden bowl and ladle are still in use in small dairies for working
butter, and are undoubtedly the best for the manufacture of butter on a small scale. For an exten-
sive manufacture, though, other devices become
more economical.
An improved butter-worker is shown in Fig.
963. It consists of an ordinary butter-bowl
@ attached to a stand, on which it is free to re-
volve. A ladle is attached to a lever over the
bowl in such a manner that it can be worked
up and down, from one side of the bowl to the
other, and, in fact, in all directions. “Reid’s -
butter-worker ” is shown in Fig. 964. It con~
sists of a tray and a roller with paddles, which
is turned by a crank, and traverses from end
to end of the tray. The roller can be readily
removed when desired, which leaves a table to
weigh and print off of.
Butler Packages—Butter is packed in firkins,
in half firkins, in kegs, and in pails. The best
firkins and kegs are made of white oak, heavily hooped, and the sides neatly turned.
An improved form of butter-tub and cooler is shown in Fig. 965. It is made of White cedar,
and bound with galvanized iron or brass hoops. Within the tub is fitted a tin cooler, having a
movable chamber for ice at each end. On the tin is constructed a series of ledges, on which rest
the shelves lor supporting the butter (print butter); it is used without shelves for roll butter.
965.










CHEESE-MAKING.—-Uh008€-VatS.-Qllite a variety of cheese-vats are in use, but as they are built
mostly alike, a description of the most prominent ones will be all that is necessary. They all consist
of a large inner vat of tin, generally capable of holding from 400 to 650 gallons of milk, suspended
in a wooden envelope, leaving a space between the two for steam or water, or to heat or cool the
same, The tin vat is arranged so that -it may be removed at pleasure.
Fig. 966 represents a cheese-vat and engine complete. The vat has a capacity of 600 gallons.
The wooden envelope, or vat, is generally made of well-seasoned pine. The tin for the inner vat is
DAIRY APPARATUS. 439

961, imported expressly for this pur-
pose. Thcy vary in size from
12 to 16 feet long, and from 3
to 31} feet wide, and 19 inches
deep. In small creameries and
farm-dairies, cheese-vats called
“ self-heaters” are often used.
There are several methods
for warming milk and heating
curds; but Prof. Arnold states,
after trying them all, that
“throwing steam directly un-
der the milk or whey to be heat-
ed is the simplest and cheapest
way; dry steam between the
vats is most convenient, and
water heats most evenly, and
holds the heat the longest, but
is most diflicult to control.”
Steam is the most popular
method for heating, and will
probably continue so in the
large creameries.
Curd-Knives—In Fig. 967 are shown a number of perpendicular and horizontal curd-knives.
When the curd has become of the proper consistence, it is cut in half-inch cubes, first by the perpen-
dicular knife, both lengthwise and crosswise, and then with the horizontal knife.



968.














Curd-mills are usually placed over the vats, so that when the curd is ground it falls into the latter.
The object is to disintegrate the curd, so that it may be more equally salted.
Clacesc-Presa—The gang-press is shown in Fig.
970- 971- 968. This press is constructed horizontally, and
the cheese is pressed in gangs from 1 to 12in each
press, and in a horizontal position, as shown in the
figure. In Fig. 969, A is a hoop; B, the side of the
follower next the cheese, showing the elastic ring,
also representing the perforated bottom seen below
E; C, the other side of the follower, showing grooves
in which are holes for the passage of the whey; J),
bandager, on which the bandage is placed, and the
bandages inserted in the hoop, the lower edge rest-
ing on the ledge seen on the inside of the hoop,
nearly the width of the bandage from the top, form-
ing a smooth surface on the inside of the hoop.
In Figs. 970 and 971 are shown a curd agitator
and scoop of simple construction, which will need no description.
Recent Improvements—The modern dairy is fast approaching the character of .a mechanical
workshop. Not merely are constant improvements being made in the mechanical details of the
apparatus employed, but new methods of testing are being introduced which are fast substituting
scientific certainty for rule-of—thumb estimations. The more notable improvements in dairy machinery
made during the past ten years have been the introduction of the centrifugal extractor for separating
the cream from the milk by the application of centrifugal force, and thus making butter-manufaeture
practicable in all climates and in all seasons. Novel devices have also been introduced for ripening
\ and cooling cream, for mechanically working butter, and for determining the butter-value of milk.
Chums—The construction of churns has undergone comparatively little change. The type in
most extensive use is the rectangular or box churn, arranged to rotate on pivots, sometimes applied to
the sides and sometimes at diagonally opposite corners. The Curtis trunk-churn, which is one of the
latest models, is in the shape of an ordinary trunk, supported on shafts applied to the end. The lid
is a trunk-cover, which, on being lifted, allows access to the entire body of the churn, and is provided
with a novel form of clamping device, embodying a cam which acts upon a link; these parts being
supported upon the cover, and the link engaging with hooks arranged upon the body of the churn.
The Curtis testing-churn (represented in Fig. 971 A) is a novel device for applying the oil-test to milk,
the object being to determine the relative butter-value of different samples. For some time the
cream-test, though confessedly far from accurate, was accepted for what it was worth, but experience


440 DAIRY APPARATUS.

has demonstrated that cream is only less variable than milk; this variation in butter-value at times
exceeding 100 per cent. The oil-test is reported to have given very satisfactory results. In the
.' ftp ‘
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present device the body of the churn receives a number of tin “cards,” varying from 5 to 14. Each
card holds 15 bottles, which receive the milk. After the filled cards are put in place the churn is
set in operation at the rate of from 320 to 325 revo-
971B. lutions per min. When the churning is done the but-
ter in each card is reduced to oil and measured.
Another mode of determining the butter-value of
milk is by Dr. Babcock’s method, and by the use of
the device which is illustrated in Fig. 97113. This
apparatus consists of a pan which by means of sim-
ple gearing, actuated by the crank-wheel, is caused
to rotate horizontally. The pan contains hot water,
and receives a number of bottles, in which bottles is
placed the milk to be tested. The operation is as




_-
i
4
) .
971 o.


_ @1119???
|


..- __“!








DAIRY APPARATUS. ‘ 441

follows: The whole quantity of milk to be examined is thoroughly mixed by stirring and pouring from
one vessel to another, and finally a sample is put into one of the testing-bottles. An equal volume of
sulphuric acid of 1.82 specific gravity is added. The bottle is then placed in the machine, which is
rotated for 6 or 7 min. Hot water is then gradually placed in the pan until the oil begins to show at
)4: 1mm .1,” I
_.___~__._~£~
'Q—l‘.


the neck of the bottles. The revolution of the pan is then continued until apparently all the oil has
risen into the small necks of the bottles, which are graduated on a scale of fifths of 1 per cent. The
proportion of that can be read off at once, and the value of the milk determined, just as the assayer
9712:












fixes the value of ores by testing samples. The following shows the butter-value of milk containing
various percentages of fat, with butter at 25 cents per lb. :
100 lbs. milk, testing 3 per cent. fat, will make 3.27 lbs. butter, worth @ 250. . $0 82
100 “ “ 3.6 “ “ 3.98 “ “ “ @, 25¢... 1 on
100 “ “ 4.0 “ “ 4.44 “ “ “ @ 250.. 1 11
100 “ “ 4.6 “ “ 5.1‘7 “ “ “ @ 250. . l 29
100 “ “ 5.0 “ “ 5.66 “ “ “ 25c. . 1 42
100 “ “ 6.0 “ “ 6.88 “ “ “ 250. . 1 72
442 - DAIRY APPARATUS.

Cream and cheese vats are employed for cooling and warming large quantities of milk. Fig. 971 0
shows the construction of the Curtis vat, which has a double bottom, to allow of the circulation of
hot or cold water. The inner bottom inclines toward the centre of the channel or groove, which
gradually increases in depth throughout its entire length to the outlet, thus affording an effectual
means of draining and removing the contents of the vat. For gathering cream, refrigerator tanks are
used, and an improved form of one of these is shown in Fig. 9'71 D. The cream is strained as it goes
into the tank, and is maintained therein at constant temperature. This tank is used for transporting
the cream from the place where it is collected to the crcamcry; it being essential that the acidity
and temperature should be kept uniform.
The use of extractors or separators for removing cream by centrifugal action has almost completely
superseded the old method of setting the pans. A centrifugal extractor consists essentially of a
basket, which is a receptacle for the substances during the operation; of a spindle, which supports
the basket and gives it its rotary motion; of bearings for the spindle; of some method for giving




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the spindle rotary motion; and of a casing, which serves to Catch the product or products of separa-
tion. These machines are made to operate both by hand and by power, and run at high speeds, the
hand‘machine even attaining a speed of 6,500 revolutions per minute. The e'lfort, however, has been
to obtain as high a number of revolutions per minute as is consistent with safety and with the prin-
ciple of the machine. For example, creamers which are small and light make 4,000 revolutions per


DAMPER. 443

minute, although, as a rule, slower speeds are employed. The results obtained at high speeds in two
forms of improved English creamer are as follows: No. 1. Gallons of milk, 10.70; revolutions of
drum per minute, 8,120; horse-power, 0.206; units of power per lb. of milk skimmed, 742.2;
temperature of new milk, 88.7° Fahr.; percentage of fat, new milk, 2.33; temperature of separated
milk, 86° Fahr.; percentage of fat, 0.23. No. 2. Gallons of milk, 1.124; revolutions of drum per
minute, 9,136; horse-power, 0.080; units of power per lb. of milk skimmed, 742.2; temperature of
new milk, 84° Fahr.; temperature of fat, new milk, 3.25; temperature of separated milk, 79°; per-
centage of fat, new milk, 0.23.
A valuable paper on centrifugal extractors, by Mr. Robert T. Gibson, will be found in iS't-iemifin
Amw'z'ccm, Supplement, Nos. 612 and 613, in which the principles of construction of the apparatus
are fully explained, and a variety of different types discussed and illustrated.
The mechanical working of butter is effected by power-machines, of which Fig. 971 E is an example.
The table is circular in form, inclining toward the centre, and is rotated while the butter upon it is
thoroughly worked by the tapered conical rolls, which are geared together and driven by the belt-
pulley. The capacity of the machine is from 150 to 175 lbs. at each working.
Cheese-Presses are simple screw-presses, with the screws arranged vertically to move a platen down
upon the cheese, or gang-screw presses of the type illustrated in Fig. 971 r, in which a number of
cheeses placed in hoops are pressed by the action of a horizontal screw operated by a hand-lever.
‘
. s‘ _
mmmn


i‘llv'l-flr l 1
,4 ..
lllllllllllllu *
.v
The arrangement of a model creamery capable of producing from 300 to 800 lbs. of butter per day
is shown in Fig. 971 G. The manufacturers of the machinery represented, Messrs. Cornish, Curtis 8:
Greene, of Fort Atkinson, Wisconsin, describe the principal apparatus as including one 6-horse-power
horizontal engine, one 8-horse-power horizontal boiler, one SOO-gal. churn, two SOD-gal. vats with ice-
box, one power butter-worker of the kind above illustrated, one covered crank suction-pump, together
with steamers, refrigerator tanks, and various other minor appurtenances. ‘
The builders of dairy machinery generally publish in their catalogues full estimates of the articles
required for the equipment of creamerics and cheese-factories of any desired capacity; and to these
the reader may be referred for practical details. .
DAMPER. A valve placed in an air-duct by which the latter is opened or closed more or less, in
order to regulate the air-supply and so increase or diminish the energy of combustion. Dampers are
of various forms, usually in the shape of butterfly valves, hinged flaps, or sliding or rotating grates.
They bear the same relation to the air-pipe or fine as does the valve or faucet to the duct for steam
or liquids. The term “damper” is also applied to the padded finger in a piano movement which
comes against the strings and limits the period of the vibrations. (See PIANOFOR'I‘E.)
Dampers for Steam-Boilers—The area. of a. damper depends on the height of the chimney; and
where there is only one boiler it may have the same area as the chimney, if that is properly propor-
tioned to the power of the boiler. (See CHIMNEY.) As an approximate rule, we may give 110 -:— 1/
H: A, in which H: the height of the chimney in feet, and A = the area of the damper in square
inches per horse-power; thus, for a chimney 100 feet high, we have 110 + 10 : 11 inches per horse-
power. The form of damper is arbitrary, and must often be varied to suit the form of the fine; but
for ordinary cases we may adopt standard sizes, a convenient proportion being 3 to 1, and thus we
have the sizes and powers given in the following table. The powers of other sizes may be easily
calculated by the numbers in the fourth line of the table. Thus, say we require the size for a large
damper to a set of boilers 300 horse-power for a chimney 100 feet high: the table gives 11 inches
per horse-power, and we have 300 x 11 = 3,300 square inches for the area required; and if the
height was fixed at 6 feet, or 72 inches, the width must be 3,300 —:- 72 z 46 inches.
' 444 DIAMOND.

Tabla showing Sizes of Dampers to Steam-Boilers, with difi'ercnt Heights of Chimney. (From Boa:











on Heat.)
HEIGHT OF CHIMNEY IN FEET.
40 I 00 | so | 100 l 120 | 150
SIZE OF THE
DAIMPER- IN SQUARE INCHES OF DAMPER PER HORSE-POWER.
INCHES.
11.4 | 14.2 i 12.4 i 11.0 | 10.0 | 9.0
HORSE-POWER OF THE BOILER.
0 X 18 6.2 1.0 8.7 0.9 10.8 12
1 X 21 8.5 10 12 1s 15 10
s X 24 A 11 1s 10 1s 10 22
0 x 21 14 11 20 22 24 21
10 x 30 11 21 25 2s 30 a4
12 .4 30 25 31 35 40 4s 4s
14 X 42 34 41 41 5s 59 05
16 x 48 44 54 02 10 11 s5
\

Fig. 972 represents an improved form of damper-regulator, in which the lever D is the continua-
tion of a siphon pipe 0, weighted at one end with the weight E, at the other end with the metal
receivers 1'", and all in connection with the valves in the collar A. The action is as follows: With
a moderate amount of heat passing up the chimney, the water in the boiler B remains at or near the
boiling-point, and the valves remain closed; but as soon as
the volume of heat is materially increased, steam is generated,
'which forces a portion of the water through the siphon pipe
0 into the lower metal receiver. The weight of the water
overcomes the weighted end, and the disk descends, partially
opening the air~valves in the smoke-pipe, admitting a current
of cold air, which serves to reduce the force of the draught in
like proportion. Any further increase in the volume of heat
passing into the smoke-pipe will likewise increase the steam-
pressure, forcing a greater weight of water into the receivers,
opening the air-valves wider, and reducing the force of the
draught to its lowest point necessary for combustion. As
soon as the fire is checked and the smoke-pipe cools, the water
gradually returns to the boiler, reversing the action.
DAMS. See Bananas.
DEFEGATIN G PAN. See SUGAR Macnmsar.
DENSITY. See DYNAMICS.
DERRICK. See Games AND Duanrexs.
DEVIL. See PAPER MACHINERY, and INDIA-RUBBER M11-
CHINERY.
DIAMOND. The diamond is the hardest substance in nature; and, in common with some other
crystalline bodies, it is harder at the natural angles and edges, and also at the natural coat or skin of
the stone, than within, or in its general substance. Its peculiar hardness is probably altogether due
to its highly crystalline form, as by analysis the diamond, charcoal, and plumbago are found to be
nearly identical; the first is absolutely pure carbon, the others are nearly so.
The primitive form of the diamond is that of a regular octahedron; it is like two square pyramids
joined base to base; the four sides of the pyramids meet at the angle of 90°, their bases at the
angle of 190° or thereabouts. Many of the diamonds merge from the form of the octahedron into
that of the sphere, or a very long egg, in which cases, although a disposition to the development of
the 6 points, each formed by the meeting of 4 surfaces, exists, they are curiously twisted and con-
torted. The Count dc Bournon published upward of 100 forms of crystallization of the diamond,
but the irregular octahedrons with round facets are those proper for glaziers’ diamonds.
The extreme point of any diamond may be employed to scratch glass with a broad white streak,
and detach its particles in a powder, but such glass will break with difficulty (if at all) through such
a scratch; whereas the almost invisible fissure, made when the rounded edge is slid over the glass
with but slight pressure and almost without causing any sound, is that which produces the effective
cat; and the cut or split thus commenced will be readily extended through the entire thickness of
the glass, when the extremities of the sheet are bent with the fingers or appropriate nippers.
The following figures represent, say two or three times magnified, the forms of diamonds that
would be most proper for various tools ; but it will be remembered they are only selected as near to
the respective shapes as they can be found, either among imperfect diamonds, or from fragments
solit off good stones in the first stage of their manufacture for jewelry; these pieces are known as
diamond bort. The diamonds are mostly fixed in brass wires, by first drilling a shallow hole for the
insertion of the stone, which is imbedded slightly below its largest part, and the metal is pinched
around it. Shellac is also used for cementing them in, and spelter or tin solders may be fused
around them with the blow-pipe, but pinching them in annealed brass is preferred. When diamond
tools larger than those made of crystals or thin splinters are required, diamond powder is applied
upon metal plates and tools of various forms, which serve as vehicles, and into which the particles
of diamond powder are imbedded, either by slight blows of the hammer or by simple pressure.


DIAMOND. 445



In the construction of jeweled holes, and in similar works, the rubies and sapphires, although
sometimes split, are more commonly slit with a plate of iron 3 or 4 inches in diameter, mounted on a
lathe, and charged on the edge with diamond powder and oil. When sliced, they are ground parallel
one at a time on a flat plate of copper (generally a penny piece), mounted on the lathe, and into the
turned face of which small fragments of diamond have been hammered; this is called a roughing-
mill. A similar plate with finely, washed diamond powder is used for polishing them. The rubies
are afterward cemented with shellac, on the end of a small brass chuck, turned cylindrical on their
edges, and beveled for burnishing into the metal rings. They are also turned concave and convex on
their respective faces, the turning tool being a fragment or splinter of diamond, fixed in a brass wire.
973.


In Fig. 97 3, a represents the flat view and b the edge view of such a tool, but of the form more usu-
ally selected for turning hardened steel, viz., an egg-shaped diamond split in two, the circular end
being used with the flat surface upward ; the watch jeweler uses any splinter having an angular corner.
The convex surfaces of the rubies are polished with concave grinders of the same sweeps, the first
of copper, the next glass, and the last pewter, with three sizes of diamond powder, which is obtained
principally from Holland, from the men who cut diamonds for jewelry, an art which is more exten-
sively followed in that country than elsewhere. The watch jewelers wash this powder in oil, after
the same manner that will be hereafter explained in regard to emery.
In drilling the rubies, they are chucked by their edges, and a splinter of diamond, also mounted in
a wire, is used. Should the drill be too conical, the back part is turned away with a diamond tool to
reduce it to the shape of c; and from the crystalline nature of the stone, some facets or angles
always exist to cause the drill to cut. The holes in the rubies are commonly drilled out at two pro-
cesses, or from each side, and are afterward polished with a conical steel wire fed with diamond
powder. In producing either very small or very deep holes, a fine steel wire, d, is used, with dia-
mond powder applied upon the end of the same, the limit of fineness being the diameter to which the
steel wire can be reduced. In drilling larger holes in china and glass, triangular fragments of dia-
monds are fixed in the cleft extremity of a steel wire, as in e and f, either with or without shellac.
Another common practice of glass and china menders is to select a tolerably square stone, and mount
it as at g in the end of a taper tin tube, which wears away against the side of the hole so as to be-
come very thin, and by the pressure to embrace the stone by the portions intermediate between its
angles. The stone is from time to time released by the wearing away of the metal, but these work-
men are dexterous in remounting it; and that the process is neither difficult nor tedious to those
accustomed to it, is proved by the trifling sum charged for repairing articles, even when many of
the so-ealled rivets (or rather staples) are cemented in; they employ the upright drill with a cross
stafi“. A similar diamond drill mounted in brass has been used, with the ordinary drill-bow and
breast-plate, for drilling out the hardened-steel nipple of a gun, which had been broken short off in
the barrel; no material difficulty was experienced, although the stone appeared to be so slenderly
held. For larger holes, metal tubes such as h, fed with diamond powder, are used; they grind out
an annular recess, and remove a solid core. Copper and other tools fed with emery or sand may be
thus used for glass, marble, and various other substances. The same mode has been adopted for
cutting out stone water-pipes from within one another by the aid of steam machinery.
Atz' is represented the conical diamond used by engravers for the purpose of etching, either by
hand or with the various machines for ruling etching grounds, medals, and other works. Coni-
cal diamonds are turned in a lathe by a fragment of another diamond, the outside skin or an angle
being used; but the tool suifers almost as much abrasion as the conical point, from their nearly equal
hardness; therefore the process is expensive, although when properly managed entirely successful.
To conclude the notice of the diamond tools, k andl show the side and end views of a splinter
suitable for cutting fine lines and divisions upon mathematical instruments. The similitude between
this and the glazier’s diamond will be remarked, but in the present case the splinter is selected with
a fine acute edge, as the natural angle would be too obtuse for the purpose. Mr. Ross, with a dia-
mond point of this kind, was enabled to graduate ten circles upon platinum, each degree subdivided
into four parts; at the end of which time the diamond, although apparently none the worse, was
accidentally broken. A steel point would have suifered in the graduation of only one-third of a
single circle upon platinum, so as to have called for additional pressure with the progress of the
work, which in so delicate an operation is of course highly objectionable.
Diamond-cutii-ng.—Of the forms into which the rough diamond is cut, the brilliant, Fig. 9'74, dis-
plays the lustre of the stone to the greatest advantage. It is described as obtained by two truncated
pyramids united together by one common base, the upper pyramid being much more truncated than
the lower. a is the crown and e the collet, the two principal divisions formed by the girdle c. d
is the table, and the opposite side below, the eulasse. The faces are called facets, and, including
table and eulasse, may number 64. The rose diamond, Fig. 975, has a crown, but no collet; that
is, one side is flat; and it is usually made from stones and fragments which would not without
446 DIAMOND.

loss _form good brilliants. Then there are table diamonds, which are flat and have little lustre,
and bastard diamonds, or those of mixed shapes.
In 976 is represented an enlarged section of the rough gem, showing the grain, along which it
may be as cleanly cleft as a piece of wood. The resemblance to the latter substance is increased by
the fact that there are so-called knots, which cause a conehoidal instead of a straight clean fracture.
975.
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The first process is termed “cleaving.” On a small table in front of the workman is a box
divided into two compartments, the farthest containing a covered tray for the reception of stones.
The other division is made deeper and has a false bottom, being finely perforated. The diamond is
secured in a knob of cement (brick-dust arid rosin) on the end of a spindle. The fragment of a
stone that has already been operated upon is fastened in a second spindle in a similar manner.
Next, with an implement in each hand, the cleaver brings the diamonds together, steadying the
shanks of his tools against two metal projections on the edge of the box before him. Applying the
second diamond to the rough gem, with a quick grinding motion he rapidly cuts a notch in the latter.
As hardly any two stones are alike, and no rule can be laid down for the work,\some idea may be
gained of the consummate skill which enables a man to pick up a tiny fragment, glance at it once,
and instantly detect, not only flaws or streaks, but where they are located, in the heart or on the
surface; to make up his mind exactly what microscopic pieces must be removed, their size, and how
they may be out to turn them to best account; and, finally, how to so divide the stone as to pro-
duce the best color. Placing the spindle containing the gem upright before him, the operator places
one of his knives directly over the cleft. The knife used is nothing more than a piece of steel,
perfectly flat, with a square edge, and about 6 inches long. It is ground blunt purposely; for if it
were keen, the hard stone would quickly turn the edge. Tapping the back of the blade lightly
with his iron rod, the artist splits off a fragment, and then melts his cement and removes the parts.
The cutter employs the same form of box as that used by the cleaver, and the diamonds are fast-
ened by cement, as before, in the ends of spindles. The cutter’s labor is purely “diamond cut dia-
mond.” The stone to be cut is held in its setting firmly in the left hand, while the cutting piece is
moved by the right. Both gems are of course affected by the mutual abrasion, but the attention of
the workman is directed to but one. Very slowly the faces are ground away; no measurements are
taken or angles calculated; the eye is the only guide, and it seems to be a faultless one. As soon
as the first stone is finished, the diamond used for cutting it is operated upon, so that diamond N o.
2 is, in turn, out by N o. 3, this by N 0. 4, and so on. At this stage the gems present no different
appearance from rough quartz pebbles. The friction dulls them, for they are ground together with
considerable force, the workman being obliged to protect his hands by thick coatings against the
rubbing action of the tool. An ingenious machine for automatically accomplishing this work was
exhibited at the Paris Exposition of 1878. The diamond to be cut is placed in its dopp and fastened
in a reciprocating crank-rod. The cutting diamond is secured in an adjustable rest which has an
up-and-down motion, and which also, by a worm and pinion, may be rotated in a horizontal plane.
A feed-motion is provided, whereby the diamond to be cut is fed up to the cutting diamond. This
machine works with considerable accuracy, and is easily managed by a girl.
The diamonds are next set to prepare for polishing. The dopp in which the gem is imbedded
is a copper cup about 1% inch in diameter, provided with a stem of stout wire of the same metal,
and filled with plumber’s solder. This is filled with solder, and placed in a charcoal furnace. When
the solder becomes plastic, the diamond is inserted. The polishers are seated before long tables,
on which are swiftly rotating horizontal disks fastened on vertical spindles, the lower ends of which
' revolve in anti-friction steps at the rate of 2,000 turns a minute. The disks, or Shit/68, are circular
plates of a composition containing both iron and steel. They are ground in lines, at an angle
from centre to circumference, so as to hold the oil and diamond-dust used in the polishing opera-
tion. Three diamonds, set as above described, are ground at once by each polisher. The stem of
the dopp is fastened in tongs or clamps, the extremity of the latter being supported by legs an inch
or so high. Two-thirds of the dust ground off in the cutting is allowed to polish each diamond, and
this, mixed with oil, is applied to the stone by quills. The adjusting of the gem on the disk requires
wonderful accuracy, in order that exactly the proper facet be ground and no more ; for the slightest
mistake might cut away an angle and produce serious damage to the stone. So sensitive is the'
touch of the artist, that he tells by pressing on the stem of the dopp exactly whether it lies true
against the shive or not, and by his fingers adjusts the stone over incredibly minute angles and
distances. This goes on until each facet is brought to the requisite brilliancy.
Industrial Utilization of the Carbon—The carbon, or black diamond, is used to point edge or face.
DIAMOND TOOLS. 447

tools for drilling, reaming, sawing, planing, turning, shaping, carving, engraving, and dressing flint,
grindstoncs, whetstones, emery, corundum, or tripoli wheels, indium, nickel, enamels, crystals, glass,
porcelain, china, steel, hardened or otherwise, chilled iron, copper, and other metals. (See Rocx
Dams, and STONE-WORKING MACHINERY.) In Fig. 977 are represented some of the various forms to
977.


which diamonds or carbons are ground. Points No. 1, 2, and 3 are shaped carbons used for working
and turning grind and other kinds of stones, emery-wheels, etc. No. 4 is a diamond-point with angles
of 60°, used for dividing on metal or for turning out screw-taps, etc. No. 5 is a diamond barley-
corn cutter, used by watch and pencil-case makers, etc. No. 6 is a carbon double-sized trapezoid,
used in various positions for marking or working stone. N0. 7 is a diamond chisel-point for turn-
ing metal. No. 8 is a carbon drill-faced parallelogram for pointing combination drill-heads for
stones. N o. 9 is a diamond'quadrangular prism. No. 10 is a carbon truncated prism for stone. No.
11 is similar to No. 8. No. 12 is a carbon truncated prism for facing or edging ring or cylinder
drills, saws, etc., for stone. No. 13 is a carbon quadrangular drill-point for stone. No. 14 is a car-
bon reamer for stone, etc. No. 15 is a carbon block, used for the same purpose as No. 12. No.
16 is a diamond graver for metal, etc. No. 17 is a flat octahedron carbon drill-point for stone,
glass, etc. No. 18 is a flat ovoid used for the same purpose. No. 19 is a carbon tetrahedron, used
for the same as Nos. 10 and 12. N o. 20 is a pyramidal diamond-point. No. 21 is a carbon truncated
prism. N 0. 22 is a diamond-pointed reamer. No. 28 is a carbon flat-pointed drill. No. 24 is a dia-
mond chisel-point. No. 25 is a diamond double-inclined plane wedge. No. 26 is a carbon quadran-
gular wedge for turning stone, etc. No. 27 is an acute conical-turned diamond-point for engraving
and etching on steel, etc. N o. 28 is a diamond in its natural crystallized hexahedron form, as found
in the mines. The above illustrated diamond and carbon points or cutters range in size from one-
sixteenth to 10 carats each (a carat is equal to 4 grains).
DIAMOND TOOLS. See DIAMOND, ROCK DRILLS, and STONE-WORKING MACHINERY.
DIES. See TAPS, STOCKS, AND DIES.
DIFFERENTIAL PULLEY. See BLOCKS.
DIFFERENTIAL SCREW. A mechanical device for obtaining great pressure through the pro-
longed action of a small amount of power. Two screw-threads of different degrees of inclination
are formed upon the same spindle, A B, Fig. 978, the spindle itself passing through two nuts, one of
978




which, E, is part of a solid frame along a groove in which the other, D, slides. Let the numbers 5
and 4 represent the pitches of the screws at E and D. Then, upon turning A B once, the nut D is
carried forward through a space 5, and is brought back again through a space 4; it therefore ad-
vances through the difference, 1, of these intervals.
DIFFERENTIAL TACKLE. See BLOCKS.
DISINTEGRATOR. See MILLS.
DISTILLING APPARATUS. The vessel used for generating the vapor in distillation, if of
large size, is called a still. Distillation as carried on by the chemist is usually by means of reto-rts.
448 DISTILLING APPARATUS.

and the vessel that receives the distilled matter is called a receiver ; this is perhaps the most simple
method of distilling. The distillation of coal in the manufacture of illuminating gas is conducted in
cast-iron retorts, and is an example of this form of distillation.
There are two distinct operations in the production of ardent spirits. The one is the conversion
of certain vegetable principles into alcohol, the other the separation of the alcohol from other sub-
stances with which it is necessarily blended in its production. The vegetable principle which is
essential to the formation of alcohol is sugar, and this is sometimes used directly, as when molasses
and like products are subjected to immediate fermentation, or it is indirectly obtained by subjecting
amylaceous grains to certain processes by which the starch they contain is first converted. into
sugar, and the sugar afterward alcoholized. For this latter purpose, the various grains are subjected
to the operation of bruising or mas/ring, and infused under constant agitation in a proper quantity
of water in the mash-tun. In this way the wash is obtained, which is run into the fermenting vats,
where, mixed with a small quantity of yeast, it is subjected to the process of fermentation, which
requires from 6 to 12 days, the term varying with the mass of liquid and the temperature of the
atmosphere. As the fermentation progresses, the wash attenuates; when this attenuation reaches the
maximum, the wash is drawn into the still and subjected to heat. By this means the more volatile
matter, passing over first, is condensed in the worm, and yields spirit. In general, the wash is first
subjected to distillation, from which a weak spirit is obtained; then this spirit is redistilled, from
which proof spirits are obtained; the stronger spirits, being the most volatile, are the first ‘tc pass over.
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0f stills there is almost an endless variety, differing not in essential principles, but in detail. We
instance one of the earliest improved stills, that invented by Corty, and afterward much simplified
by Messrs. Shears & Sons. '
Fig. 979 is a representation of this still. A is the body of the still, into which the wash is put;
B is the still-head; 0 O 0 are three plates of copper fitted into the upper part of the boxes D D D,
which are kept at a regulated temperature by water being conducted over their outer surface, by means
of the pipe E and the distributing pipes G G G. The spirit vapor then rising from the body of
the still meets a check at the lowest plate (I, by reason of the coolness occasioned by the water;
this condenses the grosser part of the vapor and throws it back, while the lighter proceeds on to
the second plate 0, where a further coolness condenses another portion of the T per, leaving a much
purer spirit to encounter the increased coolness at the third plate 0. Here the last separation takes
place; the aqueous and oleaginous particles, being unable to sustain the temperature maintained, fall
back condensed, and only a very strong spirit passes over in the gooscneek. By means of the
cock F, in the pipe E, the supply of water to the boxes D can be very exactly regulated; and, as
a natural consequence, the temperature can be very accurately adjusted. If the temperature of
the upper box be kept at 174°, for example, the alcoholic vapor which passes over will be com-
posed of 90 per cent. of pure alcohol, or 65 over proof; but with a temperature of 194° F.
the vapor will contain only 66 per cent. pure alcohol, or 30 over proof. a is a screw-cap,
through which a jet of steam or water may be sent to clear away the deposits, which otherwise
will more or less accumulate on the upper surfaces of the plates C. At the lower end of the.
worm-pipe is alfixed, by means of the brass swivel-joint screw H, a'gas apparatus. The pecu-
DISTILLING APPARATUS. 449

liar form of the pipe I, into which the spirit runs from the worm, causes it to be filled shortly
after the still commences working; while the other branch pipe K rises to some height, then
returns, and is immersed in the small box L to the extent of about 2 inches in water. The gas
from the still escapes by this pipe through the water, as the pressure can be but trifling. It is held
that, by means of this gas apparatus, the distillation proceeds in a partial vacuum, and that thereby
980.




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there is a great economy in fuel. As the spirit enters the worm at so much lower a tempera-
ture than in the old stills, so much water is not required to cool the spirit vapor as would be other-
wise. A still of 400 gallons is said to work off four to five charges in the day of 12 hours, yield-
ing a spirit on an average of 35 per cent. over proof; which, for rum, is considered the most ad-
vantageous strength to run it at.
Fig. 980 is another arrangement of the same kind of still, being the addition of the common still
A to the patent still B. In this case the contents of B are drawn down from time to time into A,
and those of A run off as dunder, the spirit from A being conducted into B. One fire heats both
stills; and it is stated that, by the general adaptation and arrangement, a very large quantity of fine
spirit is produced by the consumption of a very inconsiderable amount of fuel.
In Fig. 981 is represented Derosne’s still. It consists of two boilers, A A’; a first reetificator,
B; a second rectificator, O; a wine-heater, D, containing a dephlegmator; a condenser, F; a sup_
ply-regulator, E, for controlling the flow of wine from the reservoir G, which is accomplished by
means of a floating ball. The still is worked in the following manner: The boilers are about two-
thirds filled with wine, or the liquor to be subjected to distillation, through the cocks c c’. The
proper quantity is indicated by the glass gauges d (1’. Wine from the reservoir G is then let into
the funnel J, by which the condenser F and the wine-heater D are filled. On the application of
heat the low-wine vapors pass from the lower into the upper boiler through the pipe Z, the extrem-
ity of which is enlarged and perforated with small holes. Here the vapors are condensed, increas-
ing the strength of the wine in the upper boiler, and consequently lowering its boiling-point. The
vapors ascend into the reetificators B and C. The lower reetificator, B, contains a number of shal-
low pans perforated with holes, and a number of spherical disks, also perforated with holes, placed
above them, in pairs, the convexity of each disk being upward, and receiving the drip of the shal~
low pan next above it. This drip is produced by warmed wine which flows from the wine-heater
through the pipe L. By these means the vapors ascending from the upper boiler have their more
watery portions condensed, while the alcoholic vapor continues to ascend. The dripping wine also
has a portion of its alcohol expelled in the form of vapor, which ascends with the vapor coming
from below into the upper rectificator through the orifice O in its bottom. This upper rectifieator
communicates through the tube ill with a worm (which is the dephlegmator) in the wine-warmer D,
the worm ending in the tube m, which again terminates in the worm contained in the condenser F
through a cylindrical connection in its upper part. The worm in F terminates in a small vessel, N,
which is furnished with an alcoholometer. The alcohol in N flows from its upper part into the
cistern H. The upper rectificator C is (ID idcd into a number of compartments by as many horizon-
tal partitions, each disk having an orifice in its centre, like the orifice at 0. To each of these ori_
fiees on the upper side of the partition is adjusted a short open vertical tube. A short distance
above each tube is placed an inverted pan, having its edges descending about three-fourths of an
2-9
450 i ’ DISTILLING APPARATUS.

inch below the level of the upper orifice of the tube. , As the vapor ascends from the lower rectifi-
eator into the upper one, a portion of it condenses and collects upon the' bottom of the compart-
ments, until it rises slightly above the edges of the inverted pans and nearly to the upper orifices
of the tubes. \Vhen this takes place the vapor can only pass upward by forcing its way under the
edges of the pans, by which means the more watery portion-is still further condensed, the more
alcoholic vapor, having a higher tension, retaining its gaseous form, and passing on through the tube
M into the dcphlegmatory worm in the wine-heater, there to be partially condensed; which process
heats the wine surrounding the worm. A phlegma collects in the lower convolutions, which may
be drawn off by means of the pipes pp p, and transferred at pleasure either into the tube in or
into the upper rectificator. The purer alcoholic vapors which arise pass through the dephlegmator
into the condensing-worm in the condenser E, whence they flow in liquid form into the vessel N, and
thence into the cistern H. The strength of the alcohol produced by this still depends upon the
number of windings of the dephlegmator, and the number of partitions in the upper rectificator.
981. , 9S2.


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Derosne’s still requires but little fuel, distills rapidly, and yields a good spirit, which may be varied
in strength at pleasure; but it is rather complicated, and may with advantage, especially when spir-
its of only one strength are required, be replaced by a simplification of it, devised by Laugier.
In Fig. 982 is represented the Savelle still in Springer & Oo.’s great spirit and yeast manu'factory
at Maisons-Alfort, near Paris, France, which is said to be capable of utilizing daily 55,000 lbs. of
barley, rye, and corn, mixed in equal proportions.
In order to obtain regular working with such large quantities of material, two conditions have to
be fulfilled: 1. Perfect cleanliness throughout the whole apparatus, and the avoidance of any stop-
page in the inner system of tubes ; 2. The complete‘separation of the liquids produced.
' The first condition is substantially obtained by the swift passage downward of the material sub-
jected to distillation. Having to travel, in passing through the apparatus, 410 feet, it accomplishes
the descent in 6 minutes. This gives a speed of 13.65 inches per second, and it is easily seen that
with so rapid a movement interior stoppages are nearly impossible.

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DISTILLING APPARATUS. . 451
Each section of the distillation column is provided with five bronze observation tubes, which allow
of an examination of the interior without interruption of the working. The second condition, which
relates to the separation of the liquid, is well fulfilled. The liquid subjected to distillation, which,
as above stated, forms a continuous stream 410 feet long, is traversed in every direction by the
steam, which carries with it the alcohol formed. The intimate commingling of steam and liquid to
be distilled causes a complete absorption by the former of the alcohol contained in the latter.
Besides this, the operation of distillation is hastened by the preparatory warming apparatus, pro-
vided with large heating surfaces, which utilizes the lost heat of the mass of alcoholic steam issu-
ing from the distillation column, and therefore saves a good deal of fuel. As there is no stoppage
in the working, it is necessary that a complete separation of the alcohol should take place regularly,
and that none should be lost in the residuary liquors, which run out from the base of the column.
This result is assured by the steam-regulator, which maintains constant working conditions. Every-
thing has been arranged so that the matter to be distilled should be kept as long as possible in
contact with the steam. The disposition described induces an energetic separation of the contents
of the material to be distilled, facilitates the departure of the subsidiary products, gives a working
season of eight consecutive months, and allows of a passage through the apparatus of 15,400,000
lbs. of material without any cleaning being needed.
The material to be distilled is first carried by the feeding-pipe m into the alcohol-warmer C,
which, as above stated, transmits to it the lost heat of the column below, thereby partially condens-
ing the alcoholic vapor. After this preparation it passes by the pipe k on to the upper surface of
the rectangular copper distillation column A, which is composed of 25 rectangular sections, bound
together by cast-iron clamps, and supported on a framework of iron. In this column the distillation
and gradual and methodic enrichment of the alcoholic vapors take place; here the material spreads
in thin layers traversed in every direction by the steam brought in by the pipe 2', and the introduc-
tion of which is regulated by the admission-valve of the steam-regulator F. A constant temper-
ature is maintained by this latter, and the feeding is regulated by the screw admission cock 2. The
foam-breaker B stops and returns to the column the substances carried over by the current of alco-
holic vapor passing to the alcohol-warmer. The tubular cooler D, arranged in compartments, rc-
ceives cold water from the reservoir H by the pipe 12, and communicates with the graduated gauge
and discharge E, which measures the flowing of the phlegm. The condensation, which is partially
accomplished in the condenser or alcohol-warmer, is finished in the cooler D. The large cylinder
G is used for the reception from the column, and drawing off by means of the conduct 0, of the
residuary products; j is the delivery-pipe of the regulator F; k and l are tubes which carry the alco-
hol from the distillation column to the foam-breaker and alcohol-warmer; r is the return-pipe from
the foam-breaker to the column, and s the air pipe of the alcohol-warmer.
The improvement made in distilling apparatuses for spirits during recent years has been chiefly in
details. Fig. 982 A represents an apparatus designed to produce alcohol free from fusel-oil and acetic
982- A.


acid, thus yielding an increased amount of “aged” product. The absence of fusel-oil and acetic
acid is the characteristic of spirits which has been “ aged.”
A is the wash-charger feeding the wash continuously through the heater 0, kept full of spent wash,
to the still-column B. The lower part of the still-column is formed into a boiler a, heated by a
452 DISTILLING APPARATUS.

steam-coil lying between the convolute partitions. b b b are the distilling trays, each consisting of an
annular space connected to the next tray lower by overflow-pipes b1. 0 is a baffle, preventing the
steam and vapor from passing through the centre of the still without passing through the wash on
the trays b. d d d are the rectifiers, charged at the beginning of an operation with cold water. They
communicate with each other by an overflow-pipe, and compel the vapors to follow a circuitous path.
The fusel-oil, condensing on the rectifiers, finds its way to the rings b’, at the lower part of the still
and out by the pipe d”. D is the condenser, in which the rectified and pure spirit is finally condensed,
after passing through a bafiie plate-box ee e, which removes the last traces of fusel-oil. The condens-
ing water is supplied to D from an overhead cistern through a regulating valve The quantity of
water supplied to this vessel regulates the purity or “ age ” of the finished spirit.
Egrot’s Tilting Still.——A still which may be easily wheeled about by a man, or used by land-owners
who have to distill upon estates distant from each other, is shown in Fig. 982 B. When alcoholic
982 n.








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liquors are distilled in an ordinary still, two operations are necessary in order to obtain even common
spirits. By means of Egrot’s apparatus ordinary rectified spirits are obtained at the first operation.
It consists essentially of a still in which the liquids to be distilled are placed, and communicating
with the refrigeratory through an inclined pipe. The still A is placed in a furnace B, of which the
part 0 is so arranged that the still can be tilted in front. It suffices for this to manaeuvre the lever
seen to the left of the engraving, when the toothed wheel D will revolve upon E, and the still will
take the position shown. The cover G of the still is provided with a screw-plug H for the filling,
and a swan’s neck connected with the refrigeratory by a screw coupling. The refrigeratory consists
of two copper worms L and ill, upon which water falls in a shower. The poor vapors that condense
in the worm L return to the still. As for the vapors rich in alcohol, they pass through the worm _M
into the refrigeratory N, and make their exit at O in the state of alcohol. lVater from a reservoir
K descends through the tube P into the refrigeratory N, and then ascends through the tube Q, above
the worm L, and falls in a shower upon both worms. This water is collected in a reservoir T. The
discharge of the water is regulated by the cocks R and S. The operation of the apparatus is very
simple. The materials to be distilled are introduced into the still A. The cover is put on and the
coupling screwed up. The cocks R and 5’ having been closed, the reservoir K is filled with water,
and a fire is lighted in the furnace. After ebullition has started in the still and the worm L has
begun to heat, the cock S is opened slightly, so that the water may spread over the worms in a very
fine shower. The impure vapors that condense in the worm L return to the still. Nothing but the
alcohol vapors pass into the worm Jll. Here they condense, are cooled in the refrigeratory N, and
are collected upon their exit. By placing a wine-heater around the worms of the still described
above, several distillations may be effected much more rapidly and economically, by making use of
the vapors to heat the liquid designed for the next operation. This is accomplished by connecting
the outlet of the heater to the still.
Water-Distilling Apparatus—Through the increased pressures in marine boilers, the use of non-
saline feed-water has become an absolute necessity; although fresh feed-water is provided by the use
of surface-condensers, the supply from this source is less than the water evaporated by the boiler, a
small. waste being unavoidable. Were this waste made up by using sea-water, the boilers are liable to
DISTILLIN G APPARATUS. 453

incrustation. Hence the necessity of special distilling apparatus to supply the fresh water required.
In the ordinary form of distillers a large quantity of water is boiled and the vapors condensed. But
this method transfers the incrustation from the boilers to the still, greatly reducing the efficiency of
its heating surface. In one form of Yaryan apparatus film evaporation takes the place of bulk
evaporation in the ordinary way of evaporating a liquid ; each time that a gas-bubble is formed on the
surface of the heated metal it displaces a corresponding volume of the liquid, and the latter can only
again come in contact with the plate after the bubble has been detached. Now, by blowing a spray
of liquid at high velocity through a heated tube, the film of liquid is constantly passing over new
portions of the heating surface, and the result is that the latter is utilized in a very much better way
than when covered with 'a thick stratum of liquid.
Each evaporator contains horizontal rows of steel tubes enclosed in a cast-iron casing. The seawater
is injected into the top row of tubes in the first evaporator through a series of nozzles, and passes suc-
cessively backward and forward through the lower rows of tubes. The casing of the first evaporator
is supplied with steam, which is preferably taken from the receiver between the intermediate and
low-pressure cylinders of the main engines. This steam condenses in the outer vessel, and the con-
densed water is carried off into the main condenser of the engine. The sea-water, in passing through
the inside of the tubes, is partly evaporated, and the mixture, containing about 25 per cent. of
steam, passes into one of the vertical vessels seen in our illustration, between the two horizontal
evaporators.
There a separation between the vapor and liquid is effected by means of an ingenious arrangement
of baffle-plates, the vapor being passed on into the second evaporator, where it acts as a heating
agent, and is in its turn condensed; while the liquid is passed through the inside of the tubes in the
second evaporator, and is there further concentrated, another 25 per cent. of the original quantity
being sent in the shape of vapor into the second vertical vessel, and there similarly condensed. In
this manner about 50 per cent. of the weight of sea-water sent into the apparatus is ultimately
obtained in the form of fresh water, which flows into the condenser of the main engines. It will thus
be seen that the evaporation of the liquid takes place in a partial vacuum, and where a condenser is
not available a small vacuum-pump, of the type shown in our illustration, may be fitted to the
apparatus.
The Yaryan evaporator has been successfully applied to different other purposes, including the
concentration of solutions of sugar, glue, etc. For detailed description and drawings of the Yaryan
evaporator, see “Modern Mechanism,” Vol. III, of this work.
Another form of distiller designed to obtain fresh water from sea-water is shown in Fig. 982 c.
The operation may be' described as follows: Steam from the boiler is admitted into the evaporator
982 c.


through a reducing valve at a pressure of about 60 lbs., and passing through the volute B evaporates
the salt water contained in the chamber 0 ; the vapor thus generated passing through the pipe .D
into the volute condenser E, where it is condensed. The fresh water thus obtained flows into the
filter, from which .it is pumped into suitable drinking-tanks.
The steam from the boiler, after passing through the volute B, is conveyed by means of a pipe to
the second volute H, where it is condensed, and the water resulting is conveyed by means of a pump
to the hot-well or feed-tank. The necessary condensing water enters at J and is discharged at If.
The method of keeping the supply of salt water in the evaporator at 'a constant level is very efficient
and ingenious. To the main circulating discharge-pipe a small pipe L is fitted, which is in communi-
454 DITCHER.

v
cation with the chamber ill, and through this the circulating seawater runs back until it attains a
working level in the evaporator, when a valve in the end of pipe L is closed by the action of the float
N, the regulation of admission being thus automatic and certain. The steam from the boiler can be
regulated by means of a stop-valve, and the pressure in the evaporator should not exceed 4 lbs., while
the pressure-gauge is so arranged that the pressure in both condenser and evaporator is shown at the
same time. A safety-valve is fitted at the top of the condenser, and an automatic blow-off valve 1’ is
arranged to blow off when a certain density of brine has been attained in the evaporator. The
“ Esco” triple pump, which has been specially manufactured'for this purpose, has three suctions and
deliveries, one for circulating water, the second for the condensed steam, and a third for the filtered
drinkingavater, so that the latter is kept fresh and clean.
Distiilers’ illachincry.—Under this title is usually grouped a variety of different kinds of apparatus
employed in breweries and distilleries. Among new devices of this kind is a non-explosive malt-mill
devised by C. Kaestner & Co., of Chicago, which is so constructed that any explosions, such as are
liable to take place in mills of this sort, are confined to one chamber of a revolving hopper, and
means are provided for allowing the escape of the gases due to such explosions as quickly as they are
formed.
A new type of mashing-machine, by the same maker, embodies a combination of vertically and at
the same time horizontally revolving shovels, which will mash under and simultaneously raise the
grains from the bottom of the mash-tub. Whatever the shovels do not reach, a series of horizon-
tally sweeping scrapers running close to a false bottom take up, and at the end of the mashing oper-
ation drive all the grains through an open valve in the bottom of the tub. A mashing-machine
intended especially for distilleries consists of two rakes working entirely independent of each other.
A larger outside or three-armed rake runs at a slow speed, while the inner or small two-armed rake
runs much faster, and, while mashing the grains in the centre of the tub, it at the same time forces
them to the outside, where they are remashed by the larger rake.
A new form of maltkiln floor is composed of steel tiles 18 x 36 in. in size, which are built up of
steel wires drawn to the shape of a penknife-blade. The tile thus formed is 15} in. high, and pre-
sents an even surface with nearly 50 per cent. of air-opening. The tiles are bolted together beneath
the floor surface, and the whole floor is so arranged that its evenness is not affected by changes of
temperature, nor by the turning, loading, or unloading of the malt.
Works for Reference—“A Practical Treatise on the Raw Materials and the Distillation of Alco-
hol,” Brannt; “ A Practical Treatise on Animal and Vegetable Fats and Oils,” Brannt; “ A Treatise
on the Manufacture and Distillation of Alcoholic Liquors,” Duplais; “The Theory and Practice of
the Preparation of Malt and Fabrication of Beer,” Thausing; “The Theory and Practice of Modern
Brewing,” Faulkner; “The Complete Practical Distiller,” Byrn.
DITCHER. See AGRICULTURAL MACHINERY.
DIVIDERS. See Comrassns.
DIVIDING MACHINE. An apparatus used for marking the graduations of, or dividing, astro_
nomical, geodetical, or other mathematical instruments, enabling the same to be accomplished auto-












matically, and with great exactness. Figs. 983, 984, and 985 represent the dividing machine used
in the U nitcd States Coast Survey Office, and rendered automatic by the late Mr. Joseph Saxton.
The machinery for rendering the dividing machine automatic consists of a brass wheel A, about
20 inches in diameter, mounted on the axis B, Fig. 983. One of the arms of the wheel A has a sht
DIVIDING I MACHINE. 455

extending from near the centre of the rim ; in this slit is fixed the crank-pin so that it can be placed
at any required distance from the centre. 0n the edge of the wheel is turned a groove, in which
runs a cord for driving the wheel. On the other end of the axis is fixed the wheel 0, which is geared
into the wheel D, on the lower end of the vertical shaft J, Fig. 984. On the upper end of the same
shaft is another wheel 11", geared into the wheel G, on the horizontal shaft II. On the end of the
shaft H is a wheel 1, which gears into the wheel J, on the axis K. The wheels 0, I), F, G, I, and J
are all bevel-wheels, having the same number of teeth (60), and work into each other at right angles.
The shaft E has on it a sliding-joint L, for altering its length; the shaft 1:! is turned and ground
of uniform thickness, so that it may slide accurately through the socket of the wheel G, and also
through its hearing at .M, in which it turns. The axis K has on it two eccentrics, N and O ; JV
to raise the tracing-point, and 0 to move it horizontally. One-half of the circumference of N is
concentric with the axis on which it turns, so as to keep the point up while the crank-wheel moves
half a revolution, and is moving the dividing plate. The other is eccentric to the axis about one-
tenth of an inch, so as to let the point rest on the circle while it is making the division. The
eccentric 0 has about one-eighth of its circumference concentric to
theaxis; the rest'is described from a point about one-eighth of an 935-
inch from the centre. N and 0 must be fixed on the axis with re- 0 r
gard to each other, so that N will raise the point before 0 begins to a Jvfi
move it back, and both with regard to the crank-wheel A, so that _/ "11; ',
the point will be raised before the crank begins to move the dividing i,
plate, and keep it up until it is done moving, and 0 has moved the
point back, and then let it down before 0 begins to let it return. i
The axis K has also on it, near the end, a small cog P, to shift the :E' U °
ratchet-wheel Q one tooth every revolution of K. The ratchet-wheel L— “R‘s-1‘33)” (‘3
has 60 teeth, and 1s kept 1n its proper posrtion by the detent spring (2
R. In front of the wheel, and fastened to it by two screws, is a cir-
cular plate S, Figs. 983 and 985, with 20 notches in‘its edge, the deepest one for the longest line, or
5°, the next for 30', and the shallowest for 15', and the edge of the plate for the 5' lines.
The segment ’1’, Figs. 983 and 985, is fixed on the vertical part of the tracing-frame U, and has a
pin in the end at V, of such a size that it can drop into the notches in S, as they are brought under
it by the revolutions of the ratchet-wheel, and so regulate the length of the division lines. The
time of raising the ratchet must be when the stop-pin is raised out of the notch, by the motion of
the traces backward. To give motion to the screw, a stout fuses-chain is used, one-eighth of an
inch broad and one-fourteenth of an inch thick, which answers well; one end is attached to the
ratchet-barrel W, round which it is wound five or six turns; the other end is attached to the crank-
pin X. Near the lower end of the chain, at Y, is a small tube, containing a strong spiral spring,
arranged like the common spring weighing-machine, but having a motion of only about one-eighth
of an inch; the spring must be so strong as not to give by the force required to turn the screw, but
only to give a little when the ratchet comes up to the stop, and the crank is just passing the lower
centre. Between the spring and the crank-pin is an arrangement for lengthening or shortening the
chain, when it is arranged for making a larger or smaller division; for this purpose, two pieces of
brass wire, about 6 inches long, having a screw cut on them their whole length, and each filed away
one-half, and two small milled nuts, tapped with the same thread, are run on each; the two wires
are laid together, and the nuts screwed up until they embrace both wires, as shown at Z, Fig. 983.
The crank-pin is fixed on a slide, projecting beyond the nut which fastens it, so that it may be
extended, if necessary, beyond the circumference of the wheel; or by reversing, it may be brought
quite to the centre. When the divisions are to have the long end toward the centre, a jointed lever,
as shown at a, Fig. 985, is used. It is screwed fast to the cross-bar 1), Figs. 984 and 985, directly
over the eccentric 0, and connected to the vertical frame U at c, and the stop-pin V is shifted to
the other end of T; and the abutting piece f, on U, is to be removed, when the eccentric 0 will act
against the lever a at d, and move the point in an opposite direction. The tracing-frame is made to
follow the eccentric, by a weight and cord passing over a pulley and hooked to the vertical part of
the tracing-frame at c c, Fig. 985.
When the adjustment is made for dividing with the long end of the division lines toward the
circumference of the circle, all the wheels connecting the axis K with the axis B should be marked
with a dot on the tooth and space in which it works, and a line should be drawn on the shafts E and
H, and a corresponding mark on the sockets through which they pass, so that they may always be
fastened in the same position. The axis K should have two short pins fastened on it, and notches
in the ends of the sockets N and O, to fix them in their proper position when the lines are toward
the circumference or centre, as the case may require. The slit in the Crank-wheel A, in which the.
crank-pin is fastened, should also he graduated, showing the distance of the pin from the centre, for
each degree, minute, and second that may be required in dividing.
By marking the position of each part of the machine in this way, much time and trouble will be
saved in making the necessary changes for different kinds of dividing, whether it be in the number
or the direction in which the long lines are to be extended. The tracing-point should be adjusted so
as not to be raised more than about the thirtieth of an inch, or it will be liable in descending to
make a small dot at the commencement of each line, which would injure the appearance. In the
drawing, the eccentric N is represented as acting on the tail of the tracing-frame, but it is better to
make it act on a steel pin in the side of the tail.
By this arrangement of the crank for turning the dividing-screw, the steps of the ratchet are
brought in contact when the crank is passing its centres, and the motion of the screw is so slow
that it is not possible for the stops to strike so hard as to do any injury, and the dividing may be
done with great rapidity.






456 DIVIDING MACHINE.

Ruthmjfm‘d’s Ruling Engine.—One of the most accurate and delicate dividing machines yet devised
is the ruling engine contrived by Mr. L. M. Rutherfurd of New York, for making gratings of fine
lines on glass, for use in lieu of prisms in the spectroscope. The apparatus is represented in Fig.
986. On a hollow east-iron block are cut, at right angles to each other, two V-shaped guides. On
one of these guides slides the iron plate .D, moved by means of a screw acting in a nut attached to
its under surface. On this plate is fastened the plane of glass or speculum metal which is to be
ruled. On the other guide slides the plate L J, having a reciprocating motion given to it by a lever,
the action of which will be described further on. To this plate is attached the tool-holder carrying
the diamond-pointed cutter. The motive power of the machine is a small turbine, from which passes
a cord around the driving-wheel. On this driving-wheel is a pin to which is jointed the connecting-
rod A F. This connecting-rod is hollow, and in it moves a rod which is constantly pressed toward
the pin on the driving-wheel by the spring shown at A. When the red A F moves upward, the arm
FI oscillates on its rocking shaft (the end of which is seen in the figure, projecting horizontally),
until the end I of this arm comes against the fixed pin placed under it, and in contact with which it
is shown in the drawing. Just before this upward movement of the red A F begins, the pawl H
falls into a notch on the wheel B, which is attached to the screw of the engine, and during the up-
ward motion of the red A F the pawl H presses against the notched wheel and rotates it a definite
fraction of an entire revolution. The pawl H having completed its “throw,” the crank-pin on the
driving-wheel passes its upper centre, and then the slotted lever G lifts the pawl out of the teeth of
the wheel B, so that no jarrings or tremors are given to the machine while the pawl is retreating to
take a fresh hold on the feed-wheel B. A pin attached to the connecting-rod passes through a slot
in the tube A F, and serves to hold the two together when therrod is making its downward motion.
The amount of rotation to be given to
the feed-wheel B is regulated by rotat-
ing to the right or to the left the col-
lar on the rock-shalt, to which the
pawl H is jointed. Directing atten-
tion to the plate L J, to which is at-
tached the cradle N carrying the dia-
mond—pointed rod 111, we observe at K
the right-hand end of a red the ex-
tremities of which pass through holes
in the iron frame of the engine. This
rod is moved parallel to the V-guide of
the plate L J by means of an oscillating
lever which works in a vertical slot
attached to the rod K, and is fixed on
'the same rock-shaft which carries the
lever F J. Projecting upward from
the rod K is a short rod whose end is
ii. P
.
all, l|
ll l,
H
'l
l
l it; "d h .
l
l
'I
I
i
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'II I
an J, _|
an .-


shown at L. This rod moves in a
short slot cut in the direction of the
length‘of the plate L J, as shown in
the figure.
' The action of the cutting point of
l, the tool ll! can now be explained.
\llli, While the pawl H is rotating the feed-
, wheel B, the rod L presses against the
i '"l; left-hand end of its slot and moves
‘ the slide J from right to left. The
, ' plate J cannot move, as above indi-
cated, until the rod L touches the left-
hand end of its shot; and when it reaches this position the left-hand end of the rod K has moved
to the left sufficiently to preSs against the lower point of the cradle N, and hold the diamond-pointed
tool it! elevated above the plate of glass or speculum metal during the entire left-hand motion of the
plate J. When the end F of the lever F I descends, the rod K moves from left to right, and the
projecting pin has to move up to the right-hand end of its slot before it can push the plate J to the
right. During this moti:n of L in its slot, the left end of the rod K has allowed the diamond-point
on J/[ to rest on the glass plate, so that before the plate J begins its right-hand motion the diamond-
point is at rest on the plate to be ruled. The plate J now moves to the right, and the diamond-point
cuts a line. But the diamond-point is lifted, before the right-hand motion of the plate J ceases, by
the side-arm 0 of the cradle N coming against the inclined surface of the side-piece P. The dia-
‘mond is thus raised, and is held in this position by the depression of *0 against .P until the left-hand
end of K has moved up to the cradle. and holds the tool elevated during the motion of the plate J to
the left. After this motion has ceased, the diamond is lowered to the glass plate, and another cut is
made; and so on, the machine working automatically until the plate is ruled. The pitch of the
screw is one forty-eighth of an inch; hence, by knowing the fraction of the revolution of the screw
made between two contiguous cuts, we know the distance, in fraction of one forty-eighth of an inch,
separating the centres of two contiguous lines on the grating. The diameter of the feed-wheel B is
6 inches, and from this dimension the reader may estimate the size of the other parts of the engine.
An accurate dividing, engine by J. Salleron of Paris is owned by the Stevens Institute of Technol-
ogy. Ingenious machines are used by engravers for ruling tint-lines on boxwood. (See “ The
Minute Measurements of Modern Science,” Mayer, Scientific American Supplement, Vol. III., N o. 56.)
DIVING. I ' 457

DIVING. The necessity for the manual execution of engineering operations under water, and the
desire to obtain cargoes of vessels, etc., which have become submerged, have led to the invention of
various apparatus whereby men may safely descend to moderate submarine depths. Devices for this
purpose may be divided into two classes, diving-bells and diving-armor.
1. Dictvzg-Bells.--The principle of the diving-bell is seen in pressing any vessel like a tumbler,
mouth downward, into water. The air within the vessel prevents the water from rising and filling it,
but the inclosed air is made to occupy less space as the pressure is increased with the augmenting
depth of water. . The most practical form of diving-bell is called the “Nautilus,” Fig. 987. This is
a sort of submarine boat, having chambers in its
walls, said chambers being connected near the 957-
bottom of the pipe, which opens by a cock out-
ward to the external surrounding water. An
opening in the bottom of the machine is closed
by movable doors. The chambers are likewise
connected at top by a smaller pipe, which opens
through the top of the machine, and to which
opening is affixed a flexible pipe, with coils of
wire spirally inclosed. Branches on this latter
pipe also allow communication with the larger or
working chamber. At the surface of the water
is a receiver, to which is attached a hollow drum
or reel, to the barrel of which is affixed the other
end of the flexible pipe leading to the top of the
nautilus. In connection with the receiver (Fig.
987) is a powerful air-condensing pump. The
operator enters the machine through the top,
which is then closed. To descend, the water-
coek is opened, and the external water flows
into the chambers; at the same time a cock on
a pipe opening from the chambers outward is
opened, in order that, the air escaping, an un-
interrupted flow of water may take place into the chambers. The weight of water entering
causes the sinking of the machine. As soon as the latter is fairly under water, in order that the
descent may be without shock, the water-cock is closed. The receiver at the surface being pre-
viously charged by the air-pump to a density somewhat greater than that of the water at the depth
proposed to be attained, one of the branch cocks on the pipe, connecting the chambers at top, is
opened, and the air rushes into the working chamber, gradually condensing, until a density equal to
the density of thc'water without is attained. The bottom is then removed, and communication is
made with the under surface, on which the nautilus is resting. In order to move about in localities
where the tides or currents do not affect operations, it is only necessary for the workman to step
out of the bottom of the machine, and, placing his hands against its sides, to push it in any direction.
Where currents or tides exist, it becomes necessary to depend upon fixed points, from which move-
ments may be made as desired. This is accomplished by placing in the bottom of the nautilus
stuffing-boxes of peculiar construction, through which cables may pass over pulleys to the external
sides, thence up through tubes (to prevent their being worn) to and over oscillating or swinging
pulleys, placed in the plane of th ‘ centre of gravity of the nautilus, and thence to the points of affix-
ment respectively. 1
Toselli’s navigable diving-bell or marine mole, Fig. 988 A, is a kind of turret divided into four com-
partments. The bottom division, A, contains lead, and serves to hold the bell in a vertical position.
i B can be filled with water by opening a cock communicating from without, or may be rendered en-
tirely empty by aid of the pump. Consequently this chamber serves to augment or diminish the
weight of the machine, and to determine its up and down travel, serving the same purpose as the
natatory vessels in fishes. In the large compartment 0 the operator and the observer are stationed ;
and, finally, F is a reservoir into which air is compressed in a quantity sufficient to last during the
time which the bell is to be submerged. I is a cock which admits air from this chamber into the
main compartment. G is the pipe for carrying off the foul atmosphere, which communicates with
the tube H and a float. The latter has a valve, h, to prevent entrance of water. The bell has a.
rudder and a screw not shown in the illustration, the screw being worked by a hand-crank by one
man, and driving the machine at the rate of about 25 feet per minute. ill is the manometer, which
indicates exterior pressure, and hence the depth of submersion. N is another manometer, which
shows the pressure of condensed air in the chamber F. R is a life-line, connecting the bell with the
ship. This contains a wire, by means of which telegraph dispatches maybe sent to the instrument
Q. U is the manhole, allowing access to the interior of the machine, and closed with a double door.
V are heavy glass dcadlights, and Z is a seat.
Should the tube H, which carries off foul air, break or choke, water would be at once pumped out
of B, the bell would ascend, and meanwhile the bad atmosphere would be allowed to escape through
the extra pipe f. In case the electric wire in the life-line should part, preventing the passage of
signals, the machine would again ascend, and communicate with the vessel through the speaking-
trumpct L. If the line remained intact, the bell could be instantly hauled to the surface by those
on the ship, in case of a breakage of the hydraulic pump, on signal being transmitted. If pump,
wire, and life-line should all break down at once, then the operator would unscrew a nut and free the
lead underneath, when he would immediately ascend to the surface. Finally, if by some extraor-
dinary circumstance the ship should break the line and lose sight of the bell, or if the vessel itself


458 DIVING.

should sink, the operator would first, by unscrewing a nut within, cast his bell loose from the life-
line, and would then ascend. As soon as he reached the surface, he would be enabled to view his
surroundings by means of a camera obscura at T; and, by revolving the same by its tube, he could









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sweep the entire horizon. Having determined his course, he could then proceed in the proPer direc-
tion by means of the screw and rudder. '
The mode of using this bell in connection with a grapnel, the latter provided with an electric
light for illuminating the depths, is represented in Fig. 988 B.
Diving-Amzor.—The diving dress or armor used at the construction of the pier foundations in
New York harbor is illustrated in Fig. 989. It consists o0 a copper helmet, tinned inside, and
supplied with thick glass windows and a copper breastplate, which has a collar, to which the helmet
is readily adjusted. The helmet is large enough for considerable rotation and lateral motion of the
head, and allows the air which is forced into it to be so diifused as to be breathed without incon-
venience. The breastplate permits a free expansion of the lungs, and sufficient motion to avoid con-


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straint of the muscles. To the lower part of it is attached an India-rubber dress, having a body, legs,
and arms; shoes are fitted on, and the whole is impervious to water. The central window of the hel-
met can be readily removed without removing the helmet.- Leaden weights are attached to the waist
DIVING. I 459

and soles of the shoes to enable the diver easily to maintain an erect position when standing or walk-
ing upon the bottom. A pump, shown in Fig. 990, which is usually supplied with three cylinders,
pumps air through a flexible but strong Indiarubber tube into an opening in the back of the hel-
met, which leads through a flat channel to the frontal portion, where it is delivered against the glass
windows, thus serving not only to supply the lungs of the diver, but to clear the moisture from the
inner surface of the windows. The air finds its exit also at the back of the helmet. The air from
the pump is free to pass down the waist and into the legs, between the person and the dress, and is
delivered with sufficient force to overcome slightly the hydrostatic pressure. Fig. 990 represents the
diver in the act of spreading a large bucket of hydraulic concrete upon the bed of a harbor, prepara-
tory to laying blocks for the foundations of a pier. A signal-rope communicates with an attendant
on a boat which contains the air-pump. The signals of the diver are communicated verbally by the
attendant to a director stationed upon the derrick, by which the buckets of concrete or blocks of
béton are moved into position, and by him bells are rung, which enables the attendant at the engine
to execute the necessary movements.
A novel form of diving-dress, devised by Mr. A. E. Stove, is illustrated in Fig. 990 a.
The way hitherto adopted of making the joint between the dress and the breastplate has been to
insert a row of studs round the edge of the breastplate, and to punch corresponding holes in the dress.
These holes were threaded over the studs, and then four brass cover-plates were put on to the studs


and screwed up with wing nuts. The Indiaq'ubber margin of the dress was thus nipped tightly
between the cover-plates and the breastplate, and a water-tight Joint was made. It will be readily
understood that it was very easy to lose the nuts, and even the plates, when working in cold weather,
which benumbed the fingers of the men who assisted the diver, while the constant adjustment of the
dress on and off the studs made it subject to rapid wear at the holes. If the dress had only to be
put on and off once in each shift, the making of the joint would be sufficiently troublesome; but as
the pressure on the abdomen often obliges men to come to the surface for relief at frequent intervals,
the wear and tear and loss of time are serious. -
In the Steve dress the neck-opening is made smaller than usual, the upper part being of exceed-
ingly elastic rubber, so that the opening can be readily stretched to the required size to admit the
diver. Around the neck of the dress there is moulded a flange or fillet shaped to correspond with a
recess turned in the collar of the breastplate. This flange is pulled up through the neck opening of
the breastplate, and drops snugly into position. The helmet is made with an interrupted screw in the
usual way, and is secured with one~sixth of a turn, its bottom edge pressing upon the rubber flange
of the dress, and making a secure joint. The difference between the old and the new methods is
seen at a glance. In the former there are 2 watertight joints, 4 cover-plates, and 12 nuts; in the
latter there is only 1 joint, and no loose pieces whatever. The advantages of the new method in
convenience and facility of adjustment are self-evident.
The electric light in the incandescent form has been adapted to the uses of divers with noteworthy
success. The ordinary form of carbon filament lamp is encased in an envelope of thick but clear
glass, and arranged in a suitable framework so that it can be carried by the diver. Arrangements
of reflectors enable him to project its beams into inaccessible or dangerous places, and thus make
examinations which would be impracticable. In comparatively shallow water the electric light thus
used allows of direct observation of reefs and obstructions, and so saves in many instances the neces-
sity of diving operations. ' _
The following practical suggestions are furnished by the divers who laid the great Folkestone
(England) pier:
“ Eight or ten fathoms (48 ft. or 60 ft.) is a reasonable depth to work in; divers are said to have
gone down 220 ft. _ At 10 ft. depth we feel the pressure, and at 20 ft. can feel the increase, but do
not feel quick or slow variations of but 4 or 5 ft. In deep water we feel the pressure all over the
outside of the body, and some divers are said to have borne a pressure of 18 or 20 lbs. to the sq. in.
At the extension of the Folkestone pier we worked at a depth of 6 or '7 fathoms at high water.
460 DOCKS.

“ In laying the foundations of the pier we first levelled the seabed; sometimes it was pretty flat,
and sometimes we had to dig away 1% or 2 ft. The concrete was slightly damped before it was sent
down to us in bags by means of the crane overhead; some of the bags contained 2 cwt. We laid
the concrete, bags and all—the average thickness of the concrete along the bottom being about 15
in. Only one of us worked at a time. When the concrete was laid, the blocks of artificial stone
were slowly lowered down to us, and we guided each one into its place; this was all the more easily
done because they weighed so much less in water than in air. They were not cemented together
beneath the water. They were not always permanently placed at the first attempt; perhaps the bed
was not at the right level, so that the block had to be raised again while we leveled it. We then
took the wooden plugs out of the lewis-holes of the block, and twisted the lewis round with a span-
ner; when the lewis was thus freed, it was drawn up by the crane. The bottom block might have
taken ten minutes or more to fix, and in exceptional cases as much as an hour. The blocks in the
second tier were all placed in ten minutes, including the freeing of the lewis, their bed being neces-
sarily all right. Currents retarded the operations considerably.”
DUCKS. A dock is an artificial inclosure in connection with a harbor or river, used for the recep-
tion of vessels, and provided with gates for keeping in or shutting out the tide. Docks are divided
into two classes : wezf clocks, or basins in which water is shut in and kept at a given level to facilitate
the loading and unloading of ships; and dry docks, or graving docks, from which the water may be
shut or pumped so as to leave a ship dry for inspection or repairs. Dry docks may be again divided
into stationary docks and floating decks, of which there are many varieties.
WET DOCKS.-—Th€ advantages of these basins are that vessels can be accommodated in the smallest
possible space and are enabled to lie constantly afloat; whereas in tidal harbors, where they take
the ground through the falling of the tide, they are apt to be strained. When a vessel is in dock
she can be easily and at all times moved from place to place, while the operation of discharging and
loading can go on regularly during any time of the tide.
Ocqoacizfy of Docks—The number of vessels that can be accommodated in each acre of a basin is
termed its available capacity. A tolerably good approximation to the capacity of a dock is found
1
by the formula n z ——t— +a ; where n represents the number of vessels per acre, and 25 their aver-
age tonnage, and a is a coefficient which may be taken at from 4 to 5. From this formula the fol-
lowing table has been calculated :
Table showing Number of Vessels of given Tonnage accommodated per Acre of Dock Area.



Tonnage. N o. of Vessels per Acre. Tonnage. No. of Vessels per Acre.
, 100 14.0 350 6.9
150 10. 6 400 (i . 5
l 200 9 .0 4.50 c . z
250 80 500 6. 0
L 300 7 .3 I

The capacity of a dock depends not on the area only, but also on the depth. It has been deter-
mined that the capacities for tonnage of different channels vary as the cubes of their depths; a law
which may be found useful when comparing the relative advantages of two docks, harbors, or-navi-
gable tracks. Mr. George Robinson has also shown that by making the Albert Dock at Leith 2 feet
deeper than the Victoria Basin, there are 296 tides per year when there will be a depth of 23 feet,
whereas at the Victoria there are only 102 tides in the year'when that depth occurs. The ratio of
the draughts of vessels to their tonnage has been gradually decreasing, but there is not much uni-
formity in this particular as regards steam-vessels. Under ENGINES, STEAM, MARINE, are tables show-
ing dimensions of many of the ocean steamers leaving the port of New York, from which deductions
on the subject can be made. At the Clyde, steam-vessels of from 250 to 400 feet in length draw
with their machinery on board from 12 to 18 feet of water, which would give the light draught :
loaded draught multiplied by .7, the last quantity being a constant depending on the build. In
wooden sailing-vessels the draught is approximately equal to the cube root of the product of the ton-
nage multiplied by a constant such as the above. This last is assumed as 10 for vessels up to 500 tons,
and 7.5 for larger craft. From this is calculated approximately (error on the safe side) the following

Table showing Size of Vessel that can enter a Dock or Channel of given Depth (Stevenson).









Fnoror. 10. Fac'ron 7 .5.
Tonnage. ! BIKE?“ Tonnage ‘ Diggegtljt’ Tonnage. t’ Tonnage. 17?:egglt’
50 vs 2m 1 13.5 500 15.6 1,300 21.4
60 8.4 800 ' 14.5 600 10.5 1,400 21.9
70 8.8 3'10 I 13.1 700 17.4 1.500 22.5
80 0 .2 400 15.8 800 18.2 1.600 23 .0
90 0.0 450 l 16.4 900 18.9 1.700 23.4
100 10.0 1,000 1.0.6 1,800 23.9
150 11.4 1,100 20.2 1.000 24.8
200 12 .5 1,200 20 .8 2.000 24 .9 j


Mr. Thomas Stevenson, in his work on the “Construction of Harbors,” whence the foregoing data
are extracted, gives a plan for a deck of the form of maximum capacity, semi-octagonal in shape,
which has internal jetties with a broken line of quay radiating inward from the angles.
DUCKS. 461

Quay Proportions—Tile proportions of quays range, according to Sir John Coode, from 200 to
250 feet per acre. Vessels of 150 tons require about 100 feet of quay, and it is desirable to have
at least 100 feet of breadth behind the quay.
Entrances—For wet docks, according to Mr. Redman, the entrance should point up stream at an
angle of about 60°. The dimensions of locksv depend on the class of shipping that has to be pro-
vided for. (See Locks, under CANALs.) Outer or half-tide basins are formed between the locks and
the sea, and are provided with sea-gates, which are kept open until half tide, so as to accommodate
additional traffic. 'In the Liverpool docks the ratio of area of outer basins to area of docks is as 1
to 8.23.
- Oovwti'uctz'on of W'ct Docks.—-Wet decks are constructed with a wall of masonry or of piling, with
‘ Concrete and tamped-clay filling, and with a clay or concrete bottom. The higher the level of the
water in the dock is kept above the low or mean tide of the harbor, the stronger and more impervious
the wall requires to be made. When the area is not too great, the water is sometimes maintained
at the highest tide-level by pumps, mainly to avoid the necessity of admitting too much sedimentary
matter with the entrance of the tide when the water in the harbor is very turbid.
The Victoria Docks, London, Fig. 991, comprise a tidal basin of 16 acres at the entrance from the
Thames, and a main deck of 74 acres. The earthy strata which occupied the site of the dock con-
sisted of a top soil one feet deep, a layer of clay about 5:} feet thick, then one of peat from 5 to 12
feet, and beneath this a bed of gravel, lying upon the London clay. The dock and basin were ex~
cavated to a depth of 26 feet below high-water mark, and its bottom was puddled with clay to a
depth of 2 feet, leaving the finished surface 24 feet below Trinity high~watcr mark. The entrance
. - *1..."
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from the river into the basin is by a lock having two pairs of wrought-iron gates, revolving in hol-
low quoins, the walls of the lock being constructed of east-iron piling, T-shaped in section, backed
with hydraulic concrete. The gates are what are called cylindrical in form; that is, they are por-
tions of a cylinder, with the convexity turned toward the basin. The loek~chamber is 80 feet
wide at the bottom and 326*}; feet long, including the upper and lower gate-platforms upon which
the gates are supported while turning upon a circular-roller path. 0n the site of the lock the sur-
face of the London clay was 37 feet below high-water mark, and to this depth the excavation
was carried at this point, and the foundations of the gate-platforms were laid. Between the plat-.
forms the bottom of the lock was filled with clay puddle to a level of 28 feet below high‘watcr
mark. The upper gate-platform is 25% feet below that mark, while the lower one is ‘28 feet, or
at the same depth as the bottom of the lock; so that, the mean fall of tide being 18 feet, there
will be 10 feet depth of water in the dock below the upper platform at low tide. The entrance
from the tidal basin into the dock is by means of a single pair of gates, similar to those of the lock,
placed between two dumb jetties or walls which separate the basin from the deck. The basin and
dock are 4,050 feet in length and 1,050 feet in width. There are six jetties—the two just men-
tioned, which are each 485 feet long, and four others extending from the north wall into the deck
a distance of 581 feet, including the pointed terminations. These with the sides of the dock and
basin afford nearly 3 miles of quay-room. The four interior jetties are each 140 feet wide for 497
feet, and the surface of the quay varies from 6 to 9 feet above high-water mark. The side-walls
are vertical, and constructed of east-iron piles 7 feet apart from centre to centre, filled in between
with brick set in Roman cement, the brickwork being arched toward the back to give strength.
Behind the piles and brickwork there is a wall of concrete which was carried up from below the
clay bottom, and behind this a filling of clay. The piles are T-shaped in section, and are 35 feet
long and 1 foot wide on the face, averaging 115 inch in thickness, and weighing about 1% ton each.
They are driven to a depth of 28 feet below high-water mark, and therefore 4 feet below the bottom
of the clock. The brickwork commences 1 foot above the bottom, and rests upon concrete 3 feet
thick. The wall is covered with a cast-iron plate bolted to the heads of the piles, and upon these
462 ‘ DOCKS.

lies a timber sill. The piles in the opposite jetty walls are connected by cross-bars, 5 and 17 feet
below their heads. Upon each jetty there is a warehouse 500 feet long and 80 feet wide, leaving
wharf-room 30 feet wide; and it is also supplied with 9 hydraulic cranes, one of 5 tons power at
the pointed end, and 8 others of 3 tons power each along the sides. Connected with the north
side is a basin which opens into 8 graving or dry docks. '
The West India Docks, constructed in 1802 in a gorge in the Isle of Dogs, comprise an import-
dock of 30 acres, an export-dock of 25 acres, communicating with the Thames at Blackwell, and a
bonded-timber dock of 19 acres. The gates are 45 feet wide, admitting vessels of 1,200 tons. The
whole space occupied by docks and warehouses is 295 acres. The East India Docks, also at Black-
wall, completed in 1806, belong to the same company as the former. They include an iniport~basin
of 18, an export-basin of 9, and an entrance-basin of acres. The gates are 48 feet wide, and
the depth of water 23 feet. The Commercial Docks, situated on the opposite side of the river,
existed in 1660 under the name of the “I-Iowland Great Wet Dock,” and subsequently of the
“ Greenland Docks,” having been prepared for the accommodation of the Greenland whaling-vessels.
In 1807 they were greatly enlarged and received their present name; and they are now used chiefly
to receive vessels laden with corn, iron, lumber, guano, and other bulky articles. They cover an area
of 120 acres, 70 of which are water. The granaries will contain 140,000 quarters of corn. The
other principal docks here are the London and the St. Katherine Docks, the latter situated between
the former and the Tower. The warehouses in the St. Katherine Docks are built upon the water’s
edge, without a quay; but this plan has since been disapproved on account of interference with the
ships’ rigging. '
There are numerous other mercantile wet docks in Great Britain, a list of which, including on-
trance-basins provided with looks, at the principal ports, is appended:



PORTS. No. Area in Acres.
London . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 850
Liverpool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 206
Birkenhead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 142
Bristol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 79
Hull, exclusively of timber pounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 'i' 46}
Great Grimsby. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . .. 2 51
Hartlepool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 20
West Hartlepool, exclusive of timber pounds . . . . . . . . . . . . . . . . . . .. 3 32
River Wear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 41
River Tyne . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. 4 107
Leith . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8 15.}
Dundee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 84
Aberdeen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 85




The Atlantic Dock at Brooklyn, Fig. 992, in reality a tidal basin, was constructed by the Atlantic
Dock Company, chartered by the State Legislature in 1840. The work was commenced in 1841, and
occupied several years. Over 200 acres of land were purchased at a point on the Long Island shore
opposite Governor’s Island, and 60 acres of the low land and marsh were converted into a basin
having 40 acres of water surface. The inclosure on the water-side was made with cribwork piers
consisting of timber filled with stone, sunk in trenches 30 feet below high-water mark. The cribs
992.
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lap IMLAV ST.
















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were 25 feet thick at the base, and were placed with their external sides 150 feet apart, that being
the width of the pier, the top of which is 10 feet above low-water mark. The space between them
was filled with sand and gravel from the excavations in the basin. Piles were driven into the filling
to a sufficient depth and sawn off 5 feet below the surface; and upon the heads of the piles the
stone foundations of the warehouses were placed. The entrance is between the north and south
piers, and is 200 feet wide. The excavation over the whole 40 acres was made principally with
dredging machines working by means of an endless chain, and was carried to an average depth of 20
feet below low -water mark, or 25 feet below high-water mark. In the basin, reaching from either
nooKs. ‘ 463

end, are wooden piers of sufficient width for the unloading of ships, built of piles covered with
timber and planking. Upon the cribwork piers, one of 1,070 and the other of 1,000 feet in length,
998


there are commodious stone warehouses, 100 feet
in depth and extending the length of the piers.
Upon the opposite or inland side of the basin is
the commercial wharf, 2,000 feet in length, and
upon this there are three blocks of warehouses,
each 460 feet long and 180 feet deep, besides an
iron-yard of the same dimensions.
DRY Docxs.--I. Stationary Docks—These in-
closures, from which, as before stated, the water
is pumped out to allow a ship’s bottom to be
graved or cleaned, are usually built of masonry,
but are sometimes constructed of piling, concrete,
and clay puddling. Dock-walls should always be
made of sufficient strength to resist a pressure of
water equal to their height. Minard assigns four-
tenths of the height for the thickness, and Ran-
kine takes the ordinary thickness at from one-
third to one-half the height. The question of the
construction of dock-gates and the strains there-
on is one regarding which there is much differ-
ence of opinion. For a discussion of the subject
the reader is referred to “Minutes of the Pro-
ceedings of the Institution of Civil Engineers,”
vols. xviii. and xix.
Construction of Dry Docks. ——The dry dock at
the Navy Yard, Brooklyn, N. Y., is the largest
structure of the kind in the United States. It
was commenced in August, 1841, and occupied
just 10 years in building. The main chamber of
the dock, a, Fig. 993, is 286 feet long and 30 feet
wide at the bottom, and 307 feet long and 98 feet
wide at the top, this being the distance between
the folding gates g g and the head of the dock 0.
Behind the folding gates is what is called the
lock-chamber, c, 52 feet long, which length may
be added to the dock when it is required, a cais-
son, d, forming the external gate, being sufficient
to exclude the water. The bottom is 26 feet be-
low mean high tide, and 30 feet 8 inches below
the coping. The foundation had to be construct-
ed in quicksand, and consisted of piling driven
to great depth, covered with 18 inches of hydrau-
lic concrete, this covered with cross-timbers of
yellow pine 12 inches square, and this again with
994.


3-foot granite blocks laid in hydraulic cement.
A cross-section is represented in Fig. 994. The
walls, composed of heavy granite blocks laid in
hydraulic cement, are carried up vertically from
this foundation, and are 108 feet from outside to
outside, being 5 feet thick at the coping and 39
feet at the bottom or lower step, and varying in
thickness between these two points in accordance
with the curve, which is irregular and made to
correspond with the general curve of the side
of a ship. ‘The distance between the quoins in
464 DOCKS.
which the folding gates revolve is 66 feet, and this is about the average width of the lock-cham-
ber, and also the length of the deck of the caisson or outer gate, which has also a beam of 16
and a depth of 30 feet. Two culverts, cc, one on either side of the entrance and below the sur-
face at low tide, admit water and carry it in a descending course to the bottom of the dock a few
feet in front of the inner gates. These culverts have a calibre of 4 feet 9 inches vertical by 2 feet
5 inches horizontal. At the points where they enter the dock commence the discharge culverts, which
are carried on either side to a point beyond the head, where they unite and empty into a well under
the engine-house. From this well the water is pumped into a culvert which descends to the river and
discharges at a point near the entrance of the dock. The pumping-engine can empty the dock in 2h.
10m., its capacity when filled by the tide being about 600,000 cubic feet. When a ship is docked,
the filling-culverts are closed, as well as the passages from the dock-chamber to the draining-culverts
leading to the pump-well, and the water is pumped from the latter; the ship is then admitted and
placed over the keel-block in the centre of the deck; the caisson is next floated to its place, over the
recess or groove, and filled with water until it sinks down to the bottom of the masonry fitted to
receive its keel ; after which the turning gates are closed by men standing on the bridge, and work—
ing- the four hand-wheels that move the machinery. The culvert-gates in the dock-chamber are next
drawn, and the water is allowed to flow into the draining-culvert and well, by which means the water
is lowered several inches in the dock in a few minutes, thus hastening the shoring and producing an
immediate pressure on the gates, so as to effectually prevent the admission of water and fix them
steadily. A complete command of the level at the moment the gates are closed, or when a ship,
especially a large one, is about to touch the blocks and requires the placing of shores, is important;
and the above method gives a more perfect control of the operation for the first foot than could be
obtained by the best regulated pumps and machinery for driving them. '
Table showing Dimensions of Important Dry Docks.






Depth at Mean
LOCALITY. Length, Feet. High Tide, Width, Feet.
- Feet. a
Brooklyn Navy Yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 286 26 80 at floor.
Boston (Mass ) Navy Yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 256 25 86
Portsmouth, England . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644 25 80
“ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644 27 88
Devonport. “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 81 73
Birkenhead, “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 29 .7 85
“ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 750 29.7 50
Sandon, Liverpool (6 docks) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 540 . . . . 70 to 45
Brest, France (double dock) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 721 55 92
Somerset Dock, Malta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 428 80 42.5


FLOATING DOCKS.——Of these there are several varieties, the chief types of which are noted below.
Rennie’s floating dock, Fig. 995, has been constructed after the patent of Mr. G. B. Ronnie in the
navy yard at Gartagena, and also for the port of Ferrol, Spain. It is 350 feet long, 105 feet wide,
and 50 feet high in extreme dimensions. The depth of the pontoon is 12% feet, leaving a height of
37:} feet from the deck of the pontoon to the deck. of the side-walls, so that, if the keel-blocks occupy
5 feet and the deck 4% feet above water, there will be a clear depth of 28 feet of water for the
admission of ships. The total weight of the dock is about 500 tons, and the displacement of the
pontoon is equal to 13,000 tons, leaving a lifting power of 8,000 tons. It is constructed of plate,
angle, and T iron, riveted together in one structure. The pontoon is divided by a water-tight bulk-
head running the whole length, each half being subdivided by 10 transverse bulkheads. There are 4
pumps on each side, of 2 feet 9 inches stroke and 26 inches diameter, worked by steam.
The Balance Floating Dacia—T his was patented by John S. Gilbert of New York, and consists of
a pontoon divided into compartments, which may be so filled with either air or water as to preserve
995. 996.



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ésVOQV‘ZVOy :5:
masses 5.








; <WW


a balance of position, and by its buoyancy to be capable of raising vessels. It may be built of tim-
ber and planking, or of wrought-iron an'd planking. Those which are used in New York have the
framework entirely of wood, and one of them has been in use for nearly 40 years. The pontoons may
be from 8 to 12 feet in depth, and 100 or more in breadth by 350 or more in length. They are
strongly girded and trussed, and have a strong bulkhead running through the middle for the whole
length, upon which the keel of the vessel is supported by keel-blocks. At either srde the dock rises
DOCKS. 465

into walled chambers, which may be also filled with water or air, and upon the deck of which are
placed steam-engines for the purpose of pumping the water from the interior. The ends of the dock
are left open, so that when the vessel is raised the water readily flows from the dock. Fig. 996
represents the larger of two docks owned by the New York Balance Dock Company. It is 325
feet long, 100 feet wide, and 30 feet from deck of pontoons to deck of side-walls, or 40 feet in all,
the pontoons being 10 feet deep. It has 8 gates on either side for admitting, and 8 others for dis-
charging water, which is pumped out by steam-engines, one upon either wall, of 40 horse-power
each. The pumps are 14 in number, 7 on either side, of 36 inches diameter and 35 inches stroke,
capable of exhausting with sufficient rapidity to raise a vessel of 3,000 tons in an hour and a half.
Its total lifting power is estimated at 8,000 tons. In docking a vessel on the balance dock, the
pumps are first set in motion by the steam-engines on the deck above, and, the discharge opening
being closed by a gate for that purpose, the water rises in the chamber above the pumps until it is
full to the deck of the dock. It is next allowed to flow into the upper chamber of the dock until
its weight, acting as ballast, sinks the dock to the required depth. When the ship is floated into
the dock, this ballast is drawn off by means of valves, causing the dock to rise by its own specific
gravity until it touches the bottom of the ship, after which the vessel is lifted by pumping the water
out of the side chambers and bottom tank; and as the dock rises, the water around the ship in the
middle chamber ebbs out, so that the quantity of water to be exhausted in raising a vessel is in pro-
portion to her weight and not to her bulk. .
77w Bermuda Floating Dacia—This dock was built in England, and towed to the island of Ber-
muda by two war-vessels. It cost $1,250,000, and has the following dimensions: Extreme length,
381 feet; width inside, 83 feet 9 inches; width over all, 123 feet 9 inches; depth, 74 feet 5 inches.
The weight of the dock is 8,350 tons. As shown in the annexed engraving, Fig. 997, it is U-shaped,


and the section throughout is similar. It is built with two skins, fore and aft, at a distance of 20
feet apart. The space between the skins is divided by a water-tight bulkhead running with the mid-
dle line the entire length of the dock, each half being divided into three chambers by similar bulk— -
heads. The three chambers are respectively named “ load,” “balance,” and “ air ” compartments.
The first-named chamber is pumped full in 8 hours when a ship is about to be docked, and the dock
is thus sunk beneath the level of the horizontal bulkheads which divide the other two chambers.
Water sufficient to sink the structure low enough to admit a vessel entering is forced into the bal-
ance-chambers by means of valves in the external skin. The vessel having floated in, the next
operation is to place and secure the end caissons, which act as gates, and eject the water from the
“ load ” chamber. > Then the dock with the vessel in it rises, the water in the dock being allowed to
decrease by opening the sluices in the caissons.
Messrs. Clark, Stanfield 8t Co.’s floating dock, Figs. 998 A. and 998 B, in its general form is composed
of a number of pontoons, either of a square or a circular section, which lie parallel to each other at
fixed distances apart, and which range transversely to the length of the dock; each of these pon-
toons is permanently connected at one end to a longitudinal structure which forms the main side of
the dock ; the pontoons project outward from the side of the dock in the same way as the fingers of
the hand, so that the whole structure in plan resembles a comb. The pontoons, when the dock is
lowered to receive a vessel, are submerged; but the side of the dock to which the pontoons are at-
tached is never totally submerged, but is of sufficient depth to allow a freeboard of 6 or 7 feet
when the pontoons are sunk beneath the bottom of the vessel. When the dock is raised, the tops
of the. pontoons are well above water, and the side of the dock some feet higher than the deck of
the vessel which it supports. Fig. 998 A shows an elevation of the dock submerged, ready to raise
a vessel, with the outrigger attached. It will be seen that these elevations resemble the letter L.
It is obvious that such a form as this—namely, a dock with only one side to it—would be perfectly
30
466 DOCKS.

unstable when submerged, but the necessary stability is imparted to it by means of the outrigger
arrangement. This outrigger consists of a broad, flat pontoon, divided into numerous compart-
ments, and loaded with concrete ballast until it is half submerged. Its form gives it immense sta-
bility. It carries along its middle line a row of rigid upright columns, which project through the
9985.. 998 B.



pontoon some distance above and below, and are stiffened by struts. To the top and bottom of each
column is hinged a pair of parallel bars or booms, Fig. 999, which are also hinged at their opposite
ends to the sides of the dock, as shown in the diagram, so that the outrigger remains stationary
while the dock is free to be raised and lowered vertically, being always retained in a horizontal posi-
tion by the action of the parallel bars or booms. The movement is, in fact, exactly that of a par-
allel ruler. Each of the pontoons is usually divided into about 6 separate compartments, by means
of 5 transverse vertical bulkheads. The side of the dock to which the pontoons are attached is
practically a long box-girder, divided by numerous bulkheads into large water-tight chambers. Its
height may vary from 20 to 50 feet, or more ; its width from 10 to 15 feet; and its length is about
equal to that of the longest vessel intended to be docked. The pontoons are about twice the length
of the beam of the vessel to be raised, so as to be available for paddle steamers. Their height
may be from 10 to 20 feet, according to the weight of the vessel, and their width from 7 to 15 feet.
In the Russian Nicolaieff dock, the side is 280 feet long, 44 feet 6 inches high, and 12 feet bread.
The pontoons are 72 feet long, 18 feet deep, and 15 feet broad, and the clear space between them is
5 feet. The machinery for working the dock is carried in the chambers of the side. It consists of
a number of powerful pumps worked by steam-engines in the usual manner. When it is necessary
to submerge the dock, the necessary valves are opened, and the water admitted through pipes to the
compartments of the pontoons ; the dock is thus gradually lowered, its horizontal position being at
all times maintained by its connection with the outrigger. The vessel is then floated over the pon-
toons, water is pumped out until the keel takes its bearing on the blocks, the bilge-blocks are hauled
into place by chains in the usual manner, and, the vessel being firmly blocked and shored, the pump-
ing is continued until the vessel is raised to its full height; the valves are then closed. In this
position it will be seen that the dock with the ship on it has very great stability quite independently
of that afforded by the outrigger; the outrigger, having in fact performed its function—namely,
that of controlling the dock when submerged—is no longer of any service, and it might, should
occasion demand, be entirely removed. It may be remarked that the dock in this condition is much
























narrower than any other form'of dock, and it might with great facility be taken through any nar_
row entrance or channel; there is, however, no necessity to remove the outrigger for any other rea- I
son. While thus docked, the vessel can be examined, painted, and repaired as in any ordinary dock,
or can be removed from place to place.
DOCKS. 467


The type of dry-dock that has been most used during the past few years is what is known as the
Timber Dry-dock, shown in Fig. 1000, built by J. E. Simpson 8: Co., of New York.
The dock is built upon spruce pile foundations throughout. the floor foundation piles being driven
in rows spaced 3 ft. from centres transversely, and about 4 ft. 8 in. longitudinally, upon which are
fitted and secured heavy transverse floor-timbers of yellow pine, covered with spruce planking to form
the floor and carrying the keel-blocks, the latter being additionally supported by four rows of piles
firmly driven under the floor-timbers and capped with heavy yellow-pine timbers along the axis of the
dock. The heads of these piles along the keelway are also enclosed in a continuous bed of Portland
1000


cement concrete. Open~box drains are provided on each side of the keelway beneath the floor-tim-
bers, leading to the drainage-culverts at the head of each deck.
The sides and heads of the docks are built with a slope of about 45° ; the alters to high-water level
are of yellow-pine timber, 9 in. rise and 10 in. tread, and bolted to side-brace timbers which are sup-
ported by piles and abut upon the ends of the floor-timbers. The alters are carefully fitted in behind
with clay puddle, as the sides are built up, and from the level of high-water to top of coping the
sides are built of concrete en masse, faced with artificial stone, the alters being continued of the Same
material to coping-level.
468 ' DRAINER.

The keel-blocks are placed upon every floor-timber, and bilge-blocks of the usual form, sliding upon
oak bearers, upon“ every other floor-timber. Lines of close sheet piling of tongued plank enclose the
floor of the dock and also extend entirely around the dock outside of the coping, and across the
entrance of the outer end of the apron and at each abutment, forming cut-offs to exclude the tide-
water, etc.
An iron caisson or floating gate is used to close the dock, made with sloping ends corresponding
substantially with the slope of side walls in the body of the dock, which bears against the sill and
, solid timber abutments, the whole length of its keel and stem, no “grooves ” being used. Each dock
has two gate sills and abutments, the outer one being provided chiefly to facilitate examination of
and repairs to the inner or main one generally used. The joint is made water-tight by means of a
rubber gasket secured to the face of sills and abutments.
The principal advantages which these decks are claimed to possess over stone docks as usually
constructed, are decreased cost, greater accessibility, better facilities for shoring vessels, better distri-
bution of light, and dryness. The narrow alters and gently sloping sides afford safer and easier means
of ingress and egress at every point, furnish a better supply of light and air, and the shoring
is more easily adjusted.
The life of timber docks is as yet unknown, though the substructure, which is kept constantly wet,
can be said to be practically imperishable. The repairs of a timber deck of good quality, of good ma-
terials and well built, would be insignificant for a period of, say, twenty years, when it would probably be
found necessary to renew all wood-work above high~water level and the face timber above half-tide
level. The relative average yearly cost of repairs of these docks as now constructed and the ordinary
stone docks, is stated to be in favor of the timber docks, especially in latitudes much above the frost-
line. The manner and cost of operating does not differ materially from other kinds of well-con-
structed excavated docks. .
Bellot Basin-Dock at Havre.-—The Bellot Basin, an important artificial improvement at Havre,
France, is constructed upon made land southward of the Tancarville Canal. It is bounded on the
south by a. masonry dike 3,280 ft. and a stockade 1,790 ft. in length. The total length of the
work, including that of the entrance-lock, is 3,762 ft. Its two divisions, known as the east and west
decks, are of a uniform width of 7 20 yards. The total area of the dock is 253,460 sq. yards. The
entrance-lock is 98 ft. wide, and is provided with tide-gates, the leaves of which are of rolled iron 54
ft. wide and 36 ft. high, arranged with air and water chambers, so that the weight upon the hinges
can be varied between the extremes of 25 and 155 tons. The sluiceways, also 98 ft. wide, are
spanned by revolving bridges operated by powerful hydraulic machinery.
The Télburg/ Decks, near London, England, consist of a tidal basin, and main and branch docks.
The tidal basin, with a water area of 19 acres, has at low-water spring tides a depth of 26 ft.,
while at ordinary high-water springs the depth is 45 ft., thus enabling the largest steamships
to enter and leave irrespective of conditions of tide. In the basin there are two arrival and depart-
ure quays (each 600 ft. long) for discharging and loading at all states of the tide. The north-
western quay of the basin, named the transshipment quay, is over 300 ft. in length, and is chiefly
intended for transshipment to and from continental steamers. The coaling jetty at the south_
western quay of the tidal basin is fitted with four 30-cwt. movable hydraulic cranes, with weighing
apparatus.
The lock connecting the main dock with the tidal basin is 80 ft. wide and 700 ft. long, divided
into two chambers respectively 555 ft. and 145 ft. in length, and there are three pairs of wrought-
iron double-skinned lock-gates. Some idea of their size may be formed when we say that each pair
weighs nearly 240 tons, the width of each leaf being 49 ft., and the depth from the top of the gates
to the sill 44 ft. Water can be pumped out of them at the rate of 650 tons per minute by means of
four centrifugal pumps.
Four large dry-docks are provided, in which scraping, painting, and repairs can be effected. Two
have a depth of 32 ft. and two 27 ft. of water on the sills at ordinary spring tides. These unusual
depths will obviate all risk of the detentions so frequently experienced by ships at other dry-docks
within the port of London. The dry-docks are enclosed and divided by caissons. The emptying of
the larger pair of dry-docks by pumping out 12,000,000 gallons of water can be performed in an
hour. There are six caissons. The weight of each is about 240 tons. The main dock is 1,800 ft.
long and 600 ft. wide, and each of the three branch docks is 1,600 ft. in length, extending from the
main dock in a northwesterly direction, the centre branch dock being 300 ft. wide, while each
of the other two has an average width of 250 ft. The depth of the main and branch docks is 38
ft. below Trinity high-water mark. At the quays in the main and branch docks, which are 13,000
ft. in length, 31 steam-vessels of the largest size can be berthed for loading or discharging, and
the depth of water admits of such vessels being at all times loaded to their full draught alongside
the quay without removal to the basin.
. DRAINER. See PAPER-MAKING.
1015' DRAWING-FRAME. See COTTON-SPINNING MACHINERY.
DRAWING—KNIFE. A blade having a handle at each end, as
shown in Fig. 1015, and used by coopers, wagon-makers, and carpen-
ters. It is usually operated in connection with a shaving-horse, wnieh
holds the stave, spoke, or other article upon which the shaving cut is
being made.
DREDGING MACHINERY. Dredging is effected in various ways—either by drags, or scoops,
or rakes, or machines. There are two sorts of hand-drags, one for raising mud, the other sand.
The first consists of an iron box pierced with holes, open in front as well as at the top; to this is
attached a slightly flexible handle, of a length proportionate to the depth it is to work in: when
this is made use of, the men in a boat make the iron box enter the sand, sustaining the handle

DREDGING MACHINERY. 469

on the shoulder; and when it is filled they raise it, and, if there be any large stones, they are dis-
engaged by means of books. One man will raise in this manner, where the depth is not more
than 4 or 5 feet, a cubic yard in the course of a day, and sometimes more.
The drag for mud is differently formed: it is an iron ring, to which a canvas bag is attached,
by passing a cord through holes made in the ring purposely to-receive it; that point of the iron
rim which is intended to touch the ground and enter the mud must be sufficiently strong. Two men
in a boat or punt are required to manoeuvre it, and in the course of a day they will raise from 12 to
14 cubic yards, if the depth does not exceed 6 feet; when the boat is made use of, it is first moored
in such a manner that it cannot drift. Such a drag allows the water to flow out of it, and retains
only the solid matter.
The Louchelte, a kind of spade, or a collection of them, is used for cutting or extracting turf
under water, without the necessity of first pumping it dry. This consists of a light iron frame,
which is armed all round with a cutting-blade, in length about 3 feet; the part between it and the
handle is open, being formed of four horizontal rods and two vertical ones ; these receive the turf
after it is cut and detached, and enable the workmen, by means of a rope and windlass, to pull it
up. These cutting instruments have a variety of forms given them to adapt them to the peculiar
work they may have to perform.
The Boa: Shovel consists of an open box fixed at the end of a long handle, usually made of iron;
the cutter traverses in a groove, and is worked by another handle ; by this the turf is cut and de-
tached, and each successive piece falls into the box. As many as four turfs may be thus drawn up
at one time.
Dredging Mae/aims have been constructed in various ways, and of iron or wood, according to the
nature of the service. Some machines have been arranged so that the system of chain and buckets
should work through a channel in the middle of the vessel; others with one system on each side;
and others with the buckets working over the extremity of the vessel.
The best adapted boilers and engines for dredging purposes are those upon the marine principle,
as in them compactness and stability are combined; and for this reason those of that description
are invariably applied; but in practice it is found disadvantageous to the profitable working of the
machine, if the engine be not of a proportionate pewer to the depth of water, the buckets of a
suitable number, and the bucket-frame of sufficient length to lie at a proper angle. Hence the fol-
lowing arranged proportions are annexed as the best adapted for working at or about the various
specified depths from which the material is to be raised:
._._..


I
Nominal Power of Engine. I Length of Bucket-Frame. I Number of Buckets. Depth of Water in Feet.
1 20 as} ’ s4 5 18
25 63 se ; 20 i
30 73} 45 25

The boat requires little or no peculiarity of form, otherwise than that of proper stability. It
must be strong-and well put together, or a constant tremulous motion is created by the action of
the machinery, and the proper effect of the machine in a measure destroyed. It must also be of
magnitude sufficient for the receiving of the machinery with a proper clearance for the buckets,
1016. 1017.














according to the depth of water and differ-
ent positions in which, on that account, they
are so frequently required.
The Scraping Dredger.—The action of the
scraping dredge in forming river-channels is
twofold: first, it cuts up and loosens the
material of which the bar is composed, and
second, conveys it down stream and deposits
it in deep water. Figs. 1016 and 1017 represent the scraper devised by Colonel S. H. Long, U. S. A.,
and used in the improvement of the Mississippi river. The scraper frame, which carries 5 buckets,
as shown at .D in Fig. 1016, is supported by a heavy bowsprit, and is raised and lowered by a hori-
zontal drum actuated by a hoisting engine.









470 DREDGING MACHINERY.

The Lake Fucino (Italy) Dredge is so constructed that a circular movement is given to the fore
part of the vessel which carries the train of buckets.
The buckets empty their contents on an endless chain P, composed of articulated receivers, and
placed in the longitudinal axis of the dredge. This chain is moved by drums placed at the ends
of a lattice-girder U, on which are laid the iron rails, one above and one below, for the endless
chain to travel upon. The lower drum is driven by the wheel V, mounted on its shaft, and to
1026.


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which motion is imparted from the engine. The endless chain of receivers empties the material
excavated on to a similar chain P’, placed like the former on a lattice-girder U', and carried by
the two barges B B. This chain, situated at right angles to the axis of the canal, empties the mate-
rial into wagons on a railway laid on the bank; the chain is moved by the wheel X on the lower
drum shaft, and driven by the portable engine Z. The lattice-girder U’, carrying the chain P’, is
of the form shown. This arrangement was adopted so that the excavated material could be dis-
charged on to the canal bank when the water level fell below the ground level on each side.
The following results were obtained per day of 10 hours: The speed at which the machine is
driven is equal to 17 buckets per minute, and the buckets are of such a capacity (about 5.25 cubic
feet) that the total amount excavated is about 2,000 cubic yards; allowing 33 per cent. for loss,
which is excessive, the cifective work of 10 hours per day is 1,330 cubic yards.
Dredging at Suez Canal.—-The great dredges used in the excavation of the Suez Canal had each a
single line of dredge-buckets, supported at the centre. The iron hulls were from 72 to 82 feet in
length. Two methods of delivering the excavated material were employed. In the first, Fig. 1026,
1026.


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chutes 230 ~feet long were sustained by lattice~girders, and supported upon a barge moored parallel to
the side of the dredge, upon telescopic frames, so that they could be raised or lowered at pleasure by
means of a hydraulic hoist, and thus might be inclined at different angles. Rotary pumps in the
dredge forced a stream of water into the upper end of the chute, so as to wash the soil down the
slope. An endless chain furnished with scrapers was also made to move along the bottom of the
chute whenever the materials were too stiff to be freely discharged by the aid of water.
The second arrangement was a portable inclined railway, Fig. 1027, extending from the dredge or
barge upward over the banks, and upon which trucks or trollies carrying the boxes filled with the
excavated material were made to ascend, and finally to dump their contents at the further end. The
boxes were hooked on to the trollies as shown in the illustration.
Centrifugal Pump System of Dredging—Fig. 1028 represents the application of a centrifugal pump
to dredging purposes, used in Holland. The pump is bolted to the side of the dredger," and is driven
at the rate of 230 revolutions per minute. It has two inlets protected by valves, the one on the bot-
tom for the admission of water, and the other on the top for regulating the entry of the material to
be transported. 0n the top of the pump is placed a cylinder or reservoir to receive, by means of a
chute, the stuff dredged up. The dredger is connected with the shore by means of wooden pipes
fitted with buoying pieces to enable them to float, and connected by leather joints, those immediately
following the dredger being arranged on the lazy-tongs principle to admit of its free movement in
DBEDGING MACHINERY. 471




‘ ‘f-J‘F,
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any direction. The action is as follows: By the revolution of the flyer A, a rapid stream. of water is
maintained through the pipes into which the dredged stufi is admitted through the pump by the
1028.
“_-__
/’0 ~_‘
\
MAIN SHAFT
FROM EN GINE


opening on the top, and is thus rapidly mixed and carried to the delivery at the opposite end of the
pipes, where the heavier materials deposit themselves in nearly level beds. I
Air-Exhaust Dredger.—Another mode of raising sand, silt, and mud is by an exhausted receiver in
1029.




the barge, connected by an adjustable pipe and flexible connections with a spout which is adapted to
suck in the mud (Fig. 1029), upon which it rests, and discharge it into the receiver for removal and
subsequent discharge at the lower valve. The steam jet or ejector has also been proposed; it dif~
fers in no substantial respect from the water-ejector.
4'72 DREDGING MACHINERY.

The Pneumatic Excavator.—-As employed during the construction of the Tay Bridge, Scotland,
this apparatus consists of four wrought-iron drums or tanks, A B, Fig. 1030 a, mounted upon a barge,
and connected in pairs to obtain constant action with two air-pumps. They have a conically-shaped
bottom, opening at a, through which the materials are discharged. The discharge-opening a is pro-
vided with a door 0, made tight by a ring of India-rubber, secured between two circular iron disks.
The method of connection of the valve er door with the lever enables the door to adjust itself
when closed, so as to bed equally around the discharge-opening. This door may be opened or
kept open, or be closed when necessary, by means of a hand-lever h fixed on a cross-shaft. One
1080 A.









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pipe 71 passes through the cover of each tank A B. Both pipes 2' i are connected with a three-way
cook, the shell of which is cast with three branches—the lower branch for connection with pipes j,
which are in communication with air-pumps. In the interior of each tank, and immediately below
the mouth of the pipe i, is mounted a valve m. This is a block of wood arranged to slide upon
rods, which are secured to the cover of the tank. A disk of Indiwrubber is secured to the upper
surface, or let into the top of the block. When the materials rise so high within the tank that
the block becomes partly immersed, it floats; and if the influx continues, it is raised until it closes
the pipe. An indicator E shows the height of the material in the tank. The curved pipes n,
which are attached to the trunk F, Fig. 1030 B, are provided at
their lower end with valves 0 for closing them during the empty-
ing of the tank. The trunk F forms the suction-pipe, the end of
which is provided with a nose-piece, and which may be moved
about to any part of the caisson. ‘
The action of the apparatus may be described as follows : One
of each pair of the tanks A is in communication with the air-
pump and with the trunk Fl In the other tank the valve 0 is
closed, and communication with the air-pump is shut off by the
three-way valve. The pump will create a vacuum in the tank A,
and the mud, gravel, and matters associated with water are sucked
through the pipe 5', Fig. 1030 B, and, ascending through the trunk
F, flow into the tank. When the tank is sufficiently filled, the
hand-wheel is turned so as to shut off the communication with
the air-pump, and air is admitted to the interior of the tank by
air-inlet cocks at. The valve 0 now closes. The door a is opened
to connect the tank B with the air-pump, so that the latter tank
begins to fill while the other tank is discharging; or the plug of
the three-way valve may be first turned into position to establish a communication between the two
tanks before opening: the cock 10, whereby a partial vacuum is at once formed in the tank B. The
two tanks are thus filled and emptied alternately. To facilitate excavation or dredging at compara-
tively great depths, a jet of compressed air may be admitted into the mouth of the aforesaid suction-
pipe by a pipe shown by dotted lines V. Two men and a boy are required for each barge, and the
quantity raised per working-day of 10 hours averages upward of 400 tons.
Fig. 1031 represents a circular radial dredging machine, designed by Mr. W. R. Kinipple, C. E.,
for dredging afloat or aground without the usual aid of bow, side, and stern chains. This machine
consists of a circular vessel having a round well or hopper, and a revolving framework carrying the
engines, machinery, and radial bucket-ladders. In the centre of the vessel is a cylindrical screw-
pile, which is screwed into the bottom of the sea or river, at any spot where dredging operations are
to be carried on. The pile is hollow, and is filled with water to aid its descent by weight ; the water
is pumped out to give additional lifting power during the process of rising. Around the pile there
is freedom for oscillation in a moderate seaway. There are two revolving anchors carried by legs,
which are lowered down to the bed of the sea. These provide additional mooring power beyond



DREDGI NG MACHINERY. 473
that obtained by the centre screw-pile, and are for the purpose of giving a rotary motion to the
dredger when it is at work. On the deck of the hull, at the outer margin, is a rail, on which the
radial dredging machinery revolves or travels. There are two radial bucket-ladders, which, when
dredging, may be worked in opposition to each other, so as to place the machine in equilibrium.
1031.
WI


The traVeling frameWOrk supporting the radial ladder may be secured in a fixed position to a quay
or wharf, and the hull of the dredger made to revolve, while one bucket-ladder is working radially
A and loading the hopper, and the other is unloading the hopper and discharging the dredged materials
into an embankment behind the quays.
474 DRESSER.

DRESSER. See COTTON-SPINNING MACHINERY.
DRIFTS. 0f drifts there are two kinds. One is a smooth, round, conical pin, employed by boiler-
makers to make the punched holes in boiler-plates come fair, so that the rivets may enter. This is
termed a stretching drift. The other is a toothed or cutting drift. The first tends to weaken the
strength of the plate at the narrowest section of metal, namely, between the hole and the edge of
the plate, where the latter, being the weakest, gives way to the pressure of the punch. Its use is
not deemed compatible with good workmanship, and hence its description is omitted.
Of cutting drifts there are two kinds, the first being that shown in Fig. 1032. A is the cutting
edge, the width and thickness at C and B being reduced so that the sides of the drift may clear the
sides of the hole. The tools are filed at A A to suit the required hole, and tempered to a brown bor-
dering upon a purple. The hole or keyway is then cut out roughly to nearly the required size, and
the drift is then driven through with a hand hammer, cutting a. clean and true hole. Care must,
however, be taken to have the work rest evenly upon a solid block of iron or (for delicate work)
lead, and to strike the punch fair and evenly; otherwise a foul blow may break the drift across the
section at O. This class of drift is adapted to small and short holes only. such as cotter-ways in
the ends of keys or bolts, for which purposes it is a very serviceable and strong tool. It must be
freely supplied with oil when used upon wrought-iron or steel.
For deeper holes, or those requiring to be very straight, true, and smooth, the drift represented by
Fig. 1033 is used. The breadth and thickness of the section at A is made to suit the shape of the
keyway or slot required. The whole body of the drift is first filed up, parallel and smooth, to the
1035.
1082. 1033.
(i






A

required size and shape ; the serrations forming the teeth are then filled in on all four sides, the
object of cutting them diagonally being to preserve the strength of the cross-section at A A, Fig. 1034.
The teeth may be made finer (that is, closer together) for very fine work, their depth, however, being
preserved so as to give room to the cuttings. To attain this object in drifts of large size, the teeth
should be made as shown in Fig. 1034, which will give room for the cuttings, and still leave the teeth
sufficiently strong not to break. The head B of the drift is tapered off so that, when it swells from
being struck by the hammer, it will still pass through the hole, since this drift is intended to pass
clear through the work. '
The method of using this tool is as follows: The hole should be roughed out to very nearly the
required size, leaving but a very little to be taken out by the drift, whose duty is, not to remove a
mass of metal, but to cut a true and straight hole. To assist in roughing out the hole true, the drift
may be driven in lightly once or twice, and then withdrawn, which will serve to mark where metal
requires to be removed. When the hole is sufficiently near the size to admit of being drifted, the
work should be bedded evenly upon a block of iron or lead, and oil supplied to both the hole and
the drift ;- the latter is then driven in, care being exercised that the drift is kept upright in the hole.
If, however, the hole is a long one, and the cuttings clog in the teeth, or the cut becomes too great,
which may be detected by the drift making but little progress, or by the blow on the drift sounding
solid, the drift may be driven out again, the cuttings removed, the surplus metal (if any there be in
the hole) cut away, the hole and drift again freely oiled, and the drift inserted and driven in as be-
fore, the operation being continued until the drift passes entirely through the hole; for the drift
will be sure to break if too much duty is placed upon it. After the drift has passed once through
the hole, it should be turned a quarter revolution, and again driven through, and then twice more, so
that each side of the drift will have been in contact with each side of the hole (supposing it to be a
square one), which is done to correct any variation in the size of the drift, and thus cut the hole true.
The great desideratum in using these drifts is to drive them true, and to strike fair blows, other-
wise they will break. While the drift is first used, it should be examined for straightness at almost
every blow; and if it requires drawing to one side, it should be done by altering the direction in
which the hammer travels, and not by tilting the hammer face. (See Fig. 1035.) Suppose A to be a
piece of work, and B and O to be drifts which have entered the keyways out of plumb, as shown by
the dotted lines D and E. If the drift 0 on the right was struck by the hammer F in the position
shown, and traveling in the direction denoted by G, it would be almost sure to break; but if the
drift B was struck by the hammer H, as shown, and traveling in the direction denoted by I, it would
draw the drift B upright without breaking it; or, in other words, the hammer face should always
strike the head of the drift level and true with it, the drawing of the drift, if any is required, being
H
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THE BEMENT BORING-MACHINE.
DRILLING AND BORING MACHINES. ' 475

done by the direction in which the hammer travels. When it is desired to cut a very smooth hole,
two or more drifts should be used, each successive one being a trifle larger in diameter than its pre-
decessor. Drifts slight in cross-section, or slight in proportion to their lengths, should be tempered
evenly-all over to a purple blue, those of stout proportions being made of a. deep brown bordering
upon a bright purple. For cutting out long narrow holes the drift has no equal, and for very true
holes no substitute. It must, however, be very carefully used, in consequence of its liability to break
from a jarring blow.
DRILL-HOLDER. See LATHE Tears, and DRILLING AND Bonmc Macmsns.
DRILLING AND BORING MACHINES. Drilling difiers in principle from almost every other
operation in metal-cutting. The tools, instead of being held and directed by guides or spindles, are
supported mainly by the bearing of the cutting edges against the material. A common angular-
pointed drill is capable of withstanding a greater amount of strain upon its edges, and rougher use,
than any other cutting instrument employed in machine-fitting. The rigid support which the edges
receive and the tendency to press them to the centre, instead of to tear them away as with other
tools, allows drills to be used even when they are imperfectly shaped or improperly tempered, and
even when the cutting edges are of unequal length. Most of the difficulties which formerly per-
tained to drilling are now removed by machine-made drills, which are manufactured and sold as an
article of trade. Such drills do not require dressing and tempering or fitting to size after they are
in use, make true holes, are more rigid than common solid-shank drills, and will drill to a consider.
able depth without clogging. A drilling machine adapted to the usual requirements of a machine-
fitting establishment consists essentially of a spindle arranged to be driven at various speeds, with
a movement for feeding the drills; a firm table set at right angles to the spindle and arranged with
a vertical adjustment to or from the spindle; and a compound adjustment in a horizontal plane. The
simplicity of the mechanism required to operate drilling tools is such that it has permitted various
modifications, such as column drills, radial drills, suspended drills, horizontal drills, bracket drills,
multiple drills, and others.
The difference between the American and European practice in constructing drilling machines,
stated in general terms, is that in this country belts are moved faster in proportion to the speed of
the drill; the changes as to speed are the same, but on' a different scale, and the tools are driven
with more power and at a slower speed. This difference is in some measure explained by the fact
that in American engineering establishments there are generallyr provided drilling machines of vari-
ous sizes. Small holes are never drilled on large machines, and boring is never attempted on small
machines.
With 'few exceptions, the driving gearing of American drilling machines approximates to the two
types illustrated by the diagrams Figs. 1036 and 1037.855 Fig. 1036 shows a method.of encasing the
spindle gearing in the framing; a is the main column, e the spindle, and c the countershaft. The
annular bearing m is turned to fit into the bottom of the circular cavity n, and when removed per-
mits easy access to the pinion o. It may seem that this mode of arranging the gearing is more
expensive, but when “ fixtures,” as they are called, are provided for boring the bearings, the work
can _be rapidly and accurately performed. The bearings are bushed with brass, so as to be replaced
if worn; but, with surface enough and material of the best kind, there is but little wear, and it is
best to avoid compensating caps, which may be either too loose or set up too close.




















. The form of framing shown in 1036 is symmetrical, and affords a good opportunity for mount-
ing feed and back gearing on the shaft 0. In Fig. 1037 the most novel feature is the adjustment of
the spindle 0 through the bearing at e. This is a peculiarity of eastern-made drilling machines; its

* Engineering, xxii., 198.
_4’76 DRILLING AND BORING MACHINES.

value in a practical way depends somewhat on the character of other machine tools in a workshop,
and also upon the kind of work to be done. Such machines have a double adjustment for depth;
the tables are arranged to be raised or lowered a distance of 2 feet or more, and the spindle adjust-
ment is as much, so that a distance of 4 feet can be had between the table and spindle. A eounter-
shaft is generally mounted on the main frame beneath the shaft d, so that the belts can be conve-
niently shifted from one step to another. The long shaft a gives ample room for back gearing and feed-
ing gearing, the whole being accessible, and yet high enough to avoid accidents in handling material.
Fig. 1038 shows the mode of resisting the thrust when a sleeve-screw is used. The end of the
sleeve a rests on one or two washers of brass or steel at o, and projects within the cup-ring or
collar e on the spindle c ,' by this arrangement oil thrown out by centrifugal force is arrested by the
collar e, and, as soon as the drill is stopped and pressure removed, it again lubricates the bearing
surfaces.
Fig. 1039 shows another device for feeding drilling-spindles. Here a is a sleeve sliding through
the bearing e by means of the rack c, and a pinion at o inclosed within the bracket m. The pinion
0 is operated by a tangent wheel, as shown at n, and a hand-wheel d on the front; 8 is the spindle
and ii are compensating collars. Thin washers of anti-friction material are placed between the end
of the sleeve a and the spindle at u. The bracket m with its attachments is eounterweighted, and
slides up or down on the front of a main column for adjusting the height of the spindle, as explained
in a former place. This arrangement is in some respects not as advantageous as the old and simple
device shown in Fig. 1040. With this there are but half as many joints to produce lost motion;
the hand-wheel a can be placed at the side or in front as may be preferred, and the power regulated
by the proportion of the bevel-wheels e. cc are shells cast in a bracket, d is a screw-sleeve, and
the wheel 72 has an internal thread. This mode of resisting thrust is in practice all that can be
desired. The speed of the bearing surfaces is of course considerable, as they are in Fig. 1038;
but in drilling the pressure generally diminishes as speed increases, or as drills of less diameter are
used, so that a joint of this kind constructed of good material is durable and reliable.
Feeding mechanism is represented in Fig.
1043, , 1041. Here a is an imaginary frame or col-
umn, e the spindle, c the feeding-shaft, and
d a circular shell or sleeve fiatted on one side
and formed into a rack. This sleeve d is
drilled through to receive an extension of
the spindle, as shown by dotted lines. At
the top of the spindle is a stirrup m, having
an oil-cup to maintain a constant lubrication
of the collar 0, which sustains the weight of
the spindle e. The counterweight n is made
heavy enough to prevent loss of motion in
the joints at each end of the sleeve d, and
.so that drills will not drop down for a short
distance when they go through a piece, as is
common when a counterweight is not used.
The sleeve (1 is moved by a pinion at i, and
this in turn by the tangent wheel at s and
the worm-pinion u at the top of the feed-
shaft 0.
The mode of arranging back gearing shown
, V in Fig. 1042 has been adopted for most Amer-
2 ' \ ican drilling machines. The end pairs of
..- _ _- _, In wheels, instead of being at each end of the
}\ step-pulleys, are placed together as shown in
i the diagram at a and cl. The movable pair


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a are mounted loose on an eccentric stud e,
‘ ,4...- and are thrown into gear by the handle c.
The strain on the stud e is not severe, and is
of a kind which permits a loose-running joint
without much danger of wear.
Vertical Drilling Zlfacln'nes.—Fig. 1043 rep-
_ // resents an improved vertical drilling machine
11"" f of French construction. A is the feed-wheel,
placed conveniently at the hand of the oper-
' ator, and the drill is rotated at double speed
- ----
/ from the belt cone-pulley. Upon arms cf
the sleeve which surrounds the supporting
I column is a parallel vise and a perforated
,/ table. By means of the crank, in connec-
._ f”- tion with the worm and pinion and rack on
the column, the work-holding attachment may
be raised or lowered at will. The pressure on
the drill is automatic. This machine weighs 1,232 lbs., and the diameter of the table is 23.4 inches.
Fig. 1044 exhibits the construction of a column drilling machine built by Sir Joseph Whitworth
8t 00. The framing A consists of a solid casting attached to the sole-plate T; and on the upper
portion a bracket is cast, which serves to carry the outer ends of the cone-spindle and back-speed
_-


DRILLING AND BORING MACHINES. 477

spindle of the machine. Upon the spindle are the driving-cone B of three speeds, the spur-wheel
0, and the bevel-pinion D. The speed-cone B is loose upon the shaft, and only communicates mo-
tion to it by means of the spur-wheel O, which is keyed upon the spindle, and to which the cone can
- be attached by a stud-pin and nut. This wheels gears with the pinion E, on the same spindle which
carries the wheel M; this in }
turn gears with the pinion N, 1044,
which is fast upon the end of
the cone B, but runs loose upon
the cone-spindle. This arrange-
ment is in every respect the
same as the ordinary back-speed
of a lathe, and serves the same
purpose. Supposing the back; '
speed removed, the cone being ,
driven b its belt causes the i? . — , d, ____
spindle lo revolve in come a fl ” A”////// \
quence of its attachment to ' j
the fast-wheel 0, and at the
same time gives motion direct-
ly to the bevel-pinion D on the
end of the spindle. This again
gears with the bevel-wheel F,
on the drill-spindle G G, which
is free to slide vertically in the
eye of the wheel, while at the
same time it is prevented from
revolving in it by a sunk feath-
er. By this means three dif-
ferent degrees of quick speed _2
may be communicated to the drill. But let the back-speed
be in gear, as represented in
Fig. 1044, and let the stud-pin
be'removed, and the cone there-
by loosened from its attachment
with the wheel 0, the motion
being communicated to it will
not drive the shaft directly as
before; but the pinion N, be-
ing fast upon it, will give mo-
tion to the wheel 11!, upon the
same spindle with the pinion
E. This last will therefore
make the same number of rev-
olutions as M, but being less
in diameter will convey a pro-
portionally less velocity to the
wheel C, with which it gears,
and which it consequently drives
with a speed diminished in the
ratio of the gearing pairs. N 0w
the wheel 0, being fast on the
shaft, conveys through it to the
bevel-pinion D the same dimin-
ished speed, and this again to
the drill-spindle G'- G. This re-
duced speed may, of course, be 'r
varied as before, by placing the
belt on one pulley or other of the speed-cone. Behind the pinion E there is a recess east in the
framing, to allow it to enter when the back-speed wheels are to be thrown out of gear; and it may
be remarked that this speed-gear is only required to be in action when the machine is employed in
boring holes of upward of an inch and a half in diameter. The wheel F is east with a long hollow
boss, which is turned, and fitted into a brass collar in the lower branch of the carrying-bracket, as
seen. As already observed, the drill-spindle passes through the wheel F, which thus serves as its
lower guide. The upper end of the spindle is at the same time guided in a collar similarly fitted
into the upper branch of the bracket at a, and is thus guided vertically in ascending and descending.
(In the drawings it is shown at the lowest limit of its travel.) To the top of the drill-spindle is
attached the back-weight H by a jointed lever and guide-link, which embraces the top of the spindle
and moves upon a vertical guide-rod, kept firm in its place by having its lower end held by a screw.
nut, in a socket cast in the bracket, in the manner of a bolt, a rulf forged upon the lower end of the
rod answering to the head of the bolt. The drill-spindle is itself screwed toward the middle of its
length; it is there embraced by two screw-wheels J J, between which it turns, and which serve the
purpose of a nut to feed down the spindle in the operation of drilling.


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478 DRILLING AND BORING MACHINES.
K is the table upon which the article to be bored rests, and to which it can be firmly held down
and adjusted by Theadcd bolts and glands in the usual way, when thought necessary. The table, it
will be observed, is recessed and grooved to receive and retain the T-hcads of the holding-bolts.
The table is itself supported upon the sole of the large carriage-bracket L, which has a vertical slid-
ing motion, and is raised and depressed by means of a hand-crank applied at U. The table has a
double movement upon the sole of the carriage-bracket; one movement is circular and the other is
in the direction of the length of the table. The feed of the tool during the operation of boring is
obtained, as before stated, by means of the two screw-wheels J J, by an arrangement of parts which
forms the chief novelty of this machine. On the axes of these wheels are placed two pulleys, the
circumferences of which are embraced by the friction-collars SS. The bearings of the axis being
attached to the framing A A of the machine, it is obvious that, the machine being in motion, if the ‘
pulleys be prevented from revolving, the wheels J J will likewise remain at rest; but, the screwed
part of the drill-spindle revolving between them, they will act as a stationary nut, and cause the
spindle to descend through a space equal to
1045- one thread of its screw during every revolution.
Again, suppose the pulleys and wheels free, the
screw of the spindle, instead of descending, will
simply cause the wheels J J to revolve on their
axes through a space equal to one tooth during
every revolution of the screw. New, between
these extremes any amount of feed or downward
motion of the drill-spindle may be obtained by
simply retarding the motion of the wheels by
means of the friction-collars S S, which embrace
the small pulleys on their axes; for the friction
of the collars being less than to prevent entirely
the motion of the wheels, and at the same time
greater than to allow a tooth to pass during a
revolution of the spindle, a downward motion of
the spindle must thus be produced equal to the
retardation of the pulleys produced by the fric-
tion-collars. Thus, any degree of feed can be
produced at pleasure by the eontrivance of the
friction-collars.
Fig. 1045 represents a patent double-geared
vertical drill, made by Messrs. W. Sellers a Go.
of Philadelphia. This has a square column and
plain or compound tables, to be raised and low-
ered by a screw operated by power. The table
is arranged to swing to one side. The knee-
carrying table is provided with a bearing to hold
the lower end of the boring bar. The drill-spin-
dle is counterbalanced with quick hand and vari-
able power fecd, always in gear, but not inter-
fering with the rapid movement of the- spindle
vertically by hand. The driving pulley is placed
on the spindle, so that when the back-gear is not
in use the spindle is driven by a belt only, pro-
ducing a particularly smooth motion for small
drilling. The cone-pulley is at the base of the
column, admitting ready change of speed. There
is a 45-ineh vertical drill, 224 inches from centre
of spindle to face of column, with either plain or
compound table. This machine, for holes of 14
inch and under in cast-iron, has its spindle driven
by belt only, but is provided with back-gear to be
used for heavier work. In an experiment with
small drills, the power feed was used in boring a
quarter-inch hole through 3 inches thickness of
- wrought-iron successfully, and in less time than
the same hole was made by a skillful workman feeding by hand.
Radial Drilling lilachines.—A radial drilling machine by William B. Bement & Son of Philadel-
phia is illustrated in Fig. 1046. Upon the inner end of the radial arm is formed the sleeve A,
which is fitted upon the turned upper portion of the column B, so as to be rotated at will. It may
be tightened by the clamping-bolt O, a slot being cut for a few inches at its lower end to admit of
the necessary contraction. The cone and gearing at D are of the usual construction, the locking of
the cone to its shaft being effected by a sliding clutch within the cone, operated by the projecting
knob E. A central vertical shaft, provided with suitable hearings in the column B, receives motion
from the cone-shaft, and transmits it to the upper horizontal shaft through mitre-gears, the upper
pair of which is seen at F. The connection between the upper horizontal shaft and the drill-spindle
will be readily understood from the engraving. The hub of the bevel-gear I is extended through its
bearing, and gives vertical movement to the spindle through the spur-gear K, cone-pulleys L and 112',
bevel-gears N, and worm and worm-wheel O; the last carrying a pinion which works in the rack V.
m'lh'lmlillillrml,
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DRILLING AND BORING MACHINES. 479

The teeth of this rack are cut on the flatted side of a steel cylinder sliding vertically in a suitable
hearing. A red rigidly attached to the spindle passes through its whole length, and has at its upper
end a collar and nuts for close vertical adjustment. The worm at O is capable of a horizontal move-
ment sufficient to take it out of contact with the wheel; the bearing just below it being arranged to
slide, and, as well as the lower
bearing N, supported in a swivel. 1045,
This disengaging movement is U v
made by an eccentric at top of
the small vertical shaft, which
has at bottom the handle R with-
in convenient reach of the work-
man. The bevel-wheel at N runs
loosely on its vertical shaft, but
can be caused to carry it by a
sliding clutch S, operated by an
internal rod ending in a knob be-
low the-hand-wheel. The coun-
terweight T is east on the outer
end of a lever, the inner end of
which is forked and jointed to
the two links U, one on each
side of the spindle; the upper
ends of the links being jointed
to a small cross_head at top of
the rack V. By the hand-lever P
a quick and easy vertical move-
ment can be given to the spindle
when the worm 0 is moved out
of gear by the handle R. ‘Whcn
the worm is in gear, a slow ver_
tical movement can be given the
spindle by the hand-wheel, while
by drawing the clutch S into
gear the downward feeding move-
ment becomes automatic. The
table H has positive steps for
its horizontal and perpendicular
positions, and can be securely
held in any intermediate one by
the clamping-bolts X. By a
pinion on the shaft Z, working
in teeth turned in the stem J, it
can be raised and lowered. It
can also be rotated as desired,
and clamped in any position by
the bolts Y. The planed and slotted base-plate G is for holding work too large for the small table.
.Multiplc Drilling illaclzines.—Of this class of machines there are many designs, each adapted to its
particular purpose, which may be stated in general terms to be to drill a number of holes simulta-
neously. In machines employed for heavy work the spindles feed the drill through the work, while
for light work it is more convenient to feed the work to the drill, which may be done by a single
feeding motion to the table on which the work rests, instead of requiring a feed-motion to each
spindle. In the machine shown in 1047, which is the design of the Pratt is Whitney Company of
Hartford, Conn, the driving-spindle stands vertical in the centre of the column, and is belted to the
four drill-spindles to drive them, the pulleys on the main spindle being marked from 1 to 4, and the
corresponding pulleys on the drill-spindle being similarly marked. By employing belt power, the
width apart of the spindles may be varied in case of necessity. The speed of the machine is varied
at the cone-pulley, the belt driving the main spindles D passing over pulleys B and C to and around
A. The table T is raised for the feed either by the handle H or by the foot-treadle I, the weight of
the table being counterbalanced by the weight l/V.
Fig. 1048 represents an improved multiple drill of English construction. In this machine the
main driving-shaft is formed of a large steel screw. When more than ten spindles are employed,
this screw is‘cut with a right-hand thread for half its length, and with a left-hand thread for the
other half, to neutralize the end thrust. This screw engages with as many worm-pinions as there
are spindles to be driven. By keeping these pinions alternately above and below the centre line of
the driving-screw, the spindles may be adjusted to a pitch of 3} inches, although the pinions are
nearly 6 inches in diameter. The adjustment is made by hand, after slacking back the bolts which
hold the spindles in place. The pinions have feather-keys taking into grooves on the spindles, which
latter are fed up and down by screws working in nuts or worm-wheels, as shown. These worm-wheels
are driven by a screw by means of reversible strap motion, which gives a slow feed and a quick re-
turn motion. Each serew is fitted at its upper part with a bush (provided with feather-key) encircled
'by a. friction-brake. When this brake is tightened by the handle shown, the screw is prevented from
revolving, and is worked up and down by the worm-wheel or nut. When the brake is released, the
screw is free to revolve with this nut without rising or sinking; or it may be raised or lowered,






480 DRILLING AND BORING MACHINES.

independently of the other spindles, by a removable hand-wheel fitted on a square at its upper end.
The lower ends of the spindles are bored out parallel, and the shanks of the drills are turned to an
exact fit, this being found to be the best method of insuring the truth of the drills. When this
10lT. 1048.


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system is adopted, no templating or centering of the holes is required, as every drill will start its
own hole with perfect accuracy. A one-sided cotter passes through the socket, and when driven up
tightens on a flat formed on one side of the drill-shank. A drill may thus be removed or inserted
without stopping the machine
A four-spindled drilling machine, designed to drill holes in the arc of any circle from 12 inches
radius up to a straight line, is represented in Fig. 1049. This machine is of special use for drilling
1050.
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the flanges of fiue~tubes when made with flanged or “Adamson” joints; it will also drill the holes
in the edges of boiler-plates before they are bent, either in a straight line or in the arc of a very
large circle, such as is required when a boiler is made with “following joints,” where each ring of
DRILLING AND BORING MACHINES. 481

plates forms the frustum of a cone. The spindles are adjustable from 4 inches to 8 inches apart,
and the two outer spindles are adjustable at right angles to the main frame, so that all four will
coincide with the desired curve. The work is carried on a rising and falling table, which sinks low
enough to admit a cylinder 3 feet in length. There is a slot in the table to admit a stud carrying
1051.
m.
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cross-arms upon which the cylinder or flue section revolves, until drilled all around the flange. For
drilling plates a traversing apparatus is fitted to the table, as shown in the end view.
Traverse Drilling llIachine.—In preparing links for bridge-work, it is advisable, in order to msure
accuracy in length, to bore the holes for the
pins in both ends at the same time. For
this purpose rights and left-hand boring ma-
chines are made, sliding on a solid bed, and
adjustable to or from each other, to suit the
required length of links. The drilling ma-
chines, as shovm in Fig. 1050, are so placed
as to permit the links to be put in place from
one side, and, when done, passed out on the
other side of the machine. The driving is ef-
fected by horizontal belts passing over guide-
pulleys, and around a drum on the spindles.
The cutters used in this machine are kept
cool by water fed to them through the cen~
tre of the spindle. In the link-boring ma-
chine the two heads are united by bars of
wrought-iron, and can slide freely on the
cast-iron bed. The expansion of the wrought-
iron bars, being the same as the expansion
of the link being bored, insures uniformity
in the length of the finished work.
Horizontal Drills.-——The introduction of
small shortstroke engines for mining pur-
poses calling for some ready means of quar-
tering wheels with a crank-throw of only 5
inches, for engines of 10-inch stroke, the
horizontal drill (wheel-quartering machine)
represented in 1051 has been construct-
ed by Mcssrs. \V. Sellers 8; 00., so as- to
quarter from 5 inches to 13 inches radius of
crank, and to here either for right- or left-
hand lead with equal accuracy. The boring.-
spindles are outside of the wheels, and bore
both crank-holes at the same time, each spin-
dle being driven separately and provided with
adjustable automatic feed, so as to rough out
the holes with fine feed, but finish with a wide
feed and light cut. The wheels on their axle
are carried by their tread on adjustable shoes,
which hold them rigidly in place, while the cen-
tres control position of axis only; this insures
stability. The machine may be used to advan-
tage as a horizontal drill for other purposes.
Portable Dialling .Machinea—Fig. 1052 represents Thorne’s portable drilling machine, which is
especially adapted for drilling all pieces which are inconvenient to move, or which cannot be readily
adjusted under stationary drilling machines. It will drill at any angle, in any position, at any dis-
tance, and in any direction from the power. The driving apparatus is so arranged that the round
belt which drives the machines passes through the centre of a hollow stud, enabling the power to be
1052.





31
482 DRILLING AND BORING MACHINES.

m
taken off in any direction, while the weighted idler keeps the belt tight at whatever distance the
machine is worked. The machine is intended to be bolted or clamped by its base to the piece being
drilled. It can be adjusted in height by drawing the post out of the socket, and radially by screw
and handle on the arm. The arm can be swung in the pillar as a centre by means of a worm and
tangent wheel, thus providing delicate adjustments in every direction. The spindle-frame swings in
a ball-andsocket bearing to any angle up to 30° from the base, and is also provided with means of
fixing it in a vertical position. The whole of the machine, including the post, can be drawn out of
the socket, and the post passed into the horizontal hole in the socket for drilling in a direction
parallel with the base. The feed-motion is self-acting and variable. (See also the Stow flexible
shaft drill, under BITS AND Auunns.
Power Required for illclal-Drz'llz'ng .llfarhines.--In drilling machines the power required to remove
a given weight of material has been found to be greater than in planing machines. This result is
due to the friction of the shavings in the holes, an inference which is especially important when the
shavings are tough and the holes small. In fact, in the case of small holes the loss of power from
this cause is so large that it has been found that the thickness of the shavings may be left entirely
out of consideration, and the formula for calculating the power required be based only upon the
diameter of the hole, and two coefficients having values depending upon the material treated. The
. . B . . . .
formula in fact may be of the form P = a + J, in which a and B are the two cocfficrents, and d 18
the diameter of the hole in inches. In the case of drilling machines, Dr. Hartig of Dresden (the
results of whose experiments we are quoting) takes, not the weight, but the volume of the material
reduced to shavings as the unit of comparison; and, denoting the volume thus reduced in cubic
inches per hour by q, we derive from his results the following equations applicable to holes from
two-fifths of an inch to 2 inches diameter and about 2 inches deep, P being the horsepower required:
0.00067)
d
For wrought-iron drilled with oil, P: g (0.0168 +
For drilling machines running empty, it is sufficient to know the number of revolutions per minute
of the gearing-shaft n, and of the drill as, to enable us to compute the value of P for all varieties of
ordinary drilling machines by the following formulae:
a. For drilling machines without gearing, P = 0.0006711 + 0.0005 122 horse-power.
I). For drilling machines with gearing for the drill-spindle, P : 0.0006m + 0.001% horse-power.
c. For radial drilling machines without intermediate gearing, P : 0.000671. 1' + 0.004112 horse-power.
(I. For radial drilling machines with intermediate gearing, P: 0.04 + 0.00061“ + 0.004% horse-
power.
lf, for example, we have a machine of the construction (l, with n, : 120 and n2 2 130, then P
will equal 0.632 horse-power.*
BORING Macnmns. I. Fen Merlin—Boring, as distinguished from drilling, consists in turning
out annular holes to true dimensions, while the term drilling is applied to perforating or sinking
holes in solid material. In boring, tools are guided by axial support independent of the bearing of
their edges on the material; while in drilling, the cutting edges are guided and supported mainly
from their contact with and bearing on the material drilled. Owing to this difference in the manner
of guiding and supporting the cutting edges, and the advantages of an axial support for tools in her-
ing, it becomes an operation by which the most accurate dimensions are attainable, while drilling is
a comparatively imperfect operation; yet the ordinary conditions of machine-fitting are such that
nearly all small holes can be drilled with sulficicnt accuracy. Boring may be called internal turning,
differing from external turning because of the tools performing the cutting movement, and in the
out being made on concave instead of convex surfaces; otherwise there is a close analogy between
the operations of turning and boring. Boring is to some extent performed on lathes, either with
boring-bars or by what is termed chuck-boring; in the latter the material is revolved and the tools
are stationary.
Boring may be divided into three operations as follows: chuck-boring on lathes; bar-boring when
a boring-bar runs on points or centres, and is supported at the ends only; and bar-boring when
bar is supported in and fed through fixed bearings. The principles are different in these operations,
each one being applicable to certain kinds of work. A workman who can distinguish between these
plans of boring, and can always determine from the nature of a certain work which is the best to
adopt, has acquired considerable knowledge of fitting operations. Chuck-boring is employed in
three cases: for holes of shallow depth, taper holes, and holes that are screw-threaded. As pieces
are overhung in lathe-boring, there is not sufficient rigidity either of the lathe-spindle or of the tools
to admit of deep boring. The tools being guided in a straight line, and capable of acting at any
angle to the axis of rotation, the facilities for making tapered holes are complete; and as the tools
are stationary, and may be instantly adjusted, the same conditions answer for cutting internal screw-
threads—an operation corresponding to cutting external screws, except that the cross motions of the
tool-slide are reversed. The second plan of boring, by means of a bar mounted on points or centres,
is one by which the greatest accuracy is attainable; it is, like chuck-boring, a lathe operation, and
one for which no better machine than a lathe has been devised, at least for the smaller kinds of
work. It is a problem whether in ordinary machine-fitting there is not a gain by performing all
boring in this manner whenever the rigidity of boring-bars is sullicicnt without auxiliary supports,
For cast-iron drilled dry, P = q (0.0168 +

* Engineering, xvlll., 838 et seq.
DRILLING AND BORING MACHINES. 483

and when the bars can pass through the work. Machines arranged for this kind of boring can be
employed in turning or boring as occasion may require. When a tool is guided by turning on points,
the movement is perfect, and the straightness or parallelism of holes bored in this manner is depen-
dent only on the truth of the carriage movement. This plan of boring is employed for small steam-
cylinders, cylindrical valve-seats, and in cases where accuracy is essential. The third plan of boring,
with bars resting in bearings, is more extensively practised, and has the largest range of adaptation.
A feature of this plan of boring is that the form of the boring-bar, or any imperfection in its bear-
ings, is communicated to the work; a want of straightness in the bar makes tapering holes. This,
of course, applies to cases where a bar is fed through fixed bearings placed at one or both ends of a
hole to be bored. If a boring-bar is bent, or out of truth between its bearings, the diameter of the


hole, being governed by the extreme sweep of the cutters, is untrue to the same extent; because, as
the cutters move along and come nearer to the bearings, the bar runs with more truth, forming a
tapering hole diminishing toward the rests or bearings. The same rule applies to some extent in
chuck-boring, the form of the lathe-spindle being communicated to holes bored; but lathe-spindles
are presumed to be quite perfect compared with boring-bars?
Seller’s patent boring mill, represented in Fig. 1053, is a useful tool for boring only. It is adapted
to bore car-wheels up to 36 inches in the chuck on the face-plate, and will here a wheel 6 feet in
diameter. It uses boring—bars with double-ended gib-cutters only, the bar being carried by a cross-
head below the table.
Bement’s Bowing .Machina—In the full-page illustration and in Figs. 1054 to 1058 is shown a boring
and turning machine designed and constructed by Messrs. W. B. Bement & Son of Philadelphia. The
1054. 1055.













1 \
general design of this machine is that of two slide-rests operating upon one cross-slide, supported by
uprights similar to those in a planer, the work being chucked upon a horizontally rotating table
below. The slide-rests may be set at any desired angle to here or turn taper or vertical. To perform

* From “ Workshop Manipulation,” by J. Richards.
484 DRILLING AND BORING MACHINES.

those operations parallel, each head may self-act for the feed-motion either parallel or horizontal to
the face of the face-plate or chuck-plate, or vertical or at an angle to the same, both slide-rests being
employed to either turn or bore simultaneously, or one to turn and the other to bore, according to
the requirements of the case. The face-plate being near to the ground facilitates the handling of
the work to chuck it; and the plane of the face-plate being horizontal also assists that operation;
while the bed-plate or framing supporting the table is from its compactness necessarily very rigid.
The details relating to the driving-gear, spindle, and face-plate will be best seen in the elevation,
Fig. 1056, and plan, Fig. 1057, each of which is partially in section. The shaft A is driven by a
cone-pulley and back-gearing B, of the usual construction, through bevel-gears and a pinion, the
latter actuating an internal spur-wheel, which is bolted to the face-plate. It also, by means of bevel-
gears and cone-pulleys, gives motion to the feeding apparatus shown in 1054. The attachment
of the face-plate to the spindle is assisted by a broad flange and eight tightly-fitted bolts. The
bushing is fitted externally to the cylindrical opening bored in the centre of the bed-plate, and inter-
nally to the conical bearing of the spindle, on which it is adjusted by bolts. The housing is rigidly
bolted to the bottom of the bed-plate, and is bored at its lower end to receive the step-bearing, which
is adjusted vertically by suitable bolts. The step 0, which carries the entire revolving weight, con-
sists of two heavy disks, composed of a hard alloy of copper and tin, between which disks is inter-
1056.














posed a third one of steel hardened and afterward ground true. The upper disk is caused to revolve
with the spindle, and the lower one to remain stationary, the intermediate steel one being left on-
tirely free. The wearing surfaces of the bronze disks and the cylindrical surface of the spindle-
bearing have suitable grooves for distributing the lubricating oil, which is supplied through the pipe
D. Such borings, etc., as may find their way into the interior of the spindle, are discharged clear of
the hearing by the openings over the inclined guards, and the lower end of the spindle is closed by a
plug, Fig. 1058. The bed-plate is hollow and internally ribbed, as shown in the sectional part of
Fig. 1056, having the necessary openings in the bottom for the support of the cores required to
mould the same. Raised facings are planed to receive the uprights which carry the cross-slide.
An independent countershaft, having a backward and forward motion, drives the pulley A, Fig.
1054, and, through the bevel-gearing B B, the vertical screws in the hollow front portions of the
uprights by which the cross-slide is heightened and lowered at will, the nuts 0 0' serving to secure
it when brought to the required position. On the inner end of the cone 3 is a worm driving the
worm-wheel. On the shaft of the latter are two opposite bevel-pinions, both of which mesh with
the bevel-wheel at the foot of the vertical splined shaft 1). Both of these pinions are loose upon
their shafts or bearings, but either can be engaged by a clutch operated by the lever E; and since
the revolutions of these pinions are in opposite directions, it follows, that the shaft .D will revolve in
opposite directions according to which of the pinions is engaged by the clutch.
DRILLING AND BORING MACHINES. 485

At the right of the cross-slide are shown three pinions, the middle one of which (and through it
the other two) is driven by a spur-wheel, which receives motion from the splined shaft F through
the medium of bevel-gearing not shown, but which is carried in a frame bolted to the back of the
cross-slide. These pinions are also loose or free upon their respective shafts, but each is furnished
with a clutch, the lower and upper ones when engaged respectively actuating the screws for the
horizontal movement to the right or left for the tools, while the middle one when engaged actuates
the splined shaft F, which gives the vertical or angular motion to both tools. In the saddles G,
which move longitudinally on the cross-slide, are fitted the swivel-slides J J, each secured in any
vertical or angular position by six bolts, the heads of which are in an annular T-groove provided in
the saddle. In the rear of each saddle is an arrangement of bevel-gears and clutch precisely similar
to that described as connected at the foot of the vertical splined shaft .D. By it is transmitted a
reversible motion from the horizontal splined shaft P to the projecting worm-shaft; and the worm-
shaft H when engaged by the clutch I actuates a pinion meshing in a steel rack inserted in the tool-
slide J. It will be seen then that while one of the rests is feeding the tool either vertically, at an
angle, upward, or downward, the other rest may feed its tool in any direction. A crank K applied to
the outer end of the worm-shaft enables the operator to feed the tool-slide at any required rate by
1059.
D
Q

50 F

EO

Ii
1..
5t












Lem“
\ \ \
hand, and when the clutch I is disengaged a rapid feed may be imparted by the hand-wheel L. The
cutting tool is held upon a hardened plate (secured to the front of the tool-slide at its lower end) by
the clamps M, which are so arranged that the tool-point may be adjusted in any position to suit the
486 ' DRILLING AND BORING MACHINES.

location of the duty. The tool-slide has sufficient length and rigidity to carry a out nearly 3 feet
below the level of the cross-slide, and hence its weight is sufficient to require a counterbalance capa-
ble of acting upon it efficiently in all its positions. For this purpose teeth are cut in one of its sides,
forming a rack in which meshes the pinion N, the connection between the latter and the weight 0-
bcing made through wire ropes. Each of the wheels Q and U is grooved spirally on its circum-
ference to receive the wire rope, and is of sufficient width to receive the greatest requisite quantity
without overlapping. Each of the weights 0 consists of a number of separate pieces readily remov-
able, so that the weight may bc varied as required, less being needed as the tool-slides are inclined
from the perpendicular. ’
Ocar-ll’lieel Boring lilachine.—Fig. 1059 represents a car-wheel boring machine constructed by the
Putnam Machine Company of Fitchburg, Mass. A is the driving cone-pulley, the spindle to which
it is attached having bearings provided in the frame. At the end of this spindle is a pinion gearing
into the teeth shown beneath the table B, and by this means the table is caused to revolve. O O is
the boring-bar, which is counterbalanced by the weighted lever D. The bearing of the bar 0 C at
that part of the frame through which it passes is made adjustable to fit the bar by the following
means: The front of the bearing is split along its entire length, and on each side of the slit are the
lugs shown at E E E E. Through these lugs pass bolts with nuts, so that by screwing up the
latter the bearing is closed to fit the spindle or boring-bar to the requisite degree. To afford a ten-
sion upon the adjustment, and thus prevent the nuts from becoming unset, a piece of wood is in-
serted into the slit referred to, and against the resistance of the wood to compression, as well as of
the iron to being sprung, the nuts are tightened. By this means a delicate adjustment is readily ob-
tained. The link or bar F is pivoted at each end to permit of a vertical motion to the bar 0 U. A
vertical movement by hand may be given the bar 0' 0 by means of a rack upon its back, geared with
a pinion attached to the shaft to which the hand-wheel H is secured. Self-actingfeed is given to the
bar by a spindle to which the gears Kare attached, and which is connected by a worm and wheel
movement to the pinion working in the rack at the back of the bar. ill is an attachment containing
a slide and tool-post for the purpose of facing off the surfaces of the hubs. To enable the machine
to bore a taper hole, the following device is resorted to: The table B is composed of two disks bolted
together, the face of one of which is beveled slightly toward the outer edge. By adjusting the bolts
so that the beveled part of the face comes in contact with the other disk, the table is thrown out of
horizontal level, and hence a taper hole is bored. In order to prevent spring and insure steadiness
in the table when thus set, two screws pass through the elevated side of the upper table, their ends
coming in contact with the face of the lower one. The machine is provided with a crane to lift the
work, as shown.
Fig. 1059 A represents Newton’s Multiple Drill, a simple form of tool adapted for all multiple work.
The engraving plainly shows the construction, in which the four vertical spindles are rotated by worm
and pinion gear from the horizontal driving shaft.
1059 A.




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II. FOR W001).‘—Boring-Machtnes.——The distinction previously noted between boring and drilling
is not followed with reference to this class of wood-working machines, the operation being always
termed boring. In the designing and arrangement of such machines the main object to be observed
is adjustment of the material or of the augers so that they can be brought to dificrent positions
with the least expenditure of time and effort. To consider the matter in a general way, we will
assume that a compound movement is required transverse to and longitudinally with the timber.
DRILLING AND BORING MACHINES. 487

The longitudinal movement, being of long and indefinite range, is best accomplished by moving the
material; the transverse movement, on the contrary, being short and less used, is best accomplished
by a lateral adjustment of the spindle. The longitudinal adjustment, having to carry the weight
of the material, must be accom-
plished for the heavier class of '
work by mechanism that will in-
crease the power of the operator
and diminish the motion so as to
secure accurate adjustment. The
lateral adjustment of the boring
tools should also be done by hand,
as no special power is needed to
perform it. For machines that
are arranged to bore holes on
one line only, the lateral motion
of the spindle becomes simply
an adjustment, as distinguished
from a continuous movement at
will. The spindle or table, when
“set,” remains fixed during the
time of boring the holes in one
line.'* Boring machines to oper_
ate sereW-bits should run at from
1,000 to 2,000 revolutions per
minute, according to the kind of
wood or the size of the bits used.
In Fig. 1066 is shown a wood
boring machine of English con-
struction. A is the driving-pul-
ley, which rotates the auger-spim
dle B by means of the bevel-
gears. The spindle is fed by
hand by depressing the lever C,
the link D being provided to af-
ford a true vertical motion to
the‘spindle. E is a weight to
counterbalance the weight of the
handle C. The head carrying the
spindle and hand-lever traverses the slide shown by operating the hand-wheel l-I'. The table sup-
porting the work travels upon the wheels, to facilitate the movement and adjustment of the work.
The horizontal boring machine shown in Fig. 1067 is of American design. The spindle A passes
1066. -


1067.


. ' ---__- m “7A..” \ > - -__ - - -————~~-~~ »- n - Vi -
. ~ \‘\ \ . \ \\\\\\\\ \\ \\\\ \\\\\\\ \\\\ \‘\\\\\\N\\\\.\\ \\\\\§\\\:s\\.:_\>>:.;:xxs\\\\\
and slides through the driving-pulley B. The forward spindle-bearing U traverses in a guide-slot
provided in the frame, and thus follows the movement of the spindle, afl’ording it at all times equal


* J. Riehards’s “ Wood-working Machines."
488 DRILLS, GRAIN.

bearing support. The spindle-feed is obtained by depressing the lever D, which operates the arm,
the latter being attached to the link F, which is pivoted at the end to the bearing C. The table is
adjustable for height by means of the hand-wheel W, which acts as a nut upon the table-spindle,
the latter having a feather-way to prevent its rotating with the wheel. The spindle has two speeds,
as shown by the stepped pulleys. The
gauge G can be placed before or behind
the work, as circumstances may render
most desirable.
Fig. 1068 represents a radial horizon-
tal car-boring machine, designed by J. A.
Pay (it Go. particularly for car and bridge
work, and for straight, angle, and end
boring. It is well known in car shops
that the holes in truck and body bolsters
for the truss-rods are among the most
difficult to be bored. This machine will
here straight or angle holes without mov-
ing the timber, all the necessary adjust-
ments being made with the head and spin-
dle carriage. The boring-spindle has a
horizontal movement of 24 inches, allow-
ing holes to be bored to that depth. The
head or carriage has a horizontal move-
ment in planed sides in the frame, which
permits it to be brought close up to the
stuff when doing angle-work. The head
is raised and lowered by a hand-wheel,
geared to a screw of coarse pitch, by
which means the auger is brought to the
exact point desired without changing the
position of the timber. The belt is kept
at the proper tension by means of a
weighted pulley hung in a slack loop of the belt, which allows the boring-arbor to be moved either
up or down, or to any angle desired.
Power Required for Wood-boring Machines—In drilling timber with holes from two-fifths of an
inch to 4 inches diameter, and. of depths up to 6 inches, Dr. Hartig’s experiments give the following
values for P (power required), the symbol d representing diameter of hole in inches, and q denoting
the volume of material reduced to shavings in cubic inches per hour:
1003.



. O V
For drilling pine, P = g (0.000125 + 20703.? .
.001423
For drilling alder, P: 9 (0.000472 + »_(-,__).
.0 1 P
For drilling white beech, P : g (0.003442 + O 6,490 .
For example, if we suppose the case of a machine employed in drilling 2-inch holes in white beech,
and suppose 1,220 cubic inches of timber to be drilled away per hour, then the value of P will
.001495
2

: 1220 (0.003442 + > z 1220 X 0.0041895 : 5.11 H.P.
If, then, such a machine requires 0.22 horse-power to drive it when empty, the total driving power
required when doing the above work will be 5.11 + .22 : 5.33 horse-power. Dr. l-lartig gives this
example as illustrating the mistake frequently made in estimating the power required to drive tools ;
it being, as he remarks, not uncommon to find about 111- horse-power allowed for driving a wood-
boring machine of the size above dealt with, while at the same time a large and heavy planing ma-
chine for iron will be allowed perhaps 5 horse-power, although in the latter case it is but rarely that
more than 1 horse-power will be necessary.'* J. R. (in part).
DRILLS, GRAIN. See AGRICULTURAL MACHINERY.
DRILLS, METAL—BORIN G. A drill is, all things considered, the most effective tool employed
by the machinist; for, while its cutting edges are necessarily of decidedly undesirable angles and
form, it sustains the very roughest of usage, and yet will bear more strain in proportion to its
strength than any other cutting tool. The reason of this is that it is supported by the metal upon
which it is operating, and is thus prevented from springing away from its duty. This support may
be of two kinds: first, that due to the wedge shape of the main cutting edges, one to the other;
and second, that to be derived from making the diameter of the drill'parallel for some little dis-
tance behind the cutting edges, so that the sides of the drill, by contact with the sides of the hole,
serve to guide and support the tool. The latter, however, only comes into operation at and after
such time as the drill has entered the metal sufficiently deep to form a recess of the full diameter of
the drill. The support given to the drill, in the instance first cited, arises from the tendency of
either of the cutting edges to spring away from the cut, which is, of course, counterbalanced by the
opposite cutting edge having the same tendency, but in an opposite direction, so that between the

* See Engineering, xvili., 388 ct seq.
DRILLS, METAL—BORING. 489

two the drill is held to a central position; and also from the tendency of the drill-point to force
itself forward (by reason of the pressure behind it) as far into the cone formed by the end of the
hole as possible, as the end of the hole and the cutting end of the drill are two cones, one being
forced into the other. In a drill properly ground (that is, having its cutting edges at an equal angle
to the centre line of the length of the drill, and of an equal length from the centre of the drill
or point of junction of the cutting edges), both the cutting edges and the sides of the drill act as
supports and guides, tending to sustain it under the strain and keep it true. If, however, the drill
is not ground true, the strain upon it becomes very great, because the whole force of the cut is then
placed upon one cutting edge only, and is continuously tending to thrust the point of the drill out-
ward from the centre of the hole being drilled, hence forming a hole larger in diameter than the
cutting part of the drill - that is to say, a hole whose diameter will be twice that of the radius of
the longest cutting edge of the drill, measured from the centre line of the length of the drill. 1f,
undersuch~ conditions, one side of the drill bears against the sides of the hole, as shown in Fig.
1069, B being the metal and A the drill, there will be created two opposing forces, independent of
the strain necessary to sever the metal: one being the endeavor of the point of the drill to keep to
the centre of the hole, because of the conical shape of the end of the hole and point of the drill ;
and the other being the endeavor of the cutting e We to force the drill to one side and the point of
the drill out of the centre of the hole. And as the pressure of the side of the drill against the side
of the hole will tend to force the drill to revolve true with that side of the drill, so that the point
of the drill will revolve in a circle and not upon its own axis, the result will be a hole neither round,
straight, nor of any definite diameter, as compared to the diameter of the drill. Drills that are a
trifle too small for the required size are sometimes purposely ground a little out of true, so as to
cause the hole to be larger than the drill; but the action of such drills is distorted, and it is impos-
sible to estimate exactly how much deviation is necessary to the required increase of diameter of the
hole. Part of the power driving the drill is lost, the loss being due to the presence of the above
opposing forces; and the drilling operation is slow by reason of only one edge of the drill per-
forming any cutting. Hence, the fecd of the drill being only half as rapid as it should be, it is an
1069. 1070.
. \\\\\\\\\\\\\\\\\\\\\T
unmechanieal expedient and a loss of time, especially if the hole is to be drilled clear through the
metal; for in that case, as soon as the point of the drill emerges through the metal, and is there-
fore released from its influence, the cutting edges will gradually adjust themselves to the hole, and
form the remainder of the hole to the size of the diameter of the drill, the hole, when finished, ap-
pearing as in Fig. 1070. Thus the end A of the hole will require to be filed out, entailing in all
more less of time than would be required to make a drill of the proper diameter.
The importance, then, of taking especial pains to grind a drill true being apparent, we may next
consider how thick the point of the drill should be. It is here that the main defect of the drill as a
cutting tool lies; for it is impossible to make the cutting edge across the centre of the drill (that is,
the cutting edge across the thickness of the drill, connecting the cutting edge of one side of the
drill to the cutting edge of the other side, as shown at A in Fig. 1071) sufficiently keen to enable it
to enter the metal easily, without grinding the angles of the two cutting edges very acute, as shown
in the edge view of Fig. 1071 by the dotted lines, which would so weaken the cutting edges as to
cause them to break from the pressure of even the lightest feeding. The only alternative, then, is
to make the point of the drill as thin as is compatible with sufficient strength ; and this will be found
to be of about the following proportions :










—
<\\\\\\\w



Diameter of Drill. Thickness at Point. Diameter of Drill. Thickness at Point.
1-8 inch. 1-64 inch. 5-8 inch. 1-16 inch.
14 “ 1-32 “ 3-4 “ 1~16 “
3-8 “ 3-64 “ 7-8 “ 1-16 “
1-2 “ 1-16 “ 1 “ 3-32 “
The flat face must be made gradually thicker as the full diameter of the drill is reached. The
angle at which to grind the end of the drill is governed to a large extent by the kind and degree of
hardness of the metal to be drilled, the angle shown in Fig. 1071 being suitable for wrought-iron,
steel, or unusually hard cast-iron; while for common cast-iron or brass a little more angle may be
given. But no definite angle can be given for any metal, because of the varying conditions under
which a drill performs its duty. From these considerations we find that the efieetiveness of a drill
arises from the support rendered to it by the work, which more than compensates for the want of
keenness‘ inherent to its form of cutting edge.
Thus far, however, we have been considering the ordinary flat drill in its most simple form. For
use on steel, wrought-iron, and cast-iron, we may improve the cutting qualities of the drill by bend-
ing each side of the cutting bevel-edges forward, thus forming what is termed a lip drill, as shown
in Fig. 1072. Such a drill will cut with much greater ease and rapidity, because the angle of the
two faces whose junction forms a cutting edge is much more acute, while the cutting edge is at the
'same time well supported by the metal behind it, which advantages are to be obtained in no other way.
4.90 DRILLS, METAL-BORING.

The Twist-Drill, with cutting edges like those last described, is formed by cutting two spiral flutes
upon a cylindrical piece, as shown in Fig. 107 Twist-drills are not of the same diameter from end
to end of the twist, but are slightly taper, diminishing toward the shank end. The taper is usually,
1071. 1072. ‘ 1073.
s



1 AT 3


however, so slight as to be of little consequence in actual practice. Neither are twist—drills round,
the diameter being eased away from a short distance behind the advance or cutting edge of the flute
backward to the next flute, as in Fig. 1074. The object of this is to give the sides of the drill as
much clearance as possible. The part of the circumference from A to B, on each side, is left of a full
circle, which maintains the diameter of the drill and steadies it in the hole. If, from excessive duty,
that part from A to B should wear away at the cutting end of the drill, leaving the corner of the
drill rounded, the drill must be ground sufficiently to cut away entirely the worn part; otherwise 0 it
will totally impair the value of the drill, causing it to grind against the metal, and no amount of
pressure will cause it to out. To give these drills strength, the flutes are made shallower at and
toward the shank. .
The chief advantage over other drills possessed by twist-drills is, that the cuttings can find free
egress, which effects a great saving of time; for plain drills have to be frequently withdrawn from
the hole to extract the cuttings, which would jam between the sides of the hole and the sides of the
drill, and the pressure will frequently become so great as to twist or break the shank of the drill,
especially in small holes. In point of fact, the advent of twist-drills has rendered the employment of
any other form for use in small holes (that is to say, from three-eighths of an inch downward) unadvi-
A 1075.






sable, except it be for metal so hard as to require a drill tempered to suit the work. The other advan-
tages of the twist-drill are, that it always runs true, requires no reforging or tempering, and, by reason
of its shape, fits closely to the hole, and hence drills a very straight and smooth hole. It is also not
liable to be influenced so much by an air or other hole or soft spot which may exist in the metal
being drilled. These qualities render the twist-drill a very superior tool for the finer classes of
work, and for such purposes as drilling metal away to form a keyway or slot; for in the latter case
the holes may be drilled so closely together that they will run one into the other, as shown in F lg.
1075, A being the piece of metal and BBB the holes. A common flat drill is incapable of perform-
ing such work. The twist-drill will not, however, in holes of a moderate depth (that is to say, holes
whose depth is not more than four times their diameter), do so much duty in a given time as a com-
mon drill, especially if, in iron or steel, the latter be slightly lipped; the reason being that the latter,
stronger in proportion to its diameter, will stand more strain, and may therefore be fed much more
rapidly in all cases wherein the depth is not so great as to prevent the cuttings from finding egress
before becoming jammed in the hole.
Twist-Drill Grinding—Fig. 1076 represents Seller’s drill-grinding machine, in which a twist-drill
is shown in position to be operated upon. The end of the drill near to the cutting edges is held in a
clamp-vise. The emery-wheel, passed back and forth over the lip, which is in a horizontal position,
. grinds it to a true line. Then, upon slacking the clamp-vise and turning the drill half-way around
by means of an index-plate at the shank end of the drill, the other lip is in position to be ground to
correspond with the first. This principle of clamping the end of the drill for each lip insures abso-
lute equality in the length and cutting property of each, provided the last pass of the wheel over the
two lips be made without vertical adjustment of the emery-wheel. .The bar which carries the socket
for holding the drill~shank is placed at an angle that has been found by experience to give the best
average result in cast and wrought iron. The drill when clamped is so placed in regard to the
emery-wheel as to insure proper clearance on fly-drills. Twist-drills will have clearance for their out
near the edge of the drill, but must be backed off up to this surface by hand on a grindstone. Fig.
1077 shows the position of the grinding wheel in reference to the edge of a fly-drill, and indicates
the method of obtaining clearance. In setting a twist or fly drill in place in the clamping jaws, care
must be taken to place its cutting edge as nearly as possible parallel with the line of motion of the
wheel in passing back and forth over its length, as is shown in Fig. 1078 A for twist-drills, and Fig.
1078 B for fly-drills. Fly-drills made as shown in Fig. 1079 cannot be ground with any exactness;
there should be a portion of the length of drill with parallel sides for some little distance above the
lips, as is shown in Fig. 1080. This condition exists in twist-drills.
DRILLS, METAL-BORING. 491.

1077.


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T/ze Recenterz'ng Drill is represented in Fig. 1081. It is used for beginning a small hole in a flat
bottomed cylindrical cavity, or else in rotation with the common piercing drill and half-round bit in
drilling small and very deep holes in the lathe.
The O'ountersink.—This tool is used for enlarging orifices. Fig. 1082 represents a taper counter-
sink, such as is employed for rivet~holes requiring to be flush or even with the surface of the riveted
plate. In tempering these tools, or any others having a pin or projection to serve as a guide in a
hole, the tool should be hardened right out from the end of the pin to about threeeighths of an inch
above the cutting edges. Then lower the temper of the metal (most at and near the cutting edges),
leaving the pin of a light straw color, which may be accomplished by pouring a little oil upon it
1081. l 1082. 1083. ] 08 i.









. during the lowering or tempering process. The object of this is to preserve it as much as possible
from the wear due to its friction against the sides of the hole. For use on wrought-iron and steel,
this countersink (as also the pin-drill) may have the front face hollowed out.
For use on holes half an inch and less in diameter, we may use a countersink made by turning up
a cone, and filing upon it teeth similar to those upon a reamcr, as shown in Fig. 1083 ; or we may
take the same turned cone and cut it away to half its diameter, similar to a half-round bit. Either
of these countersinks will cut true and smoothly, oil being applied when they are used upon steel or
wrought-iron. Common drills, ground to the requisite angle or cone, are sometimes used as counter-
sinks, but they are apt to cut central and uneven. For fine light work the pin-drill, with its cutting
edges either at right angles to the centre line of the pin or at such other angle as may be required,
forms the best countersink; it should, however, have more than two cutting edges, so that they may
steady it. Fig. 1084 presents an excellent form of this tool, A being one of the four cutting edges.
It is formed by turning up the whole body, filing out the necessary four spaces between the cutters,
and backing the latter off at the ends only, so that the circumferential edges will not cut, and hence
the recesses or countersinks will be all of one diameter.
492 DRILLS, METAL-BORIN G.

' The Pin-D1ill.—-This drill, Fig. 1085, has a pin projecting beyond and between its cutting edges,
as shown, AA being the cutting edges. The use of this drill is to face ofi the metal round the
outside of holes, the pin .8 fitting into the hole so as to steady the drill, and keep it true with the
hole. In making this tool, the pin B, the edges 0, and the ends forming the cutting edges A A,
should be turned up true in the lathe; the backing off may then be filed, leaving the cutting edges
A A with the turning marks barely cfiaccd; thus they will be sure to be true and at an equal height
from the end of the pin, so that both the cutting edges may operate. Roberts’s pin-drill, represented
in Figs. 1086 and 1087, has two grooves in its stock at an angle of about 10° with the axis, and
rather deeper behind than in front. Two steel cutters or nearly parallel blades, represented in
black, are laid in the grooves. They are fixed by the ring and two set-screws es, and are advanced,
as they become worn away, by two adjusting screws a a (one of which only is shown) placed at an
1085.


/
0 0 angle of 16° through the second ring, which for convenience of
construction is attached to the drill-shaft just beyond the square
tang whereby it is secured to the drilling" machine. The object of
A B A this eontrivance is to retain the dimensions and angles of the tool.
Stock-Cutters.-—These cutters are held in a stock or bar, as
shown in Fig. 1088, in which 8’ is the stock and D the cutter,
secured by the key K. It will be noted that the cutting edge B
stands in the rear of the line A, or fulcrum from which the springing takes place; hence, when the
tool springs, it will recede from the work 0. To avoid springing, and for very large holes, the cutter
may be a short tool, held by a stout cross-bar carried by the stock; but in any event the cutter
should be made as shown above. Cutters of a standard size, and intended to fit the pin-stock, should
be recessed to fit the end of the slot in the stock. In making these cutters, they should be first
fitted to the stock, and then turned up in the lathe, using the stock as a mandrel, the ends being then
backed off to form the cutting edges.
The use of this class of cutter-stock involves the boring of a hole to receive the pin P. To avoid
this, the tool shown in Fig. 1089 is employed. It consists of a stock A, to which are firmly bolted




1090.

















the cutters B B. In A is provided the hole containing the spiral spring C, operating upon the
cylindrical centre, which is a sliding fit to the hole, and the point of which is forced into a centre-
punch mark made in the plate by the spring 0. Thus the centre 1) serves as a guide to steady the
cutters and cause them to revolve in a true circle, so that the necessity of first drilling a hole, as
required in the employment of the form of stock shown in Fig. 1089, is obviated. The cutters are
broadest at the cutting edge, which is necessary to give the point clearance in the groove. They are
also made thinner behind at the taper part (that is to say, the part projecting below the stock) than,
at the cutting edge, which is done to give the sides clearance. It is obvious that, with suitable cut-
ters, various-sized holes may be cut with one stock.
Equilibrium TooL—Fig. 1090 is a section of McKay’s equilibrium tool for drilling and boring tube
DRILLS, METAL—BORIN G. 493

plates. The outer case is a hydraulic cylinder which is fitted into the drilling-machine spindle socket;
it contains an annular ram carrying cutters, inside of which is a steadying pin, with a piston at its
upper end working in the cutter-ram. The cylinder is charged with soap and water, which forms the
equilibrium medium, and when the tool is at rest the annular or cutter ram is kept up by two springs,
one on each side, and the centre or steadying pin is full out. When at work, the action of the tool
is as follows: The centre-pin is placed into a centre-pop, marked out as the work to be done requires;
immediately the feed is put on, the tool is driven on to the centrepin, which causes the fluid to force
down the outer ram with cutters; a perfect equilibrium is maintained during the process of drilling
by the fluid with which the tool is charged. When the hole is drilled, the springs draw up the cutter-
ram and force out the centre-pin ready for another hole. Another form contains three separate
rams: the centre ram is the steadying pin, and the two outer ones carry the cutters. The action of this
machine when at work is in every respect similar to the above, except that the cutters are indepen-
dent of each other, the three rams being all in equilibrium, and the cross-bars attached to springs on
either side draw in the cutters, and throw out the steadying pin when the tool has completed the hole
as above described. Among the advantages of this tool are stated to be saving of time and power.
In drilling, after the centre-pivot is entered into the centre-pop, no further attention is required for
centering, as the cutters at once cut a narrow groove into the surface of the plate, and have only
the thickness of the plate to go through.
Bow-Drills.--The smallest holes are those required in watch-work, and the general form of the
drill is shown on a large scale in Fig. 1091 ; it is made of a piece of steel wire, which is tapered off
. at one end, flattened with the hammer,
and then filed up in form. The reverse / 10%
end of the instrument is made into a I ‘


conical point, and is also hardened; near ' @-
this end is attached a little brass sheave I
for the line of the drill-bow, which in A
watchmaking is sometimes a fine horse-
hair, stretched by a piece of whalebone of about the size of a goose’s quill stripped of its feather.
The watchmaker holds most of his works in the fingers, both for fear of crushing them with the
table-vise, and also that he may the more sensibly feel his operations; drilling is likewise performed
by him in the same manner. Having passed the bowstring around the pulley in a single loop (or with
a round turn), the centre of the drill is inserted in one of the small centre-holes in the sides of the
table-vise, and the point of the drill is placed in the mark or cavity made in the work by the centre-
punch; the object is then pressed forward with the right hand, while the bow is moved with the left.
Clockmakers, and artisans in works of similar scale, fix the object in the tail-vise, and use drills
such as Fig. 1091, but often larger and longer; they are pressed forward by the chest, which is de-
fended from injury by the breastplate, namely, a piece of wood or metal about the size of the hand,
in the middle of which is a plate of steel, with centre-holes for the drill. The breastplate is some-
times strapped round the waist, but is more usually supported with the left hand, the fingers of which
are ready to catch the drill should it accidentally slip out of the centre. As the drill gets larger the
bow is proportionally increased in stiffness, and eventually becomes the half of a solid cone, about
an inch in diameter at the larger end and 30 inches long; the catgut string is sometimes nearly an
eighth of an inch in diameter, or is replaced by a leather thong. The string is attached to the smaller
end of the how by a loop and notch, much the same as in the archery-bow, and is passed through a
hole at the larger end, and made fast with a knot; the surplus length is wound round the cane, and
the cord finally passes through a notch at the end, which prevents it from uncoiling. The compara'
tive feebleness of the drill-bow limits the size of the drills employed with it to about one-quarter of
an inch in diameter; but as some of the tools used with the bow agree in kind with those of much
larger dimensions, it will be convenient to consider as one group the forms of the edges of those drills
which cut when moved in either direction.
Figs. 1092, 1093, and 1094 represent, of their largest sizes, the usual forms of drills proper for the
reciprocating motion of the drill-bow, because, their cutting edges being situated on the line of the
axis, and chamfered on each side, they cut, or rather scrape, with equal facility in both directions of


1092. 1033. 1094. 1095. 1096. 1097.
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motion. Fig. 1092 is the ordinary double-cutting drill; the two facets forming each edge meet at an
angle of about 50° to 70°, and the two edges forming the point meet at about 80° to 100°; but watch_
makers, who constantly employ this kind of drill, sometimes make the end as obtuse as an angle of
about 120°; the point does not then protrude through their thin works long before the completion
of the hole. Fig. 1093, with two circular chamfers, bores cast-iron more rapidly than any other re-
ciprocating drill, but it requires an entry to be first made with a pointed drill; by some, this kind is
494 DRILLS, METAL-BORING.

also preferred for wrought-iron and steel. The fiat-ended drill, Fig. 1094, is used for flattening the
bottoms of holes. Fig. 1095 is a duplex expanding drill, used by cutlers for inlaying the little plates
of metal in knife-handles; the ends are drawn full size. Fig. 1090 is also a double-cutting drill; the
cylindrical wire is filed to the diametrical line, and the end is formed with two facets. This tool has
the advantage of retaining the same diameter when it is sharpened ; it is sometimes called the Swiss
drill, and was employed by M. Le Riviere for making the numerous small holes in the delicate punch-
ing machinery for manufacturing perforated sheets of metal and pasteboard. ~ These drills are some-
times made either semicircular or flat at the extremity; they are commonly employed in the lathe.
The square countersink, Fig. 1097, is also used with the drill~bow; it is made cylindrical, and pierced
for the reception of a small central pin, after which it is sharpened to a chisel-edge, as shown. This
countersink is in some measure a diminutive of the pin-drills, and occasionally circular collars are
fitted on the pin for its temporary enlargement, or around the larger part to serve as a stop, and limit
the depth to which the countersink is allowed to penetrate, for inlaying the heads of screws. The pin
is removed when the instrument is sharpened. Steel bows are also occasionally used ; these are made
something like a fencing foil, but with a hook at the end for the knot or loop of the cord, and with a
ferrule or a ratchet, around which the spare cord is wound. Some variations also are made in the
sheaves of the large drills. Sometimes they are cylindrical with a fillet at each end ; this is desirable,
as the cord necessarily lies on the sheave at an angle, in fact in the path of a screw; it pursues that
path, and with the reciprocation of the drill-bow the cord traverses, or screws backward and forward
upon the sheave, but is prevented from sliding off by the fillet. Occasionally, indeed, the cylindrical
sheave is cut with a screw coarse enough to receive the cord, which may then make three or four coils
for increased purchase, and have its natural screw-like run without any fretting whatever; but this

109Q. 1101.


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1099. “i
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1100.








is only desirable when the holes are large and the drill is almost constantly used, as it is tedious to
wind on the cord for each individual hole. The structure of the bows, breastplates, and pulleys,
although often varied, is sufficiently familiar to be understood without figures. When the shaft of
the drill is moderately long, the workman can readily observe if the drill is square with the work as
regards the horizontal plane; and to remove the necessity for the observation of an assistant as to
the vertical plane, a trifling weight is sometimes suspended from the drill-shaft by a metal ring or
hook; the joggling motion shifts the weight to the lower extremity: the tool is only horizontal when
the weight remains central.
Drill-Stocka—The necessity for repeating the shaf t and pulley of the drill is avoided by the employ-
mt of holders of various kinds, or drill-stocks, which serve to carry any required number of drill-
points. The most simple of the drill-stocks is shown in Fig. 1098; it has the centre and pulley of
the ordinary drill, but the opposite end is pierced with a nearly cylindrical hole, just at the inner
extremity of which a diametrical notch is filed. The drill is shown separately at a; its shank is
made cylindrical, or exactly to fit the hole, and a short portion is nicked down also to the diametrical
line, so as to slide into the gap in the drill-stock, by which the drill is prevented from revolving; the
end serves also as an abutment whereby it may be thrust out with a lever. Sometimes a diametrical
transverse mortise, narrower than the hole, is made through the drill-stock, and the drill is nicked in
on both sides. The cylindrical hole of Fig. 1098 should be continued to the bottom of the notch, the
end of the drill should be filed off obliquely, and it should be prevented from rotating by a pin in-
serted through the cylindrical hole parallel with the notch; the taper end of the drill would then
wedge fast beneath the pin.
Drills are also frequently used in the drilling-lathe; this is a miniature lathe-head, the frame of
which is fixed in the table-vise; the mandrel is pierced for the drills, and has a pulley for the bow,
therein resembling Fig. 1099, except that it is used as a fixture.
DRILLS, METAL—BORING. 495

Fig. 1099 represents one variety of another common form of drill-stock, in which the revolving
spindle is fitted in a handle, so that it may be held in any position, without the necessity for the breast-
plate; the handle is hollowed out to serve for containing the drills, and is fluted to assist the grasp.
Fig. 1100 represents the socket of a “ universal drill-stock,” invented by Sir John Robinson ; it is
pierced with a hole as large as the largest of the wires of which the drills are formed, and the hole
terminates in an acute hollow cone. The end of the drill-stock is tapped with two holes, placed on a
diameter; the one screw, a, is of a very fine thread, and has at the end two shallow diametrical
notches; the other, b, is of a coarser thread and quite flat at the extremity. The wire drill is placed
against the bottom of the hole, and allowed to lean against the adjusting screw a ,' and if the drill be
not central, this screw is moved one or several quarter turns, until it is adjusted for centrality, after
. which the tool is strongly.fixcd by the plain set-screw b.
Fig. 1101 will serve to show the general character of various forms of apparatus to be used for
supplying the pressure in drilling holes with hand-braces. It consists of a cylindrical bar a, upon
which the horizontal rectangular rod b is fitted with a socket, so that it may be fixed at any height,
or in any angular position, by the set-screw 0. Upon 6 slides a socket, which is fixed at all distances
from a by its set-screw d; and lastly, this socket has a long vertical screw e, by which the brace is
thrust into the work. The object to be drilled having been placed level, either upon the ground, on
trestles, on the work-bench, or in the vise, according to circumstances, the screws 0 and d are loosened,
and the brace is put in position for work. The perpendicularity of the brace is then examined with
a plumb-line, applied in two positions (the eye being first directed as it were along the north and
south line, and then along the east and west), after which the whole is made fast by the screws 0 and
d. One hole having been drilled, the socket and screws present great facility in readjusting the in-
strument for subsequent holes, wit out the necessity for shifting the work, which would generally be
attended with more trouble than a tering the drill-frame by its screws. Sometimes the red at is rec-
tangular, and extends from the floor to the ceiling; it then traverses in fixed sockets, the lower of
which has a set-screw for retaining any required position. In the tool represented, the rod a termi-
nates in a cast-iron base, by which it may be grasped in the tail-vise, or when required it may be fixed
upon the bench. In this case the nut on a is unscrewed; the cast-iron plate, when reversed and placed
on the bench, serves as a pedestal; the stem is passed through a hole in the bench, and the nut and
washer, when screwed on the stem beneath, secure all very strongly together. Even in establishments
where the most complete drilling machines driven by power are at hand, modifications of the pressdrill
are among the indispensable tools; many are contrived with screws and clamps, by which they are
attached directly to such works as are sufficiently large and massive to serve as a foundation.
Various useful drilling tools for engineering works are fitted with left-hand screws, the unwinding
of which elongates the tools; so that for these instruments, which supply their own pressure, it is
only necessary to find a solid support for tie centre. They apply very readily in drilling holes
within boxes and panels, and the abutment is often similarly provided by projecting parts of the
castings; or pthcrwise the fixed support is derived from the wall or ceiling, by aid of props ar-
ranged in the most convenient manner that presents itself.
Fig. 1102 is the common brace, which only differs from that in Fig. 1101 in the left-hand screw;
a right-hand screw would be unwound in the act of drilling a hole when the brace is moved round
in the usual direction, which agrees with the path of a left-hand screw. The cutting motion pro-
duces no change in the length of the instrument, and the screw, being held at rest fora moment
during the revolution, sets in the cut; but toward the last the feed is discontinued, as the elasticity
of the brace and work suffices for the reduced pressure required when the drill is nearly through,
and sometimes the screw is unwound still more to reduce it.
The lever-drill, Fig. 1103, differs from the brace~drill in many respects; it is much stronger, and
applicable to larger holes; the drill-socket is sufficiently long to be cut into the left-hand screw, and

1105.
1102. , 1106.
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the piece serving as the screwed nut is a loop terminating in the centre point. The increased length
of the lever gives much greater purchase than in the crank-form brace, and in addition the lever-
brace may be applied close against a surface where the crank-brace cannot be turned round; in this
case the lever is only moved a ha'f circle at a time, and is then slid through for a new purchase, or
496 DRILLS, METAL—BORING.

sometimes a spanner or wrench is applied directly upon the square drill-socket. The same end is
more conveniently fulfilled by the ratchet-drill, Fig. 1104, apparently derived from the last; it is
made by cutting ratchet-teeth in the drill-shaft, or putting on the ratchet as a separate piece, and
fixing a pawl or detent to the handleythe latter may then be moved backward to gather up the
teeth, and forward to thrust round the tool, with less delay than the lever in Fig. 1103, and with the
same power, the two being of equal length. This tool is also peculiarly applicable to reaching into
angles and places in which neither the crank-form brace nor the lever-drill will apply. Fig. 1105
is used for lengthening drills, and is simply a bar having at one end a socket for the drill and at the


other a tang to fit the brace. Fig. 1106, the ratchet-lever, in part resembles the ratchet-drill; but the
pressure-screw of the latter instrument must be sought in some of the other contrivances referred to,
as the ratchet-lever has simply a square aperture to fit on the tang of the drill d, which latter must
be pressed forward by other means. Fig. 1107 exhibits the construction of the ratchet-drill more in
detail, FF being the ratchet.
In Fig. 1108 is shown a simple form of breast-drill, the construction of which is obvious from the
engraving. Fig. 1109 represents a hand-drilling machine designed for attachment to a wall or post.
A is the feed-wheel, and B the crank whereby the drill is rotated. A useful combination of drill and
vise is shown in Fig. 1110. In Figs. 1111 and 1112 is represented a simple drill in which the spin-
dle _is driven by a pair of bevel-pinions; the one is attached to the axis of the vertical fly-wheel, the

1111. 1112.
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other to the drill-shaft, which is depressed by a screw moved by a
small hand-wheel. Sometimes, as in the lathe, the drilling-spindle
revolves without endlong motion, and the table is raised by a treadle
or by a hand-lever ; but more generally the drill-shaft is cylindrical
and revolves in, and also slides through, fixed cylindrical bearings.
The drill-spindle is then depressed in a variety of ways ; sometimes by a simple lever, at other times
by a treadle which either lowers the shaft only one single sweep, or by a ratchet that brings it down
by several small successive steps through a greater distance; and mostly a counterpoise weight
restores the parts to their first position when the hand or foot is removed. Friction-clutches, trains
of difierential wheels, and other modes, are also used in depressing the drill-spindle, or in elevating
the table by self-acting motion. Frequently also the platform admits of an adjustment independent
of that of the spindle, for the sake of admitting larger pieces; the horizontal position of the platform
is then retained by a slide, to which a rack and pinion movement, or an elevating screw, is added.
Fig. 1113 represents a quick-speed hand-drill designed for light drilling in wood or metal. Its
chief parts are a fly-wheel carrying the drill, and a pulley spring and clutch mechanism, all of which
revolve loosely on a spindle held stationary by a handle. The action is as follows: By drawing
with one hand a string wound around the drum, the latter and the clutch, together with the fly-wheel


DYNAMICS. ' 497

and drill, are set in motion at a certain speed. At the same time the spring attached to the drum
is tightened. As soon as the tension of the hand holding the string is relaxed, the movement of the
pulley is reversed, taking up the slack at the same time. The fly-wheel and the drill do not, how-
ever, take part in the reversal of the motion, owing to the action of
the clutch. A continuous revolving movement in one direction is
thus insured for the drill, the speed varying from 500 to 1,000 revo- ‘
lutions per minute.
Drilling Square Helm—Mr. Julius Hall of London has devised
an ingenious method of drilling a square hole by a rotary drill.'
For this purpose a three-sided drill is used, either flat or fluted, hav-
ing its bottom or cutting edges perfectly flat, and three in number,
.cach cutting edge extending from one of the outer corners to the
centre of the triangle. The drill is held in a specially constructed
chuck, so made as to allow the tool to have some horizontal travel,
or, in plain terms, to allow'it to “ wobble.” The horizontal travel
or play is proportionate to the size of the hole to be drilled. Near
to the lower end or cutting edges of the drill is fixed rigidly a metal
guide-bar or plate. The guide-bar is provided with a square hole
similar to the hole it is required to drill, the dimensions of the three
sides of the drill being such that the distance from the base to the
apex of the triangle which such three sides form is the same as of
the sides of the square holes it is required to drill. The method
of operation is as follows: The three-sided drill being fixed in the
self-adjusting chuck, the guide-bar with the square guide-hole there-
in rigidly fixed above the point where it is required to drill, the
drilling-spindle carrying the chuck-drill is made to revolve, and is
screwed or pressed downward, upon which the drill works down-
ward through the square guide-hole, and drills holes similar in size
and form to that in the guide. The triangular drill may also be
used in any ordinary chuck, when the substance operated upon is not
very heavy nor stationary; then, instead of the lateral movement of the drill obtained as described,
such lateral movement will be communicated to the drill by the substance operated upon. (See
“ \Vrinkles and Recipes,” New York, 187 8, and Scientific American, xxxix., 311.) J. R. (in part).
DRIVE—WELL. See WELL-BORING.
DRYER. See SUGAR Macnrxsav.
DRYING MACHINE. See PAPER-MnKING.
DYNAMICS, properly speaking, is the science which treats of forces in the abstract; but in an
extended sense it is defined as the science which treats of the movement of bodies, and of the laws
of the forces which produce the movement. The latter, however, is properly the definition of kinet-
ics, but 'we shall use the former in its extended sense. This science was founded by Galileo, and
had its birth in the establishment of the principle of accelerating forces. Sir Isaac Newton stated
its fundamental principles in the form of three laws:
FUNDAMENTAL Laws—1. Every body confinues in a state of rest or of uniform motion in a straight
line, unless acted on by a force which compels a change. This law expresses the fact that matter is
inert and perfectly passive; that it cannot of itself change its position of rest or condition of m0~
tion; and that every change is due to an adequate cause. It has been determined that the molecules
of a body may be in a state of rapid motion in reference to each other, while the body as a whole
is considered at rest. It is necessary, therefore, to consider the term body as applicable to a mere
particle, unless otherwise stated. By a particle we mean the smallest conceivable portion of a body.
2. Change of motion is proportional to the acting force, and takes place in the direclz'on in which
the force acts. The term mot-ion. here includes all the elements of the body which enter into the
motion, and hence involves both the mass and velocity; but these jointly are called the momentum of
the body; hence the law should read: The change of momentum of a body is proportional to the
acting force. This change, then, is recognized as a measure of the cause which produces the
change. It is the first principle upon which analysis is founded. If a body at rest be acted upon
by a single force, it is evident that its line of motion must coincide with the line of action of the
force; but if a body be in motion, a force which acts at an angle with the line of motion will deflect
the body from that line, but the resultant motion will not generally coincide with the line of action
of the force. The effect, however, will be in the direction of action, that is, in a line parallel to
the action of the force. Thus, if a body be moving southerly in the plane of a meridian, and a
force acts upon it in a due easterly direction, the resulting motion of the body will not be due east,
but its deviation from the plane of the meridian will be just as much to the east of that plane
as if the body had been at rest when the force acted. Lagrange states this principle thus: “If dif-
ferent movements be impressed upon a body at the same time, the body at each instant will be
found in the same place where it would be if all the movements were combined.” Newton by means
of this law established the parallelogram of forces. To illustrate: If a body describe the side of a
polygon (Fig. 1114) with a uniform velocity of Vl in one second, and then be brought to rest; and
the side V2 in the same time, and then be brought to rest; and V8 and finally V4 in the same man-
ner; if new it were possible for these movements to take place at the same time, the body would be
found at V4 at the end of one second; and if all these movements be impressed upon the body at
the same time, it will move over the side V in one second. The acting force is the resultant of all
the forces acting upon a body at any instant. This law fully stated would read : An acting force is
one which produces a change in the velocity of a body, and is proportional to the rate of' change of
1113.


32
498 DYNAMICS.

the momentum produced in the body ; its elfect will be parallel to its line of action, and be indepen~
dent of the state of the body in regard to rest or motion at the time of action of the force.
3. Action and reaction are equal, but in contrary directions. Newton gave three illustrations of
this law, as follows: 1. If one presses a stone with his finger, his finger is also pressed by the stone.
2. If a horse "draws a load, the horse is drawn backward, so to speak, equally toward the load. 3.
If one body impinges upon another and changes the motion (momentum) of the other body, its own
motion experiences an equal change in the opposite direction. These illustrations, if unaccompanied
by explanations, are liable to mislead. Thus, if the load draws the horse back as much as the horse
draws the load, there will be equilibrium, and no motion will result from the effort. So in
regard to the first illustration, the question arises, _how can a stone or other inert body exert any
force ? An erroneous view of the law will result if we consider the action as produced by a single
body, or, generally, as an action within the bodies. The action is really between bodies. At least two
bodies are always involved in an action, and a force never acts upon a single body only. When a
ball is fired from a gun, the force of the powder acts equally against the ball and the gun. Attrac-
tion always exists between two or more bodies at the same time, and never acts upon one body only.
If the action of the force be in one direction in reference to one body, it will be in exactly the con-
trary direction in reference to the other body; and if in one direction it is called an action, then in
the opposite direction it is called a reaction. Action and reaction are precisely the same things in a
mechanical sense; they are simply two names for designating the contrary actions of the same force.
It is the force which acts equally in contrary directions, and not the bodies. Thus, when the horse
draws a load, an action is induced between the breast of the horse and the collar against which he
presses, and to maintain the pressure the horse pushes against the earth. The horse and load move
A 1115.








P-<__-_--
a
72 s
in one direction, and the earth moves a corresponding amount in the opposite direction; the action
and reaction of the force between the horse and his harness are equal and opposite; also the force
between the foot of the horse and the earth are equal and opposite. When the action is of sufficient
intensitv to move the load in one direction, something, though it be the earth, must move in the other
directioh. The law therefore ought to read: Every force acts upon two or more bodies at the same
time, and its intensity is equal in contrary directions. This corresponds to the great modern doc-
trine of energy, which will be found discussed further on.
Illustrations—1. If two boats of equal size, resting upon still water, are connected by a rope, and
a man in one boat pulls on the rope with a force of 100 lbs., the boats will approach each other with
equal velocities. And if a man in the other heat pulls on the same rope with a force of 100 lbs.,
they will not approach each other any faster. They will meet at a point midway between'the boats.
2. If several spring-balances are attached end to end, and a man pulls at one end With a force of 50
lbs., each of the balances will indicate 50 lbs. if they are all accurate. If two men pull at the ends
of a rope in opposite directions, each with a force of 50 lbs., the tensmn of the rope is 50 lbs. and
not 100 lbs.; for the action of one is the reaction of the other. 4. If a ball fired from a gun were
as heavy as the gun, the gun would fly in one direction as fast as the ball went in the opposite direc-
tion; and if the ball were heavier than the gun, the gun would be shot away from the ball, so to
speak, instead of the ball away from the gun. _ ‘
The subject of, motion may be considered independently of any cause producing it. When thus
treated, it is called kinematics, or the science of pure motion. _
VELOCITY is rate of motion. The term rate implies a comparison with some unit chosen as a
standard. In regard to motion, the unit of reference is time, and may be a second, minute, hour,
day, year, or century. In financial matters, the unit may be a.dollar, or the English pound sterling,
as when we speak of rate. of interest, rate of exchange; and in other commercial matters we have
rates of transportation, etc. Velocity is uniform when the body passes over equal successive por-
tions of space in equal times, and in all other cases it is variable. In the definition for uniform
velocity, it must be understood that the equal portions of space may be chosen arbitrarily. In
periodic motion, in which the motion is repeated, like that of the vibrations of a pendulum, the
times of successive vibrations may be equal, but the velocity along the path may constantly vary.
If the velocity be uniform, it is- measured by the space‘ovei'nvhich the body moves in a unit of
time; so that if the body moves over the space (s) in a given time (t), we have for its velocity (v),
7
v or uniform velocity is found by dividing the space passed over by the time. If the velocity be
DYNAMICS. 499

variable, it is measured by the space over which the body would pass in a unit of time if it moved
with the velocity which it had at the instant considered. Most of the investigations in regard to
variable velocity are best made by means of the calculus, but it may be determined to any degree of
approximation by finding the space passed over in a very small portion of time. We have generally
variable velocity equal to space divided by corresponding infinitesimal time. When the
velocity varies at a uniform rate, it may easily be determined if the velocity at any two instants be
known. Thus, suppose that a body starts from rest, and moves with a uniformly increasing velocity,
acquiring a velocity at at the end of the first second (Fig. 1115); then will the velocity at the end
of two seconds be 2 11,, at the end of three seconds be 3 a1, and so on; and hence, at the end of t
seconds the velocity would be t 21,. In other words, the velocity at the end of a given number of sec-
onds will equal the velocity at the end of the first second multiplied by the number ofseeonds.
Angular velocity is rate of angular movement. If the path of a body he a circle and the velocity
uniform, the angular velocity will be the quotient arising from dividing the actual velocity by the
radius of the circular path. The result may be reduced to degrees if desirable, but in this case it
will generally be better to find it directly in that form.
Examples—1. Required the angular velocity of the earth in its rotation on its axis. The earth turns
on its axis once in 24 hours, that is, in that time it turns through 360° ; in one hour its angular velocity
is 360°+24=15°; and for one minute it is 15°+60:_—15'; and for one second it is 15’—:—60:15”.
2. The angular velocity of a fly-wheel whose radius is 5 feet is 1000° per second: what will be the
actual velocity of a point on the circumference? The wheel will turn around ltPébo' == 235 times in a
second. The circumference will be 10 x 3.1416 : 31.416 feet; hence the velocity will be 21,- x
31.416 :: 87.26 feet per second.
If the motion be not along a circular path, and the velocity is variable, we must find the angular
velocity for an instant. This is best done by the use of the calculus, and for the demonstration the
reader is referred to the treatises noted at the end of this article.
ACCELERATION is the rate of change of velocity. If the acceleration be increasing, it is considered
positive; if decreasing, negative. If the velocity increase at a uniform rate, the acceleration will
be measured by the increase of the velocity for a unit of time. The unit is understood to be one
second unless otherwise stated. If the acceleration be variable, it will be measured by the amount
by which the velocity would be increased (or decreased) in a unit of time if the rate of increase had
continued the same as at the instant considered. This principle is fundamental in this science ; so
much so, that dynamics has been defined as the science of accelerations. To find the velocity (v)
of a uniformly accelerated body at the end of a given time (t), we have only to multiply the time by
the acceleration (f) for one second, or a: f t. Example : Required the velocity of a body starting
from rest, which is uniformly accelerated at the rate of 2 feet per second, at the end of 5 seconds.
21:9 x 5:10 feet per second. To find the space (8) passed over in a given time (I), multiply
the time by one-half the velocity corresponding, or s:% vt. Example: Required the space passed
over by a body, which is uniformly accelerated at the rate of 2 feet per
second, in 5 seconds. From the preceding example the velocity at the
end of 5 seconds is 10 feet; then 8 :§ x 10 x 5 = 25 feet.
FALLING BODIES.—Recognizing, as we now do, that bodies fall to the
earth on account of the action of the force of gravity, and that within
small distances from the surface of the earth the force is constant, we
may deduce the laws of falling bodies directly. Galileo rather assumed
than demonstrated that Nature would seek the simplest mode of action,
and that the simplest law was that in which the variation of the velocity
is uniform. The assumption was correct, and by means of it the laws were
deduced. The principle of “ Attwood’s machine” for this purpose consists
in counteracting a portion of the gravitating power of a body by the gravi-
tating power of a smaller body; so that the absolute velocity and the
spaces passed through shall be less than in the case of bodies descending
freely, while, as the force is constant, the same ratio of progression will
hold in both cases. Fig. 1116 represents the machine. a a a is a triangu- ,
lar frame upon three movable legs; b, a small platform suspended from I
it by a universal joint c c, and supporting two upright standards (1 d, in I
which the axis of a light brass wheel e revolves with very little friction. /
Over a groove in the periphery of the wheel passes a very light and pli- _, I
able silk thread, from the ends of which hang two equal weights f 9. Into the under side of b is screwed a square rod h, descending to the floor, to which it is secured in a perpendicular position by small pins passing through {1'
holes in the claws i on the face of the rod is a scale of inches; k is a /
brass guide, fixed at the upper part of the rod h, so that when the top of /
the weight g touches the lower side of h, the under side of g is on a level //
with the top, or commencement of the scale; l‘is a small stage, movable along the rod h, and having a hole in it sufficiently large for the weight g /
to pass: on one side is a tightening-screw m ,- n is another movable stage,
fitted with a tightening-screw o, as also a fork p, turning upon a hinge.
" The experiment is conducted as follows : A small circular weight is placed
upon 9, which is pulled up to the top of the scale, and the stage n is
screwed to the rod h, on a level with the lower part of the weight f, which is held down upon it by
the fork 13. Upon releasing f from the fork, the weight g descends with a slow but gradually accel-
erated motion, and the number of inches the weight has descended at each successive beat of a pen-
dulum (suspended from another triangle) is observed upon the scale; and if the additional weight be





5‘00 DYNAMICS.

such as to cause 9 to descend through 3 inches in the first second, then it will cause it to descend
through 1 foot in 2 seconds, and through 6;} feet in 5 seconds. It will be observed that the spaces
vary as the squares of the times; thus, in 2 seconds the space is 3 x 2“ r. 12 inches = 1 foot; in
5 seconds the space is 3 x 5": 75 inches : 61» feet. It“ the additional weight be removed, and a
small bar of equal weight, but of a length exceeding the diameter of the hole in I, be placed upon
9, and the stage l be set at any division of the scale at which the weight would arrive at the end
of any number of seconds, the stage will intercept the bar in its descent, and the weight will con-
tinue to descend with the velocity it had acquired upon reaching 1. Thus, if the velocity at the
end of the second second be 2 feet, in which case the weight would have descended 1 foot in that
time, if the stage be set at 1 foot upon the scale, it will intercept the bar at the end of the second
second, and the weight 9 will move with a uniform velocity of 2 feet per second through the remain-
ing portion of its descent. If it is required to illustrate the case of retarded motion, the small
circular weight is placed upon the weight g, and a smaller weight upon the weight f, so that g will
still descend; but as soon as the stage 1 intercepts the bar with the small weight upon it, f becomes
the heaviest, and y will descend with a velocity decreasing as the squares of the times, counted from
the time of g passing the stage Z.
By direct experiment it may be shown that the velocity of a falling body in 'vamo at the end of
one second is about 32§ feet per second, usually represented by the symbol 9; and this is the accel-
eration required. It is not, however, the same at all places on the earth: it will be greater at or
near the poles, and less at the equator; it will be less on a high mountain than at its foot; it will
be less at the bottom of a deep mine, if that point be below the natural surface of the earth; still,
in all practical cases, it is so near 32% feet that this value may be used, except where great accu—
racy is demanded. This value of g corresponds with the f in the preceding paragraph, and sub-
stituting 32% for it, we have i) = 323g 2‘, s : 16112- t2 ; and from these we find '0 : 8 4/8 nearly;
,2 .
'2) : gz-s; s = 23%;; s 2: 1} v t ,- which are the formulas for falling bodies.
Examples.——1. How far will a body fall in five seconds? Here we have s : 1611,; (5)9:40208
feet. 2. What velocity will a body acquire in falling 100 feet? Here we have a : 445% X 100 =
80 feet nearly. 3. What velocity will a body acquire that is falling four seconds? Here we have
i) 2 3216» x 4 :128§~ feet.
The law of ascent is exactly the reverse of that of descent. In the ascent the velocity will de-
crease uniformly. If a body be projected upward with a given velocity, it will rise to the same
height that it would be necessary for the body to fall in order to acquire that velocity.
When the resistance of the air is considered, these formulas are all modified. The resistance of
the air varies nearly as the square of the velocity; so that when the velocity is great the resistance
is also great, and the velocity as a consequence will be greatly reduced. If a body be projected
upward in the air with a given velocity, it will return with a less velocity. The resistance acts
against the velocity in both the upward and downward movements, tending constantly to diminish
it. The acceleration of bodies falling in the air is not therefore uniform in any case, but may be
considered as such when the fall is not more than 200 or 300 feet. When the resistance of the air
is considered, the solution of the problem of the ascent and descent of bodies requires analysis of a
high order. ,
Tones moves or tends to move any body upon which it acts. Of its essential nature we know nothing,
for it is unknowable. Laplace says : “The nature of that singular modification by means of which
a body is transported from one place to another is now, and always will be, unknown ; it is denoted
by the name of Force.” (Mécanique Celeste,” p. 1.) All that we pretend to know in regard to it is
its laws of action, and these must be learned by observation. Force may properly be regarded as
an action between bodies. There are numerous cases, however, in which the action upon one body
only is considered. Thus, when a projectile is fired from a gun, it is not generally necessary to con-
sider the motion of the gun, but that of the ball only. In considering the attraction of the sun
upon the planets, it is not necessary to consider the effect of the attraction of the planets upon
the sun; for that body is so large compared with any one or even with all of the planets, that
their combined effect is scarcely appreciable. A force, strictly speaking, is always balanced, for its
intensity is equal in contrary directions. Still we often see the expression “unbalanced force.”
This is correct only when used in reference to its action upon a single body. The term force has many
different names, such as attractive force, repulsive force, central force, centrifugal force, chemical
force, force of electricity, etc. ; but these only define the mode or character of its action. The inten-
sity of a force is measured by pounds or their equivalent in English units, by kilogrammes or their
equivalent in French units, etc. Any effect produced by a force, or any expression into which force
enters, which cannot be measured by pounds or their equivalent, is not properly force. In this
sense such expressions as force of momentum, force of ’l'iS viva, force of work, etc., are improper. The
measure of force here given is generally called its statical measure, but its value is the same whether
it produces motion or results only in pressure. Force‘ may also be measured by the change of motion
which it is capable of producing in a unit of time.
Action at a distance implies that a force may produce an effect upon a body at a distance without
any medium between the force and body. Our first experience is opposed to this. 'I he boy draws
his sled or wagon by means of a rope extending from his hand to the sled ; a man’s voice is heard
at a distance by means of the air; electricity produces an effect hundreds of miles distant through
the medium of a wire ; and we are led to suppose that a force cannot act except through a medium.
But a magnet will attract iron when placed in the most perfect vacuum, and hence when there is no
apparent medium between them; and the interposition of another body does not seem to prevent
or even modify its action. This looks like action at a distance. Philosophers assert that no two
DYNAMICS. 501

particles of matter actually touch each other; and if this be true, it appears that all action ishe-
cessarily at a distance, though in this case the distance would be inconceivably small. But this is
debatable ground, and we leave it, simply remarking that, according to our present knowledge, the
mutual action of two bodies implies an intervening medium of some kind.
The Law 0 Universal Gravitation, discovered by Sir Isaac Newton, is the most exact and far-
reaching of al known laws of force. This law is: 7 he attraction between two particles varies directly
as the product of their masses, and inversely as the square of '
the distance between them. In reference to one particle, we 111]-
would say that it attracts every other particle with a force
which varies as its mass and inversely as the square of the \ c
distance between them, from which fact the law above given
may be deduced. It follows from this law that the attraction
of a homogeneous sphere upon a particle exterior to it is the
same as if the entire mass were concentrated at the centre of A
the sphere; and hence the attraction of two homogeneous
spheres for each other varies directly as the product of their
masses, and inversely as the square of the distance between
their centres. It may also be shown by this law that the at-
traction of a perfectly homogeneous spherical shell is the
came; upon a particle placed anywhere within it (Fig. 1117);
and from this result it is easily shown that if the earth were
a homogeneous sphere, the force of gravity would be zero at
the centre, and would increase directly as the distance from -
the centre. By the aid of this law the spheroidal form of the earth and other planets is accounted
for; the form of the orbits of the planets is determined; the action of the tides, the inequalities of
the movements of the planets in their orbits, and many other interesting phenomena in astronomy,
are explained.
Some forces are repulsive in their action. The force with which two bodies repel each other, when
one is positively and the other is negatively electrified, varies inversely as the square of the distance
between them.
WEIGHT is simply a measure of the action of gravity upon the body; or, more strictly speaking, it
is, a measure of the mutual attraction of the body and the earth. It is found that if a body be
weighed with a spring-balance, it will weigh less at the equator than at high latitudes, and less on a
high mountain than at its foot; and the weight thus determined shows that the force of gravity is
different at different places. If the earth were a homogeneous sphere, the weight of a. body would
be the same at all points on its surface; but it is so flattened at the poles that the distance of the
pole from the centre is about 13 miles less than that of the equator, and a body weighs correspond-
ingly more at the poles than at the equator. The standard unit of weight in England and in the
United States is the pound avoirdupois, and this is the weight of a certain piece of platinum kept
by the proper officer for the purpose of preserving the standard. (See MEASURE, STANDARDS or.) If
any body be weighed by balancing it on a beam-scale with standard pounds, the body will weigh the
same at all places, for the force of gravity will act equally upon both. By weighing bodies in this
manner the quantity of matter in a given body compared with the standard becomes known.
Mass is quantity of matter. This is one of the most absolute quantities used in mechanics. It is
in a certain sense independent of weight, or volume, or temperature; for it is supposed to remain the
same whether it be placed at the centre of the earth, where it would have no weight, or on the sur-
face of the earth, where it would have weight, or at a certain point between the earth and moon,
where the attractive forces of these two bodies are equal, in which place it would have no weight;
or whether in these different places it should be contracted or expanded, thus changing its volume;
or whether its temperature should change: under all these conditions a certain mass is supposed to
be constant. In measuring it, therefore, such a method must be used as will give a constant result.
The method employed in mechanics is to divide the weight of the body by twice the distance through
which the body would fall freely in one second at the place where it was weighed. In this way we have:
\Veight of the body
acceleration of its [all
the weight being in pounds and the acceleration in feet per second, for English measures. Another
way is to assume an arbitrary quantity of matter as the unit of mass: then will the mass of any other
oody be found by dividing its weight by the weight of the unit of mass, both being weighed at the
same place.
It is well to observe the perfect coexistence of force and matter; we know nothing of one without
the other, and their separation is inconceivable.
DENSITY relates to the compactness of matter. In mechanics it is the mass of a unit of volume.
In physics it is sometimes used in the same sense as specific gravity. Both are equally good for
giving the idea of compactness. According to the former, the density of a body is the weight of a
unit of volume of the body divided by the acceleration due to gravity. For instance, the weight of a
cubic foot of iron is, say, 4501bs.', then will its density be 450 + 32}. = 14 nearly. The specific
gravity of the body is its weight compared with an equal volume of distilled water. A cubic foot of
distilled water weighs, say, 62); lbs. ; and hence the specific gravity of the iron would be 450 —:- 62%
= 7.2. Since both methods are used, it is necessary to indicate by the context or otherwise which is
intended. The density of the earth is very nearly 51} times that of distilled water.
Druaauc MEASURE or Fence—By the dynamic measure of force we mean a measure of the inten~
sity of so much of the force acting upon a body as is instrumental in directly producing motion.
be

= the mass of the body;
502 DYNAMICS.

Forces of great intensity may act in contrary directions upon a body, thus partially or wholly neutral-
izing each other’s efiects, and producing little or no motion. Thus, when a locomotive draws a train
of cars, a portion of the pulling force is directly neutralized by the resistance of the air, friction on
the track, and other resistances of the train. If the pulling force exceeds the resistances, the excess
will be the effective pulling force. When the resistances equal the pulling force, the motion becomes
uniform. The force which produces motion is commonly called the unbalanced force, the true signi-
fication of which has already been explained. It is, according to Newton’s second law, measured by
the rate of change of the momentum. But the rate of change of the velocity is the acceleration;
hence we have: Force :mass x acceleration. This measure of force was called by Gauss “the
absolute measure of force.”
Illustration—If two equal sleds were connected by a string, and a boy were to pull on the first one
with a constant force of 10 lbs., what would be the tension of the connecting string, supposing the
sleds to be drawn on perfectly smooth ice? There being no frictional resistance, the tension will be
caused by moving the masses; and since the force will be equally distributed throughout the masses,
the tension of the connecting string will be 5 lbs. The motion will be the same as if a pull of 5 lbs.
were applied directly to each sled. If the sleds were light, the acceleration (or speed, as the boy would
say) would be great ; but if the sleds were very massive, the acceleration would be small. The
lighter the moving parts of an engine, the greater will be their speed for a given steam-pressure
when no work is being done.
MOMENTUM is the product of the mass of a body into its velocity, and is often called quantity of
motion. It is a measure of the effect produced by a force in a given time, and hence may properly be
called a time-effect. If the force acts with a variable intensity, let the time be divided into portions
so small that the intensity of the force during each interval of time may be considered constant;
then the momentum will be the sum of the products of each force into the corresponding time.
Momentum is not a force, nor the measure of force. The unit of momentum is the momentum of a
unit of mass moving with a unit of velocity; and in English measures it is 1 pound of mass moving
with a velocity of 1 foot per second.
WORK is the overcoming of a resistance continually recurring along the path of motion. This
definition is drawn directly from the idea of work as performed by men, animals, and machines.
But in treating of forces generally, it is found advisable to extend this definition as follows: A force
is said to work when it moves its own point of application through space. Thus, if a man carries a
weight up a ladder, he does a certain amount of work; and if he drops it when he gets to the top,
gravity will do just the same amount of work in pulling it to the earth again; and when the body
strikes the earth and is brought to rest, the body does the same amount of work in tearing up the
earth that gravity did in pulling it down. A horse does work as he draws a load; rivers do work
in wearing down their beds and banks; wind does work in blowing dust, driving ships, turning wind-
mills, etc. ; electricity does work in moving electrical machines (see ELECTRICI'I‘Y); heat does work in
expanding bodies, causing vapor to rise in the air, generating steam, etc. (sec THERMO-DYNAMICS); in
short, all the agencies on the earth which produce motion do work, for the bodies moved meet with
resistances. Mere motion is not work; so that, if the planets move in void space, they do no work.
Neither is mere pressure work; motion as well as pressure is necessary.
In order to find a measure for work, we observe that if a man does a certain amount of work by
carrying a load one mile, he does twice the work by carrying it two miles, and so on for any number
of miles. Similarly, if a locomotive does a certain amount of work in drawing a train one mile, it
does twice the work in drawing it two miles, and so on, the resistance being constant. The same is
_ true for any other power or agent. Hence the amount of work, the resistance remaining constant,
varies directly as the space over which the force works. It is also evident that if the resist-
ance be doubled, twice the work will be done in the same space; and if it be made threefold, three
times the work will be done, and so on. Hence the total work done varies as the resistance and
space jointly. If U represent the work, F the constant force doing the work acting along the path
of motion, and s the space over which F acts, then we have, according to the definition, U : F x s.
The work done does not depend upon the magnitude of the load moved, but upon the resistance
overcome. A horse may do the same work in drawing a small load over a rough road as in drawing
a large lead over a smooth road. An engine on an improperly constructed vessel may do much more
mechanical work in driving the vessel from New York to Liverpool than another engine on a larger
but properly constructed vessel in driving its vessel the same distance. The work done is indepen-
dent of the time. A man does only a. definite amount of work in carrying a weight from the cellar
to the garret, whether it be done in one minute or one hour. The one who does a given amount of
work in the shortest time is the most efi‘icz'ent, and may be the most profitable; but that involves
other elements than mere work. If a boy is required to draw all the water out of a cistern, he will,
in performing the task, do a certain amount of mechanical work; and the work will be done when
the cistern is emptied, whether it be done in an hour or a day. It is true that time is required in
order to do work, and all that is meant by work being independent of time is, that the time is not
limited by the conditions of the problem. The unit of work is the work of raising 1 pound 1 foot
high, and is called afoot-pound.
To determine the work done by an animal or machine, it is necessary to measure the force exerted
by the agent and the space through which it acts. In many cases the force is variable, and it is de-
sirable to have an automatic record of the force and the corresponding space. The force is measured
by some kind of a spring-balance, called a dynamometer (see DYNAMOMETER), placed between the
power and resistance. An index indicates the pounds of pull; and by having a piece of paper pass
under the end of the index, having a rate of movement proportional to that of the working agent, a
line may be traced which will enable one to determine the work done. For instance, if the resistance
be constant, the figure formed will be a rectangle, A B C D, Fig. 1118, in which the bases will rep-
DYNAMICS. 503

resent the space according to some scale, and the altitude F the force according to some other scale.
But if the force is not constant, a curved or broken line will be traced, Fig. 1118 A, the base of
which will represent the space, and the perpendiculars 0 ill, N D, etc., from which to the curved


1118. 1119 A.
D 0
N
M
F
1)
A s B A c



line will represent the resistances at the corresponding point of the path. The area of the figure
thus found will represent the work in foot-pounds. The area may be found to any degree of ap-
proximation by dividing the figure into trapezoids so small that the portion of the curved line
between any two consecutive ordinates may be considered as straight. If the force acts at an
angle with the path along which the body moves, we find how much force is required to pull the
body when it acts parallel to the path. Let P, Fig. 1118 B, be the latter force; then, to find the
work which it can do, multiply the force in pounds by the space in feet over which the body is
drawn by this force. When the force is inclined upward, it lifts upon the body, so that it may not
require as much to. draw the body along as when it acts horizontally. If we know the force and
the angle at which it is inclined upward, we may find how much it lifts upon the body, and how
much it pulls along, as follows: Draw the line 0F, making the same inclination upward as the
actual force, and let Get on the scale represent the number of pounds in the force. Draw 0 b hori-
zontal and a 6 vertical ; then will a I: represent the lift on the load and O b the horizontal pull.
1118 B. 1118 c.




m-——_,-_-

P
'A ./ -/m” E
Example—Let the force be 100 lbs. pulling upward at
an angle of 30°. Let 0 a = 1 inch; then it will be found
that ab will = 1} inch and O b = 0.86 of an inch, and the
upward lift will be 11- of 100 = 50 lbs., and the horizon-
tal pull will be 0.86 x 100: 86 lbs. If the lift on the \_ _
load should reduce the resistance, so that it would draw A 3
easier than before, there might be a gain in drawing at
an angle with the path; but if it did not diminish the resistance, there would be a loss. For if the
pull be 100 lbs. drawn over a space of 50 feet, the work would be 100 x 50: 5,000 foot-pounds;
but when it draws at an angle of 30°, we see that the horizontal pull is 86 lbs., and the work will be
86 x 50 = 4,300 feet-pounds.
In machinery the path described by a working point may be much longer than that described by
the force. Thus, in a steam-engine, let E F, Fig. 1118 0, represent the stroke of the piston, D the
centre of the crank, DB the length of the crank, and EB F the circumference described by the
extremity of the crank. The diameter E F will equal the stroke of the piston. To find the work
done by the steam in driving the crank—pin B around the circumference of a circle, we divide the cir_
cumference into small parts, and draw lines through the points of division perpendicular to the diam-
eter E F. In passing from A to B, Fig. 1118 e, the path is along the are, but the force of the steam
is along 0' D; and while the point is moving from A to B, the piston will have moved a distance
equal to CD ; therefore the work done by the steam will equal the total steam-pressure upon the
piston multiplied by C’ D, and similarly for all the other ar'cs. Hence the total work done in driving
the point B around a semi-circumference will be the steam-pressure multiplied by the diameter E F,
which is the same as the pressure multiplied by the length of the stroke of the piston. Therefore, we
conclude, if friction be discarded, that no war/c is lost in ekmzgingfrom reciprocating to rotary motion ,-
and that the piston, crank, and fly-wheel are well adapted to each other for transmitting work.
Work is divided into useful and prejudicial. That is useful which produces the thing desired, as
the production of flour from wheat, the making of a tool from steel, etc.; and that is prejudicial
which wears out machinery or produces damage, as the friction of the axles of machinery, the wear-
ing away of the beds and banks of streams, the wearing out of the rails on a railroad, etc. Prejudi-
cial work always accompanies useful work, and it is not easy to draw a definite line between them ;
but we know that, in point of economy, it is desirable to reduce the former as much as possible.
When the motion is 1miform, we know that the space over which a body moves is the product of






504. DYNAMICS.

the time by the velocity. If, new, two machines work at different rates, the ratio of work which
they can do in a given time will be directly as their velocities. Thus, if one moves at the rate of 4-
miles an hour and the other at the rate of 8 miles an hour, then the latter goes twice as fast as the
former, and in two hours it will go twice as far, and so on for any number of hours. Therefore, in
order to determine the efficiency of machines, it is only necessary to determine their rate of doing
work. This is called mechanical power by some writers, dynamic effect by others, and simply power
by others. It implies the ability of an animal or machine to do work at a certain rate, and may
be called work-rate. Its value is found by multiplying the force in pounds by the velocity in feet
per minute. The unit of power is _1 horse-power, which is equivalent to raising 33,000 lbs. 1 foot per
minute. To find the horsepower of a machine, find its mechanical power per minute, and divide
by 33,000.
Fa'amples.-——1. A spring-balance being placed between the cvener and a plough, it is observed that
a span of horses pull with a constant force of 200 lbs. in drawing the plough at the rate of 2 miles
per hour: what horse-power is expended in working the plough ‘2 First find the velocity in feet ; it
will be 2 x 5,280 r: 10,560 feet per hour, and 10,560 —:- 60 = 176 feet per minute; hence the work
per minute will be 200 x 17 6 = 35,200 foot-pounds, which, divided by 33,000, gives 35,200 + 33,000
: 1.06 horse-power. ,
2. A train of cars whose weight is 300 tons is drawn at the rate of 40 miles per hour, if the fric-
tion of the train is 8 lbs. per ton: required the horse-power expended by the engine. Solution: 'I he ‘
resistance will be 300 x 8 : 2,400 lbs. The velocity of 40 miles per hour will be 40 x 5,280 :
211,200 feet per hour; and the velocity per minute will be 211,200 —:- 60 : 3,520 feet. The work
per minute will be 2,400 x 3,520 :: 8,448,000 foot-pounds, and the number of horse-power 8,448,-
000 + 33,000 = 256.
ENERGY is a term used to express the amount of work stored in a body. Thus, we speak of the
energy of a moving body, energy in steam, solar energy, heat energy, etc. The term includes all
kinds of material activities in nature. Kinetic energy is the energy of a'moving mass. The energy
of a moving body is equal to the work expended in producing the motion; the body stores the energy
as the motion is produced, and parts with it whenever it meets with a resistance. The expression
§ 111219 is the measure of the kinetic energy of the body, and equals the amount of work which the
body will do in being brought to rest. This u as formerly called the living force by some writers,
while others called 11! v2 the living force; either of which may be used, provided only that it is
always used in the same sense in any particular problem. It varies as the square of the velocity of
the moving body. If a ball with a velocity of 10 would penetrate the earth 2 feet, then with a
velocity of 20 it would penetrate 4 feet, the resistance being uniform. This principle at first ap-
pears paradoxical, but it will be clear when it is observed that, in order to produce twice the velo-
city, the force must act through 4 times the space. In the case of falling bodies, if the times are
as 1, 2, 3, 4, etc., the velocities will also be as 1, 2, 3, 4, etc., and the spaces as 1, 4, 9, 16, etc.
Hence the spaces are as the squares of the velocities, and the same law must hold in overcoming the
velocity by a constant resistance.
In order to destroy the energy of a body, a force must act against it. If there were a hole through
the earth, and a body were dropped into it, gravity would constantly pull upon the body as it moved
from the surface to the centre, at which point the velocity would be greatest. After the body passed
the centre o'ravity would pull against it, making it go slower and slower; but gravity would not stop
the body until it had opposed the forward motion of the latter as much as it had previously ac-
celerated the same. The body would, therefore, if in a vacuum, go from one side of the earth to
the other; then it would return, and thus move to and fro like the oscillations of a pendulum, re-
quiring about 4-2 minutes to go from surface to surface. 'I he action is much the same as if one end
of a rubber string were attached to the body, and the other end fastened at the centre of the earth.
The string would pull the body toward the centre constantly, but with a diminishing force; and after
the body passed the centre the string would pull harder and harder against it until it finally stopped.
Examples—1. If a ball whose weight is 2 lbs. have a velocity of 150 feet per second, how far will
it penetrate the earth if the resistance is constant and equal to 50 lbs? Here we have 50 x s =
2
11,-376T (150) 9, which reduced gives over 14 feet.
6
2. If a train of cars whose weight is 60 tons moves with a velocity of 40 miles per hour, how
many miles will it move before being brought to rest by friction, friction beirg 8 lbs. per ton, no
allowance being made for the resistance of the air ? In the solution of this example the tons should be
60 X 2000
reduced to pounds, and the velocity to feet per second; hence we have F: 8 x 60, 111 =
32% ’
, 2 2
: w feet per second. Then, {rill V2 :§9~>i20-99->~<19-5-§g§9— : 6,386,680 foot-pounds.
60 x 60 2 x 32%;- x 602 x 602
Dividing this result by the force : 8 x 60 = 480 lbs., will give the number of feet required, and
6886680
4-80 x 5280
THE MECHANICAL EQUIVALENT 0F Hiram—Energy also exists in the motion of the particles of
bodies. Heat is not a material, as was once supposed, but consists of the rapid vibrations of the
particles of the body in which it exists; and all pressure, such as steam-pressure, atmospheric pres-
sure, and the pressure between any two bodies, is supposed to be due to the striking of particles
against the surface pressed. The dicovery that the heat in a body is capable of doing a definite
amount of work is due to Dr. Joule of England, although the fact that heat was a form of energy
was shown previously by Count Rumford, as early as the year 1798. Ile observed that boring a
that divided by 5,280 feet will give the number of miles; hence we have 22.52 miles.
DYNAMICS. 505

cannon with a blunt tool produced a high degree of temperature, and in one experiment so much heat
was generated by the friction as to cause water to boil. But Dr. Joule, during the years from 1840
to 1843, by elaborate and careful experiments, proved that the amount of heat in a body could be
expressed in terms of a certain amount of work; and that the heat necessary to raise 1 pound of
water 1° 1“. was equivalent to raising a body whose weight is 7 7 2 lbs. through a vertical height of 1
foot. This quantity of work is called the mechanical equivalent of heat, a term first introduced by
Dr. Mayer of Heilbronn in the year 1842. Dr. Joule experimented upon different substances and in
different ways, but the results of the experiments differed by only a few foot-pounds. The formula
in French units is: The heat necessary to raise 1 kilogramme of water 1° is equivalent to the work
of raising 424 kilogrammes vertically 1 metre. The establishment of this principle led scientists
to investigate the matter in regard to other agents, such as electricity, magnetism, light, and every-
thing which in any way afl'ecis our senses, or which operates in the economy of nature; and although
it has not been possible to trace the energies from one phase to another in such a manner as to
measure the exact equivalents, yet it is found that to produce energy in any form there is a loss of
energy in the agent producing it. For instance, in electric machines, now used for producing light,
the horse-power necessary to produce a light equivalent to a given number of wax candles of given
size can be measured, Electricity may be generated by the expenditure of a certain amount of work,
and similarly for other active agents. Such experiments and extended observation have led to the
establishment of the following
Laws OF THE CONSERVATION OF ENERGY.—-1. The total amount of energy in the universe is constant;
from which it follows that energy is indestructible. 2. The various forms of energy may be converted
the one into the other. These laws are believed to be as extensive and as rigidly exact as the law of
universal gravitation. They are made the foundation of many investigations in modern physics.
According to them, a perpetual-motion machine is an impossibility; for the energy of the machine
consists of that which is put into it from an external source; in other words, it has no power within
itself to create energy; and hence, if there is any external resistance, such as friction, its energy
will be constantly consumed in overcoming that resistance, and it will come to rest when its energy
is all expended. The energy of the machine will have passed into surrounding bodies. In the
present state of science, it is impossible to change a given amount of heat into an equivalent
amount of mechanical work, much being lost in the transformation. At every attempt to change
energy from one form to another, there appears to be a degradation of energy, that is, a production
of an energy of an inferior form- so called; or, more properly, there is apparently a dissipation of
energy. Reasoning in this way, many modern writers have predicted that ultimately the total energy
of the universe would become uniformly diffused throughout space in the form of heat, and the
universe thus become mechanically dead. But as we are unable at present to include all the elements
of the problem, and much less to trace their influence throughout the circuit of their action, the
basis of the argument is necessarily hypothetical. ()n the other hand, if we assume that the ul-
timate condition of the universe is that of perfect elasticity, it is certain that, if any amount of
visible energy is put into the universe, that amount must forever exist; and hence, according to this
hypothesis, the universe can never become mechanically dead. Energies work only as they are
transmitted from one condition to another; and to secure this transmission there must be a non-
equilibrium of energies. If there be an effort in nature to produce a state of universal equilibrium,
its effect is only to reduce that which was above the average to an energy equally below it, and that
which was below to that equally above, and so on; just as the waves of the sea at one point rise
first above the general level, and then below; or like the oscillations of the pendulum, first descend-
- ing to the lowest position, then rising to the same height as before on the opposite side, and so on.
life are not, however, able to realize the condition of peij'ect elasticity in physical experiments, and
hence this reasoning is also hypothetical.
POTENTIAL ENERGY implies a latent energy. To illustrate, if a stone rests on the top of a tower, it
has no energy; but in reference to some point below, it has the ability to do a certain amount of
work when its support is removed. Similarly, the steam simply inclosed in a boiler does no work;
but when a hole is made in the boiler, permitting the steam to escape, it rushes out and does work
in various ways, and, passing through an engine, may be made to do mechanical work. An elastic
rod held in a bent position does no work; but if the force which holds it be removed, it will, by
virtue of the motion which results, be capable of doing work. Potential energy has no absolute
unit; its value is determined only in reference to some fixed condition. Thus, in regard to the stone
on the tower, we say that, in reference to a point 10 feet below, its potential energy will be 10 times
the weight of the body; and if the point of reference be 20 feet below, it will be 20 times the
weight, and so on. If it actually falls 20 feet, the kinetic energy of the body will be 20 times the
weight, so that all of the potential energy will have been changed to kinetic. Similarly, in regard
to steam-pressure, if the point of reference be that of atmospheric pressure, the potential energy
will have one value; and if the reference be that of a perfect vacuum, it will have another value.
The point of reference having been fixed, we have this important principle : The sum of the potential
and kinetic energies remains constant. This is equivalent to saying that work which a force has done
added to that which it is capable of doing equals that which it was capable of doing at first. If the
stone on the tower be 100 feet from the ground, its potential energy will be 100 times its weight;
but if it fall 10 feet, the kinetic energy stored in the body will equal 10 times its weight, and the
potential energy in reference to the earth 90 times its weight, and therefore both together will be 100
times its weight; and so on for any amount of fall less than 100 feet. If the tower were 150 feet
high, the reasoning would be the same.
GENTRIFUGAL AND GENTRIPETAL Foucns.-- The centrifugal force, in reference to circular motion, is
defined as a force acting directly away from the centre, and centripetal force as one acting directly
toward the same centre. If a body is made to revolve in the arc of a circle, there must necessarily
- 506 DYNAMITE.

be a force applied to it at every point of its path to deflect it from a tangent to the path. If a string
be attached to the body and to a fixed point, the constant pull of the string will cause the body to
travel in the arc of a circle. The pull of the string represents the centripetal force acting toward
the centre of the circle. But if we examine the pin to which the string is attached at the centre
of the circle, it will be seen that the body is apparently pulling on this pin. This is the centrifugal
force, acting directly away from the centre. The two forces are equal and directly contrary in their
action. If the string be cut at any point and forces applied at each end where it is cut, producing
the same tension as before, it will be observed that these forces must be equal and opposite. The
force acting upon that part of the string attached to the body will pull toward the centre, and will
be centripetal; while the one acting on the piece attached to the pin at the centre will act directly
away from it, and will be the centrifugal force. Like the action of a force between bodies, where
the action is upon one body and the reaction directly contrary upon the other body; so here, the cen-
tripetal and centrifugal forces are an action between bodies, one of which acts upon the revolv-
ing body toward the centre, the other upon the central body away from the centre. They never
exist singly; one always accompanies the other. Both never act upon the same body at the same
time. When a boy swings his sling, he is conscious of a pull upon his hand; but it is no more cor-
rect to say that the revolving body pulls, than it is to say that his sled or wagon pulls on his hand
as he draws it; and it is just as proper to say one as the other. In both cases the body is inert, and
the active agent exists in the hand, or even further back if we desire to trace it. In the case of a
train of cars running around a curve, the rails on the curve force the train constantly toward the
centre, and force is developed between the rim of the wheels and the rail, which force acts equally
in contrary directions; that acting upon the wheels toward the centre is centripetal, and the other,
acting upon the rails, is centrifugal. By elevating the outer rail properly, gravity is made to take
the place of the centripetal force, and the resultant pressure may be directly upon the face of the rails.
In the solar system, the attraction of the sun upon any planet is the centripetal force upon that
planet, and the attraction of the planet upon the sun is the centrifugal force upon the sun due to
that planet. The centrifugal force upon the matter of the earth due to its rotation on its axis acts
against gravity at all places except at or near the poles, thereby making the matter on the equator
less heavy than it otherwise would be; and this causes the matter to be elevated at the equator and
depressed at the poles, giving to the earth a spheroidal form. Bodies on the equator now weigh less
than they otherwise would by about gig; of their present weight; and if the earth revolved in 117' of
its present time, or in say 1 hour and 25 minutes, they would weigh nothing. The centrifugal force
diminishes from the equator toward the poles nearly as the square of the sine of the latitude. The
form which the earth ought to assume for equilibrium, on the hypothesis that it was once in a fluid
state, or that its density varies according to an assumed law and subjected to known laws, has been
the subject of profound analysis by such mathematicians as Huygens, Newton, Laplace, Ivory, and
others; from which it appears that one of the theoretical forms agrees nearly with the actual form.
The forces on the surface of the earth are now in equilibrium, so that there is no more tendency for
bodies to move toward the equator on account of the centrifugal force than in any other direction.
All the planets are known to be spheroidal, their equatorial diameter being greater than their polar axis.
It is not correct, strictly speaking, to say, in reference to the revolving body, that the centrifugal
force tends to throw it away from the centre; for no such force acts upon the body. If the cen-
tripetal force be destroyed, the centrifugal force is destroyed at the same time; and the body, in
obedience to the first law, goes off on a tangent, and not radially outward. But the expression need
not be entirely condemned, for it is a popular and convenient term to express what appears to be
true; just as we say “the sun rises,” to express an appearance, whereas the sun in fact does not move.
Thus, the common expression, “ The centrifugal force caused the fiy-wheel to burst,” striet‘ly means
that the arms of the wheel were not sufficiently strong to compel the rim to move in a circle, and in
their effort to do it the arms were broken. But the cause of the breakage is as well understood
from the common expression as from a scientific explanation of it.
It is found that the centrifugal force varies directly as the square of the velocity and inversely as
the radius, and directly as the mass of the body; hence we have :
weight x (velocity) 9.
32%; x radius
Eramplcs.—-l. The arms of a fly-wheel will each sustain a pull of 45,000 lbs. ; the weight of the rim
between two arms is 1,000 lbs. ; the radius of the wheel is 4 feet; and the wheel makes 500 revolu-
tions per minute: will it burst on account of this velocity ‘? The velocity in feet per second will be
3% x 4 x 500
60
Centrifugal force :

: 101 feet; hence we have:
1000 x (101)2
W = 80,000 lbs. nearly,
which is nearly twice the strength of the arm ; hence it would burst.
2. Would it burst at 300 revolutions per minute? For this we find:
, 1000 x (6011;)2 _ ‘ ’
Centrifugal force z—W~Ll—~— _ 28,000 lbs. neaily,
which is a little more than one-half the strength of the arm, and hence it would not burst; but in
practice the arms should be 6 or 8 times as strong as the centrifugal force.
Worksfo'r reference on dynamics will be found classified under MECHANICS. DE V. W.
DYNAMITE. See EXPLOSIVES.
DYNAMO—ELECTRIC MACHINES. Apparatus for the production and collection of induced
currents of dynamic electricity; or, more strictly, for the transformation of mechanical work into
electricity. The term “ dynamo-electric machine,” while it may well include all apparatus based on
Centrifugal force :-
DYNAMOMETER. 507

the principle outlined below it is now more commonly applied to apparatus in which the field mag-
nets are electro-magnets, the term “ magneto-electric machine ” being applied to that type in which
permanent magnets form the field. The usual types of dynamo are the “ series ” form, in which the
field-magnet coils are in series circuit with the armature; the “ shunt " form, in which the field-mag-
net coils and the main circuit are in loops or multiple arc circuit with the armature; and the “ sep-
arately,” excited form, where the current from the brushes goes directly to the line, and the field-magnets
are excited from a smaller dynamo. Dynamos are also divided into those which give a direct and
those which give an alternating current. See .“ Modern Mechanism ” (vol. of this work).
DYNAMOMETER. A dynamometer, strictly speaking, is a device to measure force overcoming
resistance or producing motion. Ordinary scales and spring-balances become dynamometers when
used to measure the intensities of applied forces, instead of dead weights. But the name is usually
employed to designate apparatus for special purposes, embodying in its construction devices for in-
dicating or recording the distance the forces move through, as well as the intensities of the suc-
cessive forces exerted. If the force be measured in pounds, and the distance the force moves through
in feet, the work done in foot-pounds equals the product of the force by the distance. The unit of
power is one horse-power, equivalent to 33,000 foot-pounds per minute (or 550 foot-pounds per second,
1,980,000 per hour, etc); so the number of horse-powers developed in any given case equals the
number of foot-pounds of work performed per minute divided by 33,000. For instance, if a horse
pull a. load through a spring-balance showing an average tension of 150 lbs., the work done in mov-
ing the lead 220 feet would be 150 x 220 2: 33,000 foot-pounds; and if it were done in one minute,
there would have been developed what is conventionally termed one horse-power. To obtain the
power requires then three classes of apparatus: 1, the dynamometer proper, to measure the forces
exerted; 2, devices to measure and indicate or register the distance the forces act through—such
devices often forming part of the dynamometric apparatus; and 3, devices for ascertaining the time
in which the work is performed. Frequently the inspection of a timepiece in connection with the
readings of the instrument is considered sufficient for the purpose last named, though occasionally
elaborate velocimeters are embodied in the construction of the dynamometer.
Dynamometers may be divided into three classes, viz. : traction, thrust, and rotary. Traction
dynamometers are employed chiefly to ascertain the absolute and relative resistance of vehicles of
different kinds, when varied in the details of construction, or used under various conditions as to
the road, the grade, the loads imposed, the size of wheels, the lubrication, etc.
SPRING-BALANCES—An ordinary Spring-Balance is a simple spiral spring, to be extended by the
application of a load, the degree of extension being marked by an index on a scale attached to the
case of the instrument. In the larger instruments one or more smaller springs are put inside a larger
one. \Vhen it is desired to indicate the smaller fractional parts of a pound with instruments of











considerable capacity, the movement of the free end of ‘the spring is applied through a rack and
pinion to move an index on a dial, thereby obtaining a wider range for the smaller divisions, the
larger ones being marked on the slide.
A curved Spring-Balance, of a French type, is shown in Fig. 1143. The spring is flat and bent to
508 DYN AMOMETER.

the shape 0' KB. The upper branch passes through a draw-plate which carries the case of the instru‘
ment. The lower branch is attached to the lower draw-plate, which has at its lower end a hook to
receive the load, and is connected above to a rack engaging with a central pinion on an axis carrying
an external index-finger, operating in connection with a dial engraved on the case, as shown.
An open Steel-Ring Balance is shown in Fig. 1144. A dial is secured to the rear of the spring D,
and the index is traversed over it by connection of the two free ends A and O of the spring respec-
tively with the fulcrum and end of the index-lever.
5p1~ing-Balance and B}:rouvette.—The spring-balance illustrated in Fig. 1145 is formed of two steel
branches A 0,, U B, bent at an angle of 45° ; each of the arcs D p g E, J H G, is fixed to one of the
branches and traverses the other. By drawing the rings E G, which terminate the arcs, in opposite
directions, we bring the branch A 6' near B O ; a circular scale figured from 5 to 40 indicates the
respective positions of these two branches. The branch A C pushes before it a small cursor is of
card or leather, which slides easily on the metallic wire f 9, attached to the branch 0 B of the bal-
ance. To graduate the scale, suspend the balance by a ring E fixed to the branch A O, and attach
weights to the ring G, which is at the extremity of the scale. The numbers on the scale indicate the
tension of the spring. Regnier has made an excellent instrument of this spring-balance for trying
the strength of powder. The length of the branches A O and C B is about 4.8 inches, and their
1146.





breadth about an inch; a small brass cannon, whose breech H is on the branch 0' B of the balance,
and whose mouth I is closed by the fuse I L of the obturation D I L E fixed on the other branch
A O of the balance, contains a given weight of the powder to be tried ; it is primed by a little pow-
der put in the pan F; the powder within the cannon is fired and drives it away ; after the ignition
the two branches of the balance approach, and the cursor 7: indicates on the scale the tension of the
spring at the moment of the explosion. The iron D E, and the brass arc G H, on which the scale is
drawn, pass through openings p q, r s, made in the middle of the plates C B and C A.
Regm'er’s Dynamometer, represented in Fig. 1146, resembles a common graphometer, the principal
part of which instrument is a steel spring bent in the form of an ellipse; it should be properly tem-
pered and well welded, and covered with leather, to prevent injury to the hands when used. This
spring is represented by A A’, B B’, formed by two equal plates united at the ends by rounded half-
rings. The dimensions of this spring vary according to the tension required, or the weight to which
it is applied. The dynamometer used to ascertain human strength weighs little more than 2 lbs.,
and serves to measure a thousand times that weight; its total length is about 12 or 13 inches, its
greatest breadth, as measured in the middle of the two ares, is 2.2 inches, and the least breadth at
the extremity of these arcs is three-quarters of an inch. The thickness of the ares at their centres is
nearly 2 inches, and its height, which decreases from the centre toward its ends, from one-tenth to
four-tenths of an inch; the chords of the two ares are 6.4 inches. This length, added to that of the
' two demi-rings, gives for the total length of the dynamometer 12 or 13 inches. The distance between
the parallel chords is about three-quarters of an inch, and the perpendiculars of the arcs are each
seven-tenths of an inch, giving about 2.2 inches for the total distance between the centres of the arcs.
There are two methods of stretching the spring, viz., by pressing it in the direction of the perpen-
\
DYNAMOMETER. 509

dicular of the two arcs which form it, and by drawing it with the two rings at right angles to that
perpendicular. Separate scales are provided for the two modes of operation, ranging respectively
from zero to 264 lbs. avoirdupois, and from zero to one gross ton. They are engraved on a quadrant
attached to one limb of the spring, and the double-pointed index cl is operated by the other limb
through a connection a and bent lever b. The index is provided with a friction-washer at K, and
retains the maximum position to which it is carried, which is in general undesirable, as a dynamome
ter should show the average indications. There is, however, another scale on a covering plate (shown
detached), on which the averages may be estimated from the end of the bent lever 12. The capacity
of the machine may be doubled by placing it between the two ends of a cord passing over double
pulleys, as shown on the left.
In Moran’s Dynamomele'r, Fig. 1147, plate springs thickened at the centre and connected together
at the ends are used instead of the elliptical spring above illustrated, and apparatus applied to record
continuously the magnitude of the forces exerted. The operation will be understood from the
description of other apparatus embodying similar details difierently arranged.
Drnamomrrmc REGISTERING AND Ixrnenxnxe APPARATUS.—-If a drum carrying a band of paper be
put in motion by the vehicle or machine to which the dynamometer is applied, and connections he
made so that the straining of the springs will cause a proportional movement of a pencil along the
drum parallel with its axis, a diagram will be traced similar to that in Fig. 115. 9, in which the ver-
tical heights will represent the tensions at the various points, and the undulations show the changes
of propelling force or resistance which constantly occur in nearly all machinery, but is particularly
noticeable in drawing a common carriage. Registering or recording apparatus of this kind is gener-
ally provided with two pencils: one stationary, to mark the zero line of pressure, and a movable one
showing the intensities of the efforts. The average force exerted equals the mean height of the
diagram, which may be obtained in the manner explained for indicator diagrams. (See Ixmcxron.)
M. Morin has however pointed out a simpler method, which is to weigh the paper band on which the
diagram is taken and ascertain its surface, then to cut out the diagram and weigh it carefully, when
its area in relation to that of the original band may be ascertained by a simple proportion. The dis-
tance moved and the time are usually obtained by separate devices, but may be recorded by marks
on the band, as in speed indicators.
Integrating apparatus is designed to continually multiply the intensity of the effort by the distance
moved through, and thus show a record of the work done. The principle of operation may be under-
stood from Fig. 1148. A is an operating disk revolved by connection with the machine or vehicle to
be tested. B is the integrating disk, which is kept in contact with the disk A and is moved across its
face from the centre outward by a connection from the dynamometer springs. When the springs are
not strained, the integrating disk is at the centre of disk A, and receives no motion ; but when the
load is applied, the disk B is moved outward from the centre of A a distance proportioned to the
1148.






tension put upon the springs, and consequently by frictional con-
tact receives motion proportioncd to that of A and to the forces
exerted. A train of wheels with indices is employed to register the
revolutions of disk B, the indications of which show directly, or
when multiplied by a constant, the number of foot-pounds of work
performed; and by inspection of the same in connection with a
timepiece, the power may readily be obtained. When the appa-
ratus is permanently attached to a particular machine, the move-
ment of the indices may be regulated to show the horse-power ex-
erted, by taking the difi’erences of the readings for one minute or
one hour, as previously arranged. An equivalent arrangement is
shown in Fig. 1149, in which a cone A, revolved by the machine or vehicle, is also moved longi-
tudinally in contact with an integrating disk B by connection with the dynamometer springs.
Traction Dyna-mometer for Ordinary Vehicles.--Figs. 1150 to 1154 inclusive show the horse dyna-
mometer used by the Royal Agricultural Society at Bedford, England. The whole apparatus is mounted
upon a separate vehicle, as shown, to which a horse is hitched at one end and the vehicle to be tested
behind, with the shafts extended either side of the machine and connected by chains E F to either
side of a yoke G, carried upon casters and pivoted at E to the draw-bar ll", which is connected to a
pair of plate springs A A. The draw-bar W also connects with a piston D in a cylinder filled with.
fluid, the displacement of which from one end to the other can be regulated by a cock in the upper


510 DYNAMOMETER.

port shown, and thereby the indicating and registering apparatus be relieved of the sudden move-
ments and continual vibrations incident to rapid variations in force and resistance, without affecting
the average results. The movement of the springs is multiplied by a lever H, which gives motion






























1150.
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to a slide carrying an integrating disk K and aregister, also an index on a scale 11! at the left, and
a pencil for operating on a paper-drum N. The integrating disk K receives motion from an oper-
ating disk L, which in turn is revolved by connection with the hind axle. From the same train of
gearing the paper-drum N is operated. To determine the weight ordinarily carried upon the shoul-
1151.




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ders of a horse, the shafts are suspended from a yoke P, which is supported at one end of a lever
Q, having at the other end the spring-balance R. The results are however modified by the vertical
component of the tension on the yoke G. Springs of different resistances are provided for the
apparatus, and provision is made to test the same in place by means of the bell-crank lever B
1152. 1158.












and weights I. Experiments made with this apparatus in the year 1874 (see Engineering, xviii., 33)
show that ordinary wagons without springs constructed by diiferent makers, with some differences
in width of tires and inclination of wheels, required with one exception but 44 to 51 lbs. draught
per ton of gross load carried on a road at a speed of about 2% miles per hour. One wagon with
'
DYNAMOMETER. ' 511

springs required but 33 lbs. draught per ton, showing a saving of 25 per cent. compared with a simi~
lar wagon without springs. The spring wagon showed no advantage in a field, where the draught of
the various wagons varied from 188 to 229 lbs. per ton; the diifercnces in this case being chiefly
due to the widths of the tires, which varied from 2% to 4 inches, the latter of course sinking less into
the soft ground. Two carts required 30 to 36 lbs. draught per ton of gross load hauled on the road
at a speed of 2% miles per hour, and 140 to 143 lbs. per ton when on the field; the width of tires
being 3% and 4 inches.
A dynamometer car, employed by MAI. Vuillemin, Guebhard, and Dieudonné on railroads in
France, contained very complete apparatus for measuring the resistance of railway rolling-stock
under various conditions. A plan view of the springs employed is shown in Fig. 1155. It is com~
posed of 14 bars of the shape shown, each 40.94 inches long and 2.08 inches wide, seven of which
are connected at their centres to each of the draw-bars A and B, and the ends of the springs are
connected by pins in plates (7 as shown. The bars D D carry checks at the ends to limit the ex-
treme movement of springs. By removing the pins from the two ends of plates 0 at the same time,
the number of springs in action may be reduced. Separate scales are provided for each of the
groups thus formed. The tables accompanying a report of the trials of this instrument show that
it recorded tractions of upward of 18,700 lbs.
Dudley’s Dyvwgraph is an apparatus for the same purpose as the above, but with different details,
which has been used on railroads in the United States.
Duckham’s Hydrostatic Weighing Machine and Dlqnanwmeterw—Fig. 1156 represents a front view
and Fig. 1157 a transverse section of the machine. From the latter it will be seen that the machine
1155.


consists of a cylinder and piston, the latter kept tight with leather packing both in the piston itself
and on the piston-rod. Attached to this cylinder is an ordinary metal gauge, which shows the pres-
sure to which the fluid in the cylinder is subjected by the weight suspended from the piston-rod. It
of course does not matter if there should be a slight leakage about the piston or rod, because as
soon as the weight is suspended from the rod the leather packing becomes tight, and produces the
same pressure on the fluid (caster-oil is generally used) in the cylinder as though no leakage had
taken place. A peculiar merit of this apparatus is its lightness. A machine of 84 lbs. weight is
capable of weighing 10 tons; and as soon as merchandise or other bodies are raised and suspended
from it, the weight of the same is indicated on the dial. The machine can be used for weighing all
kinds of goods, and affords a very convenient testing machine for bar-iron, wire, chains, cordage,
etc. It can also be used as a dynamometer to ascertain the resistance of trains or vessels.
A displacement dynamometer has been suggested, in which the forces are to act to push a parallel
plunger into a fluid, on the general principle of the Stiles steam-gauge.
Dynamometer for illeasuring the Newest of a Serew-Shafl.—This instrument, 1158, is merely
( O
512 ' ' DYNAMOMETER.


a lever, or a combination of levers, with the shaft pressing near the fulcrum, and the farther end of
the lever, or combination, attached to a spring-balance. A B is the screw-shaft, pressing as it re-
volves against a movable pin, which presses against a knife-edge on the lever D E. The rod E F is
connected with the spring-balance, which cannot be seen in the figure, being concealed by the cylin-
drical barrel G H. A slide attached to the rod E F has several grooves in it, so that the pencil 10
may be brought into contact with more than one part of the barrel if desired. The barrel is made
to revolve by means of a belt a 1), connecting it with the screw-shaft; and there are pulleys of
different sizes connected with the bulkhead at M and the shaft at N, by which the motion of the
cylinder can be regulated, and be made quicker or slower at pleasure.
When the engines are directly connected to the propeller, the thrust-bearing is made free to move
longitudinally, and the levers are connected to it. A hydraulic regulating cylinder should be con-
nected to the levers, to reduce the amplitude of the vibration of the spring. A diagram from a
thrust dynamometer is shown in Fig. 1159. The mean ordinate may be obtained by either of the
methods mentioned in treating of indicators. The diagram shown was taken in connection with two
others, and the mean pressure of the three was found to be 41.309 lbs., which was multiplied by a
system of levers so that the actual thrust was 8,086.4 lbs. The speed of the ship was 9.893 knots
per hour, equal to (9.893 x 6,080 + 60 :) 1,002.49 feet per minute; so the work per minute was
(10,0249 x 8,086.4 :) 8,106,535 foot-pounds, showing a development of (8,106,585 -:- 33,000 =) 245.65
effective horse-powers. The indicated horse-power at the same time was 465.6; so the efficiency of
the propelling machinery was (245.65 -:- 465.6 2) 52.76 per cent., and (100 — 52.76 =) 47.24 per
cent. was absorbed in resistances of various kinds, including the friction of the engine and shafting,
the slip of the screw (represented by the water propelled aft), and the fluid resistance on the screw-
bladcs. The efficiency is higher than has been obtained in many other cases, though the writer in
a series of trials of the machinery of the U. S. Coast Survey steamer Blake found that the efficiency
averaged as high as 56.22 per cent. The vessel had compound engines, and the screw, which was
entirely submerged, had a fine pitch, and was of large diameter for the size of vessel.
A hydrostatic thrust dynamometer is made by running the screw-shaft through a cylinder and
piston, so that the thrust will be borne by the piston, and the stress is computed from the reading
of a gauge, as in the Duckham machine shown in Fig. 1156.
ROTARY DYNAMOMETERS are of two kinds, absorbing and transmitting. In the former the power is
1160.







absorbed in friction during the act of measurement; in the latter it is simply transmitted through
the instrument.
Prom/s Fraction-Brake is the basis of all absorbing dynamometers. The apparatus consists essen_
tially of a clamp tightened upon a revolving pulley and tending to revolve therewith, but held in
position by weights or springs representing the intensity of the effort. A simple form, consisting of
a pair of wooden clamps tightened by bolts and connected through a lever to a spring-balance, is
shown in Fig. 1160. Often, however, iron straps faced with wood are used, and held in position by
weights, springs, or both, connected directly to the strap or an attached lever. When the clamps are
tightened so that the weight is lifted, the surface of the pulley, moving with a known velocity, is
regularly overcoming a resistance measured by the weight and strain on the springs, increased by the
leverage if any ; and the distance moved by the surface multiplied by such increased force represents
the work done. The result would be the same if the radius of the pulley were increased to the
point of application of the weight, and the work calculated from the actual revolutions and weights
imposed. If N: revolutions of shaft per minute, R :: the distance from the centre of shaft to a
vertical line passing through the point of suspension of the weights, W: weights imposed, including
strain on spring if used, and .P : the horse-power developed ; then
3.1416 X 2RNIV
P : -———~33000-———-— _ .0001904 R N W7.
To prevent extreme oscillations, a regulating piston in a cylinder filled with fluid is generally con-
nected with some part of the lever; and it is usually necessary to apply water continuously to the
surface of the pulley to absorb the heat developed by the friction.
A Turbine Idiot/ion Dynamometer is shown in Fig. 1161, which is applicable for use on any vertical
shaft. It is an ordinary Prony brake in a horizontal position, acting upon the weights through a
bell-crank. The regulating cylinder is shown applied to the end of the bell-crank lever opposite the
weights. Pipes are also shown to conduct water to the surface of the pulley, the necessity of which
is explained above. -
Froude’s .Dymmzomete'r is one of the absorbing type, designed for the use of the British Admiralty,
to be applied directly to the shaft of a screw-steamer in place of the screw, as shown in Fig. 1162.
DYNAMOMETER. 513

It consists of a disk-wheel resembling that of a turbine, with' a large circumferential‘groove on
either side opposite similar grooves in the casing. The grooves in both the wheel and easing contain
curved inclined buckets, which act when the apparatus is immersed to throw water forcibly back and
forth from the wheel and casing. The resistance produced tends to revolve the case, which is re-
'-
.. llllllllll l


sisted by lever-arms G G, connected at their ends through a rod H with springs and recording ap-
paratus on the wharf. Gates located in the projection on the side of the case are operated by
gear connected with the inclined rods shown, to close off part of the area between the cavities in the
wheel and case, and thus reduce the resistance as desired within large limits.
In using the ordinary friction-brakes, it is necessary to constantly adjust the screws tightening the
clamps so as to lift the weights clear without striking a stop in the opposite direction. To avoid this,
several brakes have been designed, in which the friction is regulated automatically. The simplest plan
of doingthis is shown in Fig. 1163, but is applicable only when the power to be controlled is small.
A strap placed over a pulley is secured at one end to a spring-balance c, and loaded at the other
with a weight b. The pulley turning in the direction of the arrow lifts the weight and reduces the
tension on the spring-balance until the wheel turns in the band, when the force to be measured is
shown by the difference between the weight b and the reading of the spring-balance c.
The Appold Brake, shown in Fig. 1164, consists of a strap lined with wood, with its ends secured
to a lever a f at the positions shown, the upper end of the lever at a being held stationary. The
action of the weight at Wis to carry the bottom of the lever to the right and tighten the strap. The
motion of the pulley in the direction of the arrow lifts the weight W, and carries the strap around
until it becomes sulficiently loose to permit the pulley to turn on the brake. For instance, if con-
nections to weight are properly arranged, the point of suspension :1: may move to 6, when f would
1162.
ti 1163.


l=




1°”. is" , {v , .l... l
move to d. The length of the band may be adjusted by the screw 3]. This brake is perfectly self-
adjusting, but its accuracy has been questioned on account of the neglect of the strain at the upper
end a of the lever, and the difierence in friction arising from necessary differences in tension on the
two parts of the band, caused by the lever connection. To obviate this difficulty, Mr. W. Balk has
designed a dynamometer in which a tightening-lever is placed horizontally opposite the connection to
weights, and the end provided with a pan to receive small weights, which are varied as necessary to
adjust the friction.
33
514 DYN AMQMETER.

A Friction Dlz/namomez‘cr designed by Mr. C. E. Emery of New York is shown in Fig. 1165. One
end of a frict_on-band is connected at the point 0 with the weight W and one end of a lever L. The
lever receives at an intermediate point I) a connection from the other end of the band, and is sup-
ported at the outer end a by a spring balance 8 or one end of a lever ll]. First, supposing the lever M
omitted, the weight W will tend to depress the lever L and strain the spring 8 (a stop shown being
provided to prevent overstrain). When, however, the pulley revolves in the direction 01’ the arrow,
the weight and lever will rise until the tension is reduced, so that the pulley slips in the band.
Putting II : the force required to balance the load on the line from c to W, W: the weight (includ-
ing of course the permanent weight or preponderance), and a, b, and c the forces at the points a, b,
and c due to the action of the spring-balance S ; then the downward forces acting on the band :-
W + c, and the upward force : b. llence F: W + c -- I). But I) = a + 0; hence F: W+ c -
(a +0) : W— a. Therefore the force required to balance the load equals the weight less the ten-
1165.








sion on the spring-balance. The force represented by the latter may be subtracted automatically by
adding another lever below L, provided with a central fulcrum on the bed-plate, and connected at
the ends to the ends of the lever L ; in which case the spring-balance would be omitted. The extra
lever and connections, or a pulley and cord, may however be located above the lever L, as shown in
dotted lines, and the balance either be retained or omitted as desired. During a preliminary run,
\ 1166.
\


l...
/ r


the screw .7) in the frietirn-band should be adjusted to bring the lever L nearly horizontal, when the
action of the apparatus will be absolutely automatic.
A Zi'ansmz'tting Dyncrmomclcr invented by Mr. S. Brown of Lowell is shown in Fi . 1166. The
power is transmitted from a spur-gear O to another, E, through an intermediate gear , the axis of
which hangs in a stirrup supported by a steelyard F, the short arm of which is extended and con-
nected to a regulating piston in the cylinder G, as shown. The force transmitted at the pitch-lines
of the gears is the same on either side of the centre of pulley D, so that the strain communicated
from the latter to the short arm of the steelyard is double that transmitted at the pitch—lines.
The Bevel-gear Transmitting Dynamomctcr shown in Figs. 1167 and 1168 operates upon the same
general principle as that previously described. The power is applied to a bevel-wheel .D, and is trans-
mitted to another similar wheel F through bevel-gears E E, provided with bearings on a lever J
turning on the shaft at G. The stress transmitted to the centres of the transmitting wheels E E is
double that at the pitch-line, as in previous cases. As shown in Fig. 1167, the lever is bent from a
DYNAMOMETER 5m



radial line to pass by the gears, and carries at the end opposite the scale a counterbalance weight .M.
On both sides of the machine are fast and loose pulleys. The fast pulley on the driving sideA







1167 1168.
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operates the bevel-gear D, and the corresponding gear F on the opposite side operates the fast
pulley B. By disconnecting a line shaft at the coupling and running a belt from pulleys on either


side to the pulleys A and B, the power transmitted may be measured; and the motion of the two
parts of the main shaft will be in opposite directions if both connecting belts are straight, but in
the same direction if one of them is crossed.
516 EARTHWORK CUTTING.

In an improvement by Mr. J. B Francis of Lowell, the motion on the side Bof the machine is
reversed by gearing to a second shaft, carrying a pulley from which a straight belt may be run to
the main shaft without reversing the direction of its motion. There are also other improvements in
details. The beam is balanced without the use of a movable weight 111, and to this end a regulating
piston is attached, as in Brown’s machine. A register is operated by an endless screw on the extra
shaft, and a bell strikes at every 50th revolution. The beam J is so graduated that the weight
raised 1 foot high per second is obtained directly, by dividing the weight as shown on the beam by
the number of seconds occupied by the shaft in making 50 revolutions. The friction of the machine
was ascertained by the use of Prony’s friction-brake placed on the extra pulley.
A German Transmitting Dynamomcter is shown in Fig. 1169. The power is transmitted from a
wheel D with internal gear to a central spur gear-wheel E, through opposite transmitting gear-wheels
If 11’ attached to arms on a sleeve carrying a pulley L, which through a band Z strains the dyna-
mometer springs F F.
Ncer’s Rotary Transmitting Dynamometcr is shown in F ig. 1170. The main shaft is disconnected
at a coupling, on either side of which are secured the disks A and B. l~rom the circumference of
the disk A, which is the driving
side, chains are carried around
the pulleys I) on the disk B,
which chains tend to move a disk
_' I y W v I, _1 f3}, . 6' parallel with the shaft, and
p. , 33ml? compress the sprines shown be-
.' _"'"l"‘_"i_"_“_i‘_‘lf-r:‘(‘u(gRE" ' , ,_ . tween disks C’ andDB. The ex-
lllll/llt-,, . ~ ' - - I] ' g . : tent of this movement showing
Wit ' " T ' ' - the transmitted stress is, by a.
fork in a slot on the hub of the
disk 0, transferred through a
cord to a pulley on a shaft car-
rying an index which shows the
stress on a dial E. This part of
the apparatus is supported in a
groove on a separate revolving
boss, and part of the circumfer-
ence of the latter is provided
with an endless screw operating
another index on a dial F, to
show the revolutions. The dial
frame is prevented from revolving by a cord attached to the lower arm shown. All the disks are
made in halves, and the disks A and B are recessed to go over the coupling \\ hen desired, so that
the apparatus may be applied in a very short time. The acting distance of the transmitted force is
from the centre of the shaft to the centre of the chains.
In Sultan’s Dynamometer lugs on the side of a driving disk operate upon spiral springs placed
against similar lugs on a driven disk. The acting distance of the springs is slightly varied at dif-
ferent compressions, but the error is scarcely appreciable when the disks are large, and may in any
case be corrected on the scale.
In Emm'son’s Dg/namomcter the revolving stresses are transferred to longitudinal ones by a system
of levers, and the latter measured by a bent-lever balance. 0. E. E.
1170.


EARTHWORK CUTTING. See Excavarme MACHINERY.
ELECTRIC BELLS. Bells or gongs struck by hammers vibrated by an electro-magnet placed in an
electric circuit. The apparatus and accessories consist of the bell, the push-button or circuit-closer,
the conducting wire, and» the battery. The battery may be composed of any of the constant elements
described under ELECTRO-GALVANIC Bananas. For household purposes the Leclanché cell will be
found excellently well suited, the number of elements used being regulated by the extent and conse-
quent resistance of the circuit. The button or circuit-closer consists of two metallic strips p and 9,
Fig. 1171, placed one above the other. In its normal state the upper strip is separated from the
lower one by a spring. To the strips p and g the conducting wires a and c are secured, and as the
strips are separated the circuit remains open. It is closed when desired by pressing the knob 12'.
The button is inclosed in a wooden or rubber case. Fig. 1172 is a convenient device for combining
a number of keys within a small compass. Eight push-buttons, corresponding to as many distinct
circuits, are arranged at equal distances around a cylindrical case, within which the connections be-
tween the metallic strips and wires are made. Each wire is separately insulated by a silk covering,
and all are made into a single strand as they leave the case.
The ordinary form of bell used for giving single taps is shown in Fig. 1173. It consists of an
electro-magnet M M', opposite the poles n s of which is placed the armature with its clapper k. The
latter in its normal position is held back from the bell G by a spiral spring attached to the movable
upright d, which serves to regulate its tension. The stroke of the armature is limited by the set-
screw 0*.
By a slight modification of the connections in the bell instrument, the apparatus can be used both
as a vibrator and as an instrument to give single taps. The general plan is shown in Fig. 1174, in
which Ill and e are the electro-rnagnet and armature. S is a switch which can be turned on B or E
at pleasure. When it is on E, the apparatus becomes a vibrating instrument; when turned on B,
there is no interruption of the current with the attraction of the armature, and the instrument
simply responds by single taps to each closing of the circuit by the push-button. The path of the
ELECTRIC BELLS. 517
r
1 172.


current, when the switch is on B and E respectively, is sufficiently evident from the figure withou
further description.
When it is desirable to produce a very loud sound, the double bells and double electro-magnets
1175.
y
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are usually employed in the vibrating apparatus. In general, the principle of all vibrating bells is
that of the self-acting make and break; but, when the contacts are rigid points, the vibrations of
518 ELECTRIC CLOCK.

a
the armature take place only within narrow limits, and the arrangement cannot very well be utilized
for ringing a bell. Siemens has devised a plan, in his dial instruments, which answers the purpose
much better, by giving the armature a greater range of movement; but the adaptation of this device
to the ringing of bells for simple calls is a little troublesome, and in fact, for general use, would be
altogether too“ complicated. By far the most preferable way of obtaining the desired range of stroke
is that already described, in which a spring of some kind forms part of the path for the current,
and which, with the attraction of the armature, follows the latter for such a distance as may be
required.
When one battery is to serve for operating several of the bells above described, the vibrators can
not all be placed in one circuit, as each one interrupts the circuit independently of the others; and
it is impossible, or rather impracticable, to make the armatures of the various instruments so that
they will all vibrate in exactly the same time, or always be in unison. The plan generally adopted
for such cases is shown in Fig. 1175, where each bell, I, II, III, has a separate conducting wire of
its own, as represented by the numerals 1, 2, 3, and a return wire, LL, serves for all. If, now, one
of the bells is operated by the pressure of a push-button in 1, 2, or 3, as the case may be, it acts
without in any way interfering with the others, as they are all quite independent of the circuit thus
interrupted.
The fault just noticed in connection with the vibrating armature, causing a break at each vibra-
tion, may be remedied in a very easy manner simply by causing the armature to cut its own magnet
out of circuit after each attraction. The principle works very satisfactorily, and will be readily
understood by reference to Fig. 1176. m m are the coils of the electro-magnet; a, the armature, to
which the clapper It is attached by means of a rather stiff spring; and f, an elastic steel spring, which
readily follows the to-and-fro movement of the armature fora short distance. As will be seen, a
' current arriving at 0 passes through the wire 1, coils m m, and wire 2, to the line L; the armature
is thus attracted to the spring f. The forward movement of the armature brings the spring 7" against
a contact 0, and forms the shunt quite independent of the armature. As the resistance of this route
is exceedingly small compared to that of the helices, almost the entire current passes by the new
path, and the cores become demagnetized. The rctractile force of the spring now preponderates,
and the armature falls against the back stop, breaking the shunt circuit on its way. As this arrange-
ment does not break the main circuit, any desired number can be placed in the same line and
worked without interfering with each other.
When the bell system is to be used for long distances, or when a very loud ringing is desired, for
which purpose the main line current, as a rule, is not sufficient, a relay and local battery are gener-
ally used; and with the heaviest apparatus, requiring still more power, the ringing is done by means
of weights. Fig. 1177 represents an arrangement devised by Aubine, in which a single set of elec-
tro-magnets, .111 11!, serve both for the relay and the call. A small projection on the upper end of the
armature a, when the latter is in its normal position, supports the lever 3, keeping it from making
contact with spring 4, and at the same time holding it firmly against spring 2. When new a current
is sent into the line, it passes along the connection 1 to spring 2, thence to lever 3 and its connecting
wire to spring f and armature a, and from there on through the coils to earth. This causes an
attraction of the armature; lever 3 falls down on spring 4- and closes the local circuit, which again
results in a magnetization of the core. The armature is thus made to vibrate in the manner already
described, and a violent ringing is set up, which continues until, by pressure on the knob b, lever 3
is again raised and supported by the armature projection. (See “The Speaking Telephone, Talking
Phonograph, and other Novelties,” Prescott, New York, 1879, from which the foregoing is abridged.)
ELECTRIC CLOCK. See WATCHES AND CLoCKs.
ELECTRIC ENGRAVIN G MACHINE. A machine for engraving the cylinders of copper or brass
employed in printing woven fabrics and paper hangings. (See CALICO-PRINTING.) The current is
used to determine, by means of electro-magnets, the slight simultaneous advance or withdrawal of
any number of engraving diamond-points from the varnished surface of the copper rollers to be
engraved, according to the position of a corresponding metal contact-point on the non-conducting
surface of a prepared pattern. The pattern and cylinder to be engraved are moved mechanically in
concert, and the proportion of their relative movements can be varied by mechanical adjustment.
The engraving points have a slight vibrating action given to them, which scratches ofi the varnish
whenever brought into contact with it, and produces a series of fine zigzag lines, which facilitate the
retention of the pasty coloring matter used. The prepared pattern determines the moments at which
this contact occurs ; and the concert between the movements of the pattern and the roller produces
a similar agreement between the pattern and the figures engraved, which may clearly be made larger
or smaller than the pattern in any desired proportion and in any required number. The copper when
exposed is afterward etched by an acid bath.
ELECTRIC FUSE. See BLASTING, and FUSES.
ELECTRIC GAS—LIGHTER. Numerous devices have been invented for the ignition and regula-
tion of street gas-lamps by electricity, the current not only lighting the gas, but, by means of an
electro-magnet, turning on or ofi the supply. One of the most successful contrivanccs for this pur-
pose is that devised by Mr. St. George L. Fox of London, and represented in Fig. 1178. The socket
F is screwed on to the top of the gas-pipe, and the frame H is made hollow, for the purpose of allow-
ing the gas to flow up to the nipple at the summit. The gas is turned on or off by means of a valve
or stop-cock, the lover of which is seen caught by one of the studs A. The two studs AA are
borne on the upper part of the permanent horseshoe magnet C, the latter being supported on the
point of a fine pivot working in a cross-piece in the frame H. This permanent magnet is capable of
a reciprocating horizontal movement; and supposing its position in the drawing to be reversed, the
other stud A would carry the pin or lever back through a short space. This shifting of the lever
one way or the other serves to turn the gas either on or off, as may be desired. The movement of
ELECTRIC GAS-LIGHTER. 519

the magnet is efl’ected by a change in the polarity of an electro-magnet consisting of a soft-iron core
in a coil at B. According as the current is sent forward or backward through the coil, so the polar-
ity of the core is altered, and the permanent magnet is turned on its pivot. The electric current
which turns the gas on or off is obtained from the magneto-electric machine
at the station, and is conveyed by the wire D D, which wire connects all the 1178-
lamps. Supposing the current to be sent in such a direction as to turn the '
gas on; the next operation consists in transmitting along the wire D D a
powerful discharge obtained from a condenser raised to an electromotive
force of several thousand volts or units by means of a Ruhmkorfi coil.
Around the primary coil at .B is wound a secondary coil of fine wire, and of
much greater length. The discharge from the condenser has the effect of
producing a secondary current along the wire E E, thereby developing a
small spark just over the burner. The discharge which passes through the
primary wire has the same effect simultaneously on the secondary wire in all
the lamps of the circuit, so that, the gas being previously turned on in the
manner described, the whole of the lamps are lit. If the first and last lamp
in each circuit be in sight of the station, the continuity of the circuit will
be proved by the lighting of these two lamps. When it is required that
the lamps shall be extinguished, a reverse current through the primary wire
will cause the permanent magnet to turn on its pivot and strike the lever of
the stop-cock, so as to turn off the gas. The stop-cock consists of a brass
tube forming a vertical socket, and fitting into the cylindrical part above
the horseshoe magnet. The socket thus formed has a small aperture on
one side, opening into the hollow of the frame H: The plug of the cock is
made with a very slight downward taper, and is hollowed out in the middle.
At the side of the plug is an aperture corresponding to that in the socket.
\Vhen the aperture of the plug is thus brought opposite the aperture in the
socket, the gas flows up toward the burner; and, in like manner, when the
plug is so turned as to remove its aperture from coincidence with that of
the socket, the gas is intercepted, and the supply turned off.
There are two other and more modern types of apparatus of this descrip-
tion. The first combines the stop-cock and the lighting apparatus, so that
the opening of the stop-cock causes the production of a spark at the burner-tip and the simultaneous
ignition of the gas. The second burner is known as “ automatic,” and is usually so constructed that
the gas may be turned on and lighted, and also turned out when desired, by the simple pressure 01'
a button from any distant point. A still older class of electric gas-lighters is now in common use in
theatresand other public halls which use the ordinary fixed electrodes at the burner-tips; these elec-
trodes being connected in circuit, so that when the current passes, the spark leaps across from one
burner to the other, thus lighting the gas, which is turned on from some central station.
An example of the ordinary hand-lighter is given in Fig. 117 9. Here there is a '2-armed lever
pivoted on the burner and arranged with a suitable retracting spring. One of the arms is a piece of
spring-wire having a protruding end. The cord or chain for working the device is attached to the
other arm. Near the top of the burner there is a ring, which is insulated from the body of the de-
vice by a sleeve of asbestos. A projection extends from this ring to just above the top of the
burner. The spring-arm on the moving-lever, and the fixed ring secured on the burner, are con-


1179.


nected with the battery. When the lever-arm is pulled down, the projecting end of the spring
thereon comes in contact with the fixed electrode near the burner-tip, wipes over the same, and on
separating produces a spark which ignites the gas. Fig. 1180 is an example of the thumb-cock
burner, in which the lighting device is connected to the valve by which the gas is turned on. By
the opening movement of the gascock the vibrating arm of this elastic contact-point is forced
against and past the fixed electrode, tripped, and then returned by means of the retractal spring,
leaving the gas turned on and lighted. A quarter turn of the thumb-cock backward extinguishes
the gas. Instead of using the thumb-cock, other forms of burner operate the valve by means of a
ratchet-wheel and pawl, as shown in Fig. 1181, the pawl engaging with the ratchet, and the chain
connected when the short arm of the vibrating lever is drauqi downward.
520 ' ELECTRIC LAMPS.

There are numerous forms of automatic burners, all substantially alike in general principle. The
current goes to an electromagnet, which causes a vibration of its armature, thus moving an electrode
near the burner-tip into and out of contact with the fixed electrode, and so producing a succession of
sparks whereby the gas is ignited. The armature is also usuallyr connected to a stop-cock, which it
1182.


rotates, and so turns on the gas. The construction is generally such that a second current sent to
the apparatus, setting the magnet once more in operation, causes the stop-cock to be turned still
farther, and the supply of gas thus shut ofi.
Fig. 1182 shows a burner of this type, in which the armature is pivoted above the magnet, and
the movable electrode is moved vertically thereby. The construction here is such that the current
passes through only one coil of the magnet at a time, but energizes both poles. One coil operates to
light the gas, and the other to extinguish it.
ELECTRIC LAMPS. Aac-Lamrs.-—These lamps differ chiefly in the mechanical devices for caus-
ing the feeding of the carbons. The most complete classification which has been made of them is
that prepared by Professor S. P. Thompson, and embodied in a lecture delivered by him before the
Society of Arts, London, in 1889. It is, however, pointed out that an accurate classification is diffi-
cult. Thus in a very large class of lamps there is a train of wheel-work, usually driven by the weight
of the descending carbon-rods, the last'member of the train being controlled, through a detent or
brake, by the electro-magnet that is responsible for the feeding of the lamp. Most, but not all, of
these lamps have a rack upon the upper carbon-rod to drive the train. But the rack-lamps differ
greatly among themselves. Again, there is another class of lamps in which the upper carbon-rod
is smooth, but is assisted and controlled in its descent by a clutch or clamp, the clutch or clamp
being in turn controlled by the feeding electro-magnet. But there are also rack-lamps in which a
clutch or clamp is applied, not to the rod itself, but to a wheel driven by the descending rack. There
are, however, certain main features of classification about which there need be no ambiguity.
Professor Thompson’s classification of the feed-motions is as follows :
I. Rae/t and Train controlled by a, star wheel and detent; b, fly and detent; c, brake-wheel and
brake; cl, escapement with pendulum or balance and detent; e, escapement and paddle ; f, governor
with detent or moderator; g, magnetic brake-wheel or detent; and h, liquid brake.
II. Clutch or Clamp on Rod.—a, Tilting ring, tilting eyelet, etc. ; b, split cone gripped by fork; 0, split
nozzle forced into cone mouth-piece; (l, split tube held together by oblique levers; e, gripping springs
at side; f, gripping fingers; g, washer jambed by ball-bearing; h, tilting clamp or nipping clamp;
j, nipping lever ; lc, scissors lever; l, spiral spring surrounding rod; and m, forward-pointing springs
(lobster trap).
III. Clutch- Wheel or Brakc- Wheel—a, Nipping lever outside brake-wheel ; b, nipping lever inside rim
of Wheel; 0, elastic-band brake; (l, elastic internal ring brake; e, wheel lifted against brake or de-
tent; f, brake-wheel lifted upon brake-lever; and g, friction-pad or rim of wheel.
IV. ScrewJVIotion.—-a, Screw worked by weight of upper rod; b, screw worked by motor; 0, screw
worked by step-feed ; and d, screw worked by vibrated wheel. '
V. 00711 and Pulley illolion.——a, Cord and pulley to core of solenoid; b, cord and pulley connecting
carbons, with long-travel solenoid; c, cord gripped by controlling cam; and d, cord and pulley for
difierential feed.
VI. Step-by-Sfcp Jl/[oz‘iona—a, Step dedent worked by electro-magnet.
VII. Magnetic Clamps and Clutches—ca, Tilting magnet clutch on red; and b, magnetic clamp on
brake-wheel.
VHI. Electric .Motor Action—ct, Motor screws carbon up or down; b, winds up with cord or rack;
c, motor itself controlled by shunt magnet; and d, motor with copper damper.
IX. Hydrostatic and Pneumatic Action—a, Carbons controlled by admission of liquid or gas.
X. Vibrating Fcccls.——a, Make-and-brake lever vibrate forward-pointing springs; b, make-and-brake
lever actuates escapement; c, make-and-brake lever actuates detent on train; d, make-and-brake lever
hammers rod through clutch ; c, make-and-brake lever works internal clutch wheel-feed; and f, make-
and-brake lever drives pallet and screW-feed.
XI. Periodic Fcecls.—a, Periodic drop of upper carbon and lift through definite range; and b, pe-
riodic currents to magnet sent through second wire.
ELECTRIC LAMPS. 521

XII. Continuous Feeds—a, Clockwork step-feed, length of stroke varied by magnet; b, pendulum
or governor, having rate varied by magnet; and c, rack-train controlled by magnetic retardation on
co er wheel.
Iiiin. Hammering Feeds.-—a, Rod driven through clutch by vibrating hammer; b, ditto, by tilting
lever; and c, ditto, by magnetic piledriver on rod.
In the accompanying engravings a variety of the modern forms of feeding mechanism is presented.
Fig. 1183 represents the Brockie-Pell lamp which has a seesaw lever F carrying the carbon G.
To this lever are connected the cores A B of the magnets E1 and E2, which are respectively series and
1184.
1183.



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shunt wound. Another form of seesaw lamp is the Kennedy lamp, shown in Fig. 1184. Here the
lever F is replaced by a pulley over which passes a cord. The shunt solenoid S has a plunger-core
P2. The series solenoid 111 has a plunger-core P1, and also an external iron mantle to increase its
power. The smaller pulley communicates'motion by the cord d to a clutch R, which is provided
with an adjusting-screw H This clutch connects with the carbon-rod C by a slender spring s. This
lamp may be used either as a constant potential or a constant-current lamp. In the former case the
shunt-coil holds up its end while the seesaw is operated by the variations of the current in the series-
coil. In the latter case the actions are the inverse of this.
Much ingenuity has been expended in devising the forms of clutches which constitute the character-
istic features of many lamps. The Slater & Watson clutch (Fig. 1185) has two rings which are tilted
by the attraction of an electro-magnet to grip and raise the carbon-rod. In the Slater &. 'Watson split
cone clutch (Fig. 1186) there is a split conical washer R, the halves of which are hinged together and
are compressed by the rishig of the fork F, so that the rod 0 is thus lifted. Fig. 1187 is known as
1186. 1187.











Lever’s modification of the tilting-ring used in the Brush lamps. The ring R, as it is lifted, tilts and
so grasps the carbon C. The rim or flange on the ring causes the thrust to act more obliquely at first.
In the latest forms of this clutch the ring has a taiLpiece which is hinged to the frame of the lamp.
The Joel scissors—point clutch (Fig. 1188) consistsof a series of jointed levers L I R, which at the
upper end connect with an electro-magnet. As this end is raised they grip and raise the carbon-rod,
and relax their hold on being lowered to feed the arc. The Newton clutch (Fig. 1189) consists of a
ball-bearing which, on the raising of the coiler in which it lies, jams against and so holds the carbon-
rod.
The Rogers clutch (Fig. 1190) consists of a split tube G, the parts of which are connected together
by a pair of oblique links H H, making a sort of parallel motion.
522 ELECTRIC LAMPS.

The Thomson-Houston lamp (Fig. 1191) has a peculiar clutch consisting of a pair of levers pointed
together, one of them being perforated with an eyelet through which the carbon-rod passes. The
mechanism of this lamp consists of a seesaw lever L L, pivoted at 0, and provided with a long tail
T, the motion of which is moderated by an air dash-pot. Below is an electro-magnet M in the main
circuit, and above is a second S, which is connected as a shunt. The pole-pieces of both are of co-
noidal shape, protruding through apertures in the armatures a a and b b, to give longer range of pull.
The lower and upper arms of the clutch, marked R and In, close together when the tail T rises, grip-
ping the carbon-rod 0 and raising it. From this diagram, which also shows the electric connections,
it appears that the current entering the lamp through an insulated terminal at P flows first round M,
and then goes to the frame of the lamp. Thence it divides, the main current finding its way to the
upper carbon-holder, and so through an arc to the lower carbon, whence it returns (by a route not
shown) to the insulated negative terminal Q. A smaller portion of the current flows up round the
shunt electro-magnet to Q. The are is struck by the preponderating main circuit current in all at-
tracting the lever end of the seesaw lever, and raising the clutch. The feeding is accomplished by
the preponderating pull of the shunt-magnet as the are increases in length. The resistance-wire R
constitutes a cut-out circuit, which is brought into operation by the augmented current in S on any
failure of the main current. The small coil connected across from P to the lamp-frame is a mere ad-
justment to regulate once for all the power of the series-coil M, relatively to that of the shunt-coil S.
1191.
1190.




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ml J





It will be noted that in the operation of all these clutch actions there are really four periods. In
striking the are there is a first stage of affairs, where the clutch rises sufficiently to grip the carbon-
rod, immediately followed by a second stage, during which it rises still farther, and lifts the carbon-
rod, so striking the arc. During the third stage or period the clutch still retains its grip, but as the
arc burns away the clutch is gradually lowered. This is due, in constant potential lamps, to the
weakening of the main current; in constant-current lamps, to the increasing opposing action of the
shunt. The fourth stage is reached when the are has burned away so far that the clutch has been
lowered to the point where it begins to relax its grip, and now feeding commences, the rod slipping
a little, but the clutch simultaneously rises a little, and grips again, again to descend.
In a well-adjusted clutch-lamp the clutch is indeed incessantly rising and falling through minute
distances about the critical position. A bad clutch, or one that is deranged by dirt, will overfeed, and
then rise too far, feeding spasmodically. Theoretically, all these clutches possess the rctractile prop-
erty so useful in keeping a steady are when the carbons are of indifferent quality.
Clutches of the forward feeding class have for the most part no rctractile power. An example of
this type is the Holmes clutch, shown in Fig. 1192. Here a shunt electro-magnet S attracts an armw
ture, a, the latter being mounted upon a vertical lever. The carbon-rod C 01 is gripped between two
blocks which are pressed against its sides by two curved springs $1 and at. The armature-lever is
attached to 8;, and is connected across by a small rod 12 to the spring, 82. When the armature a is
alternately vibrated backward and forward by the magnet, the gripping-blocks propel the carbon
downward. The make-and-brake device which turns the current off and on in the magnet-coils is not
shown in the out.
In lamps of the clutch-wheel or brake-wheel type a clutch applied to the periphery of the wheel
first grips the wheel and then turns it a little. The weight of the carbon-rod propels the wheel in a
direction opposed to the grip ot the clutch, and the feeding takes place at those instants when the
clutch releases its grip.
In the Common & Jones clutch (Fig. 1193) the descending rack R drives the wheel D by means of
the pivot P. Pivoted loosely around the same arbor is a heavy lever, which is prevented by a stop 8'
from descending too far. Pivoted to this lever at L is a second lever, with an enlarged end to grip
against the surface of the wheel.
The tail of this nipping-lever is attached by a pin to the iron core of a solenoid M (The latter is
ELECTRIC LAMPS. 523

wound with a main-circuit coil only if wanted for use in parallel, or with a main coil and an opposing
shunt coil if for use in series.) When the current in the solenoid draws up the core, the nipping-lever
first turns around L and grips the wheel; any further rise of the core will cause the two levers and
the wheel to turn bodily together round the arbor, and this second action causes the arc to be struck.
Then begins the third period of action, during which the levers slowly descend until the weight-lever
touches S. Then the fourth period begins; any further descent of the core causing the nipping-lever
to release its grip, and allowing feeding to take place, followed by a slight rise in the core and re-
1192. 1193. 1194.













































newal of the grip. In the Broekie-Pell clutch (Fig. 1194) the descending carbon-rod drives a wheel
D having a projecting rim, to the inner surface of which is applied a brake-pad 1U fastened toa short
arm which projects downward from the nipping-lever L, pivoted at Q to a sector-shaped lever behind,
which carries two weights lV Wto increase its downward-bearing power. This weightlever is loosely
pivoted on the arbor P, and turns solidly with the wheel when the brake is applied. There is a stop
8’ to limit the descent, but it is in this case applied to the tail of the nipping-lever. A connecting
link E joins the nipping-lever L to the seesaw. The internal position of the brake appears to have

524 ELECTRIC LAMPS.
two advantages, namely, longer leverage around the fixed pin, making the feed more sensitive, and
giving greater protection from dust and dirt.
The Crampton-Orable double differential lamp, represented in Figs. 1195 and 1196, has the car-
bon-rods 111 and N, of which N comes first into operation, afterward changing over. On each‘carbon~
rod is cut a rack which drives a brakewheel, or rather a pair of brake-wheels, one behind the other
on the same pinion. The arbor-bearing is not, as in the two preceding lamps, fixed in the frame of
the lamp, but passes through a short sleeve or jockey, which, when the wheel is free to turn, can slide
up or down on the carbon~rod, but is prevented from turning sidewise by a guide-pin 9 above.
Below the brake-wheels stands a lever L pivoted at o, and attached by a link H to the solenoid over»
head. This lever carries a small table it and a brake-piece I), faced with phosphor-bronze.
When the lamp is out of action the free end of the lever is down, and the weight of the wheels and
the carbon-holder bears down upon the table it through a pin p which projects down from the jockey-
sleeve. In this position the wheels do not touch the brake~piece b, and are free. When the current
is turned on, the main coil of the solenoid attracts its core, first drawing up the lever, which, turning
on its pivot as it rises, brings the brake-piece against the rim of the brake-wheels and clamps it.
Secondly, the wheels being thus prevented from turning, any further rise of the lever lifts the brake-
wheel, jockey, and carbon-holder bodily (the weight of them all resting on the brake-piece), thus
1 200. 1199. _ - 1201.
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striking the arc. Thirdly, as the arc burns away, the lever again descends,
until, fourthly, when the tail-piece rests on the table and takes the weight
off the brake, the feeding begins.
A novel form of clutch-wheel, illustrated in Fig. 1197, has been devised
by Mr. Alexander Siemens. It is about 1 in. in external diameter, and has
a projecting rim R, within which lies an internal metal ring B, slightly
sprung outward, and cut obliquely, somewhat in the manner of the elastic
metal packing-rings used in engine-pistons. The two ends of this internal
split rim are joined by two pins to a small lever L which projects outward.
When a reciprocating motion of either large or small range is imparted to
the forked end of this lever, this internal clutch alternately bites against the
rim and pushes it forward and then releases its grip and draws back.
The Pilsen lamp (Fig. 1198) and the Menges lamp (Fig. 1199) are exam-
ples of the class in which cord and pulley mechanism is employed in con-
junction with a long-range open solenoid—in the Pilsen lamp the core A
being drawn into the main circuit solenoid O, to strike the arc, while the
differentially wound solenoid P varies its pull on the core B, according as
the carbons are required to approach, to stand still, or to recede, the former
action occurring when the shunt current prevails. In the Menges lamp the long core 8 N is drawn
~up into the solenoid, wound differentially with a coarse wire A and a fine wire winding B. A heavy
piston of metal on the top of the' upper carbon-holder d serves both to counterpoise the weight of
the core and to check, as it slides in the surrounding tubes, any too sudden moveme'nts.
De Puydt’s lamp (Fig. 1200) is an example of a rack-train lamp which strikes its are by lowering
the lower carbon and raising the upper simultaneously, and feeds, with a fly and detent controlled by
a shunt-magnet. The main-circuit magnet M attracts obliquely its armature, rocking the train of
wheels around the pivot of the first wheel. A lever L, bent to an elbow which rests on the set~screw
V, is also pivoted around the same arbor, and has a vertical arm which carries two attachments: a
fork which engages on a pin on the train-frame, and a detent which arrests the fly. The other end of
the lever L is held back by a spring, but can be attracted up by the shunt-magnet 8', when the detent
is to be released in order to feed.
A variety of focussing mechanisms for giving to the carbons the desired differential rates of approach
is illustrated in Fig. 1201, which gives four methods of producing a motion of the carbons in the
ratio of two to one, and four methods of “commercial focussing,” in which the carbons are moved
toward one another at equal rates. ‘
“Cut-out” mechanisms may be purely mechanical; but they are more usually electrical, and, in
modern forms, enable the lamp to “cut in ” again on the re-establishment of its proper circuit.
Cut-outs which enable a shunt-magnet to strike and feed the are are used in the Thomson-Rice lamp.


ELECTRIC LAMPS. 525

In many lamps the cut-out circuit is merely a shunt electro-magnet stiffly set, which, on the failure of
the lamp, receives the whole current, and pulls over a cut-out switch. Other devices depend on ex-
pansion by heat. In the Pilsen lamp (Fig. 1198) the cut-out is in an auxiliary main circuit. Cutouts
depending on the fusion of a wire or of a washer have also been proposed. ‘
Incasnsscnu'r Laura—All forms of these lamps, at the present time, depend upon the bringing to
incandescence of a narrow strip or filament of carbon by passing the electric current through it. Carbon
is found to be the most advantageous material for the purpose on account of its infusibility and its
high resistance, which is about 250 times that of platinum. As\the carbon becomes volatilized at high
temperatures in the presence of oxygen, it is necessary to seal it in a glass bulb in which a high
vacuum is made by means of a mercury-pump. A great variety of materials is used for the manu-
facture of the carbon, such as paper, bamboo, cotton, linen, silk, etc., which are subjected to various
manipulations to give them the requisite hardness, tenacity, elasticity, and durability. The principal
steps are the forming, carbonizing by baking at a high temperature with exclusion of air, and “ flash-
ing," which consists in heating the carbonized filaments to incandescence by the .electric current or
otherwise in a bath of carbon-vapor, the current from which is thus deposited on them, forming an
even, dense, and hard coating. The carbon of some filaments is entirely built up in this way on a
base of fine platinum wire. There are also filaments made of hollow tubes for increase of surface.
The average durability of a filament in the 16-candle-power lamp is from 600 to 1,000 hours; the
heating and cooling, molecular action, and general wastage, finally terminating in its rupture, requir-
ing renewal of both filament and containing bulb. Its electric resistance, when heated to incandescence,
is about half its cold resistance, ranging from 50 to 200 ohms, according to its length, cross-section,
and composition.
Each filament when completed is attached at both ends, as
shown, to platinum terminals sealed into the glass, after which
the air is exhausted and the bulb hermetically sealed.
Each bulb is then attached to a socket, from which it can be
easily removed for replacement, in which is a device, operating
with springs, for closing or opening the circuit by turning the
insulating handle shown, by which the current is passed through
the filament or excluded from it for lighting or extinguishing the
lamp.
The position of this lamp when in use is entirely a matter of
convenience, as its illumination seldom exceeds 16-candle-power,
and its current s to § of an ampere. The current may be either
direct or alternating, according to the system of lighting, each
system having numerous distinctive features.
The Edison form of incandescent lamp is illustrated in Fig.
1202, the construction of which is as follows: The lamp is formed
from a longish, pear-shaped bulb, narrowing at one end to meet
a hollow glass stem. These, on being
melted together and filled up at the
junction with plaster of Paris, become
the base of the lamp. The other end
of the bulb serves for the connection
to an air-pump, and after the air has
been exhausted by the pump, that end
is hermetically sealed by melting the
glass there so that it forms a little
nipple or knob. The chamber of glass
has thus become a vacuum in which
the “high resistance ” horseshoe or fila-
ment of carbon can be brought to the
required illuminating point by the pas-
sage of the current for hundreds and
even _thousands of hours without any
change in the structure of the filament
and without any appreciable deterioration of the lamp from the light-giving standpoint. This fila-
ment of carbon is held at its two ends by little conducting wires of platinum which run out through
the plaster to similar fine wires of copper. The glass bulb holds on tightly by means of horns or
spurs to the plaster base, and this base in turn is capped with a thin metal shell, grooved like a
screw, and to which one end of the tiny copper wires from the filament is brought. The other little
copper wire goes to a flat copper button insulated from the screw-cap by the plaster. The lamp is
now ready to go into a socket, upon turning whose key the circuit can be closed or opened, so as to
bring the current into the lamp or to shut it 013?.
The standard'socket for the Edison lamp is illustrated in Fig. 1203. T and E are the leading-in
wires, one of which communicates with a plate in the bottom of the socket, and the other one with
a threaded metal sleeve I. The base of the lamp 1' is similarly threaded to enter the sleeve I. The
lamp also has a metal projection 1V, which meets the bottom plate in the holder. In this way circuit
is made from one wire, as T, for example, to the sleeve 1, thence to the lamp-sleeve J', and so through
the carbon filament in the lamp back to the projection N, then to the plate in the bottom of the
'socket, and finally to the wire E.
These lamp-sockets exist in a great variety of forms. In Fig. 1204 is illustrated the Sawyer-Han
lamp with its holder, the holder being taken apart. Here the base of the lamp is provided with a
1202.
1203.


526 ELECTRIC LAMPS.

grooved sleeve which enters a spring sleeve on the holder. At the bottom of the lamp is a metal
projection which is received between two metal springs. These metal springs may be moved apart
by means of the finger-key shown; and
in this way circuit through the lamp
may be broken at will for the purpose
of extinguishing it.
The ordinary form of incandescent
lamp-regulator simply establishes or
breaks the current for the purpose of
lighting or putting out the lamp. Va-
rious attempts have been made to con-
struct a regulating attachment by means
of which the degree of light can be ad-
justed. A very ingenious example of
this device is illustrated in Fig. 1205,
which shows the regulating socket in-
vented by Mr. E. E. Ries, in sectional
elevation, in side elevation with part of
enclosing shell broken away, and in dia_
gram view exhibiting the coil and cir-
cuit connections.
As will be seen, the socket comprises
a finely laminated iron ring A wrapped
at one operation with a cable B com-
posed of a number of welLinsulated
copper wires, the ends of which are
brought to a row of contactpins C ar-
ranged in the path of an arm D, con-
nected with the operating key in such a
manner that all the wires of the cable
are, by means of these pins, connected
in series with each other and with the
lamp. The coil thus formed is mount-
ed upon an insulating block H contained within the enclosing shell, to which block are likewise
secured the lamp—holding contacts, the operating key, and the binding screws L ill, to which the lead-
ing-in wires are attached.
The amount of counter E. M. F. gen-
erated by this socket varies according to
the position of the operating key and its
arm. The coil is so arranged that when
the arm D’ is removed from its open-
circuit position at the extreme right and
rests upon contact N o. '7, all of the wind-
ing B is in circuit with the lamp. In
this position the counter E. M. F. gener-
ated by the coil is greatest, so that only
a small portion of the applied E. M. F.,
sufficient to just render the lamp‘ filament










\ visible in the dark, is permitted to pass
1§ " I
eggs? to the lamp. As the arm D' 1s moved
.\\ 4 .
\-=__ '2 toward the left over the series of contact-
re



pins 0, it cuts out successive sections of
the winding B, thereby reducing the
length of wire subjected to the inductive
r 1 action ofvthe core A, and correspondingly
increasing the amount of light given by
the lamp, until when the arm finally rests
upon contact N0. 1, practically all of the
coil sections are cut out and the lamp
burns at, its greatest brilliancy. In some
cases the coil is arranged to generate a
counter E. M. F. that is nominally almost
[ equal to and balances the direct E. M. F.,
+ _. in which case the light is extinguished
' without the necessity of opening the cir-
cuit in which it is placed. This latter arrangement practically introduces
a new system of electric-lighting, in which the lamp filament is at all
times subjected to two opposing electro-motive forces, one being variable
with respect to the other, the light produced being due to the difference
of potential between the two electro-motive forces as determined by the
position of the operating key of the socket.
The construction of the socket is such that it will take lamps of any voltage up to the normal
voltage of the supply circuit, or of any candle-power up to its rated capacity.









ELECTRIC PEN. 527

Miniature incandescent lamps have been successfully applied to surgical purposes. The arrange-
ment of such a lamp in connection with a tongue depressor is shown in Fig. 1206.
1206. 1207. 1208.


it










A
V
+ l '1» I
Distribution—The large number of lamps required on an incandes-
cent lighting circuit, and the small current required for each, makes the
parallel system of distribution the most economical and practical. This
system is illustrated in Fig. 1207, in which are represented two heavy
copper mains issuing from the dynamo, between which the lamps are
mounted on fine wire connections. A number of short series of lamps
may take the place of single lamps on a parallel circuit, producing what
is called a “multiple-series” installation; or a number of groups with
lamps in parallel in each may be placed in series, producing what is
termed “ series-multiple ” installation.
In the Edison three-wire system, illustrated in Fig. 1208, two parallel
circuits with two dynamos are combined, the dynamos being connected together in series as shown,
and a single central main attached to the short connector which joins them, takes the place of the
two interior mains, and equalizes the current through the lamps.
ELECTRIC PEN. This apparatus is the invention of Mr. T. A. Edison, and its object is the pro-
duction of a stencil from which any number of copies of the writing made thereon can be produced.
The pen consists of a metallic tube, in the centre of which a fine needle is reciprocated by means of
a small electro-magnetic engine placed on the top of the pen. The current is transmitted to this
engine through two fine wig-es connected with an electric battery. The battery is placed on the table
or anywhere near the writer, and occupies but little space. The pen being held in an upright posi-
tion, and moved over the paper, the rapidly succeeding thrusts of the needle cause the surface of the
paper to become punctured with the characters which the hand has traced. After the writing is fin-
ished nothing but a faint line appears on the surface of the paper, but on holding it up to the light
' the writing is clearly visible. This sheet, which is called the stencil,
is then placed over a sheet of plain paper in a frame, which, when
closed, binds the two around their edges. An inked roller is then
passed over it, and the ink penetrating the holes in the stencil
transmits the written matter to the clean sheet, the lines being com-
posed of a series of very fine dots. In this way, and by placing a
number of sheets in succession under the stencil, about 500 copies or
more in facsimile may be taken, each copy being very clear and dis-
tinct.
An end view of the pen is given in Fig. 1214. The current A en-
ters the engine by the binding-screw B, and thence passes by the
wire B D into the coil 11', which together with 5" forms an electro-
magnet. On leaving 11' it traverses the wire CE, and enters the
coil 3', and on leaving the latter passes to the screw L, and thence
to the platinum point K; and when the latter is in contact with
the other platinum point ll! attached to the spring Nil[ 0, it re-
turns by the binding-screw P to the battery. Q R is a small fly-
wheel, on the axis of which at Z there is a cam, which in certain
positions of the wheel presses against the spring Nil! 0, and so sep-
arates the platinum points 111K, and at the same time interrupts the
current. When the wheel has revolved half round, the cam no longer presses against the spring,
and the current passes.
ELECTRO—BALLISTIC MACHINES. ' Apparatus for the determination of the velocity of a pro-
jectile at any point of its trajectory. (Sec Ounnimer, and PROJECTILES.) The earliest eontrivance
for this purpose was the ballistic pendulum, which consisted of a tripod, from the top of which was
suspended a pendulum vibrating freely on its axis of suspension, Fig. 1215. The bob was arranged
to receive the impact of the projectile. The pendulum being at rest, it was struck by the projectile,
a body of known weight. ~ The degree of vibration due to the impact was then registered, and from
this the velocity of the striking body was determined, the quantity of motion of the body before
impact being equal to that of the pendulum and body after impact. The gun-pendulum, Fig. 1216,
consisted of a cannon suspended in a horizontal position and vibrating freely, the are of its recoil
being accurately measured when the gun was fired. The quantity of motion of the gun as a pendu-
lum is equal to that of the projectile, the charge of powder, and the air. From this the velocity of





528 ' ELECTRO-BALLISTIC MACHINES.

the projectile may be deduced. A complete description of this machine, together with reference to
the extended experiments made with it by Major Mordecai, U. S. A., will be found in the former edi-
tions of this work (“Appletons’ Dictionary of Mechanics ”). It has now given placate the very inge-
nious devices known as electro-ballistic machines, though in reality they are exceedingly delicate
chronoscopes or measurers of brief intervals of time. Their operation is based either upon the action
of gravity upon a falling body, the time being deduced from the space passed over during the inter-
1215. ' ' 1216.
1 -


. . A
/







val to be measured ; or upon the number of vibrations made by a tuning fork during the interval of
time to be measured, the rate of vibration of the fork being accurately known; or upon the direct
action of electro-magnets upon a recording stylus, said magnets being demagnetized by the rupture
of the circuit by the projectile.
To the first class of apparatus belong those dependent upon the pendulum, upon the free fall of a
weight, upon the downward movement of a weight transformed into rotary motion, and upon the
1217.
____________________ __ ,2, _> .
, .
I
_-
---_-
--.__




escape of liquids. Examples of the second and third classes occur in the Schultz and Bashforth
instruments, which will be described further on. ‘
Gravity Instruments—Of the pendulum apparatus the Navez-Leurs Olwonoscope is the most suc-
cessful. Two wire targets are placed in front of the gun so that the projectile passes through them,
as indicated by the arrow in Fig. 1217. As the projectile passes through the first target it breaks a
ELECTRO-BALLISTIC MACHINES. 529

circuit and demagnetizes the electro-magnet a. The pendulum-bob sustained by this magnet then
begins to fall, carrying with it an index-needle. When the projectile cuts the wires of the second
target, the second circuit is broken, and the magnet of the register-pendulum bis demagnetized. The
bob falls, carrying with it an arc and stirrup cl, which knocks away a wedge-lever and closes springs
on a disk 0, which clamps the index-needle. The time due to the arc of vibration is ascertained by
the theory of the pendulum.
In the Le Boulmgé Chronograph the shot is made successively to cut two currents, and thus to
demagnetize two electro-magnets which had previously supported two heavy bodies; the fall of these
bodies under the action of gravity is the measure of the time taken by the shot to pass over a known
distance. '
The principle of action of the Noble Chronoscope, Fig. 1218, consists in registering by means of
electric currents upon a recording surface, traveling at a uniform and very high speed, the precise
instant at which a projectile passes certain defined points in the bore. It is in two portions: the
mechanical apparatus for obtaining the necessary speed and keeping that speed uniform, and the
electrical recording arrangement. The first part of the instrument consists of a series of thin metal
disks A A, each 36 inches in circumference, fixed at intervals upon a horizontal shaft S S, which is
driven at a high speed by a heavy descending weight B, through a train of gearing multiplying 625
times. The precise rate of the disks is obtained by means of the stop-clock D, which can at plea-
sure be connected or disconnected with the revolving shaft E, and the time of making any number
of revolutions of this shaft can be recorded with accuracy to one-tenth of a second. The speed
usually attained in working this instrument is about 1,000 inches per second, linear velocity, at the
circumference of the revolving disks, so that each inch traveled at that speed represents the thou-
sandth of a second; and, as the inch is subdivided by the vernier V into 1,000 parts, a linear repre-
sentation at the circumference is thus obtained of intervals of time as minute as one-millionth of a
second. The arrangements for obtaining the electrical records are as follows: The revolving disks
are covered on the edge with a strip of white paper, and are connected with one of the secondary
wires G of an induction coil. The other secondary wire H, carefully insulated, is brought to a dis-
charger I opposite the edge of its corresponding disk, and is fixed so as to be just clear of the latter.
When a spark passes from the discharger to the disk, a minute hole is perforated in the paper cov-
ering (which is lampblacked) upon that part of the disk which was opposite the discharger at the
instant of the passage of the spark. By means of the micrometer the distance between the sparks
on the disks is read off. From this is known the time which the projectile occupies from the com-
mencement of motion in reaching different parts of the bore, and from these time records may
1218.












"r "umn/lullzzzami'g/W /////./ .._._. __.________- .___ M
w
’ // / /////////////'ilF’//'///// //fl'/////. r // / l//////// / / // ’ / '
“ir‘L‘L‘fiW/W/ IS"








1//'/ i=2:

l
l l
i l i l | l l |
_ v I .. , 3' R" - a" 4": 4" ’iZHZ‘g'
n‘ g ‘ lsv a Is ‘ ‘ 1 ‘ . i an”:
:2 n IO 9 B 7 6 6 4 a 2 I
be deduced the velocity with which the projectile is passing through the different parts of the bore,
and the pressures in the gun which correspond to these velocities.
The EZecirz'c Olepsg/dra measures time by means of the weight of mercury which escapes during
the interval to be measured. . _
VIBRATION INSTRUMENTS.——T]L8 Schultz Chronoscope, Fig. 1219, has a tuning-fork, making an as-
certained number of vibrations per second, and arranged to trace on the blackened surface of a re-
volving cylinder a sinuous line showing the beginning and end of each vibration. This sinuous
trace will be an actual scale of time. If, then, the instant the projectile reaches each of the two
given points in its trajectory be marked upon the cylinder, beside the sinuous line or scale of time,
the number of vibrations comprised between the two marks will be an exact measure of the time
required. The general arrangement of parts will be understood from Fig. 1219, in which 1 is the
blackened cylinder; 2, the actuating clockwork; 3, the pendulum; 4, the vibrating fork; 5, the
Ruhmkorff coil; 6, the interrupter; and 7, the micrometer. At 8 the mode of construction of the
target is shown. To use the Ruhmkorfl’ coil, the primary wire is connected with the battery and
the targets, and the secondary wire with the instrument. One of the ends is brought through a
3
530 ELECTRO-BALLISTIC MAGHIN ES.

glass tube close to the cylinder just over the fork; the other end is connected with the bed-plate and
thence with the cylinder and other parts of the machine, except the support for the glass tube,
which is insulated. By this arrangement, when the primary current is broken by the rupture of the
target wire, a secondary current is induced, and a spark is projected from the end in the glass tube
1219.









































to the face of the cylinder, which represents the other end, where a bright spot beside the trace in-
dicates the exact instant the rupture took place. The pendulum is used to determine the number of
vibrations of the fork in a second of time; and the micrometer is used to divide a vibration on the
cylinder into very small parts for close reading.
The Bashforth Chronograph, Fig. 1220, has a ily-wheel A, which revolves about a vertical axis,
carrying with it the cylinder K, which is covered with prepared paper for the reception of the clock
and screen records. The length of the cylinder is 12 or 14 inches, and the diameter 4 inches. B is
a toothed wheel which gears with the wheelwork hf, so as to allow the spring 0 H to be slowly un-
wrapped from its drum. The other end of C D, being attached to the platform 5‘, allows it to de-
scend slowly along the slide L, about a quarter of an inch for each revolution of the cylinder. E E'
are electro-magnets; (1 cl’ are frames supporting the keepers; and f f' are the ends of the springs,
which act against the attraction of the clectro-magnets. When the current is interrupted in one
circuit, as E, the magnetism of the electro-magnet is destroyed, and the spring f carries back the
keeper, which, by means of the arm a, gives a blow to the lever 1). Thus the marker m is made to
depart from the uniform spiral it was describing. When the current is restored the keeper is at-
tracted, and thus the marker m is brought back, which continues to trace its spiral as if nothing had
happened. E’ is connected with the clock, and its marker m’ records the seconds. E is connected
with the screen, and records the passage of the projectile through the screens. By comparing the
marks made by m m’ the exact velocity of the projectile can be calculated at all points of its
course. -
Works for Reference—The foregoing illustrations and abridged descriptions are taken from “A
ELECTRO—GALVANIC AND THERMIC BATTERIES. 531

Text-Book of Ordnance and Naval Gunnery,” by Commander A. P. Cooke, U. S. N ., New York, 1875.
See also “ The Le Boulengé Chronograph,” Michaelis, New York. 1872; “ Electra-Ballistic Machines
and the Schultz Chronoscope,” Benet, New York, 1866; “The Determination of the Flight of Pro-
1220.


\
-‘
~__.~
-
L1 1- i
’tljtniilli .


jeetilcs,” etc., Le Boulengé (translated by Marvin), Washington, 1873. Also the various works re-
ferred to under Onnmnes.
ELECTRO-GALVANIG AND THERMIG BATTERIES. I. GALvame Bauhaus—When a piece
of zinc is dropped into a vessel containing acidulated water, bubbles of gas are seen to issue from
the metal, and the electro-dynamic impulses are propagated therefrom in every direction. By these
counterbalanced opposite directions, the impulses neutralize each other’s actions and reactions; con-
sequently, no decided electro-dynamic action is perceptible. This experience was repeated thousands
of times before the discovery of the galvanic battery arrangement, without developing electric excita-
tion. But if a plate of copper or platinum, as at C, Fig. 1221, be placed opposite to the zinc Z, the
impulses are determined through the water to the atoms of the copper plate, in one common specific
direction. When the zinc is dissolving it gives off hydrogen and heat, while forming the more satis-
fied compound sulphate of zinc (the water being acidulated with sulphuric acid). The energy set
free by the zinc entering into new combinations takes that form which we call electricity, instead of
the other form which we call heat, and is capable of manifesting itself by its magnetic, ehemical, or
calorific effects (Sprague).
When the two free ends of the wire are brought- in contact as shown, a current of positive electricity
is generated, which, as indicated by the arrows, passes from the zinc through the liquid to the copper,
and, traversing the copper plate from it, through the wires toward the zinc. At the same time a cur-
rent of negative electricity is supposed to start from the immersed part of the copper plate, traveling
532 _ ELECTRO—GALVANIC AND THERMIC BATTERIES.


in the opposite direction through the liquid to the zinc plate, and out of the cell from the zinc by the
wire connected with 'it toward the copper. The particles (molecules) of the liquid through which
the current passes are supposed to undergo polarization, i. e., the separation
of the electricity of the respective molecules, so that one half of each mole-
cule becomes positively and the other negatively charged (Angell), by which
their invisible transfer is effected.
Definitions—The combination of parts above described constitutes a couple.
Many couples connected form a battery; couples of certain forms are called
cells. The two metals or their equivalents are called elements, the one most
acted upon being always the positive substance, and the other the negative.
The supposed positive electric fluid will, however,'always come out from the
negative. The liquid employed is commonly called the exciting liquid. That
metal which has the strongest affinity for okygen is usually the most electro-
positive, and one metal may therefore hear an electro-positive relation to a
second, while it is electro-negative when compared to a third. Potassium
is the most electro-positive of all bodies, but its attraction for oxygen is so
violent as to make it practically useless as an element in the galvanic circuit.
Among those which can be usefully employed as electro-positive elements,
zinc ranks first, while platinum is the most highly electro-negative metal.
But the relative electrical condition of several of the metals changes when
immersed in ditferent liquids; thus, if an iron and a copper plate be con-
nected with the electrodes of a galvanometer and immersed in dilute sul-
phuric acid, the needle will be deflected in one direction; while if the plates
are immersed in a solution of sulphide of potassium, the deflection will be in
the opposite direction. The following table shows a few of the results obtained by Faraday:
1221.


Comparison of Difl'erent Metals in the Presence of Diferent Liquids.
Dilute sulph. acid. Hydrochloric acid. Sol. of potash. Sol. sulphide of potash.
Silver. Antimony. Silver. Iron.
Copper. Silver. Nickel. Nickel.
Antimony. Nickel. Copper. Bismuth.
Bismuth. Bismuth. Iron. Lead.
N iekel. Copper. Bismuth. Silver.
Iron. Iron. Lead. Antimony.
Lead. Lead. Antimony. Tin.
Tin. Tin. Cadmium. Copper.
Cadmium. Cadmium. Tin. Zinc.
Zinc. Zinc. Zinc. Cadmium.
The order in each column places the most positive metal in regard to the fluid at the bottom, and
the most electro~negative at the top. It has been demonstrated by Poggendorif that the electromo-
tive force between any two metals is equal to the sum of the electromotive forces between all the
intervening metals. '
The conductive circuit comprises the wires, instruments, etc., forming the path for the passage of
the current (Prescott). Resistance is the opposition presented by the circuit to the development of
the current; it is an inherent property of every substance, varying in degree in each substance,
from silver, the best conductor, up to gutta-percha and other so-called non-conductors. The force of
a battery, sometimes called the tension of the current, is the power which it has to transmit a cur-
rent against resistance, such as that oifered by a bad, long, or thin conductor, and is designated as its
electromotive force. The unit of electromotive force is called a volt. The unit of resistance to the
passage of an electric current is the ohm, and is about equal to that of a cylindrical wire of. pure
copper, .05 inch in diameter and 250 feet in length (No. 18 Birmingham wire gauge), or of 330 feet
of N o. 9 iron wire (.155 inch in diameter) of the average quality. The unit of the current is called
a farad, and is equivalent to the quantity of electricity flowing per second in a circuit having an elec-
tromotive force of one volt and a resistance of one ohm. The quantity of electricity passing in a
circuit, or the strength of the current, is estimated by the power of the current to deflect the magnet-
ic needle, by the chemical decomposition it effects, or by the temperature to which it raises a wire of
given thickness and material. The strength of the current must not be confounded with the strength
of the element or battery which produces it. A battery of 100 cells has 100 times the electromo-
tive force of a single cell of the same kind, yet in certain circumstances the one cell will produce as
strong a current as the 100. The greatest quantity of current which a given galvanic element can
produce is proportional to its surface. By doubling the size of the plates, the amount of current is
doubled, provided the connecting-wire offers no appreciable resistance, and the quantity is not in-
creased by increasing the number of cells. The electromotive force of a battery, on the contrary, is
not affected by the size of plates, but by the number of cells in combination.
Electrodes is the term applied by Faraday to the poles or plates leading the current into and out of a
cell. Electrolysis is the act of decomposition by an electric current. Electrolytes are bodies capable of
being so decomposed (Sprague). Ohm’s laws are formulas devised by Ohm for calculating unknown
electrical magnitudes from certain given data. The symbols should represent fixed units to obtain
definite results. They are as follows: 1. Current equals electromotive force divided by resistance.
2. Resistance equals electromotive force divided by current. 3. Electromotive force equals current
multiplied by resistance. The chief diflerence between frictional and voltaic electricity consists in
the fact that the latter is generated in very large quantities, but its electromotive force is so
ELEC’lRO-GALVANIC AND THERMIC BATTERIES. 533

I
feeble as to render it incapable of overcoming a comparatively slight resistance ; while the former,
'on the contrary, is generated in very minute quantities, but its electromotive force is so great as to
enable it readily to overcome a resistance many million times as great as that which would entirely
stop the passage of a current of voltaic electricity. The quantity of electricity which is denoted by
unity in calculations based on clectro-magnetic phenomena is nearly thirty thousand million times as
great as the quantity denoted by unity when electro-static phenomena are taken as the basis of
measurement.
The Voltaic Pile—The voltaic pile of Volta, Fig. 1222, is constructed by placing upon a bottom
piece of wood a disk of copper, and upon this a disk of cloth moistened with dilute acid or a solu-
tion of some salt, and upon this a disk of zinc, repeating the order indefinitely, one end of the pile
terminating in a copper, the other in a zinc disk. In Cruikshank’s battery, Fig. 1223, plates of zinc
and copper are placed together in pairs and held in vertical grooves, all the zinc plates facing in
one and all the copper plates in the other direction; the connection between the plates should be
impervious to the fluid of the trough. This arrangement is really a horizontal voltaic pile.
The Dry Galvanic Pile of De Lac is constructed of sheets of paper, coated on one side with gold
or silver leaf, and alternated with thin leaves of zinc. By means of a circular steel punch, about
an inch in diameter, disks may be cut out of sheets of this paper foil, all of one exact size, adapted
to be packed neatly together in a long glass tube. The atoms of the leaves of zinc very slowly
become united with the atoms of oxygen of the air, recoiling to their natural polarized condition of
groupings of an oxide, whereby a feeble propagation of electro-dynamic action is sustained during
surprisingly long periods of time. Mr. Singer constructed a dry pile of 20,000 series of disks of
silver, zinc, and writing paper, which propagated an intense electro-dynamic action, like that produced
by frictional electrical machines, causing a pair of pith balls of an electroscope to become divergent.
A pith ball suspended by a silk thread between two metallic knobs, one connected by a wire with the
top cap of the pile, and the other with the lower cap of the pile, continued to vibrate unceasingly
between the two knobs during several years. A thin glass jar containing 50 square inches of
coated surface, charged by 10 minutes’ contact with the column, was found by Mr. Singer to propa-
gate sufficient electro-dynamic action to fuse one inch in length of platinum wire of the diameter of
filg‘gth part of an inch. He states that an efficient pile may be made of one kind of metal only, as
of zinc foil, if one side he made bright, and thus rendered more readily oxidizable than the opposite
surface.
The black oxide of manganese contains an extraordinary excess of oxygen, capable of freely unit»
ing with zinc and other metals. Zamboni improved Dc Luc’s pile by coating one side of the paper
1223 . 1224.


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. disks with this substance, mixed with sulphate of zinc, and the other side with tin foil. These piles
are capable of developing sparks across a space of air of one-sixteenth of an inch, and also of pro“
ducing chemical decompositions.
A common form of battery, which is merely a modification of Cruikshank’s, is represented in Fig.
1224. It consists of' a wooden trough divided into separate compartments containing the exciting
fluid, into each of which are suspended a zinc and a copper or a zinc and a platinum plate, from a
534 ELECTRO—GALVANIC AND THERMIC BATTERIES.

horizontal wooden beam, the opposite elements in each compartment being connected together. The
beam slides in vertical grooves in posts at the end of the trough, by which means the plates may
be raised out of or lowered into the liquid. They may also be easily removed from the beam and
cleaned or amalgamated with mercury, an operation which it is essential to perform with zinc plates
which are not of pure metal; and, it not being practical to procure this, the operation of amalgw
mation is therefore universal. It consists in applying metallic mercury to the cleared surface of
the zinc plates, by which the pure zinc becomes dissolved and brought to the surface, where the
action of the acid is confined. In impure unamalgamated zinc local polarization takes place, form-
ing local currents which greatly diminish or annul the electromotive force. A modification devised
by Wollaston consisted in having a sheet of copper brought around one end of a zinc plate and
separated from it by pieces of cork. Any number of couples can be united by using a trough di-
vided into compartments, or by employing a number of glass or earthen cups such as are repre-
sented in Fig. 1225.
Here’s Deflagrator, Fig. l226.——A powerful form of battery for heating purposes, in consequence
of the immense quantity of electricity it generates, was constructed by Prof. Hare of Philadelphia,
and consists of one or only a few simple couples, having a great metallic surface. A large sheet of
zinc of several hundred square feet of surface, and a
similar one of copper, are separated by a piece of felt 1227.
or cloth saturated with acidulated water and then rolled
together in the form of a cylinder.
Grave’s Element, Fig. 1227.—A glass or earthen ves-
sel A, containing dilute sulphuric acid, receives a cylin-
der of zinc, within which is a porous earthenware cup
V containing strong nitric acid, and in which there is
immersed a platinum plate P. A cover attached to it
confines the fumes of hyponitric acid, which are liber-
ated by the decomposing nitric acid. The electromotive
force is 1.956 volt.
The Scsguioxide of Iron Element of Messrs. Clamond
and Gaiffc is composed of a prism of charcoal which
contains sesquioxide of iron in its pores, and a small
rod of amalgamated zinc. The latter passes through
the stopper, in the under surface of which is fixed the
charcoal. A solution of ammonium chloride is used as
the exciting liquid. The reactions are the same as in
Leelanché’s couple, where oxide of manganese is used. Its electromotive power is as 12 to 10 of
the sulphate-of-copper battery, and it is thus well adapted for industrial purposes.
The Daniell Improved Element, Fig. 1228.—A porous-clay cylinder t is surrounded by a zinc cyl-
inder 2. Within the former is suspended a thin sheet of copper, which is attached to the copper
wire a, connected to the zinc cylinder of the next cell. At the upper part of the copper sheet 0 a
sieve-like perforated copper plate is attached, which serves to hold the sulphate-of-copper crystals.
The glass vessel and porous cup of each cell is filled with water, and the crystals of sulphate of



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copper are placed as stated. Adapted for electro-deposition, gilding, silvering, electro-magnets, and
large telegraphs ; scentless, develops no poisonous vapors ; electromotive force in volts, 1.08.
The Siemens-Hals/ce Element, Fig. 1229.—A, glass vessel; 0, glass tube; k,lperpendicular copper
plate bent in spirals; 6, wire attached to it; 0, thin pasteboard disk; f, diaphragm in place of
porous cell in-Daniell’s battery, formed of a peculiarly-prepared mass of paper 2 ; h, zinc ring,
with clamp. Inner glass cylinder filled with crystals of sulphate of copper and water poured on.
Ring-shaped intermediate space filled with water, to Which on first filling is added acid or common
salt. Quite constant, cheap, owing to prevention of chemical consumption of zinc and copper.
Adapted for working long telegraph-lines ; electromotive force same as Daniell’s.
The Maid/anger Element, Fig. 1230.—-A, glass vessel, in which is placed cemented small glass ves-
sel cl, surrounded by zinc disk Z. Inside wall of d covered by copper sheet e, to which insulated
ELECTRO—GALVANIC AND THERMIC BATTERIES. 535

copper wire 9 is riveted. Mouth of vessel closed by wooden plate, which receives glass cylinder h,
having an opening below. This is filled with sulphate-of-copper crystals. Large vessel filled with
diluted solution of Epsom salts. Valuable where long duration and a current of moderate but con-
stant strength is required, and especially so for operating Morse telegraph, electrical clocks, hotel
telegraphs, and electric bells. Electromotive force same as Daniell’s.
Gravity Element, Fig. 1231.——A cylinder of zinc is suspended near the top of a glass jar, and a
copper plate is placed at bottom. Jar filled with saturated solution of sulphate of copper and a
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dilute solution of sulphate of zinc. The difference in the specific gravity of the two solutions
causes them to separate at once and become superposed in the jar, the sulphate of copper occupy-
ing the lower and the sulphate of zinc the upper portions. Does not have the inconvenience expe-
rienced in use of Daniell battery from deposit of copper on porous cell. Electromotive force same
as Daniell’s.
An improvement on this form of battery has been devised by Edison, and is extensively used on
telegraphs in this country. The modification consists in preventing the difiusion of the two liquids
through each other by placing the copper element on top of a large quantity of the crystals of sul-
phate of copper, the tendency to diffusion being checked by the decomposition of the sulphate of
copper.
Callaud’s Element is constructed on the gravity principle, and works constantly for some months
if care is taken to replace water lost by evaporation. It consists of a glass or earthenware vessel
in which is a copper plate soldered to a wire insulated by gutta-percha. On the plate is a layer of
crystals of sulphate of copper. The whole is then filled with water, and the zinc cylinder immersed
in it. The lower part of the liquid becomes saturated with sulphate of copper. The action of the
battery is that of a Daniell, and the sulphate of zinc which gradually forms floats on the solution
of the sulphate of copper owing to its lower density.
Sir William. fl’homson’s Element, Fig. 1232, consists of a containing vessel of sheet lead, in the
bottom of which is placed 5 or 6 lbs. of sulphate of copper. This is covered with a layer of clean
pine sawdust from 1 to 2 inches thick, upon which the zinc plate rests. The vessel is then nearly
filled with soft water, or for quick action with a solution of sulphate of zinc. Remains constant,
giving strong current for from three months to a year. Internal resistance low. Adapted for
working circuits of small resistance, where comparatively strong and continuous currents are required.
The Bunsen Element, Fig. 1233.—This consists of a carbon cylinder, open at the bottom, placed
in a narrow-mouthed glass vessel. In the hollow of the carbon cylinder is inserted a hollow porous-
clay cylinder closed at the bottom. A ring a is closely laid around the upper part of the carbon cyl-
inder, and is attached to a hollow cylinder 0, of rolled zine. The porous-clay cup is filled with sul-
phuric acid, and the glass vessel with concentrated nitric acid. The zinc cylinder 0, belonging to the
next element of the battery, hangs in the porous cup filled with sulphuric acid. The positive current
in this battery passes in the closing wire, outside the fluid, from carbon to zinc. The Bunsen ele-
ment, like the Grove, develops a very powerful current, but it evolves a heavy deleterious gas. The
carbons are sawn from the carbon deposited in 'gas retorts. A modification of the Bunsen battery
is in use, in which a solution of bichromate of _potash and sulphuric acid takes the place of the
nitric acid. Electromotive force, nitric acid, 1.964; chromic acid, 2.028.
The Grenet Element, Fig. 1234.—This has a bottle-shaped cell, containing a mixture of 2 parts
bichromate of potash, dissolved in 20 parts of hot water, and 1 part. of sulphuric acid. To the
' wooden cover, which is inclosed in a brass frame, are attached two carbon plates, which permanently
dip into the fluid ; and between the carbon plates a zinc plate is suspended, which may be plunged
into the fluid or withdrawn at pleasure. This element is not suitable for continuous use ; but in all
cases where a powerful current is required for a brief period, it may be economically employed.
Electromotive force, 1.095.
The Smee Battery, Fig. 1235, consists of a strip of platinum, 1 inch wide by 10 in length, fast-
ened to a beam of wood, upon the opposite side of which is a plate of zinc covered with mercury.
Both are plunged into the glass vessel. A is the wooden bar, B brass clamps, Z zinc plate, P plati-
nized silver plate or strips of platinum. Electromotive force when not in action, 1.090; in action,
0.482.
The Leclanché Elmnnt, Fig. 1236.—Thc + pole consists of a carbon plate, which on its upper
end is coated with resin and provided with a binding-screw; it stands in a porous cup, which is
536 ELECTRO—GALVANIO AND THERMIC BATTERIES.

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filled with a coarse-grained mixture of the needle form of peroxide of manganese and carbon from gas
retorts. The — pole consists of an amalgamated zinc rod. Both poles stand in a diluted solution of
sal-ammoniac, which is poured into the outside glass vessel. There is no waste of material when the
battery is not in action, so that, if the evaporation of the liquid is prevented, it may be allowed to
remain untouched for months without losing power. It is well suited for a telegraph-wire not in

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constant use, and worked upon the open circuit plan or for electric bells. It is not suitable for per-
manent currents or local circuits, because when placed in short circuit it polarizes very rapidly and
loses power. Electromotive force, 1.481.
The .Zlfcu'ié-Da'vg/ EYemcnt, Fig. 1237.——The zinc stands in pure water, and the carbon in a paste
of moistened protosulphatc of mercury in a porous cup. While this makes a powerful battery
which produces excellent effects, its maintenance is expensive, and it is not adapted for continuous
work, owing to the slow solubility of the salt. Electromotive force, 1.524.
The .Byrne Compound-Plate Battery—The special feature of this battery consists in the negative
plate, which, instead of being of one material, is constructed of three'dif'ferent metals soldered to-
gether. The surface exposed to the exciting solution and opposed to the positive or zinc plate is
platinum; this platinum is backed by and soldered to a plate of sheet lead; behind this again is a
plate of copper backed by a fold of the first lead plate doubled on to the back of the copper. The
back surface of this second layer of lead is coated with asphaltum varnish. The arrangement will
be understood from Fig. 1238, in which A represents a vertical cross-section of the compound nega-
tive plate, the thickness of its laminae being greatly exaggerated in order to show its construction.
Each cell consists of a central zinc plate placed between two of the compound plates, as shown at
0. The exciting solution consists of 5 ounces of potassium bichromate dissolved in 5 pints of boil-
ing water, to which is slowly added when cold 1 pint of strong sulphuric acid. In the pneumatic
form of the compound-plate battery the exciting solution is kept in a state of mechanical agitation
by air being pumped into the cells through a perforated tube leading from each cell-cover to the
bottom of the cell, where it turns at right angles, so as to lie in a horizontal position underneath
and in a line with the central zinc plate and between the compound plates. Jets of air are thus in-
jected into the cell, which, rising in the form of bubbles between the plates, keep the solution in
violent agitation, washing off from the plates bubbles of hydrogen which othermse would collect,










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and insuring fresh fluid being continually brought into contact with the plates. The position of
the air-tube is shown at B and (7, leading to a small hand-syringe or bellows. A battery of 10
cells has heated to incandescence no less than 36 inches of stout platinum wire (No. 14 B. W. G.),
and has decomposed aeidulated water at the rate of producing 16 cubic inches of gas per minute.
This battery has been tried with Mr. Spottiswoode’s 18-inch induction cell, which it was capable of
charging to its fullest extent, giving sparks 'in air 18 inches in length while the air was being
ELECTRO—GALVANIC AND THERMIC BATTERIES. 537

pumped in, but which fell to 8 inches when the air supply was cut off. Mr. \V. H. Precce, C. E., has
determined that the greatly increased current is due partly to the diminution of resistance in the
compound plate, partly to a second diminution of resistance in the liquid itself caused by the pass-
ing of the air through it, and partly to the production of heat, which, by modifying the chemical
affinity between the molecules of the solution, reduces its resistance. Mr. Preecc’s experiments lead
him to the belief that the action of the air is principally and directly mechanical, and indirectly
chemical; for by mechanical agitation it removes adherent hydrogen from the negative plate, as
well as the chrome alum which is formed there, and, by causing a circulation in the liquid, brings
fresh acid into contact with the zinc, thereby assisting its consumption, and by the generation of
heat reduces the resistance of the solution, and again aids the acid in dissolving the zinc. (See En-
gineering, xxv., 417—421.)
Trozwé’s Portable Battery—M. Trouvé has devised a simple and cheap form of portable battery
suitable for military telegraphing, etc., which contains from 40 to 80 elements. Each of the elements
is composed thus: Between two disks, one of copper, the other of zinc, are placed a number of
round pieces of blotting-paper. One half of the rouleau is saturated with sulphate of copper, the
other half with sulphate of zinc. The elements are arranged for tension in a case of hardened
caoutchoue, and about a commutator and galvanometer, the whole being inclosed in a mahogany
box. When the apparatus is to be used, the elements are immersed in water, which, absorbed by
the paper, dissolves the sulphate of copper and sulphate of zinc, producing the chemical action neces-
sary to a current. The paper remains moist for a long time. To recharge the pile, it is sufficient
to immerse it one half in sulphate-of-copper solution, since the sulphate of zinc is continually being
produced. (See Les Alondes, xxxiii., 3; Scientific American, xxxvii., No. 21.)
The ll'laynooth Battery is essentially the same as the Grove battery, except that it has a plate of
iron instead of platinum, and is therefore much cheaper.
Earth Batteries—These are simply voltaic couples in which the layers of aeidulated cloth, etc.,
are replaced by a layer of moist earth. Large plates of copper and zinc have been buried several
miles apart, and a powerful electric current has been found in a wire connecting them. The con-
struction of such earth batteries, easy and simple as it appears to be, has never become a settled
practice, by reason of the laborious digging required, it being much easier to plunge plates into cups
and renew them after a while, than to dig up the oxidized zinc plates in order to replace them by
new ones. However, when a brook or river is at hand, the use of earth batteries may be recom-
mended, as in that case the zinc plate has only to be sunk at a convenient and safe spot. Then at
any time, if the current becomes weak, the plate may be easily replaced by a fresh one, while in
place of the copper a quantity of coke may be buried in the moist earth. The great objection to
this form of battery is, however, the unavoidable total lack of intensity; as the latter quality
depends upon the number of cups, and the earth or water acts as but one single cup, and thus the
burial of several plates is equivalent only to the immersion of them in a single cup. If the plates are
connected for quantity (that is, all the zines together and all the coppers or cokes together), the series
will act like a single pair, of which the surface is equal to the sum of the individual plates, and thus
as one pair of large surface. If, on the other hand, the plates are connected for intensity (that is,
every alternate zinc to the next copper), only the two plates at the extremes of the series will be of
use, because the several intermediate pairs discharge mutually all the electricity generated into the
moist earth through their metallic connections.
Carbon-consuming Elmzents.--It has been stated as probable that when the discovery shall have
been made of how to oxidize carbon in the galvanic battery, the cheapest source of electricity will have
been attained. Crookes’s battery, in which carbon is claimed to be oxidized, consists of an iron ladle,
which serves both as a containing vessel and as the non-attackablc electrode. In this is melted
nitrate of potash, and into the liquid thus produced carbon is plunged. The oxygen in the nitrate
with the carbon produces carbonic acid, which unites with the remaining potash, forming carbonate
of potash, and by the chemical action a current of electricity, which “ affects the galvanometer,” is
liberated. A better current is obtained by a plate of platinum placed with the carbon in the fused
salt. M. J ablochkoflf has devised another form of carbon battery essentially the same as the fore-
going. He rejects the platinum in favor of iron alone, and suspends his carbon in a wire basket in
the liquid ; but he says that by adding different metallic salts he is enabled to vary the power of the
battery and the rapidity of expenditure of carbon, and with these salts there is received a galvano-
plastic deposit of the metals on the non-attachable electrode. The electromotive force of the batter y
is stated to vary between 2 and 3 units, according to the nature of the metallic salts used.
Bccquerel’s Two-Liquid Element—fig. 1239 represents a galvanic couple composed of two liquids
and one metal, devised by Becquerel, and called an oxygen circuit. A bottle, (1’, contains nitric acid,
and into its mouth is inserted a tube containing a solution of caustic potash, and having a cork in
the top through which passes a wire. The bottom of the tube is stopped by a piece of linen cloth,
which is covered with clay, and this with cotton wool, to prevent the clay from mixing with the
liquid. The wire connects two plates of platinum, a and p, and the connection may be made through
the coil of a galvanometer if it is desired to measure the strength of the current. The two liquids
meet each other in the clay, and a current of considerable strength is generated, which passes
through the wire from the acid to the potash solution, and through the clay from the potash soluticn
to the acid ; the latter answering to the copper plate of an ordinary couple, and the potash solution
to the zinc. The water in the potash solution is decomposed, its oxygen escaping in bubbles, and
its hydrogen going to the nitric acid, which it reduces to nitrous acid. The current which is gener-
ated is of constant strength, and the plates do not become polarized. The power is increased by
making the plate in the potash solution of amalgamated zinc, which being attacked by the nascent
oxygen produces polarization in the direction of the current. A simple couple of this kind is suffi-
cient to eifect the electrolysis of water, and several couples form a powerful battery.
538 ELECTRO—GALVANIO AND THERMIO BATTERIES.

Gas and Secondary Banana—In the electrolysis of water or any body which causes oxygen to be
evolved at one electrode and hydrogen at the other, a thin film of gas becomes attached to each plate,
having sufficient electromotive force to send a current in the contrary direction when the battery is
removed and a connecting-wire introduced. Such currents, produced by polarized plates, are called
secondary currents; and upon this principle Prof. Grove
1240.
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constructed a gas battery which is capable of producing a 12
continuous current. Two glass tubes, Fig. 1240, closed at -
the top, each contain a strip of platinum, which is sus-
pended by a platinum wire passing through the top of the
tube. The surfaces of the strips present the metal in a
finely divided state. The tubes at their upper extremities
are closely sealed and filled with dilute sulphuric acid, and
their lower ends, which are open, are placed in the same
liquid in the vessel a a. The platinum strips are then con-
nected with the poles of a battery, and by electrolysis hydro-
gen is collected in one tube and oxygen in the other. Upon
removing the battery and connecting the platinum strips
either through a galvanometer or an easily decomposed elec-
trolyte, as iodide of potassium, a current will flow from the
oxygen to the hydrogen tube, and in the opposite direction
to that produced by the battery used in evolving the. gases,
while during the action the gases in the tubes will gradually
disappear, the hydrogen twice as fast as the oxygen. Rit-
ter’s secondary pile is constructed upon the same principle.
A number of disks of the same metal are separated by
pieces of moistened cloth. After passing for a time a
galvanic current through the system, on removing the battery and connecting the ends of the pile
a current will be found passing in the opposite direction to the battery current.
M. Gaston Planté has devised a secondary element, which consists of a tall vessel of glass, gutta-
pereha, or ebonite, in which are placed two sheets of lead, rolled spirally, and parallel one to the
other, and kept from touching by two cords of Indiarubber rolled up with them ; they are im-
mersed in a solution of 1 part of sulphuric acid to 9 parts of water. The vessel is closed by a sealed
cover pierced with a small hole, through which the liquid can be poured in or extracted, and which
also allows the escape of any gas which may be generated during the charging of the battery. The
1242.
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apparatus is surmounted by a disk of ebonite, upon which are fixed two contact pieces in connection
with the two electrodes ; two clips are also provided for the purpose of holding metallic wires to be
made red-hot or melted by the secondary current. Two Bunsen cells, or in their stead three Daniell
cells, are required to charge this secondary element. During the operation of charging, one of the
electrodes oxidizes, a brown coating of peroxide of lead soon shows itself, and the metallic appear-
ance disappears entirely; the other electrode also changes in appearance, its surface becoming
covered with a powdery gray coating. When the charge has attained its maximum—that is to say.
when oxygen begins to be given off by the brown electrode—the secondary element is disconnected
from the charging. battery, for any further expenditure of the polarizing current is entirely wasted.
The secondary element, once charged in this manner and left _to itself, will retain a portion of its
charge for several days; and even at the end of a week it is still far from being exhausted. The
secondary element, when fully charged, has an electromotive force once and a half greater than that
of Bunsen; it will redden a platinum wire of a greater or lesser diameter according to its size, or
rather according to the size of the electrodes. Secondary elements can be joined together either for
intensity or quantity, and form batteries capable of producing very powerful effects for short periods
of time. (See Scientific American Supplement, i., 65. As to effects of large numbers of these ele-
ments when coupled together producing the electro-silicic light, see Scientific American, xxxviii., 313.)
Connection of E/ements in Batteries—The coupling of elements to overcome external resistance is
represented in Fig. 1241. This is termed coupling for intensity or in series, and is the arrange-
ment adopted in telegraph batteries and in galvanoplastic operations. Coupling for quantity is
represented in Fig. 1242, where plates of the same metal are grouped together. It has the same
effect as the employment of one pair of plates having an equal area of surface.
Discharges from Great Numbers of Celia—Some remarkable experiments showing the effects of
discharges of great numbers of cells have been made by Messrs. Warren de la Rue, Spottiswoode,
and Muller. (See Proceedings of the Royal Society, No. 160, 1875, and No. 166, 1876.) The element
ELECTRO—GALVANIC AND THERMIC BATTERIES. 539

consisted of a flattened wire of silver and a rod of zinc. At one end of the silver a cylinder of
chloride of silver was cast. In order to prevent contact between the rods of zinc and chloride of
silver, the latter was surrounded with a cylinder open at top and bottom, and made of vegetable
parchment. The cell was a glass tube, the stopper a cork saturated with parafiine, and through
which a rod of non-amalgamated zinc was inserted. The exciting liquid was a solution of 23
grammes of chloride of ammonium to 1 litre of water. On examining the length of discharge from
various numbers of these elements, its length was found to be in the direct ratio of the square of
their number, as follows:
N o. of cells. Striking distance. No. of cells. Striking distance.
600 .0033 inch. 1,800 .0345 inch.
1,200 .0130 “ 2,400 .0535 “
These are very nearly the squares of the number of cells. As the experiments were carried
further, it was found that the striking distance probably increases in far greater ratio. Taking as a
basis the spark with 600 cells: .0033 inch, the investigators point out that a unit of 1,000 such
2
903365021—000 =0.009166 inch; one hundred units (100,000), a Spark Of
91.66 inches; and a thousand units (1,000,000), a spark of 9,166 inches, or 764 feet—nearly a true
flash of lightning, not only in distance but in quantity. With 5,640 cells sparks were obtained over
.139 and .140 inch; and other phenomena were noted, which will be found described in detail in the
references above given.
An excellent series of lectures on the voltaic battery by Dr. Gladstone, F. R. S, appears in the
Telegraphic Journal, iii., 14. See also the list of works for reference given under the general head-
ing of ELECTRICITY.
II. THERMO-ELECTRIC Bxmnlss.—Whenever two pieces of unlike metal are heated together and the
parts not heated are joined, a current passes through the whole circuit. The direction which this
current takes is always reversed if, instead of being heated, the place of contact of the two is cooled.
In the following table the metals are arranged in such order that, on heating the point of contact
of any pair, the current passes through the point of contact from the one above to the one below :
cells would give a spark of
1. Bismuth. 8. Manganese. 15. Molybdenum. 22. Platinum (3).
2. Nickel. 9. Titanium. 16. Rhodium. 23. Cadmium.
3. Cobalt. 10. Mercury. 17. Indium. 24. Steel.
4. Palladium. 11. Lead. 18. Gold. 25. Iron.
5. Platinum (1). 12. Tin. 19. Silver. 26. Arsenic.
6. Uranium. 13. Platinum (2). 20. Zinc. 27. Antimony.
7. Copper. 14. Chromium. 21. Tungsten. 28. Tellurium.
In experimenting with thermo-elcctric batteries formed of plates of bismuth and antimony, the
bismuth being fusible at a low temperature, a very moderate heat must be applied. For this reason
German silver and brass are preferred, as they admit of being safely excited by the contact of the
red-hot iron, which will melt the bismuth.
To render the arrangement of the series of plates or wires of a thermo-eleetric battery more
compact, they are laid side by side, as shown in Fig. 1243. They are insulated from each other by
pasteboard, except at the ends, where the respective plates of bismuth and antimony, or of German
silver and brass, are alternately soldered together, as in the arrangement of the series of plates of a
1243.

voltaic pile. Fig. 1243 represents a series of 10 pairs. The heat of the palm of the hand held in
contact with the soldered ends of this battery induces sufficient excitation to affect a galvanometer
needle.
A more perfect thermo-electric battery is commonly constructed as exhibited in Fig. 1244, consist
ing of 60 pairs of plates of bismuth and antimony, each three-quarters of an inch broad and one_
quarter of an inch thicx. They are packed together in a case B, but are insulated from one another,
except at the soldered junctions of their ends, as above stated. The soldered ends of one series are
arranged together on the under side of the case, where they may be heated by the radiation of the
hot iron plate E, the edge of which only is exhibited in the cut. The opposite series of the soldered
ends are arranged together on the upper side of the case, as seen at A, which forms a reservoir for
receiving a refrigerating mixture of snow or ice and table salt. The plates are insulated from each
other, and from the case, by pouring fluid plaster therein; which also serves to render the consoli-
dated mass impervious to the water resulting from the melting ice. By thus combining two extremes
of temperature at the opposite ends of the plates, there is produced a correspondingly extreme dis-
turbance of the temperature of the plates, and development of electric forces, as tested by the two
conjoined iron semicircles D, environed by a coil of the conducting-wire 0, whereby “a weight of
40 or 50 lbs. is required to sepaiatc them.” Indeed, this thermo-eleetric battery is adequate to
540 ELECTRO—GALVANIG AND THERMIC BATTERIES.
exhibiting various electro-inagnetic phenomena which a galvanic battery is commonly used to exhibit,
and also to give shocks and sparks.
The mechanical forces brought into action upon the needle of a galvanomcter by slight disturbances
of temperature have been illustrated in an interesting manner by the experiments of Nobili and



Melloni. The thermo-electric battery employed by them consisted of 50 small bars of bismuth and
antimony, forming a bundle about 11} inch long and about 1 inch in diameter, inclosed in a band, as
shown in Fig. 1245. To facilitate the radiating and imbibing properties of the two extremities of
the bundle of bars, the conjoined ends are all blackened. The extremities of the circuit are termi-
nated at the two poles a: y. The bars of antimony and bismuth are insulated from each other by
coatings of dry paper or silk throughout their lengths, and are soldered together alternately at their
ends. The terminating bar of each series is separately connected with the ends of a wire forming
the coil beneath the galvanometer n m, Fig. 1246, in the same manner as the copper and zinc plates
of a galvanic battery are connected by the'wires g and h with the battery poles a: 3/ of Fig. 1245.
In the position of the instrument indicated in the figure, it is intended to denote at p the blackened
ends of the bars of the thermo-electric series, heated by a lamp with a reflector. The dotted lines
represent the radiation of the heat through the aperture of the screen 1', while the temperature of
the other ends of the bars p remains the same as that of the surrounding air. The heat of the
lamp induces a disturbance in the electrical equilibrium of the bars of antimony and bismuth. The
electricity is determined to move in one uniform direction in a closed circuit through the conducting-
1246.




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wires soldered thereto, and through the coil in proximity to the galvanometer needle, which is thereby
swung around on its pivot. To prevent local disturbances of the needle by currents of air, the gal-
vanometer is inclosed under a bell-glass. and is suspended from d by a very flexible fibre of silk. At
0 'is a movable screen, designed to intercept the propagation of heat from the lamp when an experi-
ment is suspended. The least radiation of heat from a lamp, or from the bodies of living animals,



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7;



ELECTRO-GALVANIC AND THERMIC BATTERIES. 541

presented before the aperture of this instrument, causes the needle of the galvanometer to move
around on its pivot. This thermo-electrie battery, taken in connection with the appended galvanom-
eter, constitutes a far more sensitive test of the approach of a warm body than the most delicate
thermometer. The approach of
a person within 30 feet of it
causes the needle to move, as
stated by Nobili and Mclloni.
The slight heat of the bodies of
insects, of phosphorescent wood,
putrefying- fish, etc., was thus
detected.
iVoc’s Pile. Fig. 1247, consists
of small cylinders, about 111- inch
long and three-eighths of an
inch diameter, of an alloy of
about 364,» parts of zinc and 621}
of antimony as the positive, and
stout German-silver wire as the
negative element. Twelve of
these pairs have an electromo-
tive force of one Daniell’s cell,
and 20 of them that of one
Bunsen. The resistance of 20
of them is about equal to one ohm. With a great external resistance, 20 of them are equal to one
Bunsen’s; and with a small external resistance, 20 quadrupled ones are somewhat stronger than one
of Bunsen’s elements. The construction of a few elements is shown in the figure. The junctions of
the elements are heated by small gas-flames, and the alternate junctions are cooled by the heat being
conducted away by large blackened sheets of thin copper. To protect the German-silver wire from
oxidation, it is inclosed in a tube of that
1248_ alloy where the flame impinges against
it; and to prevent the ends of the posi_
tive cylinders being melted, they are faced
with iron and a thin sheet of mica. The
German-silver wire may be heated to low
redness. The usual form of the appa-
ratus is in 96 elements, which may be
used either as 96 by 1, 48 by 2, or 24 by
4, and instantly changed from one to
the other of these arrangements by
means of a most ingenious and effective
current-transposer, which does not re-
quire cleaning. The current attains its
maximum strength in about one minute;
that from the single series decomposes
water rapidly, and that from the quad-
ruple series excites a large cleetro-mag-
net powerfully.
Fig. 1248 represents a small Clamond’s
Pile, connected for intensity. Iron plates
are bent back on themselves irregularly,
so as to present many re'éntcring angles.
These are made to envelop the bar, so
that, as the latter heats, it expands more
than the surrounding metal, and so forces
itself lightly into the angles. The couples
are made of. an alloy of zinc and anti-
mony. The bars of alloy are assembled
in crowns, which are each composed of
ten bars, superposed and separated by
collars of asbestos. The apparatus forms
a cylinder, the interior of which is lined
with asbestos, and heated by means of a perforated pipe of refractory clay. The gas burns in the
annular space between the tube and bars. The consumption of gas is said to be 1 cubic foot for
each volt of tension per hour. The electromotive force of this combination is such that 20 elements
are about equal to 1 Daniell cell—about 1 volt.
New Forms on Ganvame Bunnies—Renard’s Chloro-Clu-omz'c Call is represented in Fig. 1249.
The battery generally has the form of a cylinder of a length ten times its diameter.
In the pneumatic battery designed for lighting, the elementary vessels A are sealed to the cover
of a large, tight vessel H, and the lower part contains an orifice O of small diameter. Upon forcing
air into the large vessel by means of a rubber bulb d, or of a pump, the liquid is made to rise in all
the elements at once. A cock permits of regulating the immersion of the elements, and consequently
the internal resistance of the current. This arrangement is adapted to attenuated liquids only; with
the normal liquid the cooling would not proceed quickly enough. The vessel L and the bulb d serve
a lllllllllllllllllll
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542 ELECTRO—GALVANIC AND TI‘IERMIC BATTERIES.

to fill and empty the battery. The positive electrode of the light batteries is formed of a tube of
platinized silver 0.1 mm. in thickness. The weight of the platinum on the two surfaces is about one-
tenth that of the silver, and its thickness is about 155 mm. The use of platinized silver greatly
reduces the weight, the volume, and the internal resistance of the elements. On account of the high
price of these electrodes, carbon B is substituted for them in the batteries in which attenuated liquids
are employed, and in which lightness does not play an essential ro‘le. In order to facilitate the free
circulation of the liquid, and to exhaust all the supply contained in the cylindrical vessel, the tube is
split throughout its entire length to a width of a few millimetres. The negative electrode consists of
1249. 1250.



a cylinder of zinc or non-amalgamated zinc wire,
whose diameter is about 145%“ of that of the ves-
sel, and is calculated to serve but once. This is
guided and held in the centre of the platinized silver tube by several disks of ebonite. The solution
employed consists of free chromic acid and hydrochloric acid more or less diluted or mixed with sul-
phuric acid.
The Renault Dry CeH (Fig. 1250) consists of a vessel made of retort carbon, in the bottom of
which there is chromic acid mixed with gelatinous silica, which possesses the remarkable property of
absorbing 60 times its volume of water. This mixture constitutes the active part of the battery.
This part is isolated from the rest of the apparatus by a pipe-clay disk supporting a zinc spiral z con-
taining simple gelatinous silica in its convolutions. The action of the chromic acid is exerted upon
the zinc in passing through the disk, and produces a current. The advantages of this battery reside
in the wide extent of surface of the carbon vessel and of the zinc spiral, thus giving a maximum of
surface along with a minimum of space. This battery may be employed for domestic uses. The
model which we here figure is combined with a dinner-table call-bell.
The Hussey Bisulphate-ofrlfereury Cell uses bisulphate of mercury packed around the carbon in the
porous vessel. Water is used for charging. The Hussey blue-stone cell has an inner vessel contain-
ing the zinc, which is non-porous at the bottom and porous above. It rests upon the copper, and the
space in the jar below and around the lower part of the cell contains the sulphate of copper. The
porous cell is filled with aeidulated water and the zinc is amalgamated.
The Lalancle-Chaperon Cell uses an outer vessel of cast-iron, which serves as one of the electrodes.
In the small pattern, the iron cell V is closed by a rubber stopper G, through which passes a brass rod
K, provided at its upper end with a binding-post F, and carrying at its lower end the zinc cylinder D.
A lug A on the cell is provided with a binding-screw for clamping the conductor C. The cell is
filled with a saturated solution of caustic potash, and upon the bottom of the cell is distributed a
quantity of black oxide of copper. A valve H, formed of a piece of rubber tubing, is inserted in the
stopper to admit of the escape of gas. The large pattern shown in Fig. 2 is 9 in. in diameter. It is
similar in its construction to the smaller cell. The zine element in this case is formed of a plate bent
spirally. It is not necessary to amalgamate the zines in this battery. It is stated that the small cell
yields a current of 2 amperes, while the larger one is capable of yielding 8 amperes. The E. M. F.
is one volt.
The Schamchz'efi' Cell uses zinc-carbon electrodes with a solution of basic sulphate of mercury. The
residue of this battery is principally mercury, but zinc is also consumed, and is converted into sulphate
of zinc. The mercury which is thrown down by the decomposition of the mercuric sulphate can
either be reconstructed into mercuric sulphate by Mr. Schansehieif’s process, or it can be sold in the
market or taken in exchange in part payment for additional solution. The duration of the light is
simply a question of the lamp and the size of the battery. One ampere flowing‘for one hour requires
about 1 oz. of mercuric solution per cell. Given a certain lamp to burn a certain number of hours,
the size of the battery to maintain it alight is very simply calculated. The battery has a high electro-
motive force and very low internal resistance. It is highly efficient, is a constant cell, showing almost
entire freedom from polarization.
Fawre’s Carbonate-qf-[ron Battery is composed of wooden troughs, say, about 27 ft. long by 3 ft.
9 in. high and 6 ft. 6 in. wide, enclosing some hundred or so double electrodes 6 ft. 6 in. wide. These
electrodes are constituted of an agglomerate of carbon obtained by grinding up in a mill, drying, and


ELECTRO-GALVANIC AND THERMIC BATTERIES. 543

then carbonizing at 1,400° (l, a paste composed of quarter by weight of oats, quarter of bituminous
coal, and half of very porous clayey earth. An agglomerate is thus obtained which is extremely
porous, with which one side of the electrodes only is covered, the other receiving a coating of tar,
rendered entirely impermeable by rebaking. The porous side of the electrode is covered with a large
piece of netting or coarse sail~cloth. The space between these double electrodes is filled in with
granulated iron. The liquid used is salt water led in by tubes. The current is taken from two iron
plates at the two extremities ; the space between one of the plates and the last electrode is filled in
with coke or copper turnings of a sufficient conductivity to carry the current of 1,000 amp‘eres, gen-
erated by this battery at a pressure of about 1.15 volts. The installation of a Faure primary battery
comprises, therefore, besides the battery properly so called (1,000 elements), a pump capable of forc-
ing 1,000 cub. met. of carbonic acid per hour, a machine to agglomerate the carbonate of iron passed
out of the channels, imo bricks, and the reducing chamber. According to M. F aure, the consumption
of fuel in the retort is not more than 0.3 lb. (f coal per pound of iron used in the battery, or per
horse-power hour at the battery terminals.
New Form of Leclamhé Cell—A Munich inventor has produced a modified battery-cell resembling
an ordinary Leclanché, in which the carbon of the latter is replaced by copper in sulphate of copper,
the zinc rod being in sal-ammoniac. There is a special modification in the porous pot itself, which is
prepared by dipping it, to onethird of its height, into melted paraffine wax, and then filling it with an
aqueous solution of ammonia. The ammonia solution is then poured out and replaced by copper
sulphate, which is in its turn poured away, and, finally, the pot is allowed to drain dry. The object
of this successive dipping into ammonia and copper sulphate solutions is the formation of a double
sulphate of copper and ammonium, which fills up the pores of the cell, and, being insoluble in either
of the solutions used in the battery, prevents them from mixing.
Urguhart’s Cell (represented in Fig. 1251) has an arrangement by means of which gravity causes
the exciting liquid to continue in motion until it is exhausted. The engraving represents an element
made according to this device. The containing vessel is cylindrical and deep. The plates are two
disks of carbon and one of zinc, placed in a horizontal plane, in a wooden case fitting the containing
vessel in the manner of an air-tight piston. The piston is packed by means of a rubber ring, stretched
in a groove turned in the face, as represented in section. The carbon plates may be connected
together by means of a metallic stem, which is free of the zinc by an aperture cut in the centre.
This metallic stem must be of platinum. Ivory or ebonite may be used, and the connection may thus
be made between the carbon plates, and to the exterior conductor, by means of a piece of platinum
wire in the wooden annular frame. The connection with the zinc is made by means of a plug and
taper tube of platinum, with a gutta-percha-covered wire leading out of the cell. By these means the
zinc plate may be replaced by a fresh disk, when worn, without trouble. No soldering is necessary
at any part of the element. The lifting stem may either be of two parts, so as to divide, or it may
be made to act as a nut to screw down upon the car. The exciting liquid is poured into the upper
1251. 1252.
















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half of the containing vessel, and flows into the element through a hole in
the upper carbon. It escapes through a smaller hole in the lower carbon
plate into the lower compartment, in which there is a small air outlet. By this means it is claimed
that the action of the cell is rendered continuous as long as any of the exciting fluid remains in the
upper compartment. The internal resistance is said to be not more than 0.1 ohm.
The Crowdus Cell (represented in Fig. 1252) has a novel construction by which the connections are
made through the bottom of the cell to terminals on the exterior at one side or at the ends. The
containing vessel has a removable bottom a and a false bottom b, leaving the space 0 between them
for the wire connections. Above the false bottom is a porous partition B dividing the cell into the
two chambers al and e, in the former of which is the electrolyte for the negative plate, and in the
latter that for the positive. The negative electrode C consists of a plate of porous carbon placed
close to the partition, so as to assist the latter in preventing the mixing of the electrolytes, while the
positive electrode E stands with its lower edge in a mercury bat-h D. The sides of both plates rest
in grooves in the walls of the cell, and are held in place by a filling of wax. A wax coating is also
applied to the bottom of the cell, extending under the plates as shown at f. The mercury-trough is
formed of metal and placed at the lowest point of the chamber, as shown at g. The connecting wire
h is soldered to the trough and drawn down through the false bottom. The wire '5 similarly connects
with the bottom of the negative plate by passing through the bottom I). . If the plate be of carbon,
its lower edge is electroplated with copper. A bar of metal is then soldered to one side of this


544 ELECTRO-GALVANIC AND TI-IERMIO BATTERIES.
_. "——

copper rim and the wire 2' embedded in or soldered to the bar. The wires h and 2' are carried through
the bottom space to either side of the cell, and pass out through holes for connection with binding-
posts. The bottom a is made removable, so that the connections can be properly arranged before it
is fastened on. This is the construction for single cells. '
The Gabe-Premier Cell is of the single fluid type, of carbon and zinc, and contains, in addition, a
reoxidizing apparatus for reoxidizing the depolarizer, which becomes reduced in the course of working
by the nascent hydrogen. Besides the outer vessel and the elements, the cell contains a porous tube
with perforated bottom. This tube is tightly packed with the depolarizer, and only requires renewal
every six to nine months. In the upper part of the porous pot is a glass tube (with side tube and
glass stopper), the side tube going down into the depolarizer itself. When it is to be used, a reoxid-
izing bag is put into the tube with the addition of a little water, and the tube closed. A chemical
action is thereby set up, which results in the liberation of oxygen, which flows through the tube into
the depolarizer, hence reoxidizing that which has been reduced. The reoxidizing bag consists of a
special mixture of chloride of lime with a few crystals of nitrate of nickel ; this, when acted upon by
water or moisture, disengages oxygen, more especially if warmed. Theoretically, the battery may be
said to run by consumption of zinc and chloride of lime.
1253 ~The Edisonllalande Cell is a modification of the Lalande and
- Chaperon cell It is repreSented in Fig. 1253. A and B are two
plates formed by mixing the copper oxide with a slight amount of
alkali-water, then moulding the same, and then exposing the same to
a red heat until the mass is locked together. These plates are held

.9 by a channelled metal frame, of copper, composed of a bottom-piece
a 9,_ $14,, _@ l) a, and two side-pieces b b’ pivoted to the bottom-piece. The pieces
may“ v \, w a. b b are channelled, so as to make a frame for supporting the oxide
g?“ M if; 5" * plates A B. To secure the oxide plates in this frame the side-pieces
Z/ l b b' are swung open, the oxide plates slipped down between them, the
l" '- % 1‘? lower one "15' th ' d th 'd - ' b b' th
_5 _ Z % i,’ res mg on e_ piece a, an e $1 epleces are en
1 , ' % v}, swung together on the oxide plates and are secured by a copper band
I / i; c, which is slipped over the side-pieces b b’. A cross-bar (l is secured

centrally to the bottom-piece a of the frame, so as to ensure the cen-
tral position of the negative 1254
C electrode in the glass jar C. — '
The top of the glass jar is
closed by a cover D, made
preferably of porcelain, and
having openings through
which the upper ends of the
side-pieces b 6' project. A
connecting wire e is secured
to one of the projecting ends
of the side-pieces. The cov-
er D is moulded with a cen-
tral rib f, extending trans-



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supported from the under
side of the cover D, on opposite sides of the rib f. Metal pins 9 from the zinc plates pass upward
through the cover D, and enter a metal block F, in which they are secured by set-screws h. A wire 2',
for making circuit connections, may be secured to the block F. The rib f maintains the zinc plates
E E ’ a definite distance apart, and between the two zinc plates is located the negative electrode formed
of the copper oxide plates A B and the sustaining frame. This construction produces a compact
form of the battery. The solution employed is preferably a 25-per-eent. solution of caustic soda.
Gassner’s Dry Cell is much the same in principle as the Leclanché, but the exciting fluid is con-
tained in a paste, and the zinc element forms the containing vessel. Two forms of the battery are
made, one being cylindrical, the other elliptical (Fig. 1254). The carbon-rod or plate occupies about
one-half of the space in the cell, and the space between the carbon and the cell is filled with the
following mixture: Oxide of zinc, 1 part, by weight; sal-ammoniac, 1 part, by weight; plaster, 3
parts, by weight; chloride of zinc, 1 part, by weight; water, 2 parts, by weight. The oxide of zinc
in this composition loosens and makes it porous, and the greater porosity thus obtained facilitates the
interchange of the gases and diminishes the tendency to the polarization of the electrodes. The
battery works well on an open circuit, and is cleanly and portable. This battery illustrates the gen-
eral form of nearly all dry batteries. The mixture used in the cell differs somewhat with different
manufacturers.
The Hansen Cell is represented in Fig._ 1255. The earthenware jar A has suspended in its. porous
cup C by means of a wooden frame B, so that the solution in the jar may come into close contact
with both the bottom and sides of the cup. The carbon plates D are suspended in this cup, and are
separated at their upper ends by a wooden strip E. The sides and tops of these carbons are electro-
plated with copper, and are connected by the copper band F, bent to form a triangular loop with the
sides of the carbons and the end of the wooden strip between them. The zine plates G have secured
to their upper ends the bent wires 9 and h, by means of which they are suspended in the jar. Two
solutions of different strength are used in the battery, the stronger being placed in the porous cup C,
while the jar A is filled with the weaker solution, which surrounds the bottom and sides of the cups.
The two solutions are not, therefore, united, but the porous cup acts as a conductor between them,
ELEVATORS AND LIFTS. 545

and thus increases the action of the battery. In one end of the frame B, beneath the cap 6, there is
set into the frame a series of mercury-cups for concentrating the currents and providing attachment
for the poles when a single battery is
used, or for attachment of the elec- 1255'
trodes when it is desired to use a se-
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ries of batteries. The frame B is cut 7*
out to receive these mercury-cups and 1 5.? L 1
their connecting bars, and they are s g; Z -I, FT“?
driven into the frame and covered by _ g 2 -' ,a_.\ '
the cap 6, which keeps them securely ,- ‘ Q j '
in place. This cap is provided with r’ f g fr { -
holes 0 which register with the mer-
v' ' ',_' $11
cury-cups. The wires h are bent in s 4,5 1
the form of a staple, one end being _ i - , ’2: iii].
attached to the zinc plate and the r 2 f-\,—]
other end passing through the cap it _ l5 ' mif'ir'
and entering one of the mercury-cups. i g .- f: i “my jr
In the apex of the triangle f of the -; .D' . -.. ‘ ._ (“4 ‘r'
copper band F there is a copper pin i» -. ‘ _l








p, which is soldered to the band and
enters one of the mercury-cups. It will be seen that the wire 11 of one of the zinc plates enters the
mercury-cup i, and that the wire of the other zinc plate enters the mercury-cup j, thus connecting the
two zinc plates, while the pin p of the negative electrode enters the mercury-cup m. Two holes are
shown at R and S respectively. These are for the purpose of filling the jar and cup without remov-
ing the electrodes.
The Kousmine Difusz'on Battery—By making use of the phenomenon of diffusion, M. Kousminc
has succeeded in overcoming the increase in internal resistance of the bichromate-of-potash battery
due to the formation of crystals on the positive electrode. The positive carbon electrode consists of
four strips attached to the lid of the battery. The negative zinc electrode consists of acircular
grating resting on the bottom of the battery. By means of a funnel a 15° Beaumé solution of
sulphuric acid is introduced until it just reaches the lower end of the carbon strips. A 6 to 7 per
cent. solution of bichromate of potash is next introduced. The two liquids do not mix, on account of
the great difference in their densities. When the battery is short circuited it is easy to see that
chemical action only takes place close to the lower end of the carbon strips, which are gradually
surrounded by a violet ring 2 or 3 mm. deep. Above this region the bichromate solution retains
its original color. The bichromate solution being very weak, the chromic crystals dissolve as
soon as they are formed, and the positive electrode is not covered by a deposit as in other batteries.
ELEVATORS AND LIFTS. Suspended platforms or boxes known as elevators are largely used
now to raise passengers and freight from the lower to the upper stories of high edifices. Since their
introduction buildings are carried much higher than before. The structure of the Western Union
Telegraph Company in New York has ten stories above the street which are occupied as oflices, while
the New York Tribune building has twelve such stories. Without a passenger elevator the upper
stories would be practically inaccessible.
Power required for Elevators—The useful power rcquircd fcr cpcrating an elevator is very small.
That employed to run either of the sets of elevators in two of the largest buildings (the \Vcstern
Union Telegraph and Even-ing .Pest buildings) in New York City amounts to less than 310- of a
horse-power.
Classes of Elevators—Elevators in general use may be divided into two general classes : 1. Steam
elevators, where the rope lifting the car is wound round a drum turned by a steam-engine; 2. Hy-
draulic elevators, where the rope lifting the car is connected with a motor worked by water. In
addition to the motor, the hydraulic elevator must have a pump to lift the water from the cellar to
the tank above.
The reasons why steam elevators are so wasteful of power are: l. The low steam-pressure and
the great back pressure in the steam cylinders; 2. The small size of the cylinders; 3. The large
proportion of power expended in overcoming friction on engine and car ; 4. The fact that the engine
runs while the car is descending, thus requiring a cylinder full of steam at least atmospheric pres-
sure. The following are the pressures on the indicator card of the engine running the elevator in
the Western Union building while carrying passengers :
Up. Down.
Initial pressure above zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.0 24.5
Terminal pressure above zero. . . .. . . .. . . .. . . .. . . .. . . .. . . .. 26.6 22.1
Mean back pressure above zero . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.6 20.4
Indicated pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.7 2.9
Friction of engine and load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 0
The sauses of the waste of power in hydraulic elevators are: 1. The ordinary steam-pump not
being an economical machine; 2. Having to use a cylinder full of water whether the car is fully
loaded or not; 3. The large proportion of power absorbed by the friction of the machine.
In the machine in the Eam'ing Post building, the dimensions are as follows: Height from surface
of water in well to surface of water in tank, 140 feet; diameter and stroke of hydraulic cylinder,
36 x 96 inches; lift of car, 96 feet. From these data may be calculated the following: Total un-
balanced load in car, equivalent to 140 feet of water on plunger, 6,000 lbs. ; number of round trips
35
546 ELEVATORS AND LIFTS.

in 6 hours, 170; actual load carried each round, calling each passenger 140 lbs., 960 lbs. Thus it
appears that five-sixths of the head of water is wasted.
The cars of both the hydraulic and steam elevators are generally in part counterbalanced. The
counterbalance is always much lighter than the car, in order to be certain that the car will not stick
fast on its passage and then drop suddenly after the rope has become slack. There are various
devices called “safeties ” to prevent this, which will be described in the proper place.
The cost of running by steam a large elevator, like that in the Western Union building, for a
year of 300 days, 8 hours a day, may be reckoned as follows :
Interest on cost of elevator, engine, and boiler, $10,000, at 7 per cent. . . $700
Annualrepairs,5pereent.......................................... 500

Sinking fund, 3 per cent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. _ 300
Engineer, at $60 per month . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720
Attendant, at $40 per month . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480
Goal, 600 lbs. per day, at $6 per ton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 540
Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $3,240
In cities where the municipal authorities will furnish water, hydraulic elevators can be run much
more cheaply than steam. In other places they are gradually gaining favor from their great simplicity,
less first cost, less liability to accident and necessity for repair, and smaller amount of fuel required.


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Steam Elevators—Two of the best types of steam elevators are illustrated in Figs. 127 5 to 1219.
Fig. 127 5 shows the car in an Otis elevator. A A A A are the guide-blocks, which may be
tightened up by screws. P P are the pawls which catch in ratchets bolted the whole length of the
guides when the hoisting rope gives way.
Fig. 1276 shows the machinery overhead in an Otis elevator. O is the drum over which the rope.
to counterbalance passes ; I), the drum over which the hoisting rope passes ; H, the hand-rope ; W,
the weight which presses the brake on the drum when the hand-rope is thrown up.
ELEVATORS AND LIFTS. 547




W/lll/l





Fig. 1277 is an end and Fig. 1278 is a side view of the hoisting engine for the Otis elevator.
L is the starting lever connected with the hand-rope. This machine works entirely through gear-
wheels, which are apt to be more durable than worms and worm-wheels.
1277.









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Fig. 1279 shows the Hanford elevator engine. D D are the drums, which turn in opposite direc
tions, being driven by right and left worms on the shaft 5'. B is the belt driving the worm-shaft.
The hoisting ropes and hand-ropes are not shown.
Hydraulic Elevators.—The water-balance elevator, Fig. 1280, is in use in the Western Union build-
ing, New York. The car or platform is similar to the ordinary
steam elevator, but is connected, by means of wire cables pass-
ing over large sheaves at the top of the well-room, to a counter-
balancing bucket instead of a steam-engine. This bucket fits
closely in a water-tight, upright tube or stand-pipe, about 2 feet
in diameter, extending from the basement to the upper story.
Near this stand-pipe in the upper story is placed a tank, and
from this tank an 8-inch discharge-pipe takes the water into



the bucket, which moves up and down in the stand-pipe. A valve in this tank is opened by
stepping upon a treadle _in the car, and the operator thus takes into the bucket enough weight of
water to overbalance the load he then has in the car. As soon as the bucket is heavier than the car,
ELEVATORS AND LIFTS. 549
it descends, and of course draws the car upward, thus using the minimum power required to raise
each load, rather than the full power of an engine each and every time.
The speed is controlled by
means of brakes or clamps, that firmly clasp wrought-iron slides secured to posts on each side of the
1280.


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well-room, the operator having control of these brakes by a lever in the car. When the car has
ascended as far as deemed, the operator_steps upon another treadle in the car connected with a valve
in the bottom of the bucket, and thus discharges the water into the receiving tank below until the
550 ELEVATORS AND LIFTS.
















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car is heavier than the bucket, and it then of
course descends. The water is thus taken
from the upper tank into the bucket, dis-
charged through the stand-pipe into the re- B
ceiving tank under the floor of the basement,
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tank, so that it is used over and over again
without loss. From the upper tank water “ ' "
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then it must be replenished.
The duplex elevator, Fig. 1281, is operated
by utilizing the weight of water within a tube,
using it both above and below one or more
pistons. It is well known that 33 feet or less
of water in a tight tube will adhere to the
bottom of a piston, and weigh the same as if
above it. By the application of this principle
an exceedingly simple machine maybe made e a
at a moderate cost, adapted to use in dwell-
ing-houses, and for all passenger and freight
purposes. The tube in which the pistons
move is connected by an open pipe to a tank,
or directly to the city mains, and discharges
its water into a tank 'or sewer below. By
Opening the valve at the bottom of the tube
the water is discharged, and the weight of the
whole column, thus thrown upon the pistons, r__
draws them'down, and raises the car attached ‘ I l .,
to them. The power is always the same, the ‘ D---_-_"_--n=5\,,g It supply of water above filling the tube as fast J: ' ,“ #1.- =
as drawn out below, so that we always have
the weight of the tubeful, or the pressure direct from the city mains, to draw the car and its load
up. By pulling the valve-rope the opposite way, a valve connecting with a return-pipe is opened,





















ELEVATORS, GRAIN. 551

and the car is allowed to descend. The upward and downward motion is perfectly smooth, noiseless,
and steady, and free from all jarring or shaking.
Fig. 1282 represents a device for giving a long travel to the car with a short travel to the hydraulic
piston. The piston is moved up and down by admitting water above and below, and the motion trans
ferred through the chain to the large drum around which the hoisting-rope is wound.
Fig. 1283 represents the general arrangement of a hydraulic elevator, in which all the machinery
except the steam-boiler is shown. A is the car; B, the hydraulic cylinder; 0, the pump; D, the
reservoir for water on the top of the building; E, the reservoir for water in the cellar.
Safeties.—These are devices to keep elevator cars from falling in case of breakage of the rope.
Fig. 1284 represents “ Baldwin’s safety.” A is a wrought-iron slide, 4 in. by {,- in. Suc slides are
firmly bolted to the posts on each side of the well-room, and act as guides to the car, and for holding
the same from falling if the ropes should break. B is the safety-block. This is made of cast-iron,
and is 15 by 16 by 5 in. Two blocks are used on each elevator, securely attached to the bottom of
the platform. D is a wrought-iron band, 24; in. square, shrunken around the safety-block to give it
additional strength. F is the safety-roll, made of corrugated steel, 114» in. diameter. G is the finger
on which the safety-roll rests, and H a rod attached to it. This safety is not operated by springs, but
by the weight of the car itself. The breaking or overstrain of one or all of the six cables brings it-
into action. Four of these cables are attached to the bottom of the car, through the safety-block.
The other two act as safety-cables, and do not come into use until the others are overstrained.
Whenever this occurs, the weight is thrown on the safety-ropes; by which means the fingers to
which they are attached, and on which the safety-rolls rest, are raised, so as to bring the safety-rolls
in contact with the slides (which are stationary and firmly secured to the posts) on one side, and the
inclined planes_ on the safety-blocks on the other; thereby wedging these rolls firmly into the slot, so
that it is impossible for the car to go down a single inch until a readjustment is made.
Electric Elevator.——There is perhaps no more severe task to which an electric motor can be put
than elevator service. In such situations the full load is constantly being thrown on or off instantly,
and the motor is subjected to the most severe strains.
A novel form of electric elevator is represented in Fig. 1284. A. constant potential motor drives a
counter-shaft connected by worm-gear to the winding-drum A. The motor is controlled entirely by
means of the switch B, which is attached by a sprocket-wheel and chain to the brake-shaft C, which
is controlled by a rope manipulated by the attendant on the elevator.
The motor is so wound that no external resistances whatever are required, the control being effected
entirely by means of the switch B. Another important advantage of the arrangement consists in the
fact that the motor stops with the elevator, so that when the elevator is not running no current what-
ever is consumed.
To accomplish the quick starting and stopping of the elevator without detriment to the motor, the
brake D is employed, which bears upon a brake-wheel mounted on the driving-shaft. It will also be
noted that the brake-shaft carries a cam E, which is so arranged that when the attendant starts the
elevator the cam lifts the weight Wattached to the brake~shoe, and allows the motor to start the
elevator.
When it is desired to stop the elevator, the cam is turned a quarter revolution in the opposite
direction, which allows the weight W at the end of the_brake-arm to fall and apply the brake,
bringing the elevator to a short stop. It will thus be seen that while the elevator can be stopped
in the shortest possible space, the motor can never be started while the brake is on, since the start-
ing-switch is directly connected to the brake-shaft.
Descriptions of new forms of elevators will be found in the files of the Scimtz'fic American, Engi-
nem‘z'ng (London), and other technical periodicals. The catalogues of the manufacturers also contain
much useful general information.
ELEVATORS, GRAIN. In this country the name of grain elevators is given to certain estab-
lishments in which the transshipment of grain is carried on, and in which it is often stored for long
periods.
The elevating device proper, by which the grain is taken from the cars, raised to the top of the build-
ing, and finally delivered into the bins, usually consists of an endless belt provided with a series of
buckets. In the more improved forms the belt consists of chain-links, sometimes in single, sometimes
in double, strand, which pass over sprocket-wheels, from which the power is communicated. The
lower wheel is held in a device termed the “ boot,” which is usually provided with means for adjust
ing the pulley.
A new form of bucket is made of seamless steel and with a round bottom. The elevator leg is
usually built straight on the lifting side. Messrs. H. XV. Caldwell 82 Son, of Chicago, Illinois, recom-
mend that the pulley on the head-shaft should be three times as large as the pulley in the boot, and
that the speed of the head-shaft should be 43 revolutions per minute, regardless of the size of pulley
when the latter is 36 in. in diameter or over. They point out the curious fact that the speed of an
elevator belt can be so great that no grain will be discharged. The material should be fed into the
boot on the front or lifting side at the centre of the pulley, and not underneath it.
For moving grain in a horizontal direction, conveyers are used which consist usually of a rotary
' horizontal shaft having spiral wings which engage with the grain and so screw it along. In turning
corners, the shafts are usually connected with bevel gears. In an improved form of conveyer the
“ flight,‘n as the spiral wing is termed, is stamped from a sheet of steel, and is so arranged as to hold
itself upon the shaft, acting as a brace or rib on the outside. Special forms of coupling are employed,
so that any portion of a long line of conveyors can be thrown out of operation when it is necessary
to use only a portion of the apparatus. The conveying device is generally arranged in conduits which
are lined with metal. Smooth friction-wheels running against iron pulleys are often employed to start
the conveyer without shock or jerk. In all grain elevators the grain is weighed when taken in, and
552 ELEVATORS, GRAIN.

again when sent out. The removal of the grain from one spot to another, necessitated by these
operations, is almost wholly effected by machinery in a very small space and in a very little time.
There are establishments capable of storing from 1,000,000 to 1,600,000 bushels of grain at once,
and these may take in from 5,000 to 8,000 bushels an hour, and send out twice that quantity in
1818.


the same time. If it be borne in mind that the distinctions of shipper, receiver, and owner have to
be kept up, it will be seen that the problem solved by the grain elevator is a very complicated one.
The buildings are approachable by vessels upon one or more sides, and have tracks for railroad
cars running into them on a level with the adjoining ground. The grain is shoveled from the cars
into receiving pits, from which it is raised by buckets attached to an endless belt to the upper part
of the building. In order to weigh it, it is stopped at the beginning of its downward motion in a
hopper resting upon a scale. To clean it, it is let fall from the top of a cylinder 15 or 20 feet long,
up which a strong current of air is driven by a fan. The grain is stored in compartments, or bins,
into which the building is divided, which are generally about 10 feet square and from 50 to 65 feet
deep. The bottoms of these bins are hopper-shaped, in order that the grain may run out of its own
accord through an orifice of limited section. A small annex to the principal building contains the
engine and boilers. The motion is transmitted by belts to one or two horizontal shafts in the upper
part of the building, which drive the elevators. Such are the general arrangements of an elevator
building. '
As an example of improved construction of grain elevators, elevations and plan of the Canton
elevator are presented in Figs. 1318, 1319, and 132057“; The structure is located at Canton, near
Baltimore, Md, and is built upon a pier 100 feet in width, which extends into the bay for a distance
of 500 feet from low-water line. The foundation is of piling 60 feet long, spaced about 2 feet
from centre to centre, and cut ofl" at 3 feet under extreme low water. Around these piles were
driven two rows of sheet-piling, and the whole space filled with oyster-shells and small stones, form-
ing a solid foundation of great strength and stability. Upon the tops of the piles was laid a plat-
form 151 feet long and 85 feet Wide, formed of two thicknesses of 12- by 12-inch Georgia pine.
This was of sawed timber laid close, and well secured by rag-bolts and locust treenails. The princi-
pal dimensions of the superstructure are given in the following table, and will serve as a guide to in-
dicate relative proportions in designing buildings of similar character :

* Engineering, xxii., 571.
ELEVATORS, GRAIN. 553

‘ Feet. Inches.
Length from outside to outside of posts . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 11
Width “ “ “ at base . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 0
“ “ “ “ on weighing floor . . . . . . . . . . . . . . . . . . . 40 8
Height from masonry to top of main rafters at centre. . . .. . . . . . . . . . . 139 6
“ “ “ to under side of grain-bins in clear . . . . . . . . . . . . 19 5
Thence to top of grain-bins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 4
“ to under side of next floor-beam, . . . . . . . . . . . . . . . . . . . . . . . . . . 25 0
“ to top of wall-plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 8
“ to top of main rafter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1
Ventilating top upon main roof adds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 0
There are 144 rectangular bins; one is used for piping and one for a hoisting pit, leaving 142 for
grain. One-half of the number measure 7 feet 41} inches by 7 feet 6 inches by 60 feet inside, ex-
cepting where each elevating tube passes through the bins, in which case a partition is cut out,



1819.
“1.5.9
r.
making a 'bin 15 feet 3 inches by 7 feet 6 inches by 60 feet inside. The engines are located above
the grain-bins at the land end of the building; they are horizontal, with two cylinders 16 inches in
diameter and 24 inches stroke. A piece of 4-inch gas-pipe, supported by bearings, extends through
the centres of all elevator tubes in each line, and receives from the main engines a horizontal move-
ment of 12 feet and about 14 double strokes per minute. To this gas-pipe, at each elevating tube,
two large scoops or shovels are attached by ropes passing through leaders properly arranged; by
I554 ELEVATORS, GRAIN.

means of these the ears are quickly unloaded. The centre line of shafting passes through the centre
of elevating tubes, and at each tube it has a paper friction-pulley, 1 foot 6 inches in diameter, built
of disks of best quality of Manilla paper, under a pressure of 60 tons, and secured by heavy fol-
lowers and bolts. Above each paper friction-pulley is one of cast-iron, double-armed, very heavy,
3 feet 9 inches in diameter and 22 inches face; it has adjusting machinery attached to its short
1320.


shaft. In the boot at the base of the elevator is a drum-pulley 2 feet 6 inches in diameter, 22 inches
face, fitted with stretching gear for the belt, and worked from the track floor. The grain-belt is of
rubber, four-ply, 20 inches wide; it connects these two last-mentioned pulleys, and is kept tight by
the stretching gear just mentioned. The grain-buckets, of heavy tin, are spaced 12 inches from
centre to centre, and secured to the belt by six bolts in each bucket. They measure 18 inches long,
51} inches deep, 6% inches wide. The shafting being in motion, the upper belt-pulley is lowered, and
rests upon the paper friction-pulley, thus causing the elevating belt to travel at about 450 feet per
minute. In front of each elevator tube are placed two sets of Fairbanks scales, each fitted with an
iron tank, having cylindrical body, conical top and bottom, with capacity for 540 bushels of wheat,
shoot-spout and valve fitted to the bottom of weighing tank. Under each pair of tanks is a conical
collecting hopper, having a crane-spout leading from it to the storage bins, shifting conveyer, or
shipping spouts, as desired. Two shifting conveyers are located, as shown in section, above the
grain-bins, and extend the whole length of the building. They consist of four-ply rubber belts, 30
inches wide, supported by wooden rollers, spaced 5 feet apart under the loaded and 10 feet apart
under the unloaded belt. They are driven by bevel friction-gear of paper, and are reversible. They
move at a speed of 550 feet per minute, and are arranged to throw off the grain wherever desired.
The belt is perfectly flat, has no raised edges, and does not spill any grain when working under a
capacity of 9,000 bushels per hour. The arrangement of crane-spouts is fully explained by the
drawings.
The ivorking of each line of elevators is as follows: Four ears of grain having been passed by
the inspector are pushed in upon one track, until stopped by the bumper at the end, which will leave
the doors nearly opposite the elevators. The car doors having been opened, two attendants enter
each car with the wooden shovels, with which they quickly discharge the grain into the receiving
hopper. The ropes which work the scoops are attached so as to work alternately, this causing a con-
tinuous flow of grain through the door of the car, so long as any remains or the gaS-pipe plunger is
kept in motion. At the beginning of this operation the grain-valve in the boot, Fig. 1320, should
be opened, so as to allow the grain to flow from the receiving hopper into the ascending belt-buckets
(all of the machinery being in operation) just fast enough to fill them.
The grain is discharged from the head of the elevator into one of the weighing tanks, where the
whole car-load is collected, weighed, and distributed. While this operation is in progress,.four cars
are pushed in on the other side of the same elevators and discharged in the same manner, as soon
as the valve at the elevator head is shifted to the other weighing tank, which is done after all of the
first lot is raised. The first line of empty cars is now drawn out and full ones take their places, and
this operation is repeated as rapidly as circumstances will allow. The weighing tank having been
filled, the grain is weighed and discharged through the valve into the collecting hopper and crane-
spout, to where it may be required. The crane-spout is made of sufficient size to deliver the grain
much faster than the elevator can lift, so that one weighing tank may always be ready to receive
grain. The crane-spout can deliver the grain into each of many storage-bins, shipping bins, shipping
spouts, or shifting conveyers, as may be desired or found necessary. Should all the elevators be
ELEVATORS, GRAIN. 555

working one kind or lot of grain to be stored in one part of the house, the cranespouts which can
reach those bins may be used, and the remainder of the grain be discharged upon the shifting con-
veyers, and by them placed in the bins. Similar use is often made of shipping conveyers when
working the whole house upon one vessel, or a single elevator upon a large vessel which cannot be
moved, the elevator being a long distance from the spout leading to the vessel. Should a vessel
be nearly ready for grain or be taking bagged grain, it is run into the shipping bins, and from them
drawn off as required. When the grain in the house or storage bins is to be shipped, spouts are
attached to the bottom of the bins, and the grain discharged into the receiving hopper in a con-
tinuous stream, elevated as before described, weighed at the top of the house, and discharged through
crane and shipping spouts into the ship. '
When grain is ordered for clean delivery, it is elevated in the regular way, weighed, and discharged
into the foot of the cleaningelevator, by which it is lifted to the top of the house and delivered into
a feeder. From the feeder it flows on to a screen made of perforated Russia iron, measuring 8 feet
wide by 12 feet long, and is set at an angle of 25° from horizontal; it is driven at a speed of 1,100
vibrations per minute. As the grain falls upon it, the cobs, sticks, straws, etc., 'are carried over the
end; the grain passes through and down an inclined plane to a wind-spout 8 feet by 1 foot, where it
is met by a strong current of air. The unsound grain, dirt, and chaff are carried off, and the cleaned
grain falls into a chamber, and is carried where desired by an iron pipe. The unsound grain is de-
posited in the dirt room, and the chaff and light dirt thrown into the water. The current of air is
produced by a large exhaust fan. As only about 10 per cent. of the grain goes through the cleaner,
it is claimed that this system of “cleaning elevators” for lifting the
grain to be cleaned is a great improvement upon the custom of building
the house high enough for the cleaner, and raising all of the grain to
that height, whether it has to be cleaned or not. A saving of 10 per cent.
in fuel is claimed by this arrangement. Each of these machines will
draw grain from four main elevators, and clean 8,000 bushels per hour.
The total storage capacity of this building is 500,000 bushels. The
total elevating capacity per hour is 32,000 bushels. The size of the
grain-bins depends upon the nature of the business, location, rules of
produce exchanges, and systems of grading. Small ones in larger num-
bers are' the most convenient, as many prefer their grain separate.
With heating grain they save loss, and where there is no grading of
grain they are necessary.
The Renhayc Elevator, Fig. 1321.—The principle on which this ap-
paratus is based is, that when divided solid matters are mixed with air
in motion in a conduit, 9. semi-fluid is formed, in which the pressures
vary according to the laws of ordinary fluids. It may be demonstrated
mathematically that in the semi-fluid column pressures vary as in ordi-
nary fluid ; that the specific weight of the semi-fluid column may augment
up to a certain limit; that the solids may be elevated to any height by
regulating the specific weight of the semi-fluid according to the pressure
obtained ; that when the specific weight of the semi-fluid column is too
considerable in proportion to the pressure, this column attains a limit
in height which it cannot pass; and that the maximum results take
place when the specific weight of the semi-fluid column is in the neigh-
borhood of its maximum. Barret and Korting have both utilized air-
pressure as a means of elevating grain, the one employing the vacuum
produced by an air-pump, the other eutraining the air by a steam-jet.
The Renhayc elevator difiers from both of these in that the air is set
in motion by a fan-blower or centrifugal ventilator, and that the specific
weight of the semi-fluid is regulated by a pneumatic regulator. Vis a
double ventilator capable of giving a pressure equivalent to 29.2 inches
of water, connected to the receiver R by the tube T. Into the receiver
R the grain passes by the tube S, which is separated from the tube T
by a plane inclined at 45°, which carries the grain to the lower part of
the chamber. In the upper portion of the latter is a perforated partition which affords passage to
the air and to dust. The grain escapes at the lower portion upon a platform placed at suitable dis-
tance to regulate the escape and hinder the reentry of air. N is a regulator which governs the
weight of the semi-fluid column according to the pressure; it consists of a piston, the joint of which
is a rubber membrane which extends without friction. A tube connects the tube 8 with the lower
portion of the regulator. The piston is connected by pulleys with a damper O, which comes down
over the lower end of pipe 8, and is designed to admit more or less air into the semi-fluid mass.
The quantity of air is by means of the piston regulated according to the pressure of the ventilator.
It will be obvious that if the exhaustion of air in S reaches too high a degree, the upper part of N
- descends and O is thus drawn up, increasing the air orifice at the bottom of the pipe.
MM. Sautter and Lemonnier have made numerous experiments on this device, of which the follow-
ing are some of the results: The receiver was placed 32 feet above the ground. The motive power
was 6-horse to elevate from 17,500 to 22,000 lbs. per hour, and the regulator worked perfectly the
instant the lower orifice of the pipe became choked. A large quantity of dust was mixed with the
grain, but the latter was delivered perfectly clean, the impurities passing ofi through the aspirating
pipe. By taking out the receiver and leading the grain through the ventilator, the material was
cleanly cracked without production of flour. To secure the best results it has been found that the
velocity of~ the solids on arriving in the receiver should be nothing, and that the velocity of the air















556 ELEVATORS, GRAIN.

leaving the ventilator should have a determined value for each kind of grain. The rising tube is
gradually increased in diameter so as to diminish progressively the velocity of the grain as it ap-
proaches the receiver. The latter is constructed so as to divide the air-current by means of numer-
ous concentric rings, and the orifice of the aspiration tube is enlarged so as to diminish the strangu-
lation of the fluid vein. At the lower part of the escape tube is placed a conical counterweighted
regulator. The regulator is placed around the rising tube, and is in communication with the air pass-
ing from the ventilator, and hence modifies the velocity of the entrained air. This arrangement is
said to give results far in advance of those reached by any other pneumatic system of elevation. It
has been determined by experiment that by giving the air a velocity of circulation of 64 feet per
second, grain, plaster, and similar substances can be elevated in a vertical tube; with a velocity of
128 feet, stone in pieces large enough for macadamizing may be lifted ; with a velocity of 192 feet,
heavy bodies, such as leaden balls, pieces of iron, etc., can be elevated. Large spikes, screw-bolts,
coke, coal, and iron chain have been thus lifted without difficulty.
Fig. 1322 represents a simple form of elevator for unloading vessels. The extremity of the shoot
0 is inserted in the hold of the vessel about to be discharged, its height being regulated by the
1822.


*-\\
_ .\ - - “.M-fl ___.


guide-frame and pulleys. The machine is put in motion by means of the prime mover A- and band-
wheel B, when by means of a series of tin dippers attached to a belt of gutta-percha or leather,
tightly stretched over the wheels at B and 0, the grain is brought up to a height of 76 feet, and dis-
charged by means of the small spout attached to the elevator into the weighing machlne; from
thence, by a repetition of the same contrivance, it is taken through the building to a shoot on the
roof, containing an Archimedean screw, by the use of which and the elevator the grain may not only
be placed on any particular floor in the warehouse, but may be transshipped.
ELEVATORS, GRAIN. 557
Floating Elevator.-Figs. 1323 to? 1326 are a plan, cross-sections, and longitudinal section of a
floating elevator designed by Messrs. Gill & Mansfield of New York. This kind of elevator is used
for transferring grain from one vessel into another. By means of them, ships can take their con-
1326.
1 324.


558 EMERY—GRIN DIN G.

signment of grain while lying in their docks and receiving the rest of their cargoes ; avoiding thereby
the expense of moving to a storage elevator, as well as the expense of storage, as grain coming into
port by boat can be immediately transferred to the vessel to which it is consigned.
The vessel carrying the elevator is constructed on the ordinary propeller model. The one here
described is 100 feet long on the keel, with 10 feet depth of hold and 27 feet breadth of beam amid-
ships. The propelling power is furnished by an engine of 150 horse-power. The engine is arranged
so as to be disconnected from the propelling apparatus when its service is required for elevating pur-
poses. Only 35 horse-power is required to work the elevator up to its full capacity, i. e., elevating,
cleaning, and transferring 5,000 bushels per hour. In the figures, A is the boat elevator; B, the
yoke in which the boat elevator hangs; C', a telescopic spout, which is lengthened or shortened as
the boat elevator is lowered or raised into position; D, a receiver or pit; E, the screen elevator; F,
the screen; G, the wind-spout; H, the shipping elevator; 1, the shipping spout; J, the fan; K, an
outlet for the dirt blown out of the grain; L, the engine—a surface condenser with two 18- by 18-
inch cylinders.
_ The position of the elevator when transferring grain is naturally between the two vessels. The
boat elevator is lowered into the hold of the vessel containing the grain, by means of a rope attached
to the drum F. The grain, being raised by the elevator A, passes downward through the spout C
into the receiving hopper W, from which by means of a valve portions of it are drawn off from time
to time into the weighing hopper W’. From this, after being weighed, it is passed into the receiver
D to the foot of the screen elevator E, by which it is again raised and passed down over the screen
F (an inclined, perforated sheet of Russia iron) into the wind—spout G, where it is met in its descent
by a strong current of air caused by the fan J. By this current of air all the chafl’ and foreign
matter in the grain is driven out through the outlet K into the river, the grain falling to the foot of
the shipping elevator H, by which it is again raised and passed out through the shipping spout I
into the vessel alongside.
EMERY—GRINDING. Emery-wheels are employed mainly for producing cutting edges and for
smoothing surfaces. Their action is abrasive, and is termed grinding or polishing, according to the
nature of the duty. It is indeed somewhat difficult to separate the grinding from the polishing duty,
as the end to be attained rather than the nature of the duty determines the name by which that duty
is known. As a general rule, however, emery polishing wheels are distinguished from grinding Wheels
in that the former are composed of wooden disks covered with leather, the surface of which is cov-
ered with emery fastened thereon by glue; while the grinding wheels are composed of emery and
cement. As a matter of fact, the action of the emery is merely abrasive in both cases ; and although
in practice wheels composed of, or covered with, the finer grades of emery (that is to say, from about
No. ’70 to N 0. 120) are used for polishing purposes, yet, as before stated, emery polishing wheels are
understood in our workshops to be wheels of wood covered with leather and coated with emery.
Notwithstanding this, however, wooden wheels are sometimes coated with emery of the coarsest
grades (from about No. 10 up to No. 50), and the action of such wheels can scarcely be properly
termed that of polishing. The duty of solid emery-wheels, composed of even the finest grades of
emery, is usually termed emery-grinding, although the result attained is in many cases that of coarse
primary polishing.
The solid emery-wheel is an American invention, and has in the smaller sizes attained great prom-
inence of late years from its special capabilities ; such, for instance, as the grinding of hardened tools
or cutters to a true edge, or of hardened surfaces to a true conformation. The larger sizes of solid
emery-wheels are used for purely abrasive or grinding purposes, for which the fast-running grindstone
is either too unwieldy, or so obstructive to the workman’s operations as to render the manipulation
both tedious and crude. Among this class of operations may be enumerated the grinding of plough-
shares, stove-plates, and wrought-iron plates, the fettling of iron castings, and the grinding of the
inner surfaces of hollow iron ware. In all the latter classes of work, however, the emery-wheel has
displaced the grindstone because of its handier and greater adaptability to the size, shape, and form
of the works, rather than to its cutting qualification. For it is an indisputable fact that, while the
speed at which an emery-wheel can be run is several times greater than that at which it is safe to
run a grindstone, yet a large grindstone will remove a given quantity of metal in less time than any
emery-wheel, even of the largest sizes yet made. Another and very successful field of operations
occupied by the solid emery-wheel is that of finishing work in the lathe. Thus, the bearings of spin-
dles and the surfaces of steel or chilled east-iron rolls may be and are finished more true and given
a finer polish by emery-wheels than is possible with lathe tools of any kind whatever.
In all cases of the employment of emery-wheels in place of steel cutting tools, the operation is
considerably slower, and it may be laid down as a rule that, save upon metal too hard to be operated
upon by steel tools, the emery-wheel cannot compete with the ordinary lathe, planer, or milling-
tool. And furthermore, the emery-wheel cannot compete with the planer or with the file in the
production of flat surfaces upon either hard or soft metals. Indeed, as a fitting-tool for fine work,
the emery-wheel, except upon cylindrical surfaces, is out of place. In the abrasive operations carried
on in the manufacture of needles, cutlery, harness-hardware, etc., the emery-wheel is a most valuable
tool, and has assumed a very important position. This is largely due to its strength in proportion to
its shape and size. For instance, vulcanite emery-wheels 18 inches in diameter, and having three-
sixteenths of an inch thickness (or “face,” as it is commonly termed), are not unfrequently used at a
speed of some 5,000 feet (measured at the circumference) per minute; whereas it would be altogether
impracticable to use a grindstone of such size and shape, because the side pressure would break it
no matter at what speed it was run. Indeed, in the superior strength of the emery-wheels of the
smaller sizes lies their main advantage, because they can be made to suit narrow curvatures, sweeps,
recesses, etc., and can be run at any requisite speed under 5,000 feet per minute, and with considera-
ble pressure upon either the circumferential or radial faces.
EMERY—GRIN DING. 559

I '
The distinctive feature of the various makes of solid emery-wheels lies in the material used to
cement the emery together, and much thought and experiment is now directed to the end of discov-
ering some cementing substance which will completely fill all the requisite qualifications. Such a
material must bind the emery together with sufficient strength to withstand the centrifugal force due
to the high speeds at which these wheels must be run to work economically; and it must neither
soften by heat nor become brittle by cold. It must not be so hard as to project above the surface
of the wheel; or in other words, it should wear away about as fast as does the emery. It must be
capable of being mixed uniformly throughout the emery, so that the wheel may be uniform in
strength, texture, and density. It must be of a nature that will not spread over the surface of the
emery, or combine with the cuttings and form a glaze on the wheel. This glazing is in fact one of
the most serious difficulties to be encountered in the use of emery-wheels for grinding purposes, while
it is a requisite for polishing uses, as will be explained further on. Many of the experiments to
prevent glazing have been in the direction of discovering a cement which would wear away under
about the same amount of duty as is'nccessary to wear away the cutting angles of the grains of
emery, thus allowing the emery to become detached from the wheel, rather than to remain upon it
in a glazed condition. In the following list of cementing materials in common use, the initial W.
prefixed signifies that the wheel thus made may be used with water; H., that the wheels are com-
pressed by hydraulic pressure; and T., that they are tamped: W. H. Hard rubber. H. Chemical
charcoal; that is, leather acted upon by acid (used to prevent shrinkage) and glue. T. Oxychloride
of zinc. W. H. Shellac, linseed oil, and litharge. T. Silicate of soda (water-glass) and chloride of
calcium; celluloid. T. Oxychloride of magnesia. W. H. Infusoria. H. Pure glue.
The speed at which an emery-wheel may be run without danger of bursting varies according to
the thickness or breadth of face of the wheel, as well as according to the quality of the cementing
material and excellence of manufacture. Hence, although a majority of manufacturers recommend
a speed of about 5,000 circumferential feet per minute, that speed may be largely exceeded in some
cases, while it would be positively dangerous in others. It is in fact impracticable in the operations
of the workshop to maintain a stated circumferential speed, because that would entail a constant in-
crease of revolutions to compensate for the wear in the diameter of the wheel. Suppose, for ex-
ample, that a wheel when new is a foot in diameter: a speed of about 1,600 revolutions per minute
would equal about 5,000 circumferential feet; whereas, when worn down to 2 inches in diameter, the
revolutions would require, to maintain the same circumferential speed, to be about 9,500 per minute,
entailing so many changes of pulleys and counter-shafting as to be impracticable. In practice, there-
fore, a uniform circumferential speed does not exist, the usual plan adopted being to run the large-
sized wheels, when new, at about the speed recommended by the manufacturer of the kind of wheel
used, and to make such changes in the speed of the wheel during wear as can be accomplished by
changing the belt upon a three-stepped cone-pulley, and perhaps one, or at most two, changes of
light pulley upon the counter-shaft. It is sometimes practicable to use wheels of a certain diameter
upon machines speedcd to suit that diameter, and to transfer them to faster-speedcd machines as
they diminish in diameter. Even by this plan, however,
only an approximation to a uniform speed can in most
cases be obtained, because as a rule certain machines are -
adapted to certain work, and the breadth of face and form
of the edge of the emery-wheel are very often made to suit ' / /
that particular work. Furthermore, a new wheel is gener- 1%
ally purchased of such a size, form, and grade of emery "
as are demanded by the work it is intended at first to per-
form. Neither is it as a rule practicable to transfer the . ;_
work with the diametrically reduced wheel to the lighter . ,
and faster-speeded grinding machine. So that, whileD it is \ -' desirable to run all emery-wheels as fast as their compo- ~ sition will with safety admit, yet there are practical objee- ~,
tions to running small wheels at a rate of speed sufficient
to make their circumferential velocities equal to those of
large wheels. The speeds recommended for the various
kinds of wheels now in use vary from about 2,700 to 5,600
circumferential feet per minute; but the speeds obtaining in workshops average between 2,000 and
4,000 feet for wheels 3 inches and less in diameter, and from about 3,000 to 5,600 feet for wheels
above 12 inches in diameter. Wheels above 15 inches in diameter, and of ample breadth of face,
are not unfrequcntly run at much greater velocities.
Emery-wheels should be held upon their driving-spindles by the flanges upon the face; for if the
bore of the wheel fits tightly upon the driving-spindle or arbor, and the latter should become heated,
its expansion would tend to burst the wheel. To prevent this, and to permit the wearing out of the
wheel without excessive variation in the circumferential speed of the wheel as the wear takes place,
the vulcanite wheels A above 14 inches in diameter are made upon a east-iron centre, as shown at B
in Fig. 1327. The spindles or arbors for emery- vheels should have a solid arbor for the wheel to
jam against, and a washer and nut on the other side. The thread should be such that the resistance
upon the washer shall be in a direction that will tend to screw up and not unscrew the nut; other-
wise the latter will be apt to become loosened. It is obvious, therefore, that where an arbor drives
two wheels, it will require a right-hand thread upon one and a left-hand thread upon the other end.
When the wheel is composed entirely of emery, that is to say, when no metallic centre is used, it is
an excellent 'plan to place between the collars and the side of the wheel a leather or other suitable
washer; and- in this case the inside face of the collars may be made slightly hollow, so as to insure
that the surface most firmly gripped shall be that at the outer diameter of the wheel. This will
._e__
\


560 EMERY—GRINDING.

tend to secure its truth as well as to maintain the grip. If the wheel requires to be taken on and
off the arbor occasionally, it is well to bore the hole in the wheel enough larger than the size of the
arbor to admit of a lead ferrule being put into the wheel, and then bored out to give the arbor an
easy working fit. In no case must a key or feather be employed, because it tends to destroy the
balance of the wheel.
The balancing of emery-wheels is a very important element; for, unless the wheel itself as well
as the arbor and driving-pulley be properly balanced, the great velocity of the wheel will cause vi-
brations which will mark the work very plainly. Messrs. Morton, Poole & 00., of Wilmington,
Delaware, found that the difference in the density of cast-iron arbors moulded horizontally was suf-
ficiently great to mar considerably the smoothness of the grinding operations for which that firm
have become famous. Hence all their arbors, pulleys, etc., are cast vertically, and with gates of
sufficient height and body to insure solidity in the castings. Each piece is separately balanced, and
the balancing process is repeated as each part is assembled. Even with all these precautions, how-
ever, it is impracticable to secure in all cases perfect truth as well as balance, especially in the
wheels themselves, because of the difficulty of securing a sufficiently uniform density. Hence, for
accurate work performed at high velocities, it is found to be preferable to turn up the perimeter of
the wheel true, and to vary the thickness of the wheel on diametrically opposite sides when that is
necessary to balance it. It will not answer to turn the emery-wheel true and balance it through the
medium of the arbor, pulley, or collar; because in that case, though the whole may be balanced at
first, the balancing will be destroyed as the diameter of the wheel diminishes. The best method of
operating upon the wheel to balance it is so to adjust the centres of the arbor, or apparatus upon
which it is turned, as to throw the side face of the wheel out of true to an amount just sufficient to
allow the face to true up when the wheel is balanced, taking very light cuts and trying the balance
after each cut. The tool employed to turn emery-wheels is the bort or black diamond, held in an
iron stock or holder. Being easily broken, it must be brought to bear gradually and not violently
against the work.
The grades of emery used for solid emery-wheels, and the smoothness of the duty as compared to
files, are as follows:
No. of Emery. Grade of Cut. No. of Emory. Grade of Cut.
8 to 10 . . . . . . . . . . . . Wood rasp. 46 to 60 . . . . . . . . . . . . Second-cut file.
16 to 20 . . . . . . . . . . . . . Itasp file. 70 to 80 . . . . . . . . . . . . Smooth file.
24 to 30 .. . . .. . . .. . . . Rough file. 90 to 100 . . . . . . . . . . . Superfine file.
36 to 40 . . . . . . . . . . . .. Bastard file. 120 . . . . . . . . . . . . Dead-smooth file.
Emery-Grindcrs.—The machines in which solid emery-wheels are used are termed emery-grind-
ers; and of these there are various kinds designed to suit various classes of duty. For general
work the class of machine represented in Fig. 1328 is employed, the rests A and B being adjustable
and secured in position by means of the hand-screws 0 and D respectively. This class of grinder is
1328.







\ a. \
. ’21—.—
A 1___ L
'-
me
Q







generally used for promiscuous work in machine shops. The rest B is made angular to facilitate
the grinding operations performed on the side as well as on the circumferential face: In using this
class of machine, it is highly essential to distribute the work evenly over all parts of the wheel face,
thus preventing it from wearing in ridges. In Fig. 1329 is shown a machine desrgned by the Tanlto
Company for grinding wood-planing-maehine knives or cutters. The knife 18 clamped at the requi-
site angle against the rest, and is presented to the side face of the emery-wheel. The rest is traversed
by a chain fed by hand, and by a self-acting feed by belt and pinion-gear at the back of the ma-
chine. A is the emery-wheel secured to the arbor, driven by the step-pulley B. 0 is a planer-knife,
\
EMERY—GRIN DIN G. 561

I'-
secured to the traversing rest D. E is the carriage supporting the rest D. F is the bed upon
which the carriage E slides. 67 is the hand-wheel by which the hand-chain feed is operated. H is
a driving-pulley, to be connected by belt to the feed-pulley I, which operates the feed-gears shown.




For grinding circular work, such as spindles, arbors, or bearings, the class of grinding machine
shown in Fig. 1329 is employed. The particular machine illustrated, and the two shown in Figs.
1330 and 1331, are the design of Messrs. Brown & Sharp of Providence, R. I. In Fig. 1330, the base
forms a support for the machine, and also provides a convenient closet for holding wheels and such


Q
_ A‘§'—:;~
\* \



parts or attachments as are not in use. Supported on this base is the bed, inside of which are the
feed—works of the machine. This bed has grooved ways for the sliding table 0, which table moves
automatically, similar to the table of a planing machine, and is of sufficient length and of a suitable
form fully to protect the slides and feed-works from grit and dust. Placed upon the table 0 is the
36
562 ~ EMERY-GRIN DING.

additional table A, fastened in the middle, so as to allow a lateral movement of the ends, which is
regulated by the tangent screw a and gauged by a graduated are. Upon the table A are fastened
the head and foot stocks of the machine, the centres of which, it will be noticed, are, by the
lateral movement of the table, always kept in line, either for straight or taper grinding. The head-
stock B also moves upon a perpendicular central bearing, allowing the spindle to be placed at any
given angle to the slides of the machine, affording a ready means for grinding taper holes. The base
of this head is graduated to degrees. One of Horton’s 6-inch universal chucks is fitted to the spin-
dle at d for holding circular work in grinding out holes, etc. The east-iron pan 1) receives the grit
and water from the grinding wheel, and also supports the back rest. The wheel-arbor and stand are
adjustable upon the table I), which is fastened upon a bed which moves around a fixed centre, on;
abling the table D to be placed and operated at any required angle to the larger table 0, by which
movement angular cutters and work of a similar character can be ground. The table D, at whatever
angle placed, is operated by the handle f. This handle, with accompanying disk, is provided with a
clamp-gauge which regulates the relation of the grinding wheel to the work upon the centres of the
machine. Graduations made upon the bed supporting the table D determine any desired angle.
The operation is as follows: The work is placed between the centres and revolved in the usual man-
ner at a high speed. The emery-wheel W is revolved in an opposite direction by means of the pulley
P, which is connected by belt to the countershaft shown in the figure at the foot of the machine.
The design of the machine shown in Fig. 1331 is as nearly that of an ordinary iron-planer as the
requirements of the case will admit. The emery-wheel A, which takes the place of the steel tool, is
1331.
W17
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driven by belt from the drum B, the latter extending across the machine, so that the belt may travel
along it as the sliding head carrying the emery-wheel is fed. To maintain the tension of the emery-
wheel belt, notwithstanding the raising or lowering of the emery-wheel to suit different thicknesses
or heights of work, the cross-slide, as will be seen, slides in slots in the side frames or standards, the
slots being the section of a circle struck from the centre of the driving drum.
In Fig. 1332 is shown an emery-grinder for sharpening small tools by hand.
In addition to the foregoing fixed machines, there is the swing-frame machine shown in Fig. 1333,
in which A is the overhead driving-pulley; B is a frame pivoted at the top upon the shaft to which
A is attached, and carrying at the lower end the grooved step-pulleys or cone 0 and the frame D ,'
E is a telescopic rod carrying the emery-wheel at its outer end, the object being to permit the emery-
wheel to revolve with the plane of its motion at any angle. The frame B swings from its top as a
centre; the frame D E swings vertically, using its bearings upon the end of the frame B as a pivot.
The twist of the emery-wheel permitted by the telescopic arm enables it, while being driven by the
belts F G, to be traversed or operated upon any surface; while the counterweight W operates to
relieve the overhanging weight of the frames and emery-wheel. The operator guides the emery-
wheel to its work by holding the handles H H. -
Emery Polishing Wheels are built up in sections of wood fastened together by gluing; and with
wooden pegs in place of nails or screws. The joints of the sections or segments are broken; that is
to say, suppose in Fig. 1334 that 1, 2, 3, etc., up to 8, represent the joints of the 8 sections of wood
forming one layer of the wheel, the next 8 sections would have their joints come at the dotted lines
A, B, 0, etc., up to H. The thickness of these sections is usually made of well-seasoned soft wood,
such as pine; and to prevent them from warping after being made into a wheel, it is advisable to
cut out the sections somewhere near the size in the rough and allow them to lie a day or two before
planing them up and fitting them together, the object being to allow any warping that may take place
EMERY-GRINDING. sea

to do so before the pieces are worked up into the wheel, because if the warping takes place afterward
it will be apt to throw the wheel out of true. To cover the circumference of the wheel sole leather
is used, its thickness being about a quarter of an inch; it should be put on soft and not hardened by
' hammering at all, and with the flesh side to the wood. The joint of the leather should not be made
straight, but diagonal with the wheel-face, the leather at the edge of the joint being chamfered off as
shown in Fig. 1335 at A, and the joint made diagonal. If the leather was put on with a square butt
'joint, there would be apt to be a crease in the joint, and
1383.
.-»-v ’fl -—- ' I. fly,"-
/_’ ‘ _ '
W 7 _.
r a,
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.71
v
the emery or other polishing material would then strike
the work with a blow, as well as presenting a keener cut-
ting edge, which would make marks in the work. It is
best not to put any polishing material on the immediate
joint, leaving one-tenth of an inch clear of polishing ma-
, , terial. It is obvious that in fastening the wheel to its
- 4 shaft it should be put on so that it will run in the diree
/ tion of the arrow, providing the operator works with the
-' wheel running from him, as is usually the case with large
wheels, that is to say, wheels over 18 inches in diameter.
In any event, however, the wheel should be put on so that
l the action of the work is to smooth the edge of the leather
joint down upon thewheel, and not catch against the edge
F of the joint, which would tend to rough it up and tear it
apart. The leather should be glued to the wheel, which
W may be slightly soaked first in hot water. The glue should
, be put on very hot, and the leather applied quickly and
bound tightly to 'the wheel with a band. After the leather
is glued to the wheel it is the custom in Europe to further
fasten it with soft wooden pegs, about three-sixteenths of
an inch in diameter, driven through the leather into the
wood and cut off slightly below the surface of the leather.
The manner of putting the emery and fastening it upon
the wheel is as follows: The face of the wheel is well sup-
plied with hot glue of the best quality, and some roll the
wheel in the emery; but in this case the emery does not
adhere so well to the leather as it does when the operation
is performed as follows: Let
the wheel either remain in
its place upon the shaft, or
else rest it upon a round
mandrel, so that the wheel
can revolve upon the same.
Then apply the hot glue to
about a foot of the circum-
ference of the wheel, and cover it as quickly as possible with the emery. Then take a piece of heard
about three-fourths of an inch thick and 28 inches long, the width being somewhat greater than that
of the polishing wheel, and, placing the flat face of the board upon the circumferential surface of the
wheel, work it by hand, and under as much pressure as possible, back and forth, so that each end will
alternately approach the circumference of the wheel, as illustrated in Fig. 1336, the movement being
indicated by the dotted lines. By adopting this method the whole pressure placed upon the board
is brought to bear upon a small area of the emery and leather, and the two hold much more firmly
together. The emery thus glued will be thicker at the junction of the gluing operations ; but it is









? an
the practice where this plan is employed to true up the new wheel by a round iron bar, resting upon
a wooden-frame rest kept for the purpose. The speed at which these wheels are used is about 7,000
feet per minute. The finest of emery applied upon wheels of this kind is used for cast-iron, wrought-
iron, and steel, to give to the work a good ordinary machine finish. But if a high polish or glaze is
564 ENERGY, POTENTIAL AND KINETIC.

1“
required, the wheels are coated with flour emery; and a wheel is made into a glaze-wheel by wear-
ing the emery down until it gets glazed, applying occasionally a little grease to the surface of the
w eel.
ENERGY, POTENTIAL AND KINETIC. Sec DYNAMICS.
ENGINE, BEATING. See PAPER-MAKING.
ENGINE, ELECTRO—MAGNETIO. See ELECTROMOTORS.
ENGINE, WASHING. Sec PAPER-MAKING.
ENGINES, AERO-STEAM AND BINARY VAPOR. If the products of combustion, after leav-
lng the furnace of a steam-boiler, are forced into the boiler, mingling with the water and steam,
instead of escaping into the atmosphere, it is reasonable to infer that a greater effect can be realized
from the fuel. There have been numerous engines invented to apply this principle, and some of
them have given very satisfactory results for a short time. So far, however, there have been many
mechanical difficulties that have interfered with their continued success, so that it is scarcely neces-
sary to present detailed descriptions showing their construction. The reader will find numerous
articles on the subject in the files of technical journals, and is especially referred to a paper on “The
Theory of Acre-Steam Engines,” by J. A. Henderson, published in the Journal of the If'a'a'nklin Ins-{2'-
tutc for July, August, and September, 1874, and to an article on “The Warsop Acre-Steam Engine,”
by R. Eaton, in “ Proceedings of the Institution of Mechanical Engineers,” 1870.
Another plan of increasing the efficiency of steam-engines, that has been very popular with inven-
tors, is to add a second engine, which is driven by the vapor of a liquid having a low boiling-point,
and receiving its heat from the exhaust steam from the first engine. Bisulphide of carbon is the
liquid ordinarily employed ; and the use of the second engine generally increases the economy as a
matlter of course, since the effect is to increase the range of temperature through which the engine
wor (S.
Although many binary-vapor engines have been brought to the notice of the public, they have been
usually short-lived, and scarcely warrant an extended notice. There are many practical objections to
most forms of binary-vapor engines, and they seem to possess no advantage, theoretical or practical,
that cannot be obtained by the use of a single fluid, with less complication and expense. It. II. B.
ENGINES, AIR. The action of air-engines, like that of all other heat-engines, consists in admit-
ting the air at a high temperature and pressure, and allowing it to perform work on the piston and
thus reduce its pressure and temperature, when it is either exhausted into the atmosphere and a fresh
supply is introduced, or it is again heated and compressed for a repetition of the former process.
It will be seen from the above that air has some advantages over steam as a working fluid under
certain circumstances. The efficiency of an engine depends upon the limits of temperature to which
the working fluid is subjected, and it is practicable to use a higher working temperature with air
than with steam, because there is no fixed relation between the temperature and pressure of air, such
as exists in the case of steam.
The principal varieties of air-engines may be classified by the following distinctive features: 1.
Change of temperature at constant pressure. 2. Heat received and rejected at a pair of constant
pressures. 3. Change of temperature at constant volume.
Ericsson’s engine, best known as the calorie engine, may be taken as an example of the first class.
In this engine, air is admitted from the atmosphere to the compressing pump at the lowest working
temperature, and compressed, the temperature being maintained constant by the action of some
refrigerating apparatus. The air when compressed enters a receiver. It is then admitted to the
working cylinder, being heated in its passage to the higher temperature, so that its volume is in-
creased and the pressure remains constant under the movement of the piston, then expands with its
temperature maintained constant at the higher limit, and is finally expelled into the atmosphere, giv-
ing up its heat to the regenerater, to be used in heating the volume of air next introduced.
This engine is represented in Figs. 1337 and 1338. In Fig. 1337, A and B are two cylinders of un-
equal diameter, accurately bored and provided with pistons a and b, the latter having air-tight metal-
lic packing rings inserted at their circumferences. A is the supply cylinder, and Bthe working
cylinder; (2’, piston-rod attached to the piston a working through a stuffing-box in the cover of the
supply cylinder. 0 is a cylinder with a spherical bottom attached to the working cylinder at c c ;
this vessel is called the expansion heater. D D, rods or braces connecting together the supply piston
a and the working piston b. E is a self-acting valve opening inward to the supply cylinder; F, a
similar valve, opening outward from said cylinder, and contained within the valve-box f. G is a
cylindrical vessel, which is called the receiver, connected to the valve-box f by means of the pipe g.
H, a cylindrical vessel with an inverted spherical bottom, is called the heater. J, a conical valve sup-
ported by the valve-stemj, and working in the valve-chamber J ', which chamber also forms a 001m
munication between the expansion heater 0 and heater H, by means of the passage h. 11' is another
conical valve, supported by the hollow valve-stem k, and contained within the valve-chamber k'. L
and M', two vessels of cubical form filled to their utmost capacity, excepting small spaces at top and
bottom, with disks of wire net, or straight wires closely packed, or with other small metallic sub-
stances, or mineral substances, such as asbestos, so arranged as to have minute channels running up
and down. These vessels L and M“, with their contents, are termed rcgenerators. Z l, m m, ]' ipcs
forming a direct communication between the receiver G and the heater H, through the rcgenerators.
N N, two ordinary slide-valves, arranged to form alternate communications between the pipes l l and
mm, and the exhaust-chambers 0 and P, on the principle of the valves of ordinary high-pressure
steam-engines ; n n, valve-stems working through stuffing-boxes n' n' ; p, pipe communicating between
the valve-ehamberh" and exhaust-chamber P; o', pipe leading from exhaust-chamber 0; Q, pipe
leading into the receiver G, provided with a stop-cock q. R R, fireplaces for heating the vessels [:1
and 0; NWT, flucs leading from said fireplaces, and terminating at r'. S, a cylindr'cal vessel
attached to the working piston 6, having a spherical bottom corresponding to the expansion vessel 0
ENGINES, AIR. ' 565

This-lve'sszel S, which is the heat-intercepting vessel, is to be filled with fire-clay at the bottom, and
ashes, chance], or other non-conducting substances toward the top, its object being to prevent any
intense-'oriinjurious heat from reaching the working piston and cylinder. T T, brickwork or other
’ fireproof material surrounding the fireplaces and heaters. Fig. 1338 represents a sectional plan of
'. ea.
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The piston-rod a' only receives and transmits the diiferential force of the piston b, viz., the excess
of its acting force over the reacting force of piston a. This differential force imparted to said
piston-rod may be communicated to machinery by any of the ordinary means, such as links, connect-
ing-rods, and cranks, or it may be transmitted directly for such purposes as pumping or blowing.
The conical valves If and J may be worked by any of the ordinary means, such as eccentrics or cams,
1838.



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provided the means adopted be so arranged that the valve K will begin to open the instant that the
piston b arrives at the full up stroke, and be again closed the instant the piston arrives at full down
stroke, while the valve J is made to open at the same moment, and to close shortly before or at the
termination of the up stroke. In like manner, the slide-valve N" is to open and close as the piston b
arrives respectively at its up and down stroke, similar to the slide-valve of an ordinary high-pressure
engine.
sec ENGINES, AIR.

Before starting the engine, fuel is put into the fireplaces R R, and ignited, a slow combustion being
kept up until the heaters and lower parts of the regenerators shall have been brought to a tempera-
ture of about 500°. By means of a hand-pump, or other simple means, atmospheric air is then forced
into the receiver G through the pipe Q, until there is an internal pressure of some 8 or 10 lbs. to the
square inch. The valve J is then opened, as shown in the figure; the pressure entering under the
piston b will cause the same to move upward, and the air contained in A will be forced through the
valve F into the receiver. The slide-valves N N being, by means of the two stems n 92, previously
so placed that the passages ll are open, the air from the receiver will pass through the wires in L
into the heater H, and further into 0, the temperature of the air augmenting and its volume increas-
ing as it passes through the heated wires and heaters. The smaller volume forced from A will, in
consequence thereof, suffice to fill the larger spaces in 0. Before the piston arrives at the top stroke,
the valve J will be closed, and at the termination of the stroke the valve K will be opened; the
pressure from below being thus removed, the piston will descend and the heated air in C’ will pass
through le', 1), P, and m into the regenerator M, and, in its passage through the numerous small spaces
or cells formed between the wires, part with the heat, gradually falling in temperature until it
passes off at 0’, nearly deprived of all its heat. The commencement of the descent of the piston
a will cause the valve F to close and the valve E to open, by which a fresh charge of atmospheric
air is taken into the cylinder A. At the termination of the full down stroke, the valve K is closed
and the valve J again opened, and thus a continued reciprocating motion kept up. It will be evident
that after a certain number of strokes the temperature of the wires or other matter contained in the
regenerators will change; that of ill will become gradually increased, and that of L diminished.
The position of the side valves NN should, therefore, be reversed at the termination of every fifty
strokes of the engine, more or less, which may be effected either by hand or by a suitable connec-
tion to the engine. The position being, by either of these means, accordingly reversed to that repre-
sented in the drawing, the heated air or other medium passing off from (7 will now pass through the
partially cooled wires in L, while the cold medium from the receiver will pass through the heated
wires of 11/, and on entering H will have attained nearly the desired working temperature. In this
manner the regenerators will alternately take up and give out heat, whereby the circulating medium
will principally become heated, independently of any combustion, after the engine shall have been
once put in motion.
The relative diameter of the supply and working cylinders will depend on the expansibility of the
acting medium employed; thus, in using atmospheric air or other permanent gases, the difference of
the area of the pistons may be nearly as 2 to 1, while in using fluids, such as oils, which dilate but
slightly, the difference of area should not much exceed one-tenth. In employing any other medium
than atmospheric air, it becomes indispensable to connect the outlet pipe 0' and the valve-box e of
the outlet valve E, as indicated by dotted lines in the drawing, these dotted lines representing the
requisite connecting-pipe. The escaping air or fluid at 0' will, when such a connecting-pipe has been
applied, furnish the supply cylinder independently of other external communication, and the acting
medium will perform a continuous circuit through the machine under this arrangement; the opera-
tion being in other respects as before described. The working cylinder may be placed horizontally
or otherwise, and it may be made double-acting; a heat-intercepting vessel may be applied at each
end of the working piston, as also an expansion heater at each end of the working cylinder. Four
working cylinders similar to the above were placed in the steamer Ericsson.
A modification of the engine just described, which has been used to a considerable extent for
light work, is represented in Fig. 1339. There are two pistons working in one cylinder, A being
the driving piston and F the pump-piston. G is the furnace, B is the fly-wheel shaft, and the
driving piston is connected to it by the crank o, connecting-rod p, lever q, and rod 9'. The crank 0
also gives motion to the pump-piston F, through the connecting-rod s, and the cranks t w, which
are secured to the shaft (7, making an angle of 7° with each other. The piston A has a valve open-
ing inward, as also has the supply piston F T his latter piston is lined with a non-conducting ma-
terial on the side next the furnace, and it carries on its periphery a cylindrical bell, which works in
the narrow annular space between the walls of the furnace and the surrounding chamber. 'ihe
valve in F opens above this bell, so that the air passing through this valve traverses the annular
space and thus has its temperature raised. D is the exhaust-valve, kept to its seat by a spling,
when not acted upon by the cam 17'. On account of the peculiar connections of the two pistons,
they have a differential movement, so that the operation of the engine is as follows:
\Vhen the two pistons are moving inward, F at first goes faster than A, and air is drawn into
the space between the two pistons from the atmosphere. A then gains upon F, and the air be
tween the two pistons is compressed. F completes its stroke before A, and commences the return
stroke while A is still moving inward, so that the air between the pistons passes through the valve in
F, and becomes heated in the annular space around the furnace. While A is making the return
stroke, F continues to move faster, and constantly displaces the air between the two pistons. A lit-
tle before the end of the outward stroke, the two pistons are nearly in contact, but the distance
between them increases slightly at the end of the stroke. The exhaust-valve is then opened and the
heated air escapes, the valve being kept open during the inward stroke, until the compression bc-
tween the two pistons commences. As the working pressure is exerted in this engine for less than
half a revolution, a heavy fly-wheel is required to maintain the motion; and the fly-wheel is coun-
terweighted so that the weight is descending during what may be called the negative part of the
revolution. To start the engine, the fly-wheel must be turned until the two pistons occupy the
proper position, and there is a click attachment working in notches in the fly-wheel, to facilitate the
turning by hand. In a test of one of these engines made by M. Tresca (Annalee dcs Mints, 5th
Series, xix.), the consumption of coal was about 9 lbs. per horse-power per hour.
In Shaw’s engine, Figs. 1340 and 1341, the products of combustion pass from the furnace into
ENGINES, AIR. ' 567

the cylinder, and at the completion of the stroke of the working piston are exhausted, passing
through a regenerator and thus being deprived of some heat, which is imparted to the next charge














of air drawn in. There is a double wall around the furnace, and all the air drawn in passes
through the space between the two walls, having its temperature still more increased before entering
1340.


the furnace The efficient means employed for heating the air constitute the chief merit of this
engine. As shown in Figs. 1340 and 1341, there are two working cylinders A A, each single-acting,
see ENGINES, AIR.
and the compressing pumps are formed by trunks on the upper sides of the pistons. B is one of
the pistons, and B’ the corresponding trunk. T is the rcgenerator. Air is drawn in by the com-
pressing pump through the valve .E, and forced into the regenerator and furnace through the valve
F. P is the exhaust-pipe.
The engines that have just been described are necessarily limited to comparatively low pressures,
and hence must be very bulky when designed to develop considerable power. This limitation is an
essential condition of their design, because the original pressure of the air which is compressed and
heated is that of the atmosphere. If, however, the working air be confined in the machine, and
originally compressed to a high pressure, this difficulty disappears. Thus, suppose it is found prac-
ticable to maintain a temperature in a given air-engine sufficient to double the original pressure of
the air. Then, if the air were admitted at the pressure of the atmosphere, the available pressure,
after heating, would be about 15 lbs. per square inch. But if the supply of air were drawn from
a reservoir, in which the pressure was 60 lbs. per square inch, the effect of increasing the tem-
perature to the same point as in the former case would be to double the original pressure, making it
120 lbs. per,square inch. It seems strange‘that the majority of inventors should have ignored this
significant principle, and that too in the face of the example afforded by one of the first air-engines
ever constructed, and which seems, from all accounts, to have been more successful and economical
than any of itssuccessors. Reference is made to Stirling’s engine, invented by Robert Stirling of
Scotland in 1827, and put in operation at the Dundee Foundry in 1840. The construction of this
engine is clearly illustrated in Figs. 1342 to 1344, and the accompanying description.
Two strong air-tight vessels are connected with the opposite ends of a cylinder, in which a piston
works in the usual manner. About four-fifths of the interior space in these vessels is occupied by


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two similar air-tight vessels or plungers, which are suspended to the opposite extremities of a beam,
and capable of being alternately moved up and down to the extent of the remaining fifth. By the
motion of these interior vessels, which are filled with non-conducting substances, the air to be oper-
ated upon is moved from one end of the exterior vessels to the other; and as one end is kept at a
high temperature, and the other as cold as possible, when the air is brought to the hot end it be-
comes heated and has its pressure increased, and when it is brought to the cold end its heat and
pressure are diminished. N ow, as the interior vessels necessarily move in opposite directions, it fol-
lows that the pressure of the inclosed air in the one vessel is increased, while that of the other is
diminished. A difference of pressure is thus produced upon the opposite sides of the piston, which
is thereby made to move from one end of the cylinder to the other; and by continually reversing the
motion of the suspended bodies or plungers, the greater pressure is successively thrown upon a dif-
ferent side, and a reciprocating motion of the piston is kept up. The piston is connected with a
fly-wheel in any of the usual modes, and the plungers, by whose motion the an is heated and
cooled, are moved in the same manner, and nearly at the same relative time. 'with the valves of a
steam-engine. The power is greatly increased and made more economical by using somewhat highlyi
compressed air, which is at first introduced, and is afterward maintained, by the continual &Ct10I1.0l
an air-pump. The pump is employed in fillintr a separate magazine with compressed am, from which
the engine can be at once charged to the working pressure.
If all the heat, however, which is necessary to raise the air to the required temperature, were to
be thrown away or lost every time that the air is cooled, the power produced by its expansion and
contraction would be much more expensive than that which is gained by the use of steam. In order,
therefore, to understand how the work of a good steam-engine has been done with about one-third
of the fuel consumed by it, it is necessary to point out the method by which the greater part of the I
ENGINES, AIR.
569

' heatis preserved, and is used repeatedly, in expanding the air, before it is finally wasted or lost.
For this purpose, when it is necessary to cool the air, after it has been brought to its greatest heat,
1342.


“91.? (_i "'7 Y L f I
it is not at once brought into contact with the coldest part of the vessels.
1
P .- f 1: is 1;, 41: '7
This would indeed effec-
tually cool it, but the heat when thus extracted would be entirely lost, because it could never again be
taken up by a body warmer than itself. Instead of this, therefore,
the air is made to pass from the hot to the cold end of the air-vessel
through a- multitude of narrow passages, whose temperature is at
first nearly as great as that of the hot air, but gradually declines till
it becomes nearly as low as the coldest part of the air-vessel. Now,
as every body by contact will give out heat to one that is colder than
itself, the air, when it enters the narrow passages, must give out a
portion of its heat even to the hottest part of these passages, and
must continue in its progress to give out more and more as the
temperature of the passages is diminished, till at last, when it is
ready to escape into the cold part of the vessel, there is only a small
portion of the heat to be extracted, in order to bring it to the lowest
temperature required. By far the greater part of the heat, therefore,
has been left behind in the metal which forms the passages, and
which is so contrived and arranged as to retain that heat until it is
again required for heating the air. It must be evident also, from the
manner in which the heat has been distributed, or spread out, over
the whole length of those passages, that it is capable of being again
employed in heating and expanding the air; for when the cold air is
again made to enter the passages for the purpose of being heated, it
immediately comes into contact with matter that is hotter than itself,
and consequently begins to acquire heat even at its first entrance;
and as it is successively applied to surfaces of a greater temperature,
it continues to receive more and more heat, so that when it comes at
last to the hot end of the vessel, it requires but a small addition. to
its temperature to give it the elasticity which is necessary to move
the piston. Thus, instead of being obliged to supply, at every stroke



W
Fl.
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of the engine, as much heat as would be sufficient to raise the air from its lowest to its highest
temperature, it is necessary to furnish only as much as will heat it the same number of degrees by
570 ENGINES, AIR.

“-
which the hottest part of the air-vessel exceeds the hottest part of the intermediate passages. In
an account of the performance of this engine, given by Mr. Patrick Stirling (see “Transactions
of the Institution of Engineers in Scotland,” vol. iv.), it is stated that the dimensions of the
working cylinder, which was double-acting, were 16 x 48 inches; the minimum pressure 10 atmos-
pheres, maximum pressure 151} atmospheres; probable range of temperature, 100° to 600° F.;
average horse-power, measured on friction-brake, 37; and coal consumed per day, 1,000 lbs., corre-
sponding to a consumption of 2.7 lbs. of coal per net horse-power per hour, the consumption fre-
quently falling as low as 2.5 lbs. per horse-power. The engine was used for four years in the regu-
lar work of the foundry, and was finally abandoned on account of the heaters burning out. From
the above record, it seems reasonable to believe that inventors would do well to turn back to Mr.
Stirling’s work, and take up the matter where he left off.
There have been several engines constructed on the general principle of Stirling’s, so far as using
the working air continuously, but they have generally neglected the second feature, of using highly
1 845. 1846.


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compressed air. Among these engines may be mentioned Lauberau’s, described in Dr. Barnard’s
“ Report on the Machinery and Processes of the Industrial Arts ;” and another of somewhat similar
design, illustrated in Figs. 134-5 to 1347. The following description is from the Iron Age of Nov.
23, 1876 : “Two vertical cylinders, power and compression, are mounted side by side upon a flanged
bed-plate, and form the lower part of the housing for the crank-shaft bearings, which are of suffi-
cient height to give the necessary length of connecting-rods. The power cylinder is fitted to a cylin~
dric heater 0 with a recessed bottom, beneath which is a small furnace. By a peculiar arrangement
of the interior of the cylinder A. and the lower part of the piston (or more properly the plunger), the
compressed air is made to pass in a thin sheet over. the surface of the heater, and becomes heated to
the required temperature almost instantly. The compression cylinder, by means of a similar device
for spreading the expanded air after its discharge from the power cylinder, cools it to or below the
temperature of the atmosphere by the circulation of water through a jacket by which it is surrounded.
Connecting the two cylinders at a point just below the bearings for the piston is the passage for
communication, 11!, which contains a device, called by the makers a ‘ regenerater,’ R. It is simply
a series of thin metallic plates, having the edges thickened so as to keep them slightly apart. The
ENGINES, DESIGNING or. 571

W
-Object of the arrangement is to economize heat, by absorbing as much as_possible from‘the hot
air discharged from the power cylinder, and in turn parting with a portien of it to the cold air In its
passage back from the compression cylinder. It will be understood that the same air is used con-
tinuously, being passed back and forth from one to the other of the cylinders, and alternately com-
pressed and heated, and expanded and cooled. Any deficiency of air caused by leakage is supplied
by a check-valve, 1’, at the foot of the compression cylinder. The arrangement of the cranks F 11
forms an important consideration, and is an angle of 95", or 5° in advance of a right angle, for the
power crank. After starting the fire and raising the heater to the proper temperature, the engine
may be started by simply closing a small pet-cock in the regenerater, and turning the fiy-wheel about
one revolution or less. The effect is to compress the cold air contained in the compression cylinder
to about one-third of its normal volume. After reaching this point, owing to the before-mentioned
positions of the cranks, the power piston begins to ascend, while the compression piston in complet-
ing the downward stroke forces the air into the heater; and as the displacement in one cyhnder 1s
equalized by the receding piston of the other, there is no noticeable change of volume. ()wmg to
the very effective method of heating the compressed air, its temperature is suddenly raised, and the
expansion due to the temperature produces a great increase of pressure, which forces the power
piston to the end of the up stroke. The compression piston is then 5’ behind half stroke and moving
upward, when the power piston, by beginning its down stroke, transfers the expanded hot air through
the regenerator and water-jacket into the compression cylinder in a thoroughly cool condition, and at
or slightly below atmospheric pressure; in the latter case the deficiency is supplied by the check-
valve. After passing the upper centre, the compression piston again begins its descent as before.
\Vhen the engine is to be stopped, it is only necessary to open the pct-cock on the regenerater, which
prevents the accumulation of pressure. Where hydrant water is not available, a small force-pump
is attached to the compression piston for the purpose of maintaining a circulation around the cylinder.
The piston-packing is composed of two rings of leather held down by a gland, that on the power
piston being kept cool by the circulation of water around it by means of a. pipe connecting with the
water-jacket of the compression cylinder.”
It has been predictedv by more than one prominent engineer that the steam-engine will yet be
superseded by the air-engine. In view of what has already been accomplished, the realization of
this idea seems by no means impossible, while at the same time it must be confessed that a great
deal has yet to be done before the air-engine can successfully compete with its present formidable
rival. As the obstacles to the complete success of the air-engine consist chiefly of mechanical diffi-
culties that must be overcome, the case does not seem absolutely hopeless. It is not possible to (lis-
cuss the subject in the present article as fully as its importance seems to warrant; but the reader
who desires to continue his investigations is referred to the following works, from which the fore-
going remarks are chiefly compiled: Rankine’s “Treatise on the Steam-Engine ;” Dr. Bernard’s
“Report on Machinery and Processes of the Industrial Arts ; ” Engineering, xix. ; “ Proceedings of
the Institution of Civil Engineers,” 1845, 1854 ; and “ Transactions of the Institution of Engineers
iii-Scotland,” iv. For further works for reference, see Exemss, Hear. R. H. B.
ENGINES, DESIGNING OF. The following example illustrates in considerable detail the appli-
cation of the theoretical considerations given under EXPANSION OF STEAM axe Gases, with their prac-
tical modifications, in designing an engine for a given purpose. The example further illustrates the
use of the tables in the above-mentioned article. Suppose it is required to design an engine that
shall develop 200 net horse-power, it being proposed that the boiler pressure shall be 90 lbs. per
square inch above zero, and that the steam shall be cut off when the piston has completed three-tenths
of the stroke. The engine is to be non-condensing; the steam is to be cushioned when the piston
has completed 151,35 of the return stroke; the piston speed is to be 600 feet per minute, the stroke
4 feet, and the connecting-rod 10 feet between the centres. \Vhilc it is impossible to foretell with
absolute certainty the performance of a proposed engine, there are various data obtained by previous
experience that can be used, since it is reasonable to infer that like causes will produce like efiects.
It is assumed, then, that the cylinder and port clearance at each end of the stroke will be 6 per cent.
of the piston displacement; that the mean back pressure up to the point where cushion commences
will be 1 lb. per square inch above the atmosphere, or 15.7 lbs. above zero; that the pressure
required to overcome the friction of the working parts of the engine will be 1.6 lb. per square inch ;
and that the initial pressure in the cylinder will be 4 lbs. less than the boiler pressure, and the
pressure at point of cut-off 5 lbs. less than the initial. (Although these allowances are larger than
are required for the very best engines, they agree well with ordinary practice, and are, indeed, too
small for many of the engines in common use.) Turning to Table VI. in the article EXPANSION or
STEAM AND Gases, it will be seen that the real cut-off for the proposed case is 0.34. The mean total
pressure up to the point of cut-ofl“ is [(90 — 4) + (90 -- 4 — 5)] -:- ‘2. = 83.5. By column 2 in Table
IV., article EXPANSION or Srsur AND Gases, the ratio of expansion corresponding to a cut-off of 0.34
is 2.94; and from column 9 in the same table, and a simple calculation, the mean total pressure
during the stroke of the piston is determined to be + 81 x 0.367 :: 58.1 lbs. per square inch.
(As calculations of this nature are only approximate, there is no necessity for carrying them beyond
one or two decimal places.) The pressure given above is, it will be noticed, the mean total pressure
throughout the 'whole stroke of the piston, including also the pressure in the clearance space ; and it
must be corrected for the mean back pressure up to the point of cushion, for the clearance and for
the cushion. Deducting the back pressure, 58.1 —- 15.7 = 42.4. The correction for clearance is
obtained by the formula 12 — c x (P —- p), where p is the mean total pressure corrected for back
pressure, P is the initial pressure, and C" is the fraction of clearance. In the present instance, the
corrected pressure is 42.4 —- 0.06 x (86 ~— 42.4): 39.8. Calling d the fraction of a stroke uncom-
572
ENGINES, DESIGNING OF.
M.

pletcd when cushion commences, and c, as before, the fraction of clearance, the ratio of compres-
sion is (d + c) -:- c, or (0.12 + 0.06) —:— 0.06 : 3, and the final cushion pressure is 15.7 x 3 :: 47.1.
The mean cushion pressure, by column 6 in Table IV., article EXPANSION or STEAM AND GASES, is
47.1 x 0.55 2 25.9. The mean pressure corrected for cushion is P— c x (R- 1) x (p’ —-p); in
which expression P is the mean pressure corrected for back pressure and clearance, c is the fraction
of clearance, R the ratio of compression, and p’ and p the mean and initial cushion pressures respec-
tively. Substituting the proper values in the above formula, the result is the indicated pressure of
the proposed engine, or 39.8 —— 0.06 x -— 1) x (25.9 -— 15.7) = 38.6. Subtracting the estimated
friction pressure, the mean net pressure is found to be 38.6 -- 1.6 : 37 lbs. per square inch. Having
determined the mean net pressure, the diameter of cylinder required can be calculated by the for-
’ II. P. '
mula, 205 x ( 17—9), where H. P. is net horse-power, P the mean net pressure in pounds per
‘ X L
square inch, and S the piston speed in feet per minute. Hence the diameter of the proposed engine
_ 200
is 205 x -—) :: 19.5 inches.
37 x 600
If a boiler is to be designed for this engine, some estimate must be formed of the amount of
steam that it will use. The examples of the performance of engines of various dimensions, given
in the various articles on ENGINES, will greatly assist the designer; but, as a further aid, a method
of making an approximate calculation is appended. As the stroke of the engine is 4 feet, and the
piston speed is 600 feet per minute, the number of revolutions per hour is (600 + 8) x 60 : 4,500.
Suppose that the steam is released when the piston has completed 190% of the stroke; the theoretical
1
_ c
R +
m + 0
tion of clearance, a: the fraction of stroke for which the pressure is required, and .P the pressure at
0.3 + 0.06
0.95 + 0.06
weight of a cubic foot of steam of this pressure, by column 10 in Table I. of article ExrANsmN or
STEAM AND GASES, is 0.071 lb. The displacement of the piston per revolution to release, including
clearance, is 16.76 cubic feet, so that the total weight of steam used per hour, neglectingr that saved
by cushion, is 16.76 x 4,500 x 0.071 2 5,355 lbs. As the space filled with cushioned steam at the
instant the exhaust-valve closes is 2.82 cubic feet per revolution, and the pressure of the steam at
this point is 15.7 lbs. per square inch, the steam saved per hour on account of cushion is 2.82 x
4,500 x 0.0404 : 513 lbs.; so that the total steam discharged from the cylinder per hour is 5,355—
513 : 4,842 lbs. (Note—In calculating the piston displacement, the mean piston area, after deduct-
ing the cross-section of the piston-rod, should be used when great accuracy is required; but it is
scarcely necessary to introduce this element into a preliminary estimate like the above. In making
calculations for horse-power or consumption of steam from actual practice, where the indicator cards
are furnished, the mean effective piston area should be employed.) To this must be added the steam
condensed for the work done during expansion, and the amount condensed on account of the change
in temperature to which the interior surfaces of the cylinder are subjected. For the first correction,
find what proportion of the total horse-power is developed during the expansion of steam, and mul-
tiply this by 1,980,000, the foot-pounds of work in one horse-power per hour. The quotient arising
from dividing the latter quantity by 772 gives the units of heat per hour equivalent to the work of
expansion, which is to be divided by the latent heat of a pound of steam at the terminal pressure,
to reduce it to pounds of water condensed. Thus, the mean total pressure of the steam, as deter-
mined above, corrected for clearance, is 58.1—[006 x (86—581)] : 56.4 ; so that the total horse-
power is (298.65 x 56.4 x 600) + 33,000 = 306. From column 9 in Table IV., article EXPANSION OF
STEAM AND GASES, it appears that the portion of the mean total pressure due to expansion is 81 X
0.367 = 29.7 lbs. per square inch, so that the total horse-power developed during expansion is
29.7
56.4
shown in Table 1., article EXPANSION or STEAM AND GASES, column 6, is 941, the steam condensed for
work per hour is (161 x 1,980,000) —:— (772 x 941) :: 440. The final allowance for condensation on
internal surfaces can only be approximately estimated at between 20 and 25 lbs. of steam per hour
per square foot of internal surface. It seems probable that there is some law by which the amount
can be definitely determined, when the mean temperatures during forward and return strokes are
known ; but further investigations are required before the law can be exactly stated. In the present
instance, it will be assumed that the condensation is at the rate of 22 lbs. per hour per square foot
of internal surface, reckoning the areas of the two heads, both sides of the piston, the cylindrical
area, the piston-rod, and the surface of the ports. In the engine under consideration, the surface
will be approximately:

pressure at this point is given by the formula

1 .
x P, where Z) is the apparent cut-off, c the frac-
point of cut-off. Hence the pressure when release takes place is x 81: 28.8. The
x 306 2 161 ; and since the latent heat of a pound of steam at the terminal pressure 28.8, as
In heads and both sides of piston . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3 square feet.
In cylindrical part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24.3 “ “
Inpiston-rod..................................... “ “
Inports.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12.0 “ “
“ “





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AM ERICAN STEAM FIRFMENGINE.





ENGINES, FIRE.
573

" So that the steam condensed per hour will be:
48x22==..... . . . . . . . . . . . . . . . . . . . . . ..1,056
Calculated from terminal pres. ure less cushion.. . . . . . . . . . . . . . . . .. . . . . . . . . . . 4,842
Steam condensed for work . . . . . . . . .. . .. . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . 440
Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .......6,338
or about 32 lbs. per net horse-power. The method of proportioning a boiler to evaporate this amount
of water is explained in the article on BOILERS. To reduce the above amount to its equivalent, from
and at 212°, as explained when treating of boilers, it is supposed that the feed water is heated by
the exhaust steam to a temperature of 180°.
AND GASES, the equivalent evaporation for this case will be 6,338 x (1.221—0.154) : 6,763lbs.
If the above calculation had
been made for a. condensing en-
gine, the only changes required
in the data would have been as
follows :' The mean back pressure
up to commencement of cushion
would have been assumed at from
3 to 3.5 lbs. per square inch
above zero, and the steam con-
densed on the interior surfaces
of the cylinder per hour at from
10 to 15 lbs. per hour per square
foot. R. H. B.
ENGINES, FIRE. The man-
ual engine, Fig. 1348, generally ,
consists of a double forcing- .
pump communicating with the
same air-vessel; and instead of
a force-pipe, a flexible leather
hose is used, through which the
water is driven by the pressure
of the condensed air in the air-
vessel. Fig. 1348A represents
a section of the apparatus. The
pipe T descends into a receiver
or vessel containing a supply of
water. This pipe communicates
with two suction-valves V, which
open into the pump-barrels of
two forcing-pumps A B, in which
solid pistons P are placed. The
piston-rods of these are connect~
ed with a working-beam E, elon-
gated, so that a number of per-
sons may work at both ends of
it at once. Force-pipes it pro-
ceed from the sides of the pump—
barrel above the valves V, and
they communicate with an air-
vessel M by means of forcing-
valves V, which also open up-
ward. The pipe descends into
the air-vessel near the bottom.
This pipe is connected with the
flexible leathern hose L, the
length of which is adapted to
the purposes to which the ma-
chine is to be applied. The ex-
tremity of the hose may be car-
ried in any. direction, and may
be introduced through the doors
and windows of buildings. By
the alternate action of the pis-
tons, water is drawn through
the suction-valve and propelled
through the forcing-valves until
the air in the top of the vessel
11! is highly compressed. The




















Thus, by Tables I. and II., article EXPANSION or STEAM
pressure acts on the surface of the water in the vessel, and forces it through the leathern hose in a
coutmuedstream, so as to spout from its extremity with a force depending partly on the degree of
condensation, and partly on the elevation of the extremity of the hose above the level of the engine.
574. ~ - ENGINES, FIRE.

It is to be considered that the pressure of the condensed air has, in the first instance, to support a
column of water, the height of which is equal to the level of the end of the tube above the level of
the water in the air-vessel; that until the pressure exceeds what is necessary for this purpose, no
water can spout from the end of the hose; and, consequently, that the force with which it will so
spout will be proportional to the excess of the pressure of the condensed air above the weight of
the column of water, the height of which is equal to the elevation of the end of ' the hose above the
level of the water in the air-vessel.
One of the most thorough trials ever made of this class of engines was conducted by a special
jury at the International Exhibition held in London in 1862. A summary of these interesting ex-~
periments is contained in the tables on page 627. '
At the present time manual fire-engines have been almost entirely superseded by the more effi-
cient steam fire-engine, the introduction of which has been largely instrumental in reducing the
ravages caused by fire and lessening fire-rates. The earliest steam fire-engine is believed to have
been built by John Braithwaite, an Englishman, in 1829, and is described in the Mechanics’ Magazine
for February 18, 1880. Captain Ericsson obtained a medal from the Mechanics’ Institute of New
York, in 1840, for a design of a steam fire-engine somewhat similar to that produced by Braithwaite;
and a steam fire-engine was constructed in 1850 by Mr. Latta of Cincinnati, who has been identified
with many important improvements in connection with this machine. Various other builders took
up the manufacture of steam fire-engines after Mr. Latta, and they have been gradually developed to
the splendid apparatus which is in use to-day.
Several steam fire-engines were exhibited at London in 1862, including one from the United States,
and the jury were desirous of investigating their qualities by a very thorough test. Only two of the
exhibitors, however, were willing to submit their engines to trial, and these were tested by the jury,
with results that are summarized in the two tables that follow, from the data given in the official report:
Principal Dimensions of Steam Fii'e-Eigines tried at London Exhibition, 1862.


























Number of engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 8
Name of maker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Merryweather & Son. Shand & Mason. Shand & Mason.
Diameter of steam cylinder, inches . . . . . . . . . . . . . , . . . 9 I 8.5 6.625
“ water “ “ . . . . . . . . . . . . . . . . . 6.5 7 5
Stroke, inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15 9 8
Contents of pump, cubic inches . . . . . . . . . . . . . . . . . . . .. 968.98 676.8 814.16
Number of deliveries open on trial . . . . . . . . . . . . . . . .. 1 I 2 1
Diameter of suction hose, inches . . . . . . . . . . . . . . . . . . . 5 8 .5 8
“ of delivery “ “ . . . . . . . . . . . . . . . . . .. 8 8.5 2.5
Weight, light, pounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 i 8,82? _ f 18 7,230 f 17 4,4180 f
- - - m n. 1' sec. mm min.. sec. rem min. 1sec. rem
Time of raising pressure to 100 pounds . . . . . . . . . . . % cold water. cold water. warm water.
Trial of Steam Fire-Engines at London Exhibition, 1862.
:1: PRESSURE, IN :11
H HOSE. STREAM. POUNDS. PER H
a Depth , sounms men. Delg'ery, 5
T from in rac-
g at“; Duration of which H . R20}? tion of g
- Trial, in Water was on“ Vertl- True An le .‘0 “- Piston
m En‘me' Le th Diameter . zontal . g tions. . m
g 5 {1g drawn, in D. cal Dis- 1318- from Stea W m Displace- g
2 m ?f Nozzle’ Feet. m '5‘ tance, tance, Hori~ m' a r' ment. 5
D Feet' m Inc 88' . nce’ in Feet. in Feet. zon. D
Z Min. Sec. "1 Feet“ Z
1 2 15 40 1 5 5 60 10 61 10" 100 60 1
2 2 . . " “ 60 10 61 10° 286 115 60 50 2
8 1 45 “ “ “ 60 10 61 10° 208 120 45 60 8
4 4 . “ 1 .38 “ 80 80 85 21 ° 547 110 75 25 4
5 1 2 50 “ “ “ 80 80 85 21° 245 120 75 58 5
6 3 . . “ “ “ 80 80 85 21° 378 110 70 22 6
7 '8 . “ “ “ 80 80 85 21° 7
8 8 . “ “ “ 80 80 85 21 ° 886 1 00 70 .21 8
9 2 20 60 1 5 5 60 10 61 10° . . . . 100 60 9
10 1 “ “ “ 60 10 61 10° . . .. 100 60 10
11 1 45 “ “ “ 60 10 61 10° 485 98 60 47 11
12 1 45 “ “ “ 60 10 61 10° 429 101 60 42 12
18 ' 3 . . “ “ “ 60 20 68 18° 714 120 58 84 18
14 2 8 . . " “ “ 60 20 68 18° 618 90 40 25 14
15 8 . . " 1 88 “ 80 20 82 14° 486 110 90 45 15
16 5 55 “ ‘ 80 20 82 14° 989 100 90 41 16
17 4 . . “ " “ 80 80 85 21 ° 588 110 80 .87 17
18 10 40 “ “ “ 100 20 102 11° 1,581 105 110 I .26 18
19 68 . . " “ “ 100 80 104 17° 9,840 90 90 05 19
20 8 . . 40 ‘ 1 5 60 10 61 10° 599 122 67 65 20
21 1 30 “ “ ‘ 60 10 61 10° 806 112 56 21
22 8 . . " “ “ 60 20 68 18° 625 135 100 68 22
28 8 . . "' ‘ “ 60 20 68 18° 581 187 85 58 28
24 8 . . " .88 ‘ 80 20 82 14° 584 170 108 80 24
25 10 55 " “ 80 20 82 14° 1,011 125 100 27 25
26 3 4 . . " “ “ 80 30 85 21° 690 125 95 18 26
27 2 50 “ " " 80 80 85 21° 680 127 100 18 27
28 8 . . “ " “ 80 80 85 21° 570 127 100 07 28
29 8 . “ “ “ 80 80 85 21° 511 180 100 16 29
30 8 . . “ “ “ 80 80 85 21 ° 485 120 90 .08 80
81 10 40 " “ " 100 20 102 11° 1,790 120 . 95 .02 81






ENGINES, FIRE. 575












































Principal Dimensions of Manual Engines tried at Lomlon Exhibition, 1862.
h I DIAMETER or g ,5 Pum' 1 Stroke of HOSE, m INCHES. i
z Han ~————-———1
m 6 NAME. Diame-f Stroke . isles, ‘
5% ner, in in , goitefnts’hm Inches. Suction. Delivery.
2 Incheallnchell. u c c a'
1 Bhand 85 Mason. London Brigade pattern . . . . . . . . . . . . 7 8 615.74 88.5 2.75 2.5
2 Merryweather & 8011, London Brigade pattern . . . . . . . 7 8 615.74 84 8 2.5
8 Rose, Manchester Brigade pattern . . . . . . . . . . . . . . . . . . . 7 8.1 628.44 81.5 8 2.18
4 Merryweather & Son, London (Hodge's Testimonial). 7 8 615.74 84 8 2.5
5 Shand 85 Mason, Military pattern . . . . . . . . . . . . . . . . . . . . 6 8 452 .88 42.5 8 2.5
6 Merryweather 85 Son, Country Brigade pattern ..... . . 6 8.2 468.69 81.1 2.5 2.5
7 Roberts, double action . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9.5 8.4 487 .31 88 8 2.5
8 Blinkhorn & (30., double action . . . . . . . . . . . . . . . . . . . . .. 7 8 615.74 86 8 2.5
9 Shandéz Mason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9 8 1,017 87 34.1 3.5 2.5
10 Broughton Goptger 00., Manchester Brigade pattern. . 7 8.4 642 81.8 3.5 2.5
11 Letestu, Breve (French) . . . . . . . . . . . . . . . . . . . . . . . . .. 4.6 r 7 281 80 8 2
Summary of Trials of Manual Engines at London Exhibition, 1862.
:1 i 1 *5
HOSE. s'mnm. i :5
5 Depth 1 ' E23
. from Total lDelivery, in
1:. Num- Duration . H ri_ I , 1 . , Num- I=.
o her at firm in which 0 Verti_ True Angle ‘ Lum- 5 Fraction _o. be r . O
c?- Engine 14ml}. I‘ifth Diameter of Nozzle, W31" “1” “$1.51 cal Dis-1 Dis- from b" °" PM” 9““ c:
22 Feet“ in Inches. ldmwn’m t 18' tance, l tance, Hori- gsmkes' Placement g
5 1 Feet” . ance’ in Feet. in Feet. zon. ! E
D in F eet. D
z r- l 2 i Z
1 so 40 Open delivery. 5 . .. 1 .. . l 27 1 .03 2s ; 1
2 so *~ “ “ “ .. .. 1 .. .. 1 as .96 “ . 2
8 30 “ “ “ “ . . . . . . . g 30 .97 “ 1 3
4 180 “ .87” “ 20 20 28 45° ; 180 .81 " t 4
5 1 180 “ “ ' “ 20 30 36 56° 1 195 .84 “ 5
6 1% “ "' “ 40 20 44 26‘I i 188 .78 “ f 6
7 120 “ "‘ “ 40 30 50 1° 136 .63 “ 7
8 120 “ 1 “ “ 60 20 63 18° 1 137 .53 "‘ f 8
9 120 “ [ .8125 “ 60 25 65 23° 1 135 , 50 "‘ 9
10 so 40 Open delivery. 5 . .. l—. _ .. iii— 11)? 25— “id—1
11 so “ -* e . .. , . . i as , .91 r 11
12 so “ “ “ v .. .. . .. ; 31 1.13 “ . 12
13 180 “ . 8'75 “ 20 20 28 45° 180 . 78 " t 1 3
14 2 130 “ “ “ 20 30 36 56° 183 . 80 "' 14
15 180 “ “ “ 40 20 44 26° 198 .73 “ 15
16 120 “ “ “ 40 30 50 37° 129 .62 “ 16
17 120 “ “ “ 60 20 63 18° 126 .35 ‘" . 17
IS 120 "' '8125 “ 60 25 65 23° 114 .31 “ f 18
19 so 40 1 Open delivery. 5 .. 1.7—“ 31 .94 2s {—19—
20 30 s; t. 55 u _ _ _ _ l .92 a. I 21 3 80 “ e r “ ._ .. Y .. .. 30 .90 “- 3 21
22 180 “ . 875 “ 2O 20 28 45° 1 67 . 75 “ I 22
23 130 “ “ “ 20 3O 36 56° ! 192 .66 “ ' ‘23
24 120 40 .875 5 oo 20 _5s _ 18° ; 180 .53 2s 1 24
25 4; 121) “ “ “ 60 20 63 18° 127 .59 “ 25
26 1‘26 “ .8125 “ 60 25 65 23° { 116 .43 “ 26
21 so 40 Open delivery. 5 . h.'_ _._._ —_’ 53 1.06 _12H§ ‘27—
28 u u. it £6 . . D . _ i ' _ 65 1 J64 ti 29 5 120 “ . 75 “ 20 2O 28 45° 124 . 93 20 29
30 186 “ “ “ 40 29 44 26° 143 .86 10 30
31 186 “ “ “ 40 20 44 26° 143 . 82 “ 31
22 so “40 _ Open delivery. 5 . _..“ . .. 76 .95 12 32
as 45 “ e- “ “ . . . . _ . 56 1 .02 “ as
34 6 60 “ “ “ l “ . . . . , , , , 55 1 .23 “ 84
35 120 ' .75 i “ 20 20 23 45° ' 129 .86 2O 35
36 ' 180 “ “ “ 40 20 4-1 26° 148 .77 10 36
37 180 “ “ i “ 40 20 44 26° 151 . 75 “ 37
as so 40 Open delivery. ' 5 ___g ; 51 1.14 2o 3—2?
39 60 “ “ e ‘ a 1 l g 60 1.10 “ % so
40 180 so .75 i 5 40 2o "—11" —25° 5 99 .72 10 Flo—
41 9 180 40 1 l 5 40 20 41 25° i 160 .11 15— in—
42 180 " “ l “ 40 39 50 37° 5 162 .72 “ 1 42
43 180 75 .s 5 _ 5 40 20 44 26° '_ 110 .70 3:11;—
44 10 180 r “ I “ 40 so 40 87° 145 .68 “ i 44
45 11 180 so 5525 ' 5 40 2o 4? 35°— _1'§_ .67 12__l_715“
'46 g 180 " “ “ 40 30 50 37° ‘ 198 .39 “ l 46


















































576
ENGINES, FIRE.

A valuable paper, containing details of these and other steam fire-engines, together with a histori-
cal account and an extended discusswn, may be found in the “Transactions of the Society of En.
gineers for 1863.”


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The steam fire-engines representing the present practice in the United States may be classed as
reciprocating engines and pumps without fly-wheels, reciprocating engines and pumps with fiy-wheels
(this class being subdivided into engines with cranks and connecting-rods, and engines with yoke
1350.



motion), and rotary engines and pumps. Representatives of all but
the first class, which differs but little from the ordinary direct-acting
pump, are illustrated and described in the following pages.
The Button engine, Fig. 1349, has two fly-wheels and the ordinary
direct-acting engine connection, the pump-piston being attached to
the cross-head. Fig. 1350 is a sectional view of the pump, which re-
quires no explanation. The boiler is of the vertical fire-tube variety.
The Gould engine, shown in section in Fig. 1351, has a vertical
fire-tube boiler, with a submerged smoke-flue. The sides of the fire-
box are tapering, for the purpose of increasing the area of the grate
and promoting the water circulation. The pump-cylinder can be
removed by taking off the bottom cover, so that the valves can be
examined and repaired.
The Silsby fire-engine, represented in Figs. 1352, 1353, 1354, and
1355, has been selected as a representative of the rotary class.
The engine, Fig. 1353, consists of two toothed wheels running to-
gether in a steam-tight case. The steam is admitted at A and ex-
hausted at B, thus moving the wheels. The long teeth of these
cams, which are intended to work steam-tight against the sides and
periphery of the case, are packed with metallic blocks which are
pressed outward by springs. There are openings in the sides of the
case for the purpose of removing and replacing the packing-blocks,
when necessary. The pump, Fig. 1354, is in the same line with the
engine, and is similar in construction. There are outside gears be-
tween the engine and pump, which act as guides. The boiler, Fig.
1355, contains both fire- and water-tubes, the latter being secured
to the lower tube-sheet and extending into the furnace. Each
water-tube has a smaller tube within it, 1" or the purpose of assisting
circulation, and superheating the steam by passing it, as formed,
through the annular spaces between the internal and external tubes.
The Amoskeag self-propelling engine is shown in a full-page
engraving, and a general sectional view in Fig. 1356. Special facilities for the examination of this
engine have been afiorded by Chief Engineer Eli Bates, of the New York City Fire Department;
ENGINES, FIRE. 5'77







578
ENGINES, FIRE.

and the writer is indebted to him, and to the officers and men of the department, for many courteous
attentions.
that many of the features described are to be found
in the other styles of engines. 'l'hese tire-engines me
made both self-propelling, in which case t\\0 engines
are always used, and with a pole for horses, engines of
this class being made single or double, as may be desired.
In the self-propelling engines, as will be seen by refer-
ence to the full-page plate, there is a pulley on the fly-
wheel shaft, which communicates motion to a pulley on
the back driving-axle through a chain connection. The
first pulley is secured to the fly-wheel shaft by a spring
key, which is readily withdrawn when it is desired to
work the pumps, and the pulley then remains stationary
on the revolving shaft, without any tendency to produce
motion in the back driving-axle. The engines are fitted
with link-motion, so that they can readily be reversed. It
will be seen that there is an upright shaft with a large
hand-wheel at the end, directly in front of the wheels-
man’s seat. There is a gear-wheel on the other end of
this shaft, which works in a rack connected to the front
driving-axle, thus enabling the wheelsman to guide the
engine in any direction. In passing around a curve, it is
evident that one of the back driving-wheels must travel
faster than the other, and provision is made for this
by an attachment commonly known as the “differential
gear.” The wheel on the back axle that is nearest to
the pulley over which the driving-chain passes is loose
on the axle. The pulley over which the driving-chain
passes is also loose on the axle, but it has within it a
wheel carrying two bevel-pinions on the periphery, which
work in two bevel-gears secured to the loose wheel and
the driving-axle respectively. This arrangement allows
the loose wheel to slip when the resistance to motiOn is
unequally distributed between the two back wheels. (A
clear illustration of this “difierential gear” may be found


A somewhat detailed description of this engine is appended, and it may be noted
in a paper on “Traction Engines,” by Prof. Thurston, published in the Journal of the Franklin Insti-
tute for January, 187
The boiler of this engine has vertical fire-tubes, and needs no particular description, being clearly




I
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lllll g
.m____
ENGINES, FIR-E. 579

illustrated in Fig. 1356. The pump-valves are circular disks of rubber, with light spiral springs
above them, and are so arranged that the seats can be easily removed. The pump-plunger is packed
with two cup-leathers. The pump has a relief-valve, which can be set to any pressure by turning a
hand-wheel,and will thus control the water-pressure which the hose sustains. It frequently happens
that the fireman has to go with the nozzle into the interior of a burning building, and, having sub- '
dued the fire, desires to stop the water before wetting valuable goods. The nozzles used in the New
York Fire Department are fitted with valves, which can be closed when desired, cutting off the dis-
charge instantly; and the relief-valve allows this to be done without injury to the hose or other con-
7; nections. Below the wheelsman’s seat, as seen in Fig. 1356, is a tank, holding about a boilerful of
, fresh water, from which the supply for feeding the boiler is drawn when salt water is being forced
bythel'pumps, and which also furnishes a supply when the engine is proceeding to a fire at a dis-
tance. When the engine is drawing water from a hydrant, the boiler feed-pumps can also be sup-
plied from the same source.
Simple arrangements are provided for checking the springs, in order to prevent vibrations when
the pumps are in action. The fuel used for generating steam is cannel coal, which, when put into
the furnace in large lumps, burns freely and without forming clinker. An engine ordinarily carries
sufficient Coral for a continuous run of an hour or a little more. When standing in the engine-house,
a pressure of about 80 lbs. per square inch is maintained in the boiler of the self-propelling engine,
and about 5 lbs. in the boilers of engines that are drawn by horses. This pressure is maintained by
connecting the boiler of the fire-engine with a small circulating boiler located in the engine-house,
the connecting pipes being so arranged that there is a constant circulation of water. In the case of
an engine drawn by horses, the circulating boiler is of the simplest description, consisting of a coil
of pipe in the fire-box of an ordinary coal-stove. When the engine is taken from the house, an
automatic arrangement shuts the valves connecting the circulating pipes with the boiler of the
fire-engine, and opens communication with a tank, through which the circulation continues. The
limits of this article will not permit mention of the many ingenious contrivances that have been
developed since the telegraph has been taken into the service by the fire department, but the reader
will find an excellent popular description of the most advanced practice in Harper’s Afagazine for
October, 1877.
The principal dimensions of the engines that have been described are given in the accompanying
table:
Table showing Dimensions of American Steam Fire-Engines.










Sq b Amoskesg Manufacturing ' A" 1 5 F Com anv. .
DETAILS. Email???“ 3' S; Eihds Manufacturing 1’) ' "
I amp“? } 01a Pattern. .Selspiepeniegf
Length, with tongue removed, feet . . . . . . . . . . . . . 12.5 12 12 .5 12 i 16 Width. feet ................................. . . 6.1 g e 1 5 .ss 1 6.25
Height, feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8 E 9.17 l 8.33 ' 9.25 ;
Weight, light, lbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,500 4,400 ; 5,200 F 6.000 8.700 r
“ equipped, lbs . . . . . . . . . . . . . . . . . . . . . . . . . . 6,100 5.000 a 5,550 .1 6,500 9,500 ‘
Diameter of boiler, inches . . . . . . . . . . . . . . . . . . . . . . 39 .5 31.5 1 36 l 31 l , 33
Height of boiler, feet ........................ . . 5 4.67 4.67 i 5.33 ’- 5 .42
Grate surface, square feet . . . . . . . . . . . . . . . . . . . . . . 7 .46 5.58 5.5 4.28 4.91
Number of tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 309 260 250 311
External diameter of tubes, inches . . . . . . . . . . . . . . 1 .2' 1.25 2, and 1.25 1.25 1 .25
Length of tubes, inches . . . . . . . . . . . . . . . . . . . . . . . . 20 4 22 18 l 18
Cross area of tubes, square feet . . . . . . . . . . . . . . . . . 3.2"2 2.062 .937 1.668 ,1 2.075
Heating surface in fire-box, square feet . . . . . . . . . 35.77 28 6 7
Total heating surface, square feet . . . . . . . . . . . . . . . 297.6 228.4 218 171 207
Ratio of heating to grate surface; . . . . . . . . . . . . .. 40 40.9 39.6 39.8 42.3
“ of tube area “ ‘- . . . . . . . . . . . . . .. 0.428 0.369 0.170 0.388 0.424
Height of chimney above grate, feet . . . . . . . . . . . 7.42 6.67 7 .83 6 7 .5
Water space, cubic feet . . . . . . . . . . . . . . . . . . . . . . . . 8 2.56 5 6. (8 7 .2
Steam “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . 12 7.27 6 6.81 7.66
Number of engines . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 1 1 2
Diameter of steam cylinder, inches . . . . . . . ; . . . .. 14 9 11 6 8
Length of stroke, inches . . . . . . . . . . . . . . . . . . . . . . . 4.5 '7 4.75 wide 8 8
Number of pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 1 1 i 1 2
Diameter of pump, inches . . . . . . . . . . . . . . . . . . . . . . 8 6 7.2" ‘ 4 4 .5
Stroke “ .................... . . 4.5 7 4.5 wide 1 s s
(‘apaeity of air-chamber. cubic feet. . . . . . . . . . . . . 5.5 2.4 2.75 2.25 2.25
Number of discharge orifices . . . . . . . . . . . . . . . . . . . 4 3 2 i 2 2
Diameter “ “ inches . . . . . . . . . . . . . 2 .5 2 .5 2- . 0 i 2 .5 2 .5
Number of suction “ . . . . . . . . . . . .- . . . . . . . 1 2 1 1 2 2
_ Diameter “ “ inches . . . . . . . . . . . . . 4.5 4.5 4 5 5 5 ;






There are but few records of trials made with modern fire-engines by competent experts; and
although the catalogues of the various builders are filled with testimonials, they are but feeble aids
for the formation of a critical opinion. Some points of interest were developed in the trial of firc~
engines at the Centennial Exposition of 1876, and a summary of the same, from the official report,
is given in the following table. The trials were conducted by \Vellington Lee, under the instruc~
tions of the Committee of Judges, Messrs. Charles T. Porter, Joseph Belknap, and E. Brugsch. Mr.
Lee says in his report: “A careful analysis of the facts brought out at the trials will justify the
theory upon which the programme and rules were made, viz. : the engine that is capable, at a fire,
> elf; exertip’g the greatest amount of power in proportion to its weight (other things being equal), is
t e best.
580
ENGINES, GAS AND VAPOR.






































Summary of Fire-Eugene Tests at International Exposition, 1876.
g: .
a g weren'r 1N POUNDS. noun.
a: Diameter Diameter 32:0 at;
g 5 NAME. _ of Steam of Water Stroke. War?“
:55 E Light. a}: Equipped. 0’ hnder' Cyundu' Cylinder. Diameter. Height. 22.???
2
Inches. Inches. Inches. Inches Inches Sq. Ft
1 Silsby . . . . . . . . . . . 6,596 7,045 8,173 13.5, 6.25 8.38, 5.25 . . . . 40 60 330
2 “ . . . . . . . . .. 4,795 5,140 36 56 197
3 Nichols . . . . . . . . . 7,122 7.323 . . . . 9 6 7 2.25 40 60 251
4 La France . . . . . . . 7,061 7,355 8,310 . . . . . . . . . . . 40 56 265
5 Ronald . . . . . . . . . . 5,812 6,022 . . . . 7.75 4.33 9 3.2 32 56 . . -
6 Clapp &. J ones. . 3,310 3,505 .. . . T 4.25 '4' 2.71 28 52 128
7 “ . . . 6,503 6,825 7,847 8 41.3 8 2 .99 38 58 248
3 Button . . . . . . . . . . 5,035 5,225 . . . . 12 8, 6.75 4 5 2.25, 3.16 34.5 60 190
9 Amoskeag . . . . . . 7,522 8,920 7 .625 4.5 8 2 .87 31 .8 64 175
10 “ . . . . . . 6,105 6,264 6.875 4.25 8 2.62 30.5 61 151
11 Clapp 85 Jones... 3,925 4,098 8 4.875 8 2.60 32 52 147
g kl. 'PRESSURE 1‘7 POUNDS BTRI‘A“
h 2 Area of _ PER SQUARE mom Average THROWR ooxsunp'rlon or s'ronns.
111 m the Four Total Time . .
co m _ _ Dlameter
m H Axle of Trial. of N ,9
2 E Journals. St W , on ' Vertical Horizontal C l O. T a1
a m cm. a.er. Height. Distauca 0a . Wood. 11. low.
Sq. In Minutes Inches Feet. Feet. Pounds Pounds. Gallons Pounds.
1 > 25.9 684. 83.0 139.6 1.46 174.7 203.4 10,880 275.75 - 2 16.5 *1 64.9 108.5 1.2 187.4 4,212 193 ° . ..
3 31.4 525.5 109.7 82.1 1.47 202.9 6,581 194 .25 ..
4 2S 3 512.5 62.8 73.9 1.46 47.7 8,054 240.25 2.5 .. .
5 21 7 515.5 67.7 64.1 1.32 27.2 4,889.5 211.25 .19 6 15 9 684.5 84.9 119 1.01 .. .. . 182.4 2.686 173.5 1.25
7 28.3 “ 90.1 157.1 1 .41 202.3 215.2 8,715 280.75 . (.7 1.25
8 21 3 52 65.6 83.2 1.24 . . . . . . . . . . 267.5 65 13 . ..
10 2%.5 . . . . . . . . .. . . . . . .. ... 11 15.9 576.5 100.7 145.5 .96 192.3 160 4 4,099 173 25 5 1.25
See also FIRE-EXTINGUISHERS. R. H. B.
ENGINES, GAS AND VAPOR. The majority of engines of this character have been designed
to use an inflammable gas to which sufficient air has been added to form an explosive compound, and
thus produce the requisite pressure. The energy is produced at the moment needed, and there is no
storing up of heat. Hence it will be seen that the gas-engines find a special applicability in cases
where continuous work is not required. Descriptions of many prominent varieties of this class of
engines, together with a historical account, may be found in Dr. Barnard’s “Report on the Machi~
nery and' Processes of the Industrial Arts.”
The great difficulty in the way of constructing a satisfactory gas-engine has always arisen from
the suddenness of the explosion and expansion which has to be utilized. In the Otto and Langen
engine this difficulty was surmounted very ingeniously by allowing the expansion to take place under
a free piston, whose velocity was not limited by the motion of a crank, and engaging the piston-rod
with the driving-shaft only on its downward stroke. In this way the sudden expansion could of
course be more completely utilized than in any case where the velocity of the piston was‘controlled
by the usual connection to a crank-shaft, but at the same time the whole arrangement had very dis-
tinct drawbacks, and was obviously open to improvement. In Herr Otto’s later arrangement the
difficulty arising from the suddenness of the explosion is removed in a totally different way, viz., by
making it less sudden. This could not be done previously because the mixture ‘of air and gas was
always drawn into the cylinder at atmospheric pressure, and was already used as dilute as was possi~
ble under these conditions. If only, however, the mixture could be used under pressure, a much
larger dilution of air could be employed without destroying its explosiveness, and in consequence the
violence and rapidity of the explosion would be very much reduced. It is upon this principle that the
engine is constructed; the sudden explosion has been reduced to what is really not much more than a
rapid combustion and expansion—not too rapid to allow it to be used, without loss, at the beginning
of the stroke of an engine arranged with connecting-rod and crank in the usual way. In general
external appearance the engine resembles a small horizontal engine, but the resemblance is only super-
ficial. The cylinder is single-acting, open at the-front end, and is so arranged that it only completes
its cycle of operations once in two complete double strokes. Its method of working is as follows :
The piston in moving forward draws into the cylinder a mixture of air and coal-gas, the latter in
measured quantity; returning, it compresses this mixture into little more than one-third of its
volume, as drawn in at atmospheric pressure; these two operations take up one complete double
stroke. As the piston is ready to commence the next stroke the compressed mixture is ignited, and,
expanding, drives the piston before it, while in the second return stroke the burnt gases are expelled
from the cylinder, and the whole made ready to start afresh. Work is actually being done on the
piston, therefore, only during one-quarter of the time it is in motion, the gearing, as well as the
work driven, being carried forward by the fly-wheel during the rest of the time.

* Eng'i/neem‘ng, xxvi., 155.
ENGINES, GAS AND VAPOR. ‘ 581

V' ' Figs; 1357, 1358, and 1359 are elevation, plan, and end elevation respectively of the engine as
' cimibited-at‘the Paris Exposition of 1878; and Fig. 1360 is a section of the cylinder and valve, on
' a someWhat larger scale. From the latter it will be seen that the cylinder, open at the front end,
1357.


is fitted at back with a cover A carrying certain ports, and having a face against which a slide-valve
B can work, this valve being kept in place by a separate cover 0 held against it by the two spiral
springs shown in Figs. 1357 and 1358. The action of the valve is as follows: When the piston is
1358.







l
i


at the back of its stroke ready to draw in the explosive mixture, the valve B is in such a position
that the port j '5 in it makes communication between the passage j andl in the cylinder-end A.
When the piston moves it draws in air through the valve from the opening a and the pipe 6, and at
582 ENGINES, GAS AND VAPOR.

the same time draws in gas through the small opening k on the back of the valve, which is then just
opposite the passage in the valve-cover c, which communicates with the pipe 7:. above. The admission
opening having been thus made and closed, the pistOn begins to return, and during its return'the
valve, moving continuously, keeps the port Z closed. Just as the second stroke commences the pas-
sage n comes opposite 1, having just been in communication with m and o. In the chamber m a
small gas-jet is always burning, fed by the pipe 772, Fig. 1359, and through 0 a small stream of gas
is allowed to pass. The passage n is thus filled with gas from 0 ignited from 111, just as'it comes to
l ,- this ignites the mixture in the cylinder and starts the stroke, while on the return stroke of the
piston the spent gases are discharged through the opening q in the bottom of the cylinder. . In order
to carry out the function we have described, it is simply necessary that the valve should make only
one reciprocation for two strokes of the piston, and for this purpose it is driven by a crank on the
end of a lay shaft which revolves with half the velocity of the crank-shaft (the bevel-gear shown in
the figures being2 : 1). This crank and the end of the shaft are seen in Fig. 1360. The same lay
shaft serves also to work the governor and two other valves. It carries a cam 2', which by means of
a lever '0 opens periodically a valve 9 (closed again by a spring), which regulates the amount of gas
admitted through h per stroke. A second cam s, by means of a lever 25 below the cylinder. opens and
closes the exhaust-valve q. The governor is worked from the lay shaft by the bevel-gearing shown
in Figs. 1357 and 1358. In the engines exhibited at Paris it diifers somewhat from the form shown
in our figures; it is merely a small loaded-ball governor of a neat arrangement. By means of a
lever w it controls the position of the cam 0' upon the shaft, so that, if the speed of the engine exceed
a certain limit, the gas~admission valve 9 is left closed, and the engine runs on until sufficient of its
stored-up energy is expended to bring the speed down to its proper level. The cylinder is inolosed
in a water-jacket in order to prevent overheating. To insure a circulation of water, it has been found
sufficient simply to connect the top and bottom of the jacket with the top and bottom of a filled
reservoir. The difference in the densities of the hot and cold water is enough to set up and maintain
the requisite circulation. The water enters by the pipe D and returns to the reservoir by E, being
cooled sufficiently by contact with the air to be used continuously. To avoid shock at exhaust, the
1861.
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hot gases are discharged through a pipe V into a reservoir placed at a little distance, from which
they pass into the atmosphere by the pipe 3/ and the nozzle z. The lubrication of the P1515011 and
valve is eifected by the self-acting lubricator a a, driven from the lay shaft. The engine is stated to
consume about 20 cubic feet of ordinary coal-gas per horse-power per hour.
ENGINES, GAS AND VAPOR. 583

For light industrial uses it would seem that the Bischof engine, represented in Figs. 1361 and
1362, is especially adapted. The machine illustrated, which was exhibited at the Paris Exposition of
1878, is known as a “ one-man power ” machine (equivalent to T33 horse-power). The machine has
only two principal castings—a base-plate, with which the vertical cylinder is cast, as well as the
valvechamber, and the cylinder cover and stuffing-box, prolonged above to form a guide for the pis-
ton-rod head, and having the bearing-bracket for the shaft east along with it. The space above the
piston communicates freely with the air by the rectangular opening shown. The bottom of the cylin-
der has a single port communicating with the chamber of a plain piston-valve, the only valve used,
which when raised opens communication with the exhaust, and when down (as in position shown)
puts the cylinder in connection with the gas- and air-inlet openings. This valve is worked by an ordi-
nary eccentric through the intervention of a rocking lever. The eccentric is placed about 135° in
1 advance of the crank. About a third of the stroke up the cylinder there is a little opening on one
side of the latter, opposite which, outside, is the nozzle of a small gas-pipe ; and directly below this
nozzle there is an ordinary burner connected with the same pipe, the gas at which is kept always
lighted. The two burners are protected from draughts by inclosure in a box casing. The upper
burner is the real ignition jet; the function of the lower one, which is burning continuously, is sim-
ply to relight the other when it is blown out. The crank-shaft lies across the machine, a considera-
ble distance from its axis, the apparent irregularity of action of this arrangement being ingeniously
taken advantage of, as will be seen. The action of the machine is as follows : The piston, being at
the bottom of its stroke, is at first raised by the energy stored in the fly-wheel and counterweight,
and draws into the cylinder the mixture of air and gas through the valve. As soon as the bottom
of the piston rises above the opening in the cylinder side above mentioned, the jet outside explodes
the mixture, and the explosion drives the piston to the top of its stroke. In the expansion thus
brought about, the pressure under the piston falls below that of the atmosphere, so that in its
descending course the piston is at first driven downward by the atmosphere acting upon it. This
helps to make the machine work more uniformly, although, of course, it is in reality only single-
acting. The position of the connecting-rod is so adjusted that it has a very direct pull on the crank
just when this is most wanted, during the time when the explosion drives the piston upward. Its
oblique position comes only when the piston is descending, and for the most part when the connect-
ing-rod is doing no work, being simply carried down by the fly-wheel. So far, therefore, as oblique
pressures are concerned, the skew action of the connecting-rod and its extreme shortness do not do
any harm, while the arrangement adopted reduces the space occupied by the engine to very small di-
mensions. Each of the two India-rubber gas-pipes is carried through a spring closer. This consists
simply of an upright bracket, having a thin flat spring carried up beside it, adjustable at the top by
a milled finger-nut. The pipe is held between the spring and the standard, and can be closed at will
by turning the nut, which gives a very fine adjustment for regulating the quantity of gas passing.
An eye is attached to the centre of the spring for the purpose of carrying away a cord from it, so
that the workman can adjust the gas supply without leaving any machine at which he is occupied.
Two special features claimed for this machine are: first, that it works without grease or other lubri-
cant on either valve or piston; and second, that it requires no water for cooling. The heat from the
cylinder is got rid of sufficiently quickly by radiation, a number of radial ribs being cast from the
cylinder to increase its surface for this purpose. The consumption of gas is about 11.6 cubic feet
or hour, or about 145 cubic feet per horse-power per hour?
The Simon engine, while based on the same principles as the Otto engine, is differently construct-
ed. The compression of the mixture is done in a separate cylinder, and the air and gas, after com-
pression, are led to the motor-cylinder. There the mixture at once meets an ignited jet, which in-
flames it. It does not enter the cylinder, however, all at once, but in small quantities, which are
successively ignited, thus determining true gradual expansion. The heat developed is small, and a
very limited quantity of water prevents overheating of the cylinder. The movement is regular and
even. According to M. Simon, the expenditure of gas is 17.6 cubic feet per horse-power per hour.
In the Lenoir engine, the mixture of gas and air is admitted into the cylinder at atmospheric pres-
sure, which is maintained until the piston has made half its stroke ; the admission of a spark deter-
mines the explosion.
In the Ravel engine, the explosive force of the mixture is employed to move the piston, which is
inclosed wholly in the cylinder, motion being taken from the cylinder and not from the piston. IV hen
the gas is exploded by a flame, the piston is driven to the opposite end of the cylinder. Its weight
at the extremity then causes the latter to overbalanec, and hence the cylinder rotates on its trunnions.
The vapor engine designed by G. H. Brayton, and illustrated in Figs. 1363 and 1364, in its earlier
form was driven by a mixture of illuminating gas and air, in such proportions that a rapid combus-
tion rather than an explosion resulted when the mixture was brought into contact with a lighted gas-
jet. In the engine as constructed at present, the vapor from petroleum mixed with air is used. Fig.
1363 is a general view of the engine, and Fig. 1364c is a section of enough of the working parts to
illustrate the action. The following description is from Engineering for Feb. 16, 1877 : i
“In Fig. 1363, A is the working cylinder and B the air-pump. A parallel motion for the piston
is provided as follows : C is a lever, the lower end of which is a vertical foot, the circle being struck
elf the centre of the cross-head to which the arm or lever C is pivoted by a journal. The radial foot
of (7 rests upon a pathway parallel with the bore of the cylinder; hence, as the piston cross-head
moves along, the radial foot rolls along the pathway. In Fig. 1364, A represents the combustion-
chamber, in which the vapor forms continuously, and B the safety device, which is composed of per,
forated plates with diaphragms of wire gauze between them, through which, on the principle of the
Davy lamp, it is impossible for the flame in the chamber to pass. At C is shown an annular groove

* Engineering, xvi, 333.
584 ENGINES, GAS AND VAPOR.
packed with felt or sponge, into which the petroleum is fed by a small pump. A small jet of air
is also introduced into the fibrous material while it is moistened with the petroleum. As the supply
of this jet is constant and under considerable pressure, the result is that the petroleum is forced out




r-
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x


in the form of spray, which is spread over and absorbed by the meshes of wire gauze. The air
under pressure delivered by the air-pump passes in volume from the air-chest D through the valve E,
to fill the cylinder. This volume of air (which is under a pressure varying from 30 lbs. to 75 lbs.,
according as regulated to suit the duty)
1364- in passing through the gauze takes up
the spray, mechanically evaporating it '
rawiél/fi/l/W/WWW as it enters the combustion-chamber.
35%.? The small air-jet is carbonized to a
=" degree rendering its combustion con-
” tinuous, as previously indicated. To
start the engine, the two plugs E E, in



m/






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\
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“e
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. r
Wild


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[a/ Fig. 1363, are taken out of the cylinder,
/ and the small pump is worked by hand
z / , '_ through the means of the small hand-



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4&\X\\\\ \\\\\\‘.\\"C~\\\\\\\\$\\\\\‘


wheel shown on the top of the gover-
nor; the small air-jet is then let in,
and a match is applied to the holes
from which the plugs were removed.
So soon as the combustion takes place,
the plugs are reinserted and the supply
of air from the reservoir is turned on,
whereupon the engine starts instantly.
In Fig. 1364, the dotted lines indicate
the water passages by which the cylin-
ders and the working piston are kept
as cool as may be desired. The motive
power then is produced by the whole
products of combustion acting upon the
piston. The point of cut-off is regula-
ted by the point at which the valve E
closes. The exhaust takes place through
fik the valve F, which is operated by a
positive motion, all the valves being
worked from one shaft, and the valve E being attached to the governor. The inlet-valves to the
pump are shown at G G; they are connected together by a rod and work automatically. The air-


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fi/lflMMWZXW/j/Z/a
S T".
\\\ \ g/
.y



éfl/fll/I/Wl/fl/fi.


‘l


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h
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/





ENGINES, HEAT. 585

pump discharge valves are shown at H H, the hole I being for the purpose of attaching apipe to
an independent reservoir, which is required in some cases. Suppose,.for example, an engine is some-
times required to perform for a short period a duty much above its average allotted duty; then,
when running under the lesser load, air may be compressed and stored in a suitable receptacle;
and when the load is excessive, the air-pump may be relieved or partially relieved of duty, and the
air stored may be used. To provide sufficient air-pressure to start the engine in the morning, the
frame of the engine contains an air-reservoir, the hole I being plugged up unless the extra air-re-
servoir referred to is employed.
“ The small pump which supplies the petroleum deserves notice. The plunger is but about thir-
teen-sixteenths of an inch in diameter, its stroke being adjustable from one-sixteenth to one-half of
an inch, by which means the supply of oil to suit any desired speed and power of engine is regula-
ted; and with a given length of stroke the same number of drops of oil will be pumped, whether
the engine is running at its slowest, that is, 80 revolutions per minute, or its calculated 180 revolu-
tions per minute.”
For works for reference, see ENGINES, HEAT. R. H. B.
ENGINES, HEAT. See Excuses, Aime-STEAM nun BINARY VAPOR—AIR—GAS AND VAPOR—SOLAR
-—STEAM, HOISTING-—STEAM, MARINE—STEAM, PORTABLE AND SEMI-PORTABLE—STEAM, PROPORTIONS OF
r—STEAM, STATIONARY, RECIPROCATiNG—SZ‘EAM, STATIONARY, ROTARY—STEAM, UNUSUAL Foams or.
Theory of Heat-Engines.——According to the dynamical theory of heat, a given amount of work is
always convertible into an equivalent amount of heat; or, to speak more definitely, one unit of heat
is the equivalent of 7’72 foot-pounds of work. (See DYNAMICS.) By a unit of heat is meant the
amount of heat required to raise the temperature of a pound of distilled water from 39° to 40° F. ;
and work of any kind can always be expressed as a given number of pounds raised so many feet
high. For instance, if a wagon is drawn along a road for a mile with a constant force of 50 lbs.,
the work done is equivalent to raising 50 lbs. through a height of 5,280 feet, or 50 x 5,280 = 264,-
000 foot-pounds; and if a perfect engine had been employed to do the work, it would have required
' 264,000 —:- 7 7 2 : 342 units of heat.
The steam, air, and vapor engines in common use offer familiar examples of the conversion of
heat into work. Coal is burned in a furnace, for instance, imparting heat to a fluid, such as water
or air; and then a portion of the heat so imparted may be utilized in performing the work of mov-
ing the engine-piston and overcoming resistance. If all the heat derived from the combustion of the
coal was imparted to the working fluid, and then by its expansion converted into work, this would
represent perfect action, which is Of course far from being realized in practice. Thus, suppose that
the heat received by the fluid from a pound of coal is 15,000 units, then the work done per hour
for each pound of coal burned is 772 x 15,000 = 11,580,000 foot-pounds, or nearly 6 horse-power;
showing that the best modern engines only utilize a small fraction of the heat developed by the
combustion of the fuel. The reasons for this waste will be given hereafter.
It will be evident from the above that any form of engine which is made to work through the
agency of heat is properly designated as a heat-engine; and that this general term covers the va-
rious classes which are described under their several headings, viz.: air-engines, steam-engines, gas-
engines, vapor-engines, and solar engines—the distinctive names referring either to the kind of work-
ing fluid employed, or the means Of imparting heat.
It may be well, at the outset, to call attention to the fact, which is Often overlooked, that the
effect of a heat-engine depends, not upon the working fluid that is employed, but upon the extremes
of temperature in the working cylinder. Suppose, for example, that the fluid is admitted into the
working cylinder at an absolute temperature T, and that, after moving the piston by its expansion,
its absolute temperature is reduced to t, when it is expelled from the cylinder; the efficiency of the
engine is represented by the fraction ZT t“ (The absolute temperature is the temperature meas-
ured from the absolute zero, which is fixed by theory at — 46133° F., so that the absolute tempera-
ture = temperature on Fahrenheit’s scale + 461.2°.) Thus, suppose that in a condensing engine the
steam is admitted at a temperature of 330°, and that at the end of its expansion in the cylinder the
(330 + 461.2) —— (200 + 461.2)
. y 330 + 461.2
of the total efficiency of the fluid. Or supposing the total efl’ect of the heat imparted to the fluid was
6 horse-power, the useful efiect would be only 0.984 horse-power, and 5.016 horse-power are lost.
From the above principle it appears that the means of increasing the efficiency of an engine con-
sists in increasing the difference of temperatures between which it works, either raising the higher
temperature, lowering the .other, or both. It appears further, from the principle, that it is a matter
of indifference what fluid is used in the engine, provided the initial and final temperatures are fixed.
It may be easier, however, to maintain a given difierence of temperature with one fluid than another,
so that under certain conditions special advantages will result from the use Of a particular fluid.
Horse-Power.—-As already remarked, resistance overcome in any case in which motion ensues, if it
can be measured, is convertible into the amount of work that is done in raising a weight equal to the
given resistance through a height equal to the space over which this resistance is moved. A com-
mon measure for a unit of work is the amount required to raise one pound through a vertical dis_
tance of one foot. To illustrate, suppose that a cut is being taken from a 6-inch shaft in a lathe,
and that the resistance to the motion of the cutting tool is 200 lbs. ; then in each revolution of the
shaft the tool takes a cut 1.5708 foot in length, so that the work done per revolution is the same as
would be expended in raising a weight of 200 lbs. through a vertical distance of 1.5708 foot, or it is
314.16 foot-pounds.
Power is the measure of the amount of work done in a given time ; and the conventional unit of

temperature is 200°; the effect would be onl x 100 : 16.4 per cent.

see ENGINES, HEAT.

power, known as a horse-power, is equivalent to 550 foot-pounds of work per second, 33,000 per
minute, or 1,980,000 per hour. If, in the preceding example, the shaft makes 20 revolutions a min-
ute, the work done per minute is 314.16 x 20 = 6,283.2 foot-pounds ; so that the power required to
drive the tool is 6,283.2 -:- 33,000 = 0.19 horse-power. The term horse-power, when used in con-
nection with an engine, is variously applied. The most common distinctions are as follows: 1.
Gross or indicated horse-power. 2. Net or effective horse-power. 3. Total horse-power. 4. N omi-
nal horse-power.
The gross or' indicated power of an engine is calculated from the mean effective pressure in the
cylinder, usually determined, in the ease of heat-engines, by an indicator. If, for example, it is
found that the mean pressure is 2,500 lbs., moving the piston at the rate of 400 feet a minute, the
0' 'oss horse ower is 2500 X 400 - 30 3
=1 p 33000 — ' '
The net or efi'eetive horse-power is calculated from the pressure exerted by the engine in useful
effect, which can be determined by a dynamometer. Suppose the useful pressure in the preceding
2200 X 400
——~—~-—~: 26.7.
33000
The total horse-power of an engine is calculated from (the total pressure in a cylinder above a
vacuum, which can be found from an indicator diagram. If, for example, the mean total pressure is
. . 4200 X 400
4,200 lbs., and the piston speed 400 feet per minute, the total horse-power 1s ——W :50.9.
Total horse-power is sometimes used in comparisons of the results of experiments. Another appli-
cation is illustrated on page 624.
The nominal horse-power of an engine can scarcely be said to have any definite meaning, since
there are a number of different rules by which it may be computed. Thus, there is the Admiralty
rule for marine engines, Mr. Bourne’s rules for condensing and non-condensing engines, and James
WVatt’s rule, all of which are in common use; and in addition numerous engine-builders have what
may be called proprietary rules. For instance, one builder, A, may say, “ I will make a steam-engine
with a cylinder 10 inches in diameter, and a stroke of 15 inches, and I will call it 8 horsepower,
nominal.” Another builder, B, who makes an engine of the same size, and desires to impress pur-
chasers with the idea that he gives them more for the same price than his competitors do, may say,
“I will rate my engine at 16 horse-power, nominal.” The above illustration represents quite accu-
rately the capricious use that is made of the term “nominal horse-power; ” and the intelligent
engine-buyer may very properly inquire of the builder, “How much will you charge me for an
engine guaranteed to develop so much horse-power, actual ? ”
l'Vorks for Rejei-ence.--The literature of the steam-engine is so extensive that it is here impossible
to give a full list. Copious references to transactions and periodical literature have been intro-
duced throughout the various articles in their proper connections, so that the list that follows is con-
fined to general treatises and text-books. Works on appliances related to the steam-engine, such as
indicators, etc., will be found quoted in the articles treating thereon.
Historical: “History of the Steam-Engine,” Stuart, London, 1824; “Treatise on the Steam-
Engine,” Farey, London, 1827 ; “Anecdotes of the Steam-Engine,” Stuart, London, 1829; “The
Steam-Engine, its Invention,” etc., Tredgold, London, 1838; “Mechanical Inventions of James
Watt,” Muirhead, London, 1854; “ Life of James lVatt,” Muirhead, London, 1859; “Life, Times,
and Scientific Labors of the Second Marquis of Worcester,” Dircks, London, 1865; “Lives of Boul-
ton and Watt,” Smiles, London, 1865; “Life of Richard Trevithick,” Trevithick, London, 1872;
“A History of the Growth of the Steam-Engine,” Thurston, New York, 1878.
Theoretical (chiefly): “ Théorie des Machines a Vapeur,” De Pambour, 2d ed., Paris, 1844; “ Rela-
tion des Experiments pour determiner les principales Lois, etc., des Machines a Vapeur,” Regnault,
Paris, 1847; “ Lecons de Mécanique Pratique,” Morin, Paris, 1846 (3d part); “Traité théorique et
pratique des Moteurs,” Courtois, Paris, 1846; “ Analytical Principles, etc., of the Expansive Steam-
Engine,” Hodge, London, 1849; “Theorie des Dampfmaschinen,” Schmidt, Freiberg, 1861; “The-
orie mécanique de la Chaleur,” Hirn, 2d ed., Paris, 1865 ; “Theorie méeanique de la Chaleur, avec
ses Applications aux Machines,” Zeuner, Paris, 1869 (“Grundziige der Mechanisehen Warmethe-
orie,” Leipsic, 1866); “Heat and Steam,” Williams, Philadelphia, 1871; “Heat as a Source of
Power,” Trowbridge, New York, 1874; “The Mechanical Theory of Ileat and its Application to
Steam-Engines,” McCulloch, New York, 1876; “Heat as a Mode of Motion,” Tyndall, New York,
1876; “Traité de Méeanique Général,” Resal, Paris, 1876; “TheSteam-Engine Considered as a
Heat-Engine,” Cotterill, New York, 1878.
Elementary Treatises (general): “The Steam-Engine familiarly Explained,” Ilenwick, Philadel-
phia, 1848; “Steam and Steam-Engines,” Clarke, London, 1875 ; “ Catechism of the Steam-Engine,”
“ Hand-book of the Steam-Engine,” Bourne, London and New York, 1876; “ The Theory and Action
of the Steam-Engine,” N orthcott, London, 1877 ; “Wrinkles and Recipes,” Benjamin, New York, 187 8.
On Marine Engines: “Catéchisme du Marin et du Méeanicien a Vapeur,” Paris, 1850; “En-
gineering Precedents,” Isherwood, New York, 1858; “ A Study of Steam and Marine Engines”
(elementary), Saxby, London, 1862; “Experimental Researches in Steam-Engineering,” Isherwood,
Philadelphia, 1863 ; “The Cadet Engineer” (elementary), Long and Buel, Philadelphia, 1865 ;
“ Marine Steam-Engine,” Main and Brown, Philadelphia, 1865; “Modern Marine Engineering,”
Burgh, London, 1867 ; “Lessons and Practical Notes on Steam,” King, New York, 1867.
General Treatises : “ Sammlung von Zeichnungen einiger ausgefiihrten Dampfkessel und Dampf-
maschinen,” Rottebohm, Berlin, 1841; “Die Hoehdruckclampfmaschine,” Alban, Rostock, 1843;
“Mémoire sur les Machines a Vapeur,” Reeeh, Paris, 1844; “Traité dcs Machines a Vapeur,”
Bataille and J ullien, Paris, 1849 ; “ Traité élémentaire et pratique des Machines a Vapeur,” Gaudry.
example is 2,200 lbs, then the net horse-power is
ENGINES, PROPORTION S OF PARTS OF. 587

Paris, 1856; “Anleitung fiir Anlage und Wartung der stationaren Dampfkessel,” Marin, Briinn,
1859 ; “American Engineering, embracing various Branches of Mechanics,” Weissenborn, New York,
1861 ; “Practical Rules for Proportions of Modern Engines and Boilers,” Burgh, Philadelphia, 1865;
“Treatise on the Steam-Engine,” Bourne, 7th ed., 1866; “A Manual of Steam-Engines and other
Prime Movers,” Rankine, 3d ed., London, 1866; “Der Fiihrer (les Machinisten,” Scholl, Braunschweig,
6th ed., 1864 ; “Die Dampfmaschinenberechnung Mittels, praktischer Tabcllen und Regeln,” Hrabak,
Prague, 1869; “Manuel de l’Ingénieur, 7° et 8c Fascieules,” De Bauve, Paris, 1873; “Compound
Steam-Engines,” Turnbull, New York, 1874; “Compound Engines,” Mallet, New York, 1874; “A
Practical Treatise on the Steam-Engine,” Bigg, London and New York, 1878; “ The Mechanics of
Engineering,” Weisbach, translated by Du Bois, Vol. II., 1878; supplement to same, 1879.
Treatises on Special Subjects: “The Slide-Valve,” Burgh, London, 1868; “ Link Motion and
Expansion Gear,” Burgh, London, 1872; “Recent Improvements in the Steam-Engine,” Bourne,
London, 1874; “Link and Valve Motion,” Auchincloss, 6th ed., New York, 1875 ; “ Designing
Valve-Gearing,” \Vcleh, New York, 1875; “The Relative Proportions of the Steam-Engine,” Marks,
New York, 1878. R. 11. B. (in part).
ENGINES, PROPORTIONS .OF PARTS OF. The rules that follow, showing the manner of cal-
culating the proper sizes for the principal parts of engines, are mainly derived from Van Buren’s
treatise on “ The Strength of Iron Parts of Steam Machiner Y,” a work which should be in the hands
of every designer. The formula for the length of crank-pins is from an amicle on the subject by
Theron Skeel, published in the Iron Age for Aug. 21, 1873.
Notation—D : diameter of cylinder in inches ; S : length of stroke in inches; l : length of rod
or pin in inches; (1 :: diameter of rod or pin in inches; 2!: thickness of cylinder in inches; {1 :
boiler pressure by gauge + 15, in pounds per square inch ; I : indicated horse-power.
1. Thickness of cylinder. 2. Diameter of piston- and connecting-rods.
l:0.0001><Dxp+0.15x VD dzconstantxD x t/p.
__ 10,000 x t 1,500 _ “maim—
D 4/ D l p — (constant)2 x D2
3. Constants for Rule 2.—-The constants depend upon the length of the rod, so that the rule must
be solved by approximation. A table is appended, giving the constants for different ratios of length
to diameter.
Constants for Diameter of Piston-reels and Connecling-rorle.








PISTON-RODS. CO NNECTINU -BODS. E PISTl )S-BODS. s' CONNECTING -RODS.
RATIO or _ ; RATIO OF LENGTH To a LENGTH 'ro , i I
DIAMETER. Wm'e'h‘ Steel. wmught Steel. i DIAMETER. “m?!” ! Steel. ’ wwgh‘ Steel
. Iron. Iron. I Iron. Iron.
8 .01531 .01250 .01553 .01268 J 25 .0183? l .01500 g .0201? .0164? l
9 .01541 .01258 .01559 .01251 F 26 .01\62 f .01511 5 .02054 016??
10 .01552 .01268 .0158? .012J6 5 2? .01889 Q .01542 E .02092 .01?08 i
11 .01565 .012?8 .01606 .0131] l 28 1 .01915 § .01564 I .02131 .0]?40 f
12 .01578 .01239 .0162? .01329 i 29 f _01942 l .01536 f .021?0 .01??2 ,
13 .01593 -01301 .01650 .0134? 5 30 1 .01970 § .01609 5 .02209 .01804 i
14 .01608 .01313 .016?4 .0136? l 31 I .01999 l .0163! § .02250 .0183?
15 .01625 .0132? .01699 .0138? 3 32 .0262? § .01655 E .0229] .f18i0 ‘
16 .01642 .01341 .01726 .01409 I 33 .0205? = .01679 , .0233? .01904 i
1? .01661 .01356 .01754 .01432 ’ 34 .0203? ? .01704 .0;3T4 .l1939 I
18 .01680 .013?2 .01?83 .01456 i 35 .0211? T .01728 ! .0241? .019?4
19 .01700 .01388 .01813 .01481 I 36 .02148 ; .01?53 t .02460 .02009
20 .01721 .01405 .01845 .01506 1 3? .021?9 I .01??9 = .025“4 _020'4 l
21 .01143 .01428 .01srs .01533 as .02210 .01305 I new .o2cso I
22 .01765 .01441 .01911 .01560 39 .02242 0 .01831 ' .02592 .02116 l
23 .01788 .01460 .01946 .01589 40 .02274 .0185? ‘ .02636 .02153 l
24 .01812 .01480 .01981 .01618 .. . . . . . . . . . . .. , . . . . . . . . . . .. l







Rule 2 can be applied for finding the dimensions of pump-rods and valve-stems, substitutingr in
the case of pumps the pressure in pounds per square inch on the pump-bucket for the steam-pressure.
For unbalanced valves, the pressure can be taken as three-tenths of the weight of the valve in the
steam-pressure. In giving this value for the coefficient of friction of the valve on its seat, it is
proper to remark that there is great difference of opinion among engineers in relation to this subject,
and extended discussions will be found in the files of technical papers. Some interesting notes on
the friction of slide-valves, with experiments by Mr. Thomas Adams, are contained in the “ Trans-
actions of the Society of Engineers” for 1866. The loss of power occasioned by this friction has
been considered so serious by many engineers, that numerous forms of balanced valves, in which the
pressure is taken off the valve by a packing ring at the back, or by connecting the back of the valve
with the condenser, have been devised. The majority of these valves have been unsuccessful, on
account of various imperfections of detail. A valve composed of two solid pistons connected by a
stem has, however, been largely introduced, and with the Davis improvement, which consists in
jacketing the steam-chest, has generally given very satisfactory results. The construction of the
Davis valve is shown in Fig. 1433.
A valve balanced by a ring on the back is represented in Figs. 1365 and 1366. ' The ring is divided
into segments which are. pressed against the inner side of the valve-chest back by spiral springs and
steam pressure. a a a is a brass ring divided into segments, as shown in the plan, the object being
to allow the ring to accommodate itself to any slight curve that may be caused by the pressure of
steam on the valve-box back or cover. I) b 6 bis a space containing about three layers of well-plaited
square gasket. 0 c c c is a brass ring in one piece fitted loosely into the groove, having on one side
588
ENGINES, PROPORTIONS or PARTS OF.

of it a number of
the ring, and by it the hemp packing is pres
slide steam-tight against the valve-box cover,


tion made between the space in which
communication is made between the con
box cover, and the condenser regulated by a cock, s
he can cause a vacuum at the back of the slides.
turned part of the valve, which slides freely in it, unin
4. Length of crank-pin.
l
5. Diameter of crank-pin.
a. Single engine:
(I:
p:
6. Double engine:
(I ::
0. Triple engine:
d=0.1159 x (D2 xp x l)
p.—
small steel pegs, d d d cl, on which are placed spiral springs. These Springs force
hard against the brass segments, causing them to
the pressure being further regulated by a communica
sed


l
III—lint
._——n——-__—_—-
-.w-__....__
#_ M -'"
_. "__-'“ M—

“....




fill
that ..


l
l' l
l. .
l 'l
l
ll
1
BACK VIEW.
fluenced by the valve-rod F F.
6. Diameter of shaft.

X _I_ a. Single engine:
cl: 0.0684 x (D2 x S x pH:
_ as X e
Jp— D2 x S
0.084 ><(D9xpxl)§
1687.5 x d3
_____._.__. 6. Double engine:
D2 x l
2208 x d8
0.09925 x (D2 x p x P = W
1022.75 X d3
1)2 x l
2);
0. Triple engine :

642.8 x d3 __1561 x d8
D‘Zxl 1”“ D’xS
the spiral springs work and the steam in the valve-box. A
denser and the space within the brass ring a a a in the valve-
0 that when the engineer is handling the engine
E EE is a wrought-iron hoop bound to fit the
d=0.0768 x (W x S xp)6
d: 0.0862 x ,(D‘2 x S xp)§
ENGINES, PROPORTION S OF PARTS OF. 589

In the case of shafts and crank-pins for double and triple engines, the rules give proportions for the
parts that‘are most strained; so that, if it is desired, each pin and journal can be of a different size,
according to the amount of strain.
7 '. Thickness of cast-iron steam-pipe.
z=o.os x VD xp.
__ 1111 x t”.
P _ n.
8. Proportions of crank.
a. Keys. A single key should have a breadth of 0.4 of the diameter of the shaft or pin if of
wrought-iron, and 0.8 of the diameter if of steel. Where two or more keys are used, the above
breadth can be divided among the whole number. .
6. Diameter of hub. For a crank of a rectangular section, such as is commonly employed, the
diameter of the hub should be 1.7 time the diameter of the shaft.
0. Diameter of eye. Where the pin is secured by keys, the diameter of the eye should be 1.6 time
the diameter of the crank-pin.
d. Proportion of web of crank. Either dimension, the breadth parallel with the shaft, or the
depth, may be assumed, and the other can be found as follows : If the depth is assumed at any point
of the web, the breadth at that point
(diameter of shaft)3 x distance from centre of crank-pin to given point
(depth)? x radius of crank

:: 1.64: X
If the breadth is assumed, the depth
__ 1 28 x [(diameter of shaft)3 x distance from centre of crank-pin to given pgilit 11-
* ' breadth X radius of crank ]

(All dimensions in inches.
9. Straps and bolts exposed to tensile strain.
The cross-section of a strap in square inches should be 0.000126 of the total strain in pounds to
which it is exposed. The strap for a connecting-rod should have a cross-section equivalent to that
of the neck of the rod. In computing the effective
section of a strap, the sectional area of. the holes for 1366'
. keys and bolts must, of course, be deducted.
The proper diameter in inches for a bolt exposed
to a given strain in pounds is 0.0132 time the square
root of the strain. If the strain is equally distributed
among several bolts, the diameter of each is equal to
“ the diameter of a single bolt suitable to resist the
strain, as determined above, divided by the square
root of the number of bolts.
10. Gibs and keys exposed to shearing strain.
The area in square inches required to resist a given
strain in pounds should be 0.00016 of the strain.
A few examples illustrating the application of the
rules are added:
1. What is the proper thickness for a cylinder 6
inches in diameter, the boiler pressure being 105 lbs.
per square inch? '3;
(l: 0.0001 x 6 X (105 + 15) +0.15 x V6: 0.439, or about seven-sixteenths of an inch.
2. Find the diameter for a steel piston-rod suitable
for a cylinder whose diameter is 60 inches, the boiler
pressure being 25 lbs. per square inch, and the length .5,
of~the rod 40 inches.
40 X 4/ 25+ 15 z: 252. Assume the proper diame- ’
ter to be 4 inches, then the ratio of length to diame-
ter is 10, and, from the table on page 639, the proper
diameter for this ratio is 252 x .0127 = 3.2, so that
the assumed diameter is too large. By one or two
similar trials in the table, it is found that the proper
diameter corresponds to a ratio of about 12, making
its value 252 X 0.0129 : 3.25 inches. 7;; ,
3. What is the ProPer working Pressure for a ' wrought-iron connecting-rod 31} inches in diameter, its \
length being '70 inches, and the diameter of the cylin-
der 24 inches ?
The ratio of length tgo diameter being 20, the work-
















. .473 j,’_;§_2/
./.'
15' '\ »'
I - . .
zifi‘ _
I 1.







TR ANSV'ERSE SECTION.




ing pressure is mé-gQ-m
sure is 62—15 = 47 lbs. per square inch.
4. An engine with a stroke of 30 inches develops 250 indicated horse-power. The proper length
I-
for the crank pin is : l = = 5.95; say 6 inches.
= 62; or the boiler pres-
PERPENDIOULAR SECTION.
30
590 ENGINES, SOLAR.

5. A certain engine has a cylinder 24 inches in diameter, and a crank-pin 5 inches long. The boiler
pressure is 65 lbs. Hence the proper diameter for the crank-pin is: d : 0.084 x (576 x 80 x 5)1l :
5.15; about 5%; inches.
6. A cast-iron pipe is 6 inches in diameter, and the boiler pressure is 50 lbs. per square inch. The
thickness, 25: 0.03 x V 6 x 65 : 0.57 ; about nine-sixteenths of an inch. R. H. B.
ENGINES, SOLAR. The total steam-power of the world has been roughly estimated by statisti~
cians at between 15,000,000 and 16,000,000 horse-power. From the data obtained by Herschel and
Pouillet, Capt. Ericsson concludes that if all the heat of the sun falling on a square mile of the
earth’s surface could be utilized in the generation of steam, it would furnish a supply for engines of
about 13,000,000 horse-power. Many investigators, desirous of utilizing at least a portion of the
immense supply of power so bonnteously placed by nature at their disposal, have turned their atten-
tion to the practical means of realizing their ideas. The most prominent experimenters of modern
times are Mouehot and Ericsson, who have each arrived at substantially the same practical result.
An interesting account of their investigations was published by L. Simonin in the Revue ([08 Dew:
llfondes for 1876, and a translation of his paper may be found in the Iron Age for Sept. 14 and 21,
1876. Says M. Simonin:
“What is coal? Fossil carbon. And was not this carbon fixed in plants by the sun’s heat, of
which it is the equivalent? Under the action of solar radiation the carbonic acid in the atmosphere
is decomposed on contact with plants; the carbon is fixed in the plant, and the oxygen goes back
into the air to serve for the respiration of animals. Hence, no sun, no vegetation; no vegetation, no
carbon, no coal. Coal in burning gives up the solar heat which was stored up in it, and therefore
it was that, on seeing a locomotive engine move, Stephenson said: ‘It is not the coal that drives
this engine, it is the sun’s heat stored up in the coal thousands of ages ago; locomotives are but the
horses of the sun.’ We might make a like comparison with respect to wine'and the alcohol it con-
tains; and the Bordelais use no mere figure of speech when they speak of their admirable Sauterne
wine as being ‘bottled sunshine.’
“When water rises in the shape of vapor, what is it that causes it to ascend? The heat of the
sun. If it comes down as rain, forming torrents and brooks which feed our mill-races and drive our
mills, what is it that turns the wheel? The sun, for it was the sun that in the first place raised the
water. W'hen the wind blows upon the sails of a windmill, or upon the sails of a ship, what is it that
drives the mill or propels the ship? The sun, for wind is simply an atmospheric current produced
by the heating of a stratum of air, which being dilated by the sun tends to an equilibrium with strata
of the same density, and hence rises, while a volume of cooler air takes its place. And what are the
tides, the propulsive power of which there is some thought of utilizing, whether directly by means of
water-wheels, or indirectly by compressing air, and so producing a constant supply of force? They
are a portion of the heat of the sun, for the seas are formed by the coming together of all those
torrents and rivers which descend into their common reservoir, the ocean. Then, too, the tides are
the result of the combined attraction of sun and moon upon the earth. Thus we find that the sun is
always and everywhere active.
“ It is, therefore, no paradox to regard the sun as the one source of fuel in the future, and as the
reservoir of force to which generations to come will at no distant day have recourse. Hence it is
that savants and great engineers, as Euclid, Archimedes, Hero, Salomon de Gaus, Buffon, Saussure,
Belidor, Evans, Herschel, Pouillct, Mouchot, Ericsson, have in every age put to themselves the ques-
tion how it might be possible to take from the sun a part of its heat for the benefit of this poor globe.”
The most successful solar boilers hitherto devised have been those constructed by Mouchot and
Ericsson, which are quite similar
in their details. An illustration of
Mouchot’s apparatus, as erected in
the courtyard of the library at Tours
and at'the Paris Exposition, 1878,
‘ is shown in Fig. 1367. It will be
seen that there is a large mirror,
which is silvered, and has the form
of a truncated cone, the sides of
which are at an angle of 45° to the
axis. The boiler, B, is made of
copper, with double walls, between
. which the water and steam spaces
are comprised, and the exterior of
the boiler is blackened. A glass
bell, A, covers the boiler, to pre-
vent the return of heat imparted
to the boiler. The pressure—gauge
is shown at K, the water-gauge at
L, and the safety-valve at I. The
apparatus is so mounted that it re-
volves 15° an hour around an axis _
_ __ __‘ parallel to that of the earth, thus
5. _< m5“, _ __ .- . “.1 5'. __ following the apparentdaily motion
of the sun; and it also inclines grad-
ually so as to change the position of its axis with the change in the sun’s declination. The dimen-
sions (Engineering, Dec. 31, 1875) are as follows: Diameter of mirror at top, 112.3 inches; at bot-
tom, 39.3 inches; area of mirror, 45 square feet. The two envelopes of the boiler are respectively


ENGINES, STEAM, HOISTING. 591

31.5 and 19.7 inches high, and 11 and 8.7 inches in diameter; water space, about 4.4 imperial gallons.
The glass bell is 15.8 inches in diameter, 33.5 inches high, and 0.2 inch thick. With this apparatus,
under favorable circumstances, 11 lbs. of water have been evaporated per hour, from a temperature
of 68° F., and at a pressure of about 75 lbs. per square inch. Such an apparatus does not, of course,
completely solve the problem of the successful application of the solar heat to driving an engine,
since it does not provide for periods in which the rays of the sun are not available. There have
been many plans proposed for storing up the heat received from the sun, to be used at night and on
cloudy days. M. Simonin suggests that it will only be necessary to heat good conductors, such as
porous stones, in the solar boiler, and then store them away. He says:
“Straw, sawdust, wool, feathers, confined air, are insulating substances which retain heat. We
might surround with a double envelope of this kind the reservoir holding the sun-heated stones, and
in this way we might have our store of solar heat, as new we have our store of ice. It is one prob-
lem whether we have to retain cold or to retain heat. N ow, ice keeps very well even when stored in
the hold of a vessel; a little sawdust and careful stowage do the whole work. The same means will
serve in storing solar heat, and, if need be, shipping it to a distance. \Ve have barely outlined the
idea, but certain we are that at the proper time the scientific man will appear who shall discover a
practical method of doing this.”
G. A. Bergh has proposed to use the solar heat in liquefying carbonic acid, and thus storing up
the work of a solar engine for future use. A translation of his remarks, first published in Poggm-
dorfi'k Annalen for 1873, is given in Van Nostrand’s Eclectic Engineering Magazine, February, 1874.
The possible solutions of the problem are by no means exhausted, and the Subject offers a vast field
for the labors of inventors, and a rich reward to him who is successful.
A paper on “Cooking by Solar Heat,” by \V. Adams, interesting in this connection, appears in
the Scientific American, xxxviii., 376. The writer, in Bombay, India, used a combination of flat
_ mirrors, of common sheet glass, silvered, fixed in rectangular frames so as to concentrate the solar
rays to a focus at a distance of 20 feet. The focus was about 2 feet in diameter. With 72 pieces
of silvered sheet glass, each 15 by 101} inches, at midday, in the month of May, a focus was formed
at a distance of 20 feet, of a temperature above 1088° F. Every kind of wood placed in this focus
was instantly ignited, without being, as in Buffon’s experiment, previously smeared with tar and
shreds of wool. A solid cylinder of water, 18 by 8 inches, co itained in a vertical copper vessel pro-
vided with a steam-pipe, was then placed in the focus, and it boiled in exactly 20 minutes. The
ebullition was exceedingly violent. Another experiment was made with 198 glasses, each 15 by 10¢}
inches, fixed in 10 rectangular frames. A copper boiler containing 9 gallons of cold water was
.placed in the focus, and began to boil in exactly 30 minutes. It was allowed to boil for exactly 1
hour, when 3'} gallons of water were found to have been evaporated. R. H. B.
ENGINES, STEAM, IIOISTIAT G. Hoisting or winding engines may be either stationary, portable,
or semi-portable. Their construct-ion being such as to adapt them to their specific purpose, they are
usually classed as a distinct type of steam-engine, and as such have become the special manufacture
of many well-known builders. Their use is the lifting of heavy weights. Their application to pas
senger-elevators is discussed under ELEVATORS; to raising material from mines, under MINE APPLI-
ANCES. The machines here presented are those which may be employed for a variety of uses.
Fig. 1368 represents a differential hoisting engine manufactured by IV. D. Andrews of New York.
The hoisting drum has a grooved friction-wheel at each end, one wheel being 30 inches and the other
26 inches in diameter. The pinions upon the engine-shaft engaging with these wheels are respec-
tively 4 and 8 inches in diameter. By means of levers which communicate with eccentrics, one of
which is shown in Fig. 1369, either wheel may be brought into or moved out of contact with its
pinion. When the large wheel is in contact, the drum has 1 revolution to 711; revolutions of the en-
gine; with the small wheel engaged, the revolutions are as 1 to 341. “Then a heavy weight is to be
raised, the large wheel is used, and a slow motion is imparted to it; for a light weight, the small
wheel is used, and the speed is doubled, the engine running at a uniform rate. A brake-lever
operated by the foot is used to cause a brake to bear upon the face of the drum-wheels, and by this
means the load can be lowered or held at any desired point. The same may be done by graduating the
pressure uponthe hand-levers. It is claimed that in these machines the power required is less than
when using cogs; and the unpleasant noise of cogs, as well as danger from their breaking by over-
straining or accident, is entirely avoided. N o concussion or jar results from throwing the drum into
or out of gear, either when loaded or light. The following table is based on 50 lbs. steam-pressure :
'able showing Dimensions, Speed, and Loads raised by Steam Hoisting Engines.




















F u i
DIAMETER DIAMETER DUTY OF DUTY OF
POWER OF DRUM- OF MAIN vOF FAST i MAIN GEAR. FAST GEAR.
' ,__ ,_ ,_ WEIGHT OF
g:; k .3 T: 3 5 ,3 i E 7:: E 3 2. MACHINE.
to 3 5 b0 u 3 g g c .1". E E 6 2 '8 5
= s .s 8 "= .=_ v E E § 2.2 '5 E, 8."
{:1 ca Q A 3 9-4 3 9-1 < a: < w 'e‘
' Inches Inches. Inches. Inches. Inches. Inches. Lbs. Feet. Lbs. Feet. Lbs.
5 HP 5 HP 6 30 4 26 8 1,500 60 750 120 3,150
8 HP 8 HP ' 8 27 30 4 26 8 2,000 75 1,000 150 3.650
12 HP 10 HP 8 30 36 0 30 1‘3 2,800 85 1.200 200 5.200
15 HP 15 HP 8 30 86 6 30 12 3,500 85 1,500 200 6,200


An improved portable hoisting engine, adapted for the removal of cargoes from vessels, etc.,
made by J. S. Mundy, is represented in Fig. 1370. The apparatus is mounted on wheels so that it
592 ENGINES, STEAM, HOISTING.

can be easily moved from place to place. The engines have plain slide-valves, workedv by an eccen-
tric direct from the main shaft. There are locomotive slides and cross-head of simple construe
1868.
'

1e
1e
0






'tion. Both engines are supplied with steam from the same boiler, which is fed by a steam-
pump attached to it on one side and an injector on the other. Fig. 1371 shows a section of the
friction-drum used in these machines. The drum is cast in one piece. The large gear is made with

















holes or pockets in the side to receive plugs of hard wood, that are fitted in and turned off to re-
ceive the cone-flange of the drum. The spiral spring between the gear and drum forces the drum
- ENGINES, STEAM, HOISTING. .593

‘ oil? the wood when relieved by the screw and pin at the other end. This can be used separate from
the engine by the application of a belt on the pulley on the lower shaft, for hoisting in warehouses,
stores, coal yards, or in any place where there can be power attached. The friction-gearing serves
1870. 1371.









as a brake in lowering fast or slow,
at the option of the operator.
Fig. 1372 represents a portable
winding engine of Belgian construc-
.}|--.









l
g E: , tion, specially designed for temporary
5;. C?%Mb ' " 3 use at the shafts of mines, where the
v i regular winding machinery has broken
down, or for use in raising pump-
-W' " l ' ' " ‘1‘ ~ gears, etc., at shafts not fitted with
aw“ >— ' fixed hoisting gear. It is propor-


tioned for raising a load of 11} ton
from a depth of 1,650 to 1,950 feet,
the rope used being 0.8 inch in diameter, and weighing 4 lbs. per yard. The apparatus consists of
a pair of wrought-iron frames of I section, mounted on iron wheels adapted for traveling on ordinary
roads. On the top of the frames just mentioned are mounted a pair of cast-iron frames carrying
the engines and winding gear. The engine cylinders, which are 7-,‘5 inches in diameter, with 11%}-
inches stroke, are fixed to the outer sides of the cast-iron frames, as shown on the plan, the con-
necting-rods taking hold of cranks at the end of the shaft 0. On this shaft is a pinion H, which



gears into a spur-wheel J, on a second shaft D placed directly above the crank-shaft. This second
shaft D also carries a pinion K, which gears into the spur-wheel L bolted to the rope-drum M. This
drum M is 4 feet 7% inches in diameter and 1 foot 7H; inches long, and it can be divided into two by
38
594 ENGINES, STEAM, MARINE.

a movable division ring, when it is desired to employ two ropes. The total ratio of the gearing is
18 : 1, the engine‘ma-king 18 revolutions to one of the drum.
ENGINES, STEAM, MARINE. I. THE AMERICAN RIVER-BOAT Enema—The beam-engine with
wooden gallows-frame is a form of engine peculiar to American practice, found principally in steam-
boats navigating the eastern rivers and sounds, and used to some extent in coasting steamers and
boats on the great lakes. The modifications made in its construction of late years have been very






















C D
“Ill
'\\.
small. The various parts and general construction of the engine are fully shown in the following
illustrations. _
Fig. 1373 is a side elevation of the engine. Fig. 1374 is an end elevation exhibiting the steam-chests,
the cylinder, and the parallel motion. Fig; 137 5 is a vertical section of the steam-cylinder, the con-
denser, the bed-plate, and the air-pumps. Fig. 1377 is a plan of the bed-plate, showing the passage
connecting the condenser with the air-pump, and the opening by which the foot-valve is introduced
to its place. Fig. 1378 is a transverse section of the steam-chests, showing the arrangement of the
balance-valves. Fig. 1379 is a plan of the steam-chest, and of the cylinder with the lid removed.
Figs. 1380 and 1381 are views of the traverse-shaft for working the valve-lifters. Figs. 1382 and
1383 are face and edge views of the crank, showing the method of binding it by a wrought-iron
strap. Figs. 1384 and 1385 are front and side views of the connecting-rod, showing the method of
bracing it by wrought-iron rods. Figs. 1386, 1387, 1388, and 1389 are elevations and plans of the
crank-shaft and main centre pedestals, showing the attachments for securing the blocks to the
framing.
The following are the literal references: A is the principal frame, which supports the main cen-
tres of the beam, and also the bearings of the crank-shaft. B are the keelsons. a a, the fore and
aft legs of the frame. 6, the upright post under the main centre. 0, oak-knees, by which the legs
are secured to the keelsons. d, timbers which support the crank-shaft bearings; the fore and aft
timbers are placed obliquely to strengthen the support. e, the back-stay for further securing the
main centre. 0 is the steam-cylinder, and O" is the cylinder bottom. f, the piston;'the under
, side of it, 1, is a solid web, rounded and in one piece with the centre 2 by which it is keyed to the
2
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" AMERICAN MARINE STEAM-ENGINE.
ENGINES, STEAM, MARINE. 595

rod, and with the circular flange 3 at the circumference, upon which the packing is laid. These
three parts are connected together by stiffening flanges, 4; and the whole is covered in by a flat
plate, .5, which holds down the packing, and is bolted to the body of the piston. g, the piston-rod.
h h,.the steam-ports; the under port is formed in the cylinder bottom, which, it will be observed, is
hoiloWed out to the form of the under side of the piston. i, the clutch and cross-head, keyed to the
upper end of the piston-rod. la, the links connecting the cross-head to the working-beam. D are
the steam-chambers, in which are placed the valves for regulating the motion of the steam into and
out of the cylinder. Z l, the chambers whence the steam is admitted to the cylinder. m m, the
chambers into which the steam is discharged from the cylinder. n n, pipes connecting the upper
and under chambers, bolted fast to upper chambers, but connected to the under chambers by expan-
sion joints. 0, the steam-valves, and p, the exhaust-valves, fixed
in pairs on the spindles, and denominated equilibrium or balance-
valves. q r, the valve-spindles, having their lower ends guided
in inverted caps, introduced through the under sides of the steam-
chests; their upper ends pass through stuffing-boxes, and are
connected on the outside to the brackets on the lifting-rods. s,
the steam-pipe from the boiler, furnished with two valves: one
of them, 0", is the throttle-valve; the other, d", is the cut-off
valve; the latter is worked by a cam fixed on the crank-shaft,
which works the lever e", the fulcrum of which is fixed on the











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timbers of the crank-shaft bearings, this lever working the lever on the valve-spindle by means of
the rod f ", the traverse-shaft and levers g", and the rod h". t, the exhaust-passage, connected to
the passage 2" in the condenser. u u, the steam-passages to the cylinder. 1) v, the lifting-rods, with >
brackets, 1 1, 2 2, fixed on them, and connected at the extremities to the valve-spindles, on which
596
ENGINES, STEAM, MARINE.

1878.











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ENGINES, STEAM, MARINE. 597

they are adjusted by nuts; 3 3, the lifting faces. to, the traverse-shaft: 1, the lifting-frame ;v 2, the
lifters; 8, the eccentric-rod lever. (See Figs. 1380 and 1381.)
The operation of the balance-valves and their peculiar advantages are as follows: Referring to
Fig. 1378, it will be observed that the valves are arranged in pairs, keyed on distinct spindles, and
that each pair, therefore, is moved as one valve; further, the valves in each pair are of unequal
diameters, the upper valves 0, on the steam side, being larger than the under valves, and, on
the contrary, the under valves )2, on the exhaust side, larger than the upper ones. And here
the peculiar and elegant adjustment is shown. The common puppet-valve sustains the full pres-
sure of the steam on its exterior surface, which must therefore be overcome before the valve
can be opened; but in the balance-valve the-steam pressure is made to balance itself (hence the
name) as it enters the steam-port from both above and below.) The upper valve in each pair on
the steam side is larger than the under by as much as will afford, by the difference of pressures
upon them, sufficient force, in conjunction with the weight of the valves, to shut them steam-tight
in their seats. Vice versa, the wnder valve in each pair on the exhaust side is the larger of the
two, so that, by the resulting tendency of the pressure of the steam from within, when entering
the cylinder through the steam-valve, the exhaust-valve may be kept shut when required. Thus,
it is clear that by regulating the relative diameters of the valves in each pair, the absolute dif-
ference of the areas of surface of each exposed to the steam-pressure may also be regulated, and
consequently also the amount of pressure effective in shutting them. In the present instance,
the valves are 10 inches and 9 inches respectively in diameter; therefore, the steam-pressure
effectively exerted in shutting them is that due to a surface equal to the difiercnce of these
areas, or to 15.2 square inches. Let the steam-pressure be 50 lbs. on the inch, then the acting
pressure will amount to 15.2 x 50 = 760 lbs., or, the weight of the valves being added, say 840 lbs.
This will, indeed, appear little when it is considered what a common puppet-valve would require. If
the puppet-valve were 11 inches in diameter, it would be subject to a pressure of 4,750 lbs. The
slides also, such as are used in British engines, weigh 3,920 lbs., without the friction of the faces
1336. less.







t-
‘ F #7 1 r'"\ m
...—... . y //2 ’“r
m '. ' m .F‘l
'3 El fl 3 2 2 _ a
1857. 1389.


(:35
being taken into account. But, in fact, as the starting lever has a power of 6 to 1, the resistance to
be overcome by the engineer in starting is only 140 lbs. _
E are the parallel guides for the cross-head of the piston-rod. These, the cross-head, and the
links k, constitute the parallel motion of the engine. The guides E are bolted to the projections
~ on the cylinder flange, seen in Fig. 1379, and are stayed to the frame A by wrought-iron ties, and
a small cast-iron cornice near the top. F is the main lever of the engine. :2, a cast-iron centre,
strung with tension-rods. y, tension-rods of wrought-iron, which are strapped to the centre-piece
at the middle, the extremities, and the intermediate points. 2, additional tension-rods, strengthen-
ing the intermediate points where the air-pump and feed-pump rods are connected. The main
centre-pedestals are represented in elevation and plan in Figs. 1388 and 1389: 1, the sole; 2 2 2,
flanges for securing the bearings more steadily to the frame. G, the connecting-rod, constructed
of wrought-iron. a', the rod, fitted with straps at the ends for embracing the bushes. b’ b’, tension-
rods for stiffening the main rod, and preventing the effects of vibration. These rods are jointed
at the upper ends to the main rod, held in tension at the middle by the strut c’, which is screwed at
the extremities to regulate the tension of the rod, and keyed up at the under ends. [-1 is the crank,
composed of a cast-iron body and a wrought-iron binding strap. 01’, the cast-iron centre, in which
the holes are formed for receiving the ends of the crank-shaft and the crank-pin ; its form in section
is that of a web terminated on both sides by flanges. e', a wrought-iron tension-rod in one piece,
passing entirely round the crank. f’ f’, horns cast upon the crank for the purpose of stretching the
strap 0’, the strength being thereby rendered available. The fellow of this crank, which is seen in
the general elevation, Fig. 1373, is differently formed, being made solid at the end, and provided with
bolt-holes, through which a strap embracing the crank-pin is introduced and screwed upon the other
side. By this arrangement, the crank-pin may at any time be readily disengaged from the crank, and
the parts are more easily put together. I is the crank-shaft. g', the pillow-block: 1, the sole of the
block resting on the timbers; 2 2, flanges for securing the block to the framing by bolts and nuts;
3 3, lugs cast on the sides of the sole, through which holding-down bolts are passed, which are secured
to the keelsons. a", the eccentric for working the balance-valves. b", the eccentric-rod, having its
length, divided, at a point near the handle, into two parts jointed together, the longer and heavier
part next the eccentric being supported on a vibrating joint. By this means it becomes an easy
matter to disengage the rod from the lever of the traverse-shaft, which is done by means of a small
rope attached to the extremity of the rod. Kis the condenser. i', the exhaust-steam passage. k',
'the injection passages. l’, the injection cocks. m' m', the flanges by which the condenser is bolted
to the principal frame. L is the air-pump. n', the bucket, the construction of which is obvious
from the section, Fig. 1375. o', the bucket-rod. p', the floating-top or delivery valve, which is.
ses ENGINES, STEAM, MARINE.

cast hollow, and has its lower edges, where it rests on the air-pump, filed true, so as to fit and form
a good joint. This serves a twofold purpose, namely, as the air-pump lid and the delivery valve.
Its action is simple and ingenious; for when the bucket arrives at a certain height, the lid is raised
and the water flows out all around, thus discharging more effectually and rapidly than by the com-
mon valve, and requiring little or no power to discharge, having only the lids to raise. q’, the hot-
well, made of copper, and riveted to the air-pump by means of a vertical flange. 0", the waste-pipe.
s', the feed-pipe. t', the pipe for drawing off the water from the hot-well. u', the rod from the
beam, which drives the air-pump rod. 11', the guide for the cross-head of the air-pump rod, stayed to
the principal frame by means of the bracket 20'. 111 is the feed-pump. x’, the pump-rod, moving
in the guides 31’ y’, driven from the beam by the rod 2’. 111’ is the bilge-pump. N is the bed-plate.
i", the foot-valve.
The following are the principal dimensions of an engine of this class built for the steamer
Osceola: Diameter of cylinder, 31 inches; length of stroke, 11 feet; length of beam, 17 feet 9
inches; length of connecting-rod, 21 feet 1 inch; length of links, 7 feet 6 inches; height of beam
from keelson, 31 feet; width between guides of piston-rod, 3 feet 6% inches; diameter of paddle-
wheel, 28 feet; number of strokes per minute, 24; velocity of piston in feet per minute, 528.
Fig. 1390 represents the beam-engine of the steamboat New World, a remarkably fine vessel
which some years since plied between Albany and New York on the Hudson River. She was de-
1390.


stroyed by fire. Her average running speed between the points named, a distance of 146 miles,
was 9 hours. Thirteen landings were made, which involved a loss of time of at least 5 minutes
each, leaving 7 hours and 55 minutes as the average running time, or about 18%- miles per hour.
This speed was often exceeded for short periods, the rate of 20 miles per hour being frequently
attained. The dimensions of the New World were: Length, 375 feet; breadth, 36 feet; breadth
over guards, 69 feet; depth of hold, 10 feet 6 inches. She was constructed of wood. A
The cylinder of this engine was 76 inches in diameter. The valves were of the type already de-
scribed. The valve-gearing was the Stevens cut-off, a device now commonly used, which may be
ENGINES, STEAM, MARINE. 599

described as follows: There are four lifter-rods, which are turned bars of wrought-iron, placed in
front of the steam-chests. They are made to move vertically up and down through guides which are
cast or bolted to the chests and side-pipes. On the lifter-rods are keyed eight projecting arms,
called lifters. Four of these embrace the extremities of the valve-spindles, which are screwed and
provided with double jam-nuts. The spindles pass quite loosely through the ends of the lifters, and
the jam-nuts are adjusted so as not to bind them: there is thus an allowance made for any slight
lateral motion which inaccuracy of adjustment or wear of guides may render requisite. The four
remaining lifters are likewise keyed upon the rods, and they are placed directly over the levers on
the rock-shafts, from which they receive their motion. There are two rock-shafts, one for the steam
and one for the exhaust valves, and they are worked by separate eccentrics. 0n the shafts there are
four levers, by which the lifters and rods are raised, and they are curved on their working faces, so
that their action is rendered perfectly smooth and noiseless. By the reciprocating or rocking
motion of the shafts, the lifter-rods, and with them the valves, are alternately raised and lowered.
The exhaust-valve levers are of a length just sufficient to give the requisite amount of lift and lead,
and they are so adjusted on their rock-shaft that the moment one red is fairly down the raising of
the other commences. The steam-levers are considerably longer, and are placed upon their rock-
shaft in a position inclined to one another, so that an interval, longer or shorter, occurs between the
falling of one rod and the rising of the other. During this interval both valves are down, and the
steam is of course shut off from the piston. This apparatus then constitutes the expansive or cut-
off gearing, and it may be varied at pleasure by simultaneously adjusting the respective positions of
the eccentric on the paddle-shaft, of the two levers on the rock-shaft, and of the pin in the eccentric-
lever. This latter has a slot in it, in which the pin travels, so that it can be moved to or from the
shaft, and fixed as required. By advancing the eccentric, and lowering the extremities of the levers,
the steam will be earlier cut off, and vice versa. The amount of lift may be regulated by moving the
eccentric-pin. The movement of the rock-shaft in the interval during which the valves are down is
very considerable, especially in a high expansion, and this, added to the additional amount of move-
ment by which the valves are lifted the requisite height, makes the total angular motion of the rock-
shaft very great, and therefore an eccentric of corresponding throw is required. Another variety of
gear in frequent use has but one rock-shaft and eccentric, with but two lifter-rods. The exhaust-
lifters and their action are precisely the same as in the gear already described. The steam-lifters,
which are like the others keyed to the rod, have spring catches fitted at their extremities, which lock
into the valve-spindles when down, and which are released at the proper time by coming in contact
either with an adjustable stop or with a reciprocating arm, moved by the engine. The valves then
fall by their own weight. To prevent damage arising from the concussion, a contrivance called the
dash-pot is made use of: this consists of a small cylinder containing water, and a piston which fits
it loosely, and is attached to the valve-stem. The height of the water is so adjusted that the piston
touches or dashes upon it before the valve reaches its seat ; the momentum is thus effectually over-
come, and injury to the surfaces of contact completely prevented. The rock-shaft, lifters, and levers
are of cast-iron, turned and finished bright. The outer supports of the rock-shafts are bolted to the
side-pipes, and the middle support, which is common to both shafts, is fastened to brackets cast on
the cylinder.
The following abstract of a report by Theron Skeel of the performance of the Mary Powell, one
of the finest day-boats now (1 87 9) running on the North River, is of unusual interest, as presenting
probably the most complete data that have been collected relative to the performances of a vessel of
this type:
Dimensions of Hull.—Length on water-line, 286 feet; length over all, 294 feet; beam at water-
line, 34 feet 3 inches; beam over all, 64 feet; depth of hold, 9 feet; height from main deck to
promenade deck, 10 feet; height from promenade deck to upper deck, 8 feet; draught of water, at
mean load of passengers and coal, 6 feet; midship section (estimated), 200 square feet; displace-
ment (estimated), 28,000 cubic feet ; projected area of surface resisting head wind, 2,000 square feet.
Personnel (exclusive of steward’s depart-zizent).—l captain, 2 engineers, 4 firemen, 4 deck-hands, 2
pilots, 1 clerk, 1 baggage-master; total, 15.
Length of trip, 5 hours and return. Average number of passengers, 250. Average fare per mile,
1} cent.
Engine—Diameter of cylinder, 6 feet; stroke of piston, 12 feet; diameter of piston-rod, 8 inches ;
diameter of air-pump, 3 feet 4 inches ; stroke of air-pump, 5 feet 2 inches ; diameter of shaft, 1 foot
3 inches; diameter of journal, 1 foot 3% inches; length of journal, 1 foot 5 inches; diameter of
crank-pin, 8%} inches; length of crank-pin, 101L inches; diameter of wheels over tips of buckets, 31
feet; length of each bucket, 10 feet 6 inches; width of each bucket, 1 foot 6 inches; number of
buckets to each paddle-wheel, 26; greatest immersion of outer edge of bucket at mean draught,
3 feet 6 inches; displacement of piston per revolution, 6'? 6 cubic feet; of clearance at both ends of
cylinder, 25 cubic feet; diameter of steam and exhaust-valve openings in steam-chest, 1 foot 2%
inches.
Boilers (two in number, steel—dimensions of cach).—Length over all, 26 feet ; length of cylindrical
shell, 16 feet 1 inch: length of fire-box, 9 feet; width of firebox, 11 feet; diameter of cylindrical
shell, 10 feet; diameter of steam-drum, 5 feet 10 inches; diameter of steam-chimney, 4 feet 2
inches; height of steam-drum, 12 feet; number of furnaces, 2 ; width of furnaces, 4 feet 10 inches;
length of furnaces, 8 feet; length of direct fines, 9 feet 1 inch; diameter of tubes (external), 41}
inches; grate surface (two boilers), 152 square feet; heating surface, 2,660 square feet ; superheat-
ing surface, 340 square feet; cross area of lower flues, 23.2 square feet; cross area of tubes, 17.2
square feet; cross area of steam-chimney, 25 square feet; diameter of smoke-stacks (two), 4 feet 6
inches; height above grate, 68 feet; number of direct fines and diameter: two flucs, 14 inches ; six
fiues, 16 inches; two flues, 9 inches.
coo ENGINES, STEAM, MARINE.

Results for Three Years.


DETAILS. 1875. 1876. 1877.
Number of observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 27
Running time from Newburgh to New York, or return, minutes. . . .. 185.5 187.5 182
Distance run in above time, miles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 60 60 00
Revolutions or round trip from Rondout to New York, and return. . . . . . . 18,100 12,190
Distance as a ove . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 90 90 90
Revolutions per minute from Newburgh to New York, or return . . . . . . . . . . 21.8 21.77
Speed in miles per hour “ “ “ “ . . . .. 19.8 19.2 19.8
Coal per round trip, gross tons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28.79 22.85 24.25
Coal per revolution, pounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.57 4 37
Slip of wheels per cent. (calculated for centre of paddle) . . . . . . . . . . . . . . . . .. 14.5 11 9
Revolutions from Newburgh to New York, or return . . . . . . . . . . . . . . . . . . . .. 4,007 3 968
Revolutions per mile from N ewburgh to New York, or return . . . . . . . . . . . .. 66.8 66
Revolutions per mile per round trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.9 67 2






(In making the estimate of running time, the time lost at the landings was deducted.)
Results for 187 7.
Total number of miles run.. . . . . . . . 15,300
Hourly quantities. -
Speed of boat in miles (5,280 feet) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.3
Revolutions of engine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,306
Pounds of coal consumed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,970
“ of combustible (ashes 16% per cent.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,870
“ of coal consumed per square foot of grate surface . . . . . . . . . . . . . . . . . 39.3
“ of combustible “ “ “ . . . . . . . . . . . . . . . . . 32.8
“ of coal “ “ of heating surface . . . . . . . . . . . . . . . 2.25
“ of combustible “ “ “ . . . . . . . . . . . . . . .. 1.88
’I'emperatures.
Atmosphere . . . . . . . . . . . . . . . . . . . . .. 70°
Hot-well . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120°
Feed-water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120°
Chimney gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(Zinc melts.)
Pressures (see indicator cards, Fig. 1391).
Steam (pounds per square inch above the atmosphere) . . . . . . . .. . . . . . . . . . . . . . 28
Vacuum (inches of mercury) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Initial pressure (pounds per square inch above zero) . . . . . . . . . . . . . . . . . . . . . . . 40
Pressure at cut-off “ “ “ . . . . . . . . . . . . . . . . . . . . . . . 31.2
“ at end of stroke (pounds per square inch above zero) . . . . . . . . . . . . . . 16.4
Mean back pressure “ “ “ . . . . . . . . . . . . . . 5.6
Pressure at end of cushion “ “ “ . . . . . . . . . . . . . . 40
Mean total pressure “ “ “ . . . . . . . . . . . . . . 29.94
“ indicated pressure (pounds per square inch) . . . . . . . . . . . . . . . . . . . . . 24.34
“ net “ “ “ (friction 1.5).. . . .. .. . . .. . . . 22.84
Point of cut-off, fraction of stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.47
“ where cushion commences, fraction of stroke . . . . . . . . . . . . . . . . . . . . . . . . 0.8
Power.
Total horse-power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,899
Indicatedhorse-power . . . . . . . . . . . . . . . . . 1,540
Net “ 1,446
Pounds of steam used per hour, from indicator diagrams . . . . . . . . . . . . . . . . . . . 42,000
Economic performance—Boiler.
Pounds of water perpound of coal, from 120°.............. . . .. . . 7
“ “ “ “ 212° . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8
“ “ of combustible, from 120° . . . . . . . . . . . . . . . . . .. . . 8.2
“ “ “ “ 212° . . . . . . . . . . . . . . . . . . . . . . 9.1
“ per square foot of heating surface, per hour. . 14
Engine.
Pounds of steam per hour, per total horse-power.. . . .. . . . . .. . . .. . . . .. . . . 22.1
“ “ “ “ indicated “ . . . . . . . . . .. 27.3
“ “ u “ u 0 I n . u n a o n I n a n e a n o o o a o o 0 0 e o a
“ coal “ “ total “ . . . . . . . . . . . . . . . . . . . . . . . . . 3.14
“ “ “ “ indicated “ . . . . . . . . . . . . . . . . . . . . . . . . . . 3.87
“ “ “ “ net “ . . . . . . . . . . . . . . . . 4.13
The results of experiments made to determine what proportion of the power of these boats is lost
through the resistance of the air and wind on the decks and cabins show that this loss does not
exceed 10 per cent. of the power applied. That is to say, when running through still air and still
ENGINES, STEAM, MARINE. 601

water, about 90 per cent. of the power is absorbed in overcoming the resistance of the water and 10
per cent. in overcoming the resistance of the air. In this connection it must be remembered that of
the total surface resisting the wind (2,000 square feet), a considerable portion, being the hull of the
boat, the paddle-boxes, and smoke-stacks (at least 800 square feet), is necessary, and could not be
reduced even if the upper decks were left off.
Among the finest illustrations of recent practice in the construction of side-wheel steamers are
those built for the several routes between New York and the cities of New England, which traverse
1391.
' ' Top. Bottom.
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Long Island Sound. Fig. 1392 exhibits the form of one of these vessels, in comparison with a
steamboat of the same type, but of the form constructed in 1836. The latter vessel was 325 feet
long, 45 feet beam, 80 feet wide over the guards, 16 feet deep, and drew 10 feet of water. The
engine had a steam-cylinder 90 inches in diameter and 12 feet stroke. In the Sound steamers Bristol
and Providence the cylinders are 110 inches in diameter and 12 feet stroke. The engine of the
Rhode Island is capable of developing 2,500 horse-power. The paddle-wheels are 3711; feet in diame-
ter and 12 feet in breadth. The weight of the hull is over 1,200 tons, of the machinery 625 tons.
The best speed is 16 knots per hour at 17 revolutions per minute; average speed, 14 knots. The
coal consumed is about 3 tons per hour, or 21} lbs. per horse-power per hour.
The steamboats on Western rivers have almost invariably horizontal non-condensing engines-—an
independent engine for each wheel in the case of side-wheel steamers, and two engines for stern-
wheel boats. The connecting-rod is usually of wood, strapped with iron, and with a length of from
three to four times the stroke. There are two steam- and two exhaust-valves, all single puppet-valves,
worked by the action of cams on long lifting levers, the cams being moved by eccentrics on the shaft.
Boilers with two flues, set in cast-iron fronts and with brick walls, very similar to the setting of
1392.


stationary boilers, are generally used. A description of these engines and boilers is contained in
King’s “Lessons and Practical Notes on Steam.” A vessel of this class is represented in Fig. 1393.
The largest steamer on the Mississippi is (1879) the Grand Republic. Her length is 340 feet, beam
56 feet, and depth 10;} feet. The draught of water of this great craft is but 31} feet forward and
41} feet aft. The two sets of compound engines, 28 and 56 inches in diameter and of 10 feet stroke,
drive wheels 38:} feet in diameter and 18 feet wide. The boilers are of steel. A similar vessel,
built on the Ohio, has the following dimensions: Length, 225 feet; breadth, 351} feet; depth, 5 feet;
cylinders, 17?, inches in diameter, stroke 6 feet.
For a paper on the “Construction of American River Steamboats,” by Theo. Allen, C. E., see
“Transactions of the American Society of Civil Engineers,” 1874.
II. EARLIER Forms or MARINE Enemies—With few exceptions, vertical engines are used at present
in large ocean steamers, the change having been made a few years after the displacement of the
paddle-wheel by the screw in ocean navigation. The details of the older forms of engines, however,
are not without interest, and some illustrations and descriptions are appended.
602 ENGINES, STEAM, MARINE.
Direct-acting mgz'nes diifer from the beam-engine simply in the method of taking the power from
the piston-rod. In the one the head of the piston-rod is connected either directly with the crank, or
by means of a connectingmod or rods; in the other, the working-beam or great lever, vibrating on


1393.




""llllnn"
its centre, receives at one end the power from the piston-rod through the modifying action of “ paral-
lel-motion” rods, or plain slides, and communicates it to the crank-shaft by a connecting-rod at-
tached to its other extremity.
The side-lever engine is a modification of the beam-engine. In our river and coast boats the work-
ing¢beam or lever is above the engine, and single; but in the sea-going steamers two of these beams
1894.



/\\§\\\.\r


































[are used instead of one, and instead of being above the engine they are brought down to the bottom,
one on each side ; and being connected by a cross-tail, they act as a single beam or lever. Hence is
Fig. 1394 will
derived the name from this disposition of the working-beam, the “ side-lever engine.”
ENGINES, STEAM, MARINE. ' 603

give an idea of the general appearance of the sidelever engine, in outline. The engines of the Col-
lins lineof steamers were of this description, and in fact the side-lever engine was used in the ma~
jority of ocean steamers fitted with paddle-wheels a few years ago.
Passing to the varieties of the direct-acting engine, we find that the attempt to produce engines
1895. 1896.

' TI ’* " 1397. 1398.
l
























=== =$ “—
more compact and of less weight and bulk has extended the examples of this class of engines into
an almost endless variety of modifications; scarcely any two are alike. Some engineers regard those
engines only as direct-acting where the piston itself seizes the crank, without the intervention of any
connecting-rods, as in the trunk and oscillating engines.
In the vertical direct-acting engine, the paddleshaft is directly over the axis of the cylinder; but
the method has the disadvantage of admitting only a short stroke and a short connecting-rod, and
1400.

/Z, 1401. 1402.

























‘_|_-—lL-__-__-J

requires that the height of the axis above the bottom of the cylinder should be at least three times
the length of the stroke. Thus one of the extremes, too short a connecting-rod, too short a stroke,
or a paddle-axis too high above the floor of the vessel, is incurred.
‘ In this country the square engine, the first variety of the vertical engine, has its cylinder immedi-
ately over the axis and cranks, to which motion is communicated from the cross-head of the piston
004 ENGINES, STEAM, MARINE.

by means of side-rods, the air-pump being worked by a separate beam connected with the cross-head
by proper links ; but this is equally unsuited to sea-going steamers on account of the height of the
cylinder above the paddle-shaft. To obtain the object sought without incurring these evils, many
descriptions of engine have been contrived; among others the steeple engine, so called, where the pis-
ton-rod is made forked, so as, passing round the shaft, to rise above it to a considerable height, from
which again descends the connecting-rod to the crank. Figs. 1395 to 1400 illustrate the principle.
The top of the piston-rod carries a four-armed cross-head h h, on each end of which stands a pillar
h h ; these four pillars again unite in another quadruple cross-head, sustained upright by a vertical
guide; and it is from this summit that a connecting-rod descends to the crank K. In Figs. 1398 and
1399, which represent one form of the steeple engine, the piston-rod is seen united to a triangular
frame, from the apex of which the connecting-rod descends to the crank. In Fig. 1400 this frame
is shown to be square, and Fig. 1397 is the side view of both varieties. *
Another method of accomplishing the direct connection without cncumbering the deck is by the
use of the trunk engine. The axis is placed at the height of half the stroke or more above the
cylinder, and a connecting-rod unites immediately the crank-pin with the centre of the piston. In this
way the connecting-rod, passing through the top of the cylinder, would allow the steam to escape
but for a large trunk or casing with which it is surrounded, and which, passing through an opening
of large area conceived to be steam-tight, rises and falls with the piston to which it is attached. In
Fig. 1401, A A is the cylinder; to its piston is attached a trunk B, which works through a stuffing-
box in the cylinder cover; to the piston the connecting-rod e e is attached. Fig. 1402 represents the
top of the cylinder A A, with its stuffing-box and the trunk.
The Gorgon, Fairbairn, and Maudsley engines are English varieties of direct-acting engines,
but little used in this country; they deserve a passing notice, as illustrative of the efforts made to
reduce the dimensions of marine engines within the least possible limit. Fig. 1403 represents the
Gorgon engine, in which A is the cylinder, B the piston-rod, 0 the crank, D the condenser, and E
the air-pump. The chief peculiarity of the engine its parallel motion for keeping the connecting-
rod in vertical line. Fairbai'rn’s engine, Fig. 1404, has a somewhat similar contrivance. Its arrange-
ment in other respects is obvious from the drawing. Fig. 1405 represents .Maudsleg d’e Field’s en-
gine, designed for use where long connecting-rods could not be employed. It will be observed that
the rods are connected by a T-plate A, to which is attached the connecting-rod B, which com-
municates with the paddle-wheel
crank. C is the air-pump, worked
by the beam D. The condenser is
at E under the cylinders.
In the oscillating engine the con-
necting-rod is altogether dispensed
with, the piston-rod being attached
directly to the crank; and because
the piston-rod, from this mode of
attachment, must either be bent
when motion ensues, or the top of .
the cylinder must move laterally,
this is provided for by allowing
the cylinder itself to vibrate in a
small arc, eifected by casting trun-
nions on to the cylinder near its
middle, as an axis upon which it
oscillates. The general arrange-
ment of the oscillating engine is
shown in Fig. 14-06. -
III. SCREW-PROPELLER ENGINES.
—-Oscillating engines have been
used to a considerable extent in
ocean steamers, frequently being
geared in screw vessels; but at
present nearly all merchant steam-
ers have vertical direct-acting en-
gines, with inverted cylinders, while
horizontal direct- or back-acting
engines are more commonly used
in war vessels, so that the machi-
nery can be placed below the water-
line. By far the largest number
of modern marine engines are of
the double-cylinder or compound variety. In this form, the steam, after being used in one cylinder,
is exhausted either into a receiver or directly into one or more other cylinders, and acts in them be-
fore being dischargcd into the condenser. It is claimed by many that engines of this form are much
more economical than simple engines (or engines in which the steam is exhausted into the condenser
after acting in one cylinder); and in the files of technical journals will be found numerous compari-
sons that have been made in support of this view. There is no doubt that great saving has been
effected in many cases by replacing the older forms of engines by those of the compound variety,
and at the same time increasing the steam-pressure and piston-speed; but it is at least questionable
whether equally favorable rcsnlts might not have been secured by substituting simple engines, and


















ENGINES, STEAM, MARINE. 605

making the other conditions the same. The matter has never been thoroughly settled by experiment,
which would seem to be the most natural method of deciding such a controversy ; but the theory of
the subject has been pretty fully set forth, with considerable experimental data, in the discussion
0
that has been conducted for several years In the columns of Engineering (which may be called pro-
1404.
1405.
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compound) and The Engineer (anti-compound). The compound engine affords one advantage, when
it-is desired to use two engines at a high grade of expansion. It will be seen by reference to diagram
'7 in the article CRANK, that for a pair of simple engines coupled at right angles, the most even dis-
tribution of pressure on the crank is ef-
fected when the cut-off takes place at half
stroke. By the use of a compound engine,
however, with the large and small cylin-
ders connected at right angles, a high
grade of expansion can be used, with an
approximately even distribution of pres-
sure on the crank. Of course, the same
thing can be effected with the simple en-
gine by the use of heavy reciprocating
parts and high piston-speed, or by having
several cylinders; but in general, the re-
sult can probably be produced more simply
by compounding theengine. Whether any
decided gain results from the use of a very
high grade of expansion is questionable;
so that the opponents of the compound
engine seem to have some reason for their
opinions. There are some special advan-
tages in the compound engine, besides the
even distribution of pressure already re-
ferred to; one of the most important being
that the cylinder in which steam of high
pressure is used is not directly exposed to
the refrigerating influence of the conden-
ser. Another practical advantage seems
to be, that while with a simple engine the
engineer frequently finds it easier to lower
the initial pressure and increase the period of admission, thus rendering the engine less economi-
cal than if it were worked at the proper steam-pressure and cut-off, with the compound engine
the pressure cannot be lowered except at the expense of the power produced. This point was
referred to by Mr. Bramwell in a valuable paper on marine engines, published in the “Trans-
actions of the Institution of Mechanical Engineers,” 1872; and it is more fully discussed in an
article by G. E. Emery on “ Compound and Non-compound Engines, Steam-Jackets, etc.,” pub-
lished in the “ Transactions of the American Society of Civil Engineers ” for February, 1875. The
last paper referred to contains records of experiments with compound and simple engines, which,















eoe * ENGINES, STEAM, MARINE.

with other experiments by the same engineer published in a pamphlet entitled “Report of the Trial
of the Steam Machinery of the United States Revenue Steamer Gallatin,” etc., constitute the prin-
cipal comparative experiments relating to this subject that have been published. Although these
experiments are hardly thorough enough to settle“ the-question definitely—being made with engines
of only moderate size, most of the trials being of very limited duration, and the conditions not being
such as to make them strictly comparative—they are of exceeding interest and value. A summary
of the experiments is given in the following table and in that on page 659.
Principal Dimensions of Engines.







DETAILS. Rush. Bache. Gallatln. Dexter. Dallas.
Number of cylinders. .. . . .' . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 1 1 1
Diameter of cylinders, inches . . . . . . . . . . . . . . . . . . . . .. 24 and 38 16 and 25 84.1 26 86
Length of stroke, inches. . . . . . . . . . . . . . . . . . . . . . . . . . . 27 24 30 36 30
Area of cylinder ports, square inches . . . . . . . . . . . . . . .. 31.5 and 64.1 ' 13.5 and 27 57 .4 ‘82 77.1
Clearance in per cent. of piston displacement . . . . . ., . 7.89 and 5.85 4.86 and 4.05 6.59 5.87 8.02

In experiments 3—10, 12, and 14, the intermediate chamber was drained during the runs; and in
experiment 22, the steam-chest was drained. The link was hauled up in experiments 27, 83, and 87 ;
and in the two last-named experiments the independent cut-ofi’ was not in use. In experiments 29
and 89, the steam-jacket was supplied direct from the boiler; and in numbers 51 and 55, the jacket
was supplied with steam at a pressure of 70 lbs. above the atmosphere. In experiments 41, 46, 48,
and 49, the steam was condensed without vacuum. For those who wish to consult the original tables,
we have inserted a column of corresponding numbers.
It will be seen that, with the exception of a single run of the Rush, the record given in the table
is scarcely conclusive in regard to the great economy of the compound engine. With respect to the
value of the steam-jacket, these experiments are also somewhat contradictory. Some very thorough
experiments on this subject are described by Chief Engineer B. F. Isherwood, in the “Annual
Report of the Chief of the Bureau of. Steam Engineering, U. S. Navy Department,” for 1875. The
engine used in the experiments had a cylinder 10 inches in diameter and 24 inches stroke of pis-
ton. The cylinder, piston, and piston-rod were steam-jacketed, and the different portions of the
jacket, or the whole, could be shut 01f at pleasure. The table appended contains a summary of the
experiments made with this engine:
Summary of Experiments on Walei'man’s Engine.














m
Fig _ STEAM-PRESSURE
7 1N CYLINDER, IN
a " rouxns PER
2 Ratio of Revolu- SQUARE INCH, water per
[-i Not Horse- net Horse- .
<1 E Expan- tions per __ BEMARLS.
z w sion. Minute. 1mm" PW" 1"“
(5 Initial Hour.
5 a ' above Mean Net.
a Zero.
A 3.62 43.1 50.6 21.25 8.66 47.75
B 1.93 43.1 37.7 21.88 8.9 54.19
C 1.47 43.1 38 8 20.75 8.46 58.62 No steam in the jackets.
' D 1.11 48.1 30 5 20.87 8.51 64.04
E 3.62 61.4 21 4.28 2.48 129.5
F 1.11 61.5 15 2 6.15 8.51 117.02
G 3.62 48.2 50 2 21.77 8.88 35.25
H 3.08 43.1 44 8 21.82 8.9 86.2
I 1.93 48.2 34 4 20.87 8.52 89.03
J 1.93 43.1 86 1 22.07 8.99 88.27 Steam of boiler pressure in the jackets.
K 1.32 43.1 31 4 21.18 8.63 48.75
L 1.11 43.2 28 6 20.84 8.64 49.52
M 1.11 61.4 13 6 5.92 3.43 80.97
N 8 .08 43.2 47.1 20.82 8.49 38 .28 Steam in jackets at, pressure of 129 lbs. above zero.
0 1.93 43.1 34.4 20.39 8.3 36.49 “ “ “ 188 “ “ “
P 1.32 43 81.9 21.73 8.48 40.84 “ “ “ 142 “ “ “
Q 3_62 431 4.“; 20_58 8.89 mm; j Stgfingfglboiler pressure in jackets—jackets not
,' Steam of boiler pressure in jackets except up-
R 1.93 43.1 36 22.31 9.09 88.56 8 per cygig,,$lr_head jack? k t. ' 1
team 0 0 er pressure njae e s except ow-
S 1.82 48.1 83.2 21.98 8.95 48.57 m, cylinder_hend jacket. ’
T 8_ 62 43.1 46 20.23 824 8917 j Steam of boiler pressure in jackets, except pis-

ton and piston-rod jacket.

Fig. 1407, which is a sectional elevation of the engines of the San Francisco, is a good example of
the modern compound engine used in ocean steamers. The San Francisco is 352 feet long over all,
with a beam of 40 feet, and a depth of hold of 28 feet 10 inches. The steam-"cylinders have diam-
eters of 51 and '88 inches, with a stroke of 5 feet. They are steam-jacketed on the sides and heads.
The main valves, each worked by two eccentrics, cut off the steam at two-thirds of the stroke, and a
cut-01f valve, consisting of two plates adjustable by right- and left-hand screws, works on the back
of each main valve, changing the point of cut-oif, as desired, from one-tenth to two-thirdsof the
ENGINES, STEAM, MARINE. 607

Gamma/2y of Baperiments with Engines of ihe United States Revenue Steamers Rue/z, Backe, Gal-
latin, Dexter, and Dallas, 1874, 1875.
































' % mum POUNDS or 4‘]
E [3 PM, noses-rowan. wuss PER g3
.- noun. .
‘5 Duration 'me’in Revo- 95 w
a? Compound or Stram- of Expe'ri- pounds 2‘10 of lotions E). .52
0 NAME‘ Simple. Jacket. ment, in Per Pm' per x E
a .5 Hon". Square sion. 7mm.” Per Per In-: E H
m 5 Inch Total Indicated Total dlcnted, E
g 45 above ' ' Hers? Horse- 5
z :2 Zero. power. power. 2;
1 1 R h Compound. In use 55 82.3 6.22 70.8 304. 266.5 16.1 18.4 1
2 2 “s - h “ 6 50.2 4.03 55.5 197.8 168.7 18.8 22.1 2
8 6 Compound. In use. 1.93 93 .5 6.98 53.2 . . . .. 99 .2 20.3 3
4 7 “ “ 1 .98 90.3 5.78 56.3 . . . .. 110.5 20.4 4
5 5 “ “ 2.07 92 9.19 48.2 . . 77.5 20.7 5
6 10 “ “ 2 87.3 4.24 60.6 . . 134.5 21.2 6
7 8 “ “ 7.07 90 5.71 55.6 106. 22 7
8 9 “ “ 15.28 88.8 5.1 53.6 . . . .. 102.3 22.4 8
9 2 “ Notinuse. 2.13 87.7 5.63 49.3 85.8 23.2 9
10 8 Bache. “ “ “ 2.07 91.1 6.66 47.7 .. 77.1 23 10
11 16 Simple. In use. 2.12 90.7 5.11 53.8 116 23.2 11
12 1 Compound. Not in use. 1.83 89.7 9.15 42.6 55.9 23.8 12
13 15 Simple. In use. 1.68 90.1 8.57 46.2 .. ... 74.6 24.1 13
14 4 Compound. “ 1.73 90.6 16.85 38.9 . . 46.4 25.1 14
15 18 Simple. Not in use. 2.05 87.4 5.82 47.1 89.1 26.2 15
16 14 “ Inuse. 2.1 88.8 12.62 39.9 54.8 27.1 16
17 12 “ Notin use. 1.98 90.7 7.62 44.9 71.8 29.6 17
18 17 “ In use. 1.88 41.5 2.18 45.8 66.7 84 18
19 11 “ Notinuse. 1.8 ' 88.9 11.82 37.3 47.2 85.1 19
20 39 In use. 2.22 85 7.31 51.1 222.2 197 18.2 20.5 20
21 48 “. 1.93 80.7 4.19 68.7 889.3 348 192 21.5 21
22 29 Not in use. 2.5 82.4 4.91 60.2 316.8 289.2 19.8 21.7 22
28 86 “ " 2.02 81.7 4.94 59.9 311.4 279.6 19.7 21.9 23
24 88 In use. 23.98 77.8 4.5 61.5 315.3 281.6 19.7 22 24
25 16 "' 2.2 54.6 4.82 45.9 158.3 136.4 19.3 22.4 25
26 14 "' 2.02 58 6.08 44.8 143.7 121.1 19.3 22.9 26
27 27 “ 2.07 70.2 3.45 58.6 298.3 258.5 19.9 23 27
28 18 “ 2.03 54.7 8.71 49.2 191.6 166.2 20.1 23.2 28
29 81 “ 1.87 82.6 4.87 58.5 289.8 255.8 20.7 23.5 29
30 85 Not in use. 2.05 80.8 5.68 56 267.8 231.4 20.6 23.8 30
81 9 “ “ 2.05 55.8 8.73 50.8 204.7 182.2 21.4 24 31
32 15 In use. 2.05 58.9 5.07 46.1 158.5 137.5 20.8 24 32
38 28 “ 1.95 63.6 2.37 60.9 884.3 284.2 20.6 24.2 33
34 33 Not in use. 23.95 76.2 4.46 60.5 304.1 268.6 21.5 24.4 34
35 11 “ “ 2.32 52.3 2.72 56 265.6 286.9 21.8 24.5 35
86 17 In use. 2.22 54.7 4.49 50.8 159.7 168.3 21.4 24.8 36
87 26 Gallatin. Simple. Not in use. 1.92 66.9 2.47 62 854.5 297.8 21 .2 25.2 37
38 20 In use. 2.08 49.3 2.4 54.5 234.5 213 23 25.3 38
39 32 “ 2.03 78.1 3.88 61.6 321.4 282.5 22.3 25.3 39
40 19 “ 3.75 52.4 8.32 51.2 217.9 185.2 21.9 25.7 40
'41 24 “ 2.05 82.6 4.07 49.5 290.6 189.6 16.9 25.9 41
42 7 Not in use. 1.77 56.3 5.92 43 142.5 122.8 22.4 26 42
48 10 “ “ 2.1 51.8 8.16 - 50.1 218 182.4 22.5 26.8 48
44 21 In use. 2.3 50.4 2.21 58.2 291 255 23.2 26.5 44
45 8 Not in use. 1.98 52.8 5.21 44.2 147.9 127.2 23 26.7 45
46 25 In use. 2.12 78.8 8.52 43.8 319.7 212.2 18.1 27.8 46
47 12 Not in use. 2.17 50.8 2.28 55.8 278.7 36.5 28.8 28.1 47
48 23 “ “ 2.22 79.1 3.48 51.7 309.2 204.8 19.4 29.4 48
49 22 “ “ 2.2 88.7 4.37 46.7 264.9 169.6 19.2 30 49
50 8 In use. 2.1 26.3 2 41.8 115.7 95.3 27.4 83.3 50
51 6 “ 2.2 25 1.54 42.8 123.2 102.9 29.1 34.9 51
52 4 “ 2.18 24.1 1.49 42.5 121.2 97.9 30.2 37.4 52
58 1 Not in use. 1.92 25.3 2.02 40.1 107.2 87 82.8 40.4 53
54 2 “ “ 2.25 23.7 1.51 40.9 121.4 90.2 35.7 44.2 54
55 5 In use. 2.22 28.9 1.8 41.1 106.7 89.7 28.6 84.1 55
56 8 2.92 80.4 4.46 56.5 204.5 185.9 21.7 23.9 56
57 5 34.5 79.2 3.49 61.1 240. 219 21.8 23.9 57
58 4 1.42 79.8 3.67 64.8 251 228.1 21.9 24.1 58
59 6 Dexter. Simple. Not jaok- 0.65 77 2.72 72.8 829 292.4 21.6 24.8 59
60 7 eted. 1.82 1 52.3 3.34 50.8 139.6 124.8 25.6 28.8 60
61 8 ‘ 1.2 51.4 2.42 55.3 181 161.8 25.9 28.9 61
62 9 0.92 53.6 2.08 70.7 221.2 196.2 28.2 31.8 62
63 10 1.52 46.9 5.07 48.7 160.1 138 23 26.7 68
64 12 81 46.6 3.18 61 .5 258.2 221.4 23.1 26.9 64
65 11 Dallas. Simple. Not jack- 1.55 47 3.89 56.9 216.1 186.8 23.3 27 65
,_ 66 18 - eted. 1.6 45.9 2.94 64.5 288.4 242.8 24.8 28.9 66
67 14 1.58 39.4 2.32 68.5 274 284.3 26.5 31 67

cos ENGINES, STEAM, MARINE.

stroke. The valves are balanced by pistons, as shown. The surface-condenser contains 2,380 tinned
brass tubes, each having a diameter of three-fourths of an inch and a length of 133- feet, thus giv-
ing 6,425 square feet of condensing surface. There are two single-acting air-pumps, each 24 inches
in diameter and 24 inches stroke; also two double-acting circulating pumps, each 14% by 24 inches.
1407.
@@ 0 0
O



The air and circulating pumps are worked by independent engines. We give in a full-page engrav-
ing a perspective view of the engines, quite similar in design, of the City of Savannah.
The engines of the United States revenue steamer Rush are illustrated in the accompanying
figures. Fig. 1408 is an elevation; Figs. 1409 and 1410, sectional views of the cylinders; Fig. 1411,
vertical cross-section of one of the pistons; Fig. 1412, diflferent views of the auxiliary starting-
valve; Figs. 1413 to 1416, air, feed, and bilge pumps; and Figs. 1417 and 1418, surface-con-
denser. The following are the principal dimensions: Hull—Length over all, 140 feet; length
between perpendiculars at water-line, 129 feet 6 inches; breadth of beam, 23 feet; depth of hold, 10
feet; load draught of water aft, 8 feet 10 inches; displacement to load line, 370 tons. Engines—
Diameter of high-pressure cylinder, 24 inches; diameter of low-pressure cylinder, 38 inches ; stroke
of pistons, 27 inches; diameter of air-pump, 19 inches; number of tubes in condenser, 781 ; diam-
eter of tubes, 0.625 inch; length of tubes, 7 feet; condensing surface, 895 square feet.
F " ENGINES, STEAM, MARINE. 609

1409.
1410.





















610 ENGINES, STEAM, MARINE.

IV. SEA-GOING STEAMEns.—One of the finest examples of American practice in the construction of
sea-going steamers is found in the City of Peking, built for the Pacific Mail Company. The hull is
1412.



423 feet long, of 48 feet beam, and 38‘} feet deep. Accommodations are furnished for150 cabin
and 1,800 steerage passengers, and the coal-bunkers stow 1,500 tons of coal. The iron plates of
1416.
1413. 1414.
O


which the sides and bottom are made are from H; to one inchin thickness. The weight of iron used
in construction was about 5,500,000 pounds. The machinery weighs nearly 2,000,000 pounds, with
1417. 1418.
D







1
. .~i
I - . . . - - . . . - . . . . . .-
IFIF y i ."f
,1/
i?
f


/ WM 2'3.
. . ,/ '/ ,gé/ .449.
l
spare'gear and accessory apparatus. The engines are compound, with two steam-cylinders of 51
inches and two of 88 inches diameter, and a stroke of piston of 41} feet. The condensing water is sent





ENGINES, STEAM, MARINE. 611

u--..,.-
through the surface-condensers by circulating pumps driven by their own engines. Ten boilers fur-
nish steam to these engines, each having a diameter of 13 feet, a length of 13% feet, and a thickness
of shell of thirteen-sixteenths of an inch. Each has three furnaces, and contains 204 tubes of
an outside diameter of 3} inches. All together, they have 520 square feet of grate surface and
17,000 square feet of heating surface. The area of cooling surface in the condensers is 10,000
square feet. The machinery is proportioned to develop 4,000 horse-power at 55 revolutions per
minute, with steam of 60 lbs. pressure, expanding down to 10 lbs. before being exhausted into the
condenser. The screw is four-bladed, 20} feet in diameter, and has a pitch of 30 feet. This
1419.


lgg.5:;;T‘ssrsl42555§5§RE§2§442§555EQ



steamer has made 15.8 knots per hour, equal to 19 statute miles, and burns from 40 to 80 tons of
coal per day, according to the speed and the state of the weather.
The largest vessel of any class yet constructed is the Great Eastern, Figs. 1419 and 1420 (which
engravings, together with others of vessels here given, are extracted from Thurston’s “ Growth of the
Steam-Engine,” New York, 1878), begun in 1854 and completed in 1859, by J. Scott Russell, on the
1420.


Thames, England. This ship is 680 feet long, 83 feet wide, 58 feet deep, 28 feet draught, and of
24,000 tons measurement. There are four paddle- and four screw-engines, the former having steam-
cylinders 74 inches in diameter, with 14 feet stroke, the latter 84 inches in diameter and 4 feet
stroke. The paddle-wheels are 56 feet in diameter, the screw 24 feet. The steam-boilers supplying
the paddle-engines have 44,000 square feet (more than an acre) of heating surface. The boilers
supplying the screw-engines are still larger. At 30 feet draught, this great vessel displaces 27,000
tons. The engines were designed to develop 10,000 horse-power, driving the ship at the rate of 16$
statute miles an hour.
Details of modern iron-clad war-vessels will be found under Aunon.
612 ENGINES, STEAM, MARINE.


The most successful steam sea-going vessels in general use are the screw steamers of the Transat-
lantic lines. These, as will be seen from the following tables, are from 350 to 450 feet in length,
and are generally propelled at from 12 to 15 knots per hour by engines of from 3,000 to 4,000
1421.
___....____
’__.__-_-'
M.- .
_____._.__-—~
M
,_.____...--I
.
_.___.__-4—‘-""-.
M
________---
___.__-—


horse-power, consuming from 70 to 100 tons of coal per day, and crossing the Atlantic in from 8 to
10 days. One of the largest of these vessels is represented in Fig. 1421.
STEAM-LAUNCH, YACHT, AND TUG-BOA'I' ENGINES.—-.B7‘0ih€7'hOOCl and Hardingham’s Three-Cylinder
Engine, represented in Fig. 1422, has been successfully applied in a number of instances to small
steam-yachts. It is also said to be well adapted to driving circulating-pumps for surface-condensers.
The engine is thus described in Engineering for October 3, 1873 : “ Three cylinders are arranged at
1422.
l








,“ ....L" 147/4."— “
wen/{mam'afil—(g
0,),


////'/'//////////,;é






| .\
9
I ’1? '
ms
"/ ' 9A
. z/ 2%
a a
p.
'7.”




’n
’///\'


angles of 120° with each other, around a central chamber, with which they communicate, the whole
being cast in one piece. Each cylinder has its own piston and connecting-rod, the three rods taking
on to one common crank. The crank-pin, after passing through the connecting-rod eyes, is pro-
longed, and fits into a hole in a rotary slide-valve, which it thus actuates. The valve has a steam
and an exhaust port, which are alternately placed in communication with the passage belonging to
ENGINES, STEAM, MARINE. 613

~___
each cylinder. In working this engine, steam is admitted to the central chamber, and exerts an
equal pressure on the inner sides of the three pistons. Thus far the machine would be in eguz'lz'bm'o.
But steam now passes through the slide-valve to the outer side of one piston, thus throwing that
piston into equilibrium, but the three pistons collectively out of equilibrium. A rotary motion of
the crank and slide-valve ensues, and the other pistons are alternately operated upon in a similar
manner, the constant effective area for pressure being a piston and a half.”
Willan’s Three-Cylinder Engine—This engine has been fitted to several fast steam-launches in
the British navy, and under circumstances of actual trial has achieved notably successful results.
Its construction, so arranged that it can be worked compound or non-compound at pleasure, is repre-
sented in Fig. 1423. When working compound, one cylinder of course acts as the high-pressure and
the other two conjointly as the lowpressure cylinders. Referring to A and B, it will be seen that
in the chamber above the valve-cylinders there is fitted a long cupped slide-valve movable by a rod
and hand-lever, one end of this valve being furnished with a projection which, when the valve is put
into the position shown in 0, comes into contact with and opens an ordinary mitre-valve fitted to a
hole in the partition which divides the chamber into two parts. When the valves are in the position
shown in A, the steam is admitted from the boiler to the left-hand compartment of the chamber
only, and it can thus gain access to but one of the valve-cylinders, namely, that on the left. When
the engine is in the gear shown, the left-hand valve controls the admission of steam to and its release
1423-





























A
from the middle cylinder, and in A this cylinder is represented just taking steam, the piston being
at the top of its stroke. On its discharge from the middle cylinder the steam first passes into the
space surrounding the left-hand valve-cylinder (which space acts as a receiver), and then up through
the port on the left, shown in A to be uncovered by the slide-valve already mentioned. In this way
' the steam reaches the top chamber, and from this chamber it is admitted to the two other valve-
eylinders, and distributed by their valves as if it were live steam from the boiler. Finally, after
acting on the two low-pressure cylinders, it is discharged into the space between the centre and right-
hand valve-cylinders, with which space the exhaust-pipe communicates. When working as a simple
engine, the slide-valve is pushed over into the position shown in O, in which position it covers both
the ports in the bottom of the chamber in which it works, and places the space between the left-
hand and centre valve-cylinders in free communication with that between the centre and right-hand
valve-cylinders, and hence also with the exhaust-pipe. At the same time the movement of the slidev
valve into the position shown in 0' opens the mitre-valve already referred to, and admits live steam
into both compartments of the top chamber, and thus each valve-cylinder takes its supply of steam
direct from the boiler. It will be seen from an examination of the arrangement that when com~
pounded the engine can be run in one direction only, but when working non-compound it can of
course be reversed by the cone-valve at the side. A launch 40 feet long, with 9 feet beam and a
draught of 3 feet 6 inches, has been driven at a speed of '74} knots by one of these engines, with a
consumption of 36 lbs. of coal per'hour. The indicated power required to drive the boat at the 7%
knot speed was not ascertained, but a speed of 8% knots was obtained with the same boat with power
of 40-horse indicated. For reports of trial of this engine in steam-launches, see Engineering, xxv., 407.
614 ENGINES, STEAM, MARINE.

High-Pressure Tugboat Engine.—-Fig. 1424- represents a single-cylinder, high-pressure, surface-con-
densing engine built by Messrs. William Cramp a Sons of Philadelphia, for tugboat use. As shown
in the engraving, the point of cut-01f is controlled by altering the stroke of the expansion—valve. It
will be seen that the lower end of the expansion-valve spindle terminates in a cross-head working in
guides. On the side of the cross-head is a pin on which is placed a link which descends as far as an
oscillating segmental arm attached at one end to one of the main pillars forming the framing of the
engine. To this arm, which is graduated, is attached the upper end of the link, to which motion is
given by a crank on the main shaft, as shown. The lower end of the link, descending from the
cross-head of the expansion-valve spindle, slides upon the graduated arm, and may be locked in any
desired position by means of the screw and handle shown; and by sliding it to and fro, any desired
degree of expansion may be obtained. The reversing gear consists of \a hand-wheel carrying a
pinion on itsshaft, which gears into a segment with internal teeth, and throws the lever attached to
the link to and fro. The air-pump is worked in the ordinary way by back-levers connected with the
crosshead, which latter works on a slipper-guide upon the main frame. The diameter of the cylin-
der is 20 inches and the length of stroke 22 inches. With 59 lbs. initial pressure in the cylinder
and a speed of 130 revolutions per minute, an indicated horse-power of 196 was developed on trial.
1424.


Fig. 1425 represents an engine designed for use in small steam-launches. It has a steam-cylinder
3 inches in diameter, and a stroke of piston of 5 inches, driving a screw 26 inches in diameter and of
3 feet pitch. The maximum power of the engine is four or five times the nominal power. The
ENGINES, STEAM, MARINE. 615

boiler is of the type usually adopted in semi-portable engines, and has a heating surface of 75 square
feet. The engine weighs about 150 lbs. per nominal horse-power, and the boilers about 300 lbs.
The table on page 672 gives dimensions of the regular sizes of launches and? their machinery as
furnished by the New York Safety Steam-Power Company, the builders of'the engine represented
in Fig. 1425. Within the last few years the building of
steam-launches for pleasure purposes has become a spe-
cialty, and the object of constructors has been to produce
engines and boilers that combine the elements of power
and strength with a minimum of weight. Single engines
are commonly employed, with their reciprocating parts so
balanced that the engines can be run at a high rate of
speed without jar or noise. Steel is frequently used in
the construction of the boilers, for the purpose of re-
ducing the weight; and a high pressure of steam being
carried, and the steam being allowed to expand in the
cylinder, the performance of the machinery can be made
quite economical. This is often of importance, since the
size of the coal-bunkers can thus be considerably re-
duced. Steam-launches intended for use in- salt water are
often fitted with a simple form of surface condenser,
consisting of a piece of pipe passing around the keel,
into one end of which the exhaust steam is discharged,
the water of cbndensation being drawn out at the other
end by an air-pump, and thus being saved to be used
again as feed-water. Losses from leakage are supplied
from a reservoir of fresh water, which does not require
to be very large, since the continuous runs of steam-
launches are generally of short duration.
The Scientific American of March 8, 1879, contains a
description of what is said to be the smallest steam-launch
ever built. The hull is modeled after the nautilus pat-
tern of canoe, being intended to carry only one person.
The length of the boat over all is 14 feet; width, 28
inches; draught, forward 6 inches, astern 8 inches. The
weight of the hull is 901bs.; boiler, 80 lbs.; engine, 25
lbs.; shaft, propeller, pump, etc., 20 lbs.; total, 215 lbs.
The speed of the boat is about 41} miles an hour in smooth
water, with a steam-pressure of 50 lbs. per square inch, the
fuel consumed per day not exceeding 40 lbs. The boat was
designed and constructed by Mr. J. Davidson of New York.
Ill
__r
;' illuuaLllfl-imhé
~__ _ M
__
I!
ll
_|._.s
m_~


Table slzozln'ng Dimensions, etc., of Iron Vessels built by the Harlan & Hollingsworih Company, at
Wilmington, .Del.

















nmnssroxs or HULL.
B 5 .5 -E-’, m i .=
NAME or VESSEL. - s 3 -= s E if
'6 go Q ~ 5 c T. cs
5’. c: '2 2 .1- v =_
3 a 5 3‘ a 3 Q
1‘3 s ‘s 5 "*F; s "s
E 5 m s a“ :5 3
£83,273?" Ft. Ft in. Ft. in. Ft.
Amelia . . . . . . . . . . . . . . . . . . . . . . . . . .. 2,300 275 38 4 3 0 18
b Morgan City
Carolina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 984.18 250 35 0 14 0 9
Republic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1,285.03 270 87 0 12 0 *7
i
mmmsroxs or enemas AND BOILERS.
.3 sagas-a lg
NAMESOF -E,, 0 ..Eafi *3 5 E “53% lg .laE =5
. was-v on is. =._ ‘5 b3 o-ms‘easn
VESbELS. ,5 o;,_.s we ._ o"; :0 g =sg=gw 3"
M #13331; c “5 <.-. 55‘ $43-95 ,§ ES.
° 5.5: mo @Q o 3 ° 2 IF?“'=E *" :"E
a: E E .M E a: - 3 5 o E a; u, :0: c
e 5 .s a; .s a] 8 :1 5; Q jfi l g I" g» 5 s o a:
E: 2 Q Q ('5 Z P1 83 $2 a: 0
Egg, Vertical direct-l In In. Ft. _ , ‘51-, !
Algiers acting, surface- ? 2 60 5 2 4-blade expanding. pitch2 O f 11.} 621~ 60 2,240
Morgan City condensmg.... J 3‘ 0 |
Carolina .... .. Vertical beam.... 1 .. 60 11 2 Side wheels . . . . . .. face g9 20 28 45 3,860
as 6 U -
“ H ‘8 (8
Republic..... 1 .. 66 12 2 ..... .. lfacemssl 20 22 4o 4,4so














* With 2,500 passengers.
919
'auravw ‘WVEILS ‘sanrena
Table showing Dimensions, etc., of Iron Vesselsil‘ built by John Roach 60 Son, at Chester, Pa., from 1871 to 1879.

















nnunnsrons OF HULL. nmnnsrons or ENGINES AND BOILERS.
== 5 ' s i“ .. a s s - s .. 6 ~11 . ..s a a 5 ° 6
NAMEOFVESSEL. 5 2;; 2 “‘5 g, '5, 0. ~52 ~56 .2 m 2 2" .2, ,-
=3
sgl. a as g a “as .s 5: “as 6 a? 52 6% £5 a;
,6. as s 6‘2 o “a z '8 2° ~=1 ‘2’? 2'42
'5) ‘3" E" ‘5 '5 73 'v e s g . Q . 63 s g, 5 E 8 ,9 ,~, 2 w a o
o = Q 3 8‘}: °‘ :: .... p. .. p. I- :1 ,, g a q, 2 F“ i: Q m
M Si 9* m a .5 .3 a z A m a a; z a m w a: w .s :3
Ft. 1n Ft in. Ft in. Ft. in. In In. Ft in. Ft. in.
S. S. San Antonio . . . . . . . . . . . . . . . . .. 1,412.50 220 0 3 0 22 0 17 0 Inverted condensing. . .. 1 .. 48 4 0 2 True . . . . . . .. 18 0 11 55 35 . . . .
Ferry-boat Garden City . . . . . . . . . . . . 825.55 170 0 88 6 18 6 7 0 Inclined side -wheel.. . . . 1 48 10 0 1 ' Side wheel. . . 22 0 10 24 80 . . . .
S. S. City of Chester . . . . . . . . . . . . . .. 1,106.21 197 0 33 6 17 4 11 6 Compound. . . . . . . . . . . .. 2 24 44 3 9 2 Hirsch . . . . . .. 10 0 11 68 80 950
S. S Colon . . . . . . . . . . . . . . . . . . . . . . .. 2,685.7 5 282 0 40 0 30 6 19 0 “ . . . . . . . . . . . .. 2 50 86 8 6 4 “ . . . . .. 16 8 12 50 60 2,450
8. S. Colima . . . . . . . . . . . . . . . . . . . . . .. 2,905.64 294 6 40 0 30 6 19 6 “ . . . . . . . . . . . .. 2 51 88 8 6 4 “ . . . . . .. 16 8 12 50 60 2,561
Ferry-boat Erie . . . . . . . . . . . . . . . . . . . . 981 180 0 36 0 15 6 6 6 Beam . . . . . . . . . . . . . . . . . . 1 .. 46 11 0 1 Side wheel. . . 22 0 10 22 30 . . . .
S. S. City of Peking . . . . . . . . . . . . . . . 5,079.25 396 6 47 4 37 2 24 0 Two compound . . . . . . .. 4 57 88 4 6 10 Hirsch . . . . . . . 20 3 141} 50 60 5,700
“ “ Tokio . . . . . . . . . . . . . . .. “ “ “ “ “ “ “ . . . . . . .. “ “ “ “ “ “ . . .. “ " “ “ “
“ “ Waco . . . . . . . . . . . . . . . .. 1,486.21 230 0 36 0 21 6 17 0 Compound . . . . . . . . . . . .. 2 80 56 4 6 _4 True screw .. 18 0 11 60 80 1,615
S. Collier Perkiomen . . . . . . . . . . . . . . . 1,035.35 218 6 37 0 18 8 12 0 “ . . . . . . . . . . . . . 2 27 45 8 0 2 “ “ . 11 0 10 62 50 . . . .
“ “ Berks . . . . . . . . . . . . . . . . . . . . 558.09 190 0 28 6 15 0 11 0 “ . . . . . . . . . . . .. 2 20} 84 2 6 1 “ “ 9 0 10 68 ' 50
S. S. State of Texas . . . . . . . . . . . . . . .. 1,548.66 284 0 86 0 21 6 17 0 “ . . . . . . . . . . . .. 2 30 56 4 6 4 Hirsch . . . . . .. 18 0 12 60 80 1,615
City of Panama ............. .. 1,490.24 242 0 36 0 22 s 17 0 “ ........... .. 2 80 56 4 6 4 ..... -- 18 0 12 60 80 1.722
“ “ Guatemala... . . . . . . . . .. 1,487.30 242 0 36 0 22 3 17 0 “ . . . . . . . . . . .. 2 30 56 4 6 4 “ . - - - . .. 13 0 12 60 80 1,724
“ Geo. W. Elder . . . . . . . . . . . . . . .. 1,561.82 242 0 88 0 22 11 17 0 “ . . . . . . . . . . . . . 2 80 56 4 6 4 “ ..... .. 18 0 13 65 80 1,726
Tug Geo. E. Weed . . . . . . . . . . . . . . . . . 80.49 78 0 16 8 8 0 7 0 Inverted H. P... .. . . .. . 1 . . 16 18 0 1 True 6 6 8 75 60 . . ..
U. s. sloop Alert ................. .. 541 175 0 s2 0 16 s 13 0 Compound ......... 2 281 421 3 6 5 “ . ..... .. 12 0 12 72 so 1,726
“ “ Huron . . . . . . . . . . . . . . . . . "' “ “ “ “ “ . . . . . . . . . . . .. “ “ “ “ “ “ . . . . . . .. “ “ “ “ “ '
8. S. City of San Francisco . . . . . . . . . 8,009.25 831 1} 40 0 80 5 22 6 “ . . . . . . . . . . . .. 2 51 88 5 0 6 Hirsch 20 0 13 50 80 4,107
“ “ New York . . . . . . . . . . . . 3 019 .56 “ “ “ “ “ . . . . . . . . . . . . . “ “ “ “ “ “ . . . . . . . “ “ “ “ "'
“ “ s dney ............. .. 32016.46 “ “ “ “ “ ........... .. “ “ “ “ “ “ “ “ “ “ “
U. S. monitor iantonomoh . . . . . . .. 2,025.75 250 0 55 0 16 6 14 0 Two compound. 4 31 54 8 6 6 “ 12 0 .. 80
Spanish gun-boat Graciosa’r . . . . . . .. 72 91 0 15 0 5 8 8 0 Inverted condensing... . 4 8 .. 9 1 “ 4 0 11 120 60 . . . .
U. S. monitor Puritani' . . . . . . . . . . . . . 2,898 280 0 60’ 0 20 0 18 0 Two compound . . . . . . .. 4 51 88 8 6 10 “ . . . . . . . 15 0 . . 80 . . . .
Str. Newberne . . . . . . . . . . . . . . . . . . . .. 412.27 150 0 24 0 9 7 8 6 Inverted condensing. .. 1 24 3 0 1 True . . . . . . . 8 0 11 75 60 . . . .
S. S. Rio Grande . . . . . . . . . . . . . . . . . .. 2,566.48 290 0 39 0 22 10 13 6 Compound . . . . . . . . . . .. 2 34 60 4 6 4 Hirsch 14 0 12 68 80 2,815
“ Niagara . . . . . . . . . . . . . . . . . . . . . . 2,265.28 272 0 88 1 24 10 17 0 “ . . . . . . . . . . . . .- 2 84 60 4 6 4 “ . . . . . .. 14 8 18 63 80 2,815
“ Saratogai: . . . . . . . . . . . . . . . . . . . . 2,285.65 “ “ “ “ “ . . . . . . . . . . . .. “ “ “ “ “ “ “ “ “ “ “
“ City of Macon . . . . . . . . . . . . . . . . 2,092.80 254 2 38 6 25 11 16 0 “ . . . . . . . . . . . .. 2 38 68 4 6 4 “ 15 0 13 64 80 2,455
“ Western Texas . . . . . . . . . . . . . .. 1,121.12 226 5 84 0 17 5 10 0 “ . . . . . . . . . . . .. 2 24 44 3 9 2 “ .. 11 6 11 66 80 922
Panama Tugi' . . . . . . . . . . . . . . . . . . . .. 105.30 91 0 18 0 6 10 5 0 Inverted condensing... . 2 20 .. 2 0 1 Expanding 6 9 10 100 60
S. 8. City of Washington . . . . . . . . . . . 2,618.21 300 0 88 0 29 8 21 0 Compound ......... . . 2 40 74 6 0 2 “ 16 0 14} 60 70 8,950
“ “ Savannah . . . . . . . . . . . . . . 2,029.40 254 2 88 6 25 11 16 0 “ . . . . . . . . . . . .. 2 38 68 4 6 4 Hirsch 15 0 13 64 80 2,455
“ Oregon . . . . . . . . . . . . . . . . . . . . .. 2,885.38 280 0 38 2 24 4 18 0 “ . . . . . . . . . . . 2 34 60 4 6 4 “ . . . . . .. 15 0 18 62 80 2,425
“ City of Rio de Janeiro . . . . . . .. 3,548.30 845 10 88 6 30 4 28 0 “ . . . . . . . . . . . .. 2 42;- 74 5 0 6 “ ..... .. 16 4 _ 18 62 80 3,860
“ “ Para . . . .. . . . . . . . . . . . . 8,582.25 345 10 88 6 30 4 23 0 “ . . . . . . . . . . . .. 2 424 74 5 0 6 “ , . . . . .. 16 4 13 62 80 8,860
“ Saratoga (No. 2) . . . . . . . . . . . . . . 2,426.18 299 10 38 0 28 6 19 0 “ . . . . . . . . . . . . . 2 0 74 4 6 4 f‘ .. 15 6 144 64 80 8,420
“ City of Columbus ........... .. 1,992.37 254 2 88 6 25 11 16 0 “ . . . . . .. 2 88 68 4 6 4 “ ..... .. 15 0 13 64 80 2,455
“ Gate City...... ............ .. 1,997.11 254 2 88 6 25 11 16 0 “ . . . . . . . . . . .. 2 38 68 4 6 4 “ . . . . . .. 15 0 13 64 80 2,455
“ Guan Mir..- . . . . . . . . . . . . . . . . .. 422. 151 7 28 1} 13 1g 10 0 Inverted condensing... 1 28 . 8 0 1 Expanding... 9 9 10 75 60 780








* Except the tugboat George E. Weed, which is of wood.
'I' Twin-screw vessels.
4,
isold to the Russian government, and converted into the corvette Africa.

'amavw ‘wvnds ‘sslnresls:
L19
0
Table showing Dimensions, Performances, etc., of Steamers of Atlantic Dines.
































. . g Q 6 6 6 6 6 5 6
5 B .6 <5 8 .2 r =6 ' B 6' ° ' "5 ° 6'» as w
4 i '6 1511?. 6 66615656 41.6
, Q .... O ‘- 0
NAME OFVESSEL. 5 3 2% g. ,3 '5 ,8 fig ,2? d E ,8 g ,5 g 23% a? ~5.5%
t 5 6 a 6, 6' a 6. a '6. 6 s 6. 6 g ' 5% l: 8 e 6
5 E 2 .5 °* 5 8 73 r? 2’ ° 5 ° 51 z“ 5' E1 a: g z '1 8 63 3 8 “1 E
White Star I/i'ne. Ft“ in, Ft, in, Ft, in, Ft, in_ Inches. In. Feet. Feet. Knots.
Britannic ...................... ---- -- 5,034 1674 Iron. 455 o 25 0 45 2 .2, . Compound. 4 48~83 60 8 4-bladed. .... ..
Celtic ................................ .. 6,667 1672 “ 467 6 24,0 40 9 {3% ‘5 . 6 4 41-76 60 12 'r 22* 31* 15* 55* 65* .... ..
Germanic ............................ .. 5,666 1874 6 455 0 25 o 45 2 1 6 4 46-66 66 8 " .... ..
Baltic... ............................. .. 6,767 1671 “ 426 o 24 0 4o 9 3 l r 4 41-78 60 12 “ .... ._
Adriatic ............................. .. 6,666 1671 “ 467 0 24 0 46 9 ‘3 . 6 4 41-78 66 12 5* _ Republic ............................ .. 6,767 1671 “ 420 o 24 o 49 9 1 g? g 1 *1 4 41-78 60 12 “ In/man Dino. 1,0,, h_ p_
City of Berlin ........................ .. 5,491 1875 Iron. 469 o 45 0 85 0 Compound. 2 77-126 66 18 4616666. Various. 16 55 75 2.2
“ Chester ........................ .. 4,566 1676 “ 444 o 44 0 84 6 ~- 2 73-126 66 14 I, 15 55 65 2.5
“ Richmond .................... .. ,607 1676 “ 441 0 46 6 84 6 6 2 76-120 66 16 “ . 15.5 55 60 2
“ Montreal ...................... .. 4.496 1671 r 419 6 44 o 84 6 r 2 77-112 64 8 , . 16 54 66 6.4
“ Brussels ...................... .. 8,775 1669 “ 390 0 40 6 84 6 “ 4 85— 75 60 4 I, 1 14.5 64 90 2.8
“ New York .................... .. 6,566 1865 “ 875 6 89 6 88 0 r 4 40— 71 66 4_ ,2 13.5 54 75 2.2
“ Paris ......................... .. 3.000 1866 “ 398 0 40 6 26 0 I-Ior. trunk. 2 69- 82 42 6 14 55 66 6.4
“ Limerick ............ ....... .. 2,766 1855 “ 661 0 66 6 30 6 Compound. 2 86- 72 42 6 “ 11 60 66 6.2
Liverpool and G. W. 88'. Line. Per hour.
Nevada .............................. .. 8,850 1868 Iron. 645 6 24 4 46 4 Effiglel 2 63.5 46 2 True screw. 26 26 12.5 53 64 6,346.6
Idaho ................................ .. 1669 r 345 6 24 4 43 4 “ 2 63.5 48 2 ...... .. 20 26 12.5 51 84 6,846.6
Wyoming ............................ .. 8,716 1870 “ 666 2 24 6 46 2 Compound. 2 60-120 42 2' ...... .. 19 27 14 55 74 6,846.6
Wisconsin ........................... .. 8,720 1676 “ 866 0 24 6 46 2 “ 2 60-120(2 42 2 ...... .. 19 26 14 58 74 6,646.6
Montana ............................ .. 4,820 1874 “ 400 4 25 0 46 7 g l “ 6 60408.5 42 6 ...... .. 21 26 15 58 80 9,666






* These figures give a fair average of general performance of the vessels named.

618
ENGINES, STEAM, MARINE.






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ENGINES, STEAM, MARINE.
619

Table showing Dimensions and Performances of several Paddle-wheel Steamers (Fall River Line).



















































Length Number
NAME or VESSEL. Tonnage. m‘ff Material. 23:31: Digit “Mamba. Depth. Type ofEngine.‘ Cor 80mm
diculan. ylmdem
~ Feet. Ft. in. Feet. Feet. Beam, con-
Provldenee ................ . . 3,000 1867 Wood. 362 9 6 48 16 densing. 1
Bristol.. . . . . . . . . . . . . . . . . . . . . 3.000 1867 Wood. 362 9 6 48 16 “ 1
Old Colony... . .. . . . . . . . . . .. 1,957 1865 Wood. 310 10 0 42 14 '*‘ 1
Newport . . . . . . . . . . . . . . . . . . .. 2,200 1865 Wood. 332 11 6 43 14 “ 1
I No. of Coal
Diameter Diameter Revolu- Steam- Consuu ed
of No. of of No. of Area of Maximum. tions of Pressure in Tons
NAME OF VESSEL Steam Stmh' Boilers. Paddle Buckets. Bucket. ' Speed. Wheel corre- per hour
Cylinders. Wheels corre- sponding. corre-
sponding. spending.
Inches. Feet. Ft. in Feet. Per hour. Pounds.
Providence . . . . . . . . . . . . . . . .. 110 12 3 39 4 48 30 17 knots 1,050 22 3}
Bristol ................... .. 110 12 3 39 4 4s 30 17 knots 1,050 22 31
Old Colony . . . . . . . . . . . . . . . . . 81 12 2 36 0 60 26 ' 16 knots 990 27 2%
Newport . . . . . . . . . . . . . . . . . . . . 85 12 4 36 0 60 26 16 knots 990 27 2%
Table showing Uomparaiioe Dimensions, etc., of several Famous Atlantic Steamers}
nmsxsmss. [ Nominal
NASBIGI?POF Owners. Vl’here Built. Year. , : Tonnage Home“ ; P ed
‘ Length Breadth. I Depth I P°W°r~ l "I" '
- Ft. in. Ft. in. ‘ Ft. ml Britannia.... Cunard Line . . . . . . . . . .. Greenock.. 1840 230 0 34 o ‘ 22 5 ; 1.150 440 ‘ Paddles.
Great Britain. Great Western Line. . . . Bristol. . . . . 1843 274 2 48 2 31 5 ' 3,270 500 Screw.
Asia ....... .. Cunard Line ......... .. Greenock.. 1850 268 o 4.5 0 24 1 l 2,22? 750 ,' Paddles.
Arctic . . . . . . Collins "' . . . . . . . . . . . New York. 1850 290 0 45 0 31 5 2,860 1,000 l “
Persia . . . . . . . Cunard “ . . . . . . . . . .. Glasgow. . . 1855 360 0 45 0 32 0 I 3,300 900 I “
1 “
Great Eastern Great Eastern s. s. 00. Millwall.... 1858 679 6 82 8 4s 2 18,915 { 3 Screw
Scotia.‘ . . . . . . . Cunard Line. . . . . . . . . .. Glasgow... 1862 379 0 47 8 30 5 3,871 1,000 g Paddles.
Oceanic . . . . . . White Star Line . . . . . . . . Belfast . . . . 1871 420 0 40 9 31 0 3,707 600 Screw. I
Con-aparatwe Table showing Rapid Passages made by Atlantic Steamers from 1840 to 187 7.
HOMEWARD.
Distance T.
YEAR. Month. N me of Steamer. Owners. From To Run in 1m?
Knots. Oocupied.
D. H. M.
1840 July ..... .. Britannia . . . . . . .. Cunard Line . . . . . . . . . Halifax . . . . . . Liverpool. . . . 2.573 10 0 0
1841 July . . . . . . . Acadia. . . . . . . . . . . “ “ . . . . . . . . . “ . . . . . . " . . . . 2,534 9 21 0
1846 May . . . . .. Great Britain .. . . Great Western Line. . New York. . . “ . . . . 3.209 10 23 0
1852 February.. Atlantic . . . . . . . .. Collins Line . . . . . . . . . “ . . . Queenstown . 2.712 9 17 15
1856 . . . . . . . . . .. Persia . . . . . . . . . .. Cunard “ . . . . . . . . .. “ " 2.732 9 1 45
1858 . . . . . . . . . .. Pacific . . . . . . . . . . . Collins “ . . . . . . . . . . St. Johns... . Galway . . . . .. 1.720 6 1 0
1863 December . Scotiu . . . . . . . . . . Cunard “ . . . . . . . . .. New York.. . Queenstown . 2.731 8 3 o
1869 December. City of Brussels. Inman “ . . . . . . . . .. “ . . . “ 2.687 7 2'2 3
1872 October.... Polynesian . . . . . .. Allan “ . . . . . . . . . . Quebec . . . . . . Moville . . . . .. 2,379 7 18 55
1878 January... Baltic . . . . . . . . . . . . White Star Line . . . . . . New York. . . Queenstown . 2.843 7 20 9
1875 October. . .. City of Berlin. . . . Inman Line. . . . . . . . . " . .. “ 2.820 7 15 28
1876 February.. Germanic . . . . . . .. White Star Lino “ “ 2.894 7 15 17
1876 December..| Britannie . . . . . . .. “ “ “ “ 2,882 7 12 41
OUTWARD.
1840 July . . . . . . Britannia . . . . . . . . Cunard Line . . . . . . . . . Liverpool. . .. Boston . . . . .. 2,755 14 8 0
1840 August Acadia, . . . . . . . . .. “ “ . . . . . . . .. “ Halifax . . . . .. 2.487 11 4 0
1845 J Lily . . . . . .. Great Britain .. . . Great Western Line. . Bristol . . . . . .. New York. .. 2.988 13 21 0
1846 . . . . . . . . . . . Europa . . . . . . . . .. Cunard Line . . . . . . . . . Liverpool. . .. “ . .. 3.017 11 8 0
1853 . . . . . . . . . .. Baltic . . . . . . . . . .. Collins “ . . . . . . . . . Queenstown . “ 2721 9 16 33
1864 . . . . . . . . . .. Scotia. . . . . . . . . . .. Cunard “ . . . . . . . .. “ “ 2,783 8 15 45
1866 July . . . . . .. Scotia . . . . . . . . . . . “ “ . . . . . . . . . “ “ 2,851 8 4 34 i
1867 November. (‘ity of Paris. . . . . Inman “ . . . . . . . .. “ “ 2.700 S 4 1
1869 August City of Paris. . .. . “ “ . . . . . . . .. “ Halifax . . . . .. 2.258 6 19 5
1872 May . . . . . .. Adriatic . . . . . . . . . White Star Line . . .. . “ New York __ 2373 7 ~33 17
1875 September City of Berlin. . .. lnman Line . . . . . . . . . . “ “ .. . 2,829 7 18 2
1876 J une . . . . .. Britannic . . . . . . .. White Star Line . . . . . “ “ 2.854 7 16 36
1876 November. Britannic . . . . . .. “ “ “ “ 2,795 7 18 11
187 7 prll . . . . . . Germanic . . . . . . . . “ “ . . . . . “ “ 2.839 7 11 37
1877 August. . . . Britannlc . . . . . . .. “ “ . . . . . “ “ 2,802 7 10 53










* This table and those following are from a valuable paper on “ Transatlantic Lines and Steamships,” by Arthur ’l‘.
Magiinnlis, read before the Liverpool Engineering Society, January 80, 1878, to which the reader is referred for further
par cu ars.
620 ENGINES, STEAM, PORTABLE AND SEMI-PORTABLE.

Table showing Average Passages of Steamships of Atlantic Lines from 1850 to 187 7.








































OUTWARD.
YEAR. Cunard Line. Collins Line. Inman Line. Gulon Line. National Line. White Star Line.
D H. M D. H. M. D H. M D. H. M. D. H. M. D. H. M.
1850 13 0 9 .. .. .. .. . .. .. .. .. .. .. ..
1852 12 19 26 11 10 26 . . . . . . . . . . .
1855 12 12 9 11 22 40 .. . .. .. .. .. .. . ..
1866 10 11 34 .. .. .. 11 15 18 . .. .. 10 11 40 .. ..
1873 10 16 49 10 22 4 12 6 38 11 21 36 9 19 48
1875 10 17 24 19 20 45 11 8 47 12 1 19 9 16 33
1876 10 I3 32 10 1 44 19 23 45 11 1 6 45 8 21 14
’l 1877 19 9 58 8 21 17 9 16 30 19 23 12 8 13 39
HOMEWARD.
1850 12 16 9 .. .. .. .. .
1855 11 12 0 19 2.) 0 .. .. .. . .. ..
1866 9 4 39 .. .. .. 10 11 40 . .. .. .. .. .. .. ..
1873 9 ' 7 59 10 9 2 10 29 18 1 9 14 16 8 22 39
1876 9 4 48 8 17 52 9 29 4 19 7 35 8 12 13
*1877 9 7 7 8 20 36 9 13 51 19 5 31 19 39
Table showing Dimensions of 'S'team- Yachts and Machinery.
HULL. J ENGINE. > PBOPELLER. BOILER. WEIGHT.
:3 g _
=5 g g CYLINDER. SHAFT. M E ,5 Q E“
:3 U = _ ' o (I) :5 -= a .5
g s e . s A. e s e “a ‘2’. .3 B 5 g
,5! . m a 0 q; q; a . 0 a z "a a g
t e 2 .2 s a E” .5 s .2 m e5 5
.3 :3 Q a 2 Q (‘5 Q .3 o '61 Q a: m {=1 <4
Ft. Ft. in. Ft. in. In. In. In In. In. Ft. In. In. Sq. Ft Lbs. Lbs.
25 5 8 2 3 4 3 5 1% 12 26 3 28 45 75 350 1.500
28 5 10 2 4 5 3i- 5 11} 13 28 3 89 46 90 375 1.700
32 6 4 2 6 6 4 6 1% 15 80 3} 33 48 115 500 2,009
38 7 6 3 2 10 51- 7 2 16 86 4 86 56 170 7 59 3,009
59 9 9 3 6 16 7 9 2% 18 42 5 46 76 246 1,209 4,809
69 0 9 4 2 26.5 9 12 3 25 48 5 59 82 3!; 2 2,700 7,509
68 11 0 4 8 37 . 5 19 12 31- 30 , 54 6 54 86 492 3,299 8.500
75 12 9 4 19 43 12 12 8% 35 56 7 69 99 504 4,999 10,000







For works for reference, see ENGINES, HEAT.
SEMI-PORTABLE. Portable engines, properly speaking,
are engines and boilers mounted on wheels, which can be drawn or propelled from place to place,
ENGINES, STEAM, PORTABLE AND









R. H. B.
and need no special preparation beyond blocking the wheels when it is desired to run them. Spch
engines are commonly employed on farms, where it is often convenient to do the work of threshing,

* First nine months.
ENGINES, STEAM, PORTABLE AND SEMI—PORTABLE. 621

etc., in the fields. Engines either attached directly to the boilers or placed on the same casting, so
that no special foundation is required, form the semi-portable class. Horizontal fire-tube boilers are
generally used for portable engines, and vertical fire-tube boilers for the semi-portable.
PORTABLE lineman—The immense demand for engines of moderate power, easily managed, and
ready for work when delivered, has been thoroughly appreciated by the engine manufacturers of this
country; so that, in selecting examples, the ob-
ject is rather to convey an idea of modern prac-
tice in this branch of engineering than to exhibit
all varieties.
Fig. 1426, the Lane do Bodleg portable engine,
is fairly representative of one great division, viz.,
portable engines with locomotive boilers, plain
slide-valves, and fixed cutoffs, the speed being
I regulated by the action of the governor upon the
throttle-valve.
In Whitman (f: Bw'rell’s portable engine, Fig.
1427, it will be seen that a return tubular boiler
is used. The cut-ofl’ of this engine can also be
readily changed when desired.
Portable engines designed with a special view
to economy and lightness have cut-offs that are
adjusted by the action of the governor, and are
designed to be run at a high speed. The cylin-
ders are usually jacketed also with live steam.
Remarks have frequently been made upon the
absurdity of using animal power to draw a port-
able engine from place to place, since it is power-
ful enough not only to propel itself, but also to haul a threshing machine or the like in addition.
Several self-propelling portables have been put into operation, and have worked very satisfactorily;
and while this is rather the exception in present practice, many manufacturers are ready to build such
engines when called for.
Fig. 1428 shows the illilZs soy-propelling engine, with locomotive boiler, jacketed cylinder, balanced
valve, automatic cut-01f, and reversing gear.
Fig. 1429 represents an improved form of traction engine or road locomotive built by Messrs.
Aveling 8t Porter of England. The following are the principal dimensions : \Veight of engine, com-









plete, 5 tons 4 ewt; steam-cylinder, diameter, 7% inches; stroke of piston, 10 inches. Revolutions of
crank to one of driving-wheels, 1'7. Driving-wheels—diameter, 60 inches; breadth of tire, 10
inches; weight, 450 lbs. each. Boiler—length over all, 8 feet; diameter of shell, 30 inches; thick-
ness of shell, 116-111011; fire-box sheets, outside, thickness, is inch. Lead on driving-wheels, 4 tons
10 ewt. The boiler is of the ordinary locomotive type, and the engine is mounted upon it, as is usual
with portable engines. The driving-pinion on the crank-shaft is made capable of being slipped out
of gear, thus allowing the engine to be kept in motion when the locomotive is at rest, either to pump
water into the boiler or to drive as a. “portable engine,” by a belt which can be carried on the
sea ENGINES, STEAM, PORTABLE AND SEMI-PORTABLE.

pulley, 4),; feet in diameter and 5 inches face, which is fitted to act as a fly-wheel. When used as a
portable engine, regulation is effected by means of a fly_ball governor conveniently attached.
The principal feature of this engine is the connection between the gearing and the driving-wheels,
\


which is eifected by the differential gear Shown in Fig. 1430. One wheel, A, turns freely on the
driving-axle at B, while the other driving-wheel is keyed fast. The latter is not shown in the cut.
A bevel-gear, O, is bolted on the hub of the wheel A, and a similar gear, .D, is keyed to the driving-
axle. Between these revolves a spur-gear, E, which is driven by the engine, and which carries two
small bevel-pinions, F F, the latter engaging both bevel-wheels, O and D, their axles being in the
plane of revolution of the large gear E. An examination of the combination will Show that, resist-
ances being equal on both wheels, if the spur-gear E be turned, it will carry with it both driving-
wheels at the same time with equal angular velocities, the effort exerted by the engine being equal
at both wheels at all times. If the engine be turning a corner, however, the greater resistance on
the inside wheel retards that, while the outer wheel necessarily moves more rapidly over its longer
path, and, while the engine still exerts the same force on both wheels, the work done is distributed
unequally between them through the then revolving bevel-pinions, without loss and without either
wheel being necessarily slipped or disengaged.
The following summary of results is taken from a report of tests of this engine, conducted by
Prof. R. H. Thurston, at South Orange, N. J ., in 187 2 (see Journal of the Franklin Institute): “A
1439.







traction engine may be so constructed as to be easily and rapidly manoeuvred on the common road ',
and an engine weighing over 5 tons may be turned continuously without difficulty on a circle of 18
feet radius, or even on a road but little wider than the length of the engine. A locomotive of 5 tons
ENGINES, STEAM, PORTABLE AND SEMI-P ORI‘ABLE. 623

4 cwt. has been constructed capable of drawing on a good road 23,000 lbs. up a grade of 533 feet
to; the mile at the rate of 4 miles .per hour; and one might be‘constructed to draw more than 63,000
lbs. up a grade of 225 feet to the mile at the rate of 2 miles an hour. It was further shown that
the coefficient of' traction, with heavily-laden wagons on a good macadamized road, is not far from
.04. The'traction power of the engine was found equal to 20 horses. The weight, exclusive of that
of the engine, that could be drawn on a level road, was 163,452 lbs. ; and the amount of fuel required
was estimated at 500, lbs. per day. The advantages claimed for the traction engine over horse-
draught are: NO necessity for a limitation of working hours; a difference in first cost in favor of
steam ; and in heavy work on a common road, the expense by steam is less than 25 per cent. of the
average cost of horse power, a traction enginenapable of doing the work of 25 horses being operated
at as little expense as .6 or 8 horses. The cost of hauling heavy loads has been estimated at 7 cents
per ton per mile.” A detailed description of a traction engine especially suited for light agricultural
work, and built by Messrs. Ransomes, Sims 8; Head, of Ipswich, England, will be found in Engineer-
ing, xxvi., 450. _
The use Of an engine on a farm for threshing purposes renders it desirable that the straw, which
is ordinarily of little value, should be used as fuel if possible. This was formerly effected in fur-
naces under stationary boilers, and it is only within a
1431- few years that straw-burning boilers have been used
L , ' P for portable engines. An interesting account of the
earlier forms of straw-burning furnaces and boilers, and
their development, is contained in the “ Proceedings
I of the Institution of Civil Engineers,” vol. xlviii. Fig.
.__—. 1431 is a section of Head c6 Schemioth’s patent straw-
bw-ni-ng furnace, which is one of the most successful
,, L , forms manufactured in England. The straw is forced
HEM, , into this furnace by rollers, as shown; and the follow-
a ' -!-!-!——-!- ing statement of the advantages of this arrangement
is given by the manufacturers: “ The theory Of the in-
vention is that, by means of a continuous mechanical
feed, the fuel can be
forced into the furnace
in a thin stream in the
form of a fan, and the
fresh fuel is practically
held in suspension for
a short time, allowing
,1 the separate stalks to
8 - fl become immersed in the
l flames, and the long
pieces of straw, reeds,
or brushwood to have
the effect of stirring up
the half-burnt material in the furnace, thus keeping the whole in motion, besides permitting a proper
ingress of atmospheric air, which is necessary for the rapid combustion of vegetable matter.” Mr.
Head gives, from numerous experiments, the following relation between different kinds of fuel:










BCHEMIOTHS
PATENT









Psi-s": I“ :t‘e,
.3;- .|.\\ \.\ .9 _
“5*!- 3.“ 235%, '

“1 lb. of good coal 1 v
$581682 grfbgcfi, (1“, wood will evaporate 8 lbs. of water in an
. ~ - . - . ‘1 i - 77
2.75 to 3 lbs. of cotton stalks or brushwood ordm‘ny tubulm b01161“
3.25 to 3.7 5 lbs. of Wheaten or barley straw
In Messrs. Clayton 8t Shuttleworth’s straw-burning furnace the grate is placed in a supplementary fire-
box, and the grate~bars are of such shape that they come close together at the front, forming a wide
dead-plate, and only about one bar in three runs the whole length of the furnace. Experiments
were made with a portable engine having this furnace by Prof. Radinger (see Engineering for Dec.
14, 187 7), and it was found that the consumption of straw per net horse-power per hour was 12.4 lbs.
The Hoaclleg portable engine, Figs. 1432 to 1435, has been chosen as a good representative of ad-
vanced practice in the United States; and the straw-burning attachment, Figs. 1432 and 1434, is
specially worthy of notice. A somewhat detailed description Of the illustrations is appended. The
boiler is strengthened by a horizontal diaphragm in the steam-space, which is also designed to prevent
priming. There is also a dry pipe in the steam-space. A Slight depression in the boiler between the
shaft-bearings allows the engine to be lowered about 2 inches. The smoke-pipe is surrounded by a cas-
ing, which furnishes a cooler surface near the driver’s back. A spark-arrester (see Fig. 1432) is fitted
to the smoke-pipe. The central cone shown in the figure deflects the products Of combustion, so that
they are discharged with considerable force, in jets, between the cone and the enlarged end of the
smoke-pipe. These jets strike the inclined surface under the conical cover, and are deflected out-
ward and downward. Solid particles go downward to the casing, and on passing near the conical
ring, which is open at both ends, are drawn up through the angular space between this ring and the
smoke-pipe, to repeat the deflection until caught or worn to dust. The gaseous products of combus-
tion escape in a continuous stream through the central outlet, which is 13 inches in diameter.
There is a small steam-pipe opening into the casing, for blowing out the solid particles from time to
time, after the sparks are extinguished.
The straw-burning apparatus, Figs. 1432 and 1434, consists of six independent series of pipes,
624 GIN ES, STEAM, PORTABLE AND SEMI—PORTABLE.

within the fire-box, at the sides, top, and back. Each set of pipes is the same, as follows: The
lower horizontal pipe, 1;]; inch in diameter, forms the grate-bar, and is connected to the front fire-
box sheet by a union attachment; the back end of this pipe is joined to two vertical pipes leading
upward, and to a third pipe which is turned down and provided with a blow-ofi cook. The other ends
9?».


of the first-named pipes connect with two horizontal pipes which unite near the front fire-box sheet,
and are connected to that sheet. Thus these series of pipes form a grate with air-spaces of 2;];
inches, and the spaces of half an inch between the vertical pipes allow sufficient opening for the
passage of flame, but do not permit the straw to go through unconsumed, and thus prevent the
obstruction of the tube with soot, etc. These pipes are also a valuable addition to the most efl‘i-
1433.















em

























cient portion of the heating surface, nearly doubling the heating surface of the fire-box. The straw
is fed into the furnace through a funnel-shaped mouth-piece, having a door hinged at the top,
which is generally left open when feeding, care being taken to keep the funnel stuffed with straw.
There are minute peep-holes for showing the condition of the fire; and if flame is not seen in the
ENGINES, STEAM, - PORTABLE AND SEMI—PORTABLE. 625
1484.






‘,'-.'
"1.14
I.
I
illiilligi'e ,
"165
fix!
$5}
a»


.lfll
I
‘4
\1 "











| 1
p t
b 1
I l

OOOOOOOO
U——-_n—_n
_——___—























. Di , (l
furnace, the feeding should be stopped for a while. The ash-pan can be readily removed, to give
access to the pipes. It is flanged around the bottom, so as to hold water for extinguishing the
sparks that fall into it.
1435.










ETB
L .1 ,9 ,3 .a .r ,1 1:- 1| 9 J” [04:10“?
. “I l i i ‘ A; I 4 . _,
I A
Luthl Ing’ l 39'7".“
Thehboiler attachments consist of a safety-valve, of the variety known as pop-valves, similar to
the one shown in Fig. 417, in the article BOILERS, STEAM; a glass water-gauge ; two gauge-cocks, the
lower one being placed at the proper working level ; steam-gauge; and whistle.
40
626 _ENGINES, STEAM, PORTABLE AND SEMI—PORTABLE.

In loCalities where straw is used as fuel, its value is generally very little ; but it is still desirable
to use it in an economical apparatus, for the purpose of reducing the weight and size of the boiler,
lessening the labor of firing, and reducing
the consumption of water (which often
has to be hauled from a distance) to a
minimum. In the engine under consid-
eration, the boiler is protected from loss
of heat by radiation, and the engine is
constructed with features which are be-
lieved by the maker to be favorable to
economical working. The cylinder is sur-
rounded by a casing which communicates
directly with the steam-space of the boil-
er. The steam-valve consists of two solid
pistons connected by a stem, and the
valve-chest is surrounded by a steam-
jacket, as shown in Figs. 1433 and 1434.
The valve is moved by an eccentric, which
is connected to a centrifugal governor on
the crank-shaft (see Fig. 1435), in such a
manner that its throw and angular ad-
vance are both varied with a variation in
the position of the governor~arms due to
a change of speed. The effect of this ar-
rangement is to change the point of cut-
off in accordance with a change of resist-
ance, always admitting steam at a pres-
sure nearly equal to that in the boiler, and
‘ _ .. a preserving the steam-lead constant at all
n ' _> ‘ points of cut-off.
. ‘ " " ' ' ' i’ Mr. Hoadley has kindly furnished some
“l
/////l it it
// . _ > A, , particulars of his experience with this en-
.__ m mm m M I \ if; " ’ I ' gine in California, when driving threshing
- mama... is i ' ‘ L. _.: - machines. He says: “The power required
“'ff;€:_*fl~‘~?§;r" w: to drive a large, 40-inch separator, with


feed apron and elevator to conduct the
unthreshed grain to the beating cylinder,
threshing and cleaning 800 to 1,200 sacks in a summer day (usually about 10 hours actual running
time), say 180 to 270 bushels per hour, varies from 12 to 30 indicated horse-power; these variations
being encountered in the same field, often in the same stack, on account of irregularity of feeding,


q . m
a, .
1 In ’9- ~_ , ._ L
. ) _ , r
1M" -
r I m
c
and the mean varying, in different fields and under varying conditions, from little above 12 to little
under 20 horse-power. Occasionally even more power is called for, 30, 40,45 horse-power—far
more than the boiler could maintain, but exerted by the engine for a few moments ; and still more
ENGINES, STEAM,
627
PORTABLE AND SEMI-PORTABLE.

rarely the long, heavy, tightly-
strained belt, unable to transmit
all the power the engine can sup-
ply and the separator demands, is
thrown off or pulled in two. The
boiler was found capable of sup-
plying all necessary steam, for a
mean of 20 horse-power, at the
rate of 30 lbs. of water per horse-
power per hour ;: '70 to 75 gallons
per hour. Very heavy threshing,
in good grain, was done with 46 to
60 gallons per hour (temperature
73° F., weight 8} lbs. per gallon);
and this rate of evaporation, yield-
ing 12 to 18 horse-power, was
maintained with great ease, with
most moderate firing. The quan-
tity of straw consumed is really
inconsiderable, being no more, in
general, than one-thirtieth to one-
fiftieth of the whole straw and
chaff ejected from the separator,
the grain being cut with the head-
er. One man finds it easy to do
firing as well as all the work of
an ‘engineer,’ and is less tired at
night than when firing with wood.”
Below will be foimd a summary
of the results obtained from a test
of one of these engines, of the
size referred to in the preceding
remarks: Diameter of cylinder, '71)
inches. Stroke of piston, 10 inch-
es. ‘Duration of trial, 2.} hours.
Average revolutions of engine per
minute, 236.7. Average net horse-
power, measured on friction-brake, 15.53.
Pounds of straw per net horse-power per heur, 22.64.
of straw burned per hour, 351.6.












of water evaporated per pound of straw, 1.84. .
SEMI-PORTABLE ENGINES, intended for places where light power is needed, usually have vertical





Pounds of water evaporated per hour, 648.4 Pounds
Pounds






628 EN (J’IN ES, STEAM, PORTABLE AN D SEMI—PORTABLE.
Dimenszons of Portable and Senzijpoa'table Engines.
Fitchbnrg .
No. DETAILS. J“ H°adl°y Steam Em (my Baxter
ompany. EU in 00. Iron Works.
3
1 Boiler horizontal or vertical . . . . . . . . . . . . . . . . . . . . . . . . Horizontal. Vertical. Horizontal Vertical
2 Length or height of boiler, ft . . . . . . . . . . . . . . . . . . . . . . . 9.125 7 11.5 4.25
3 Diameter of shell, in . . . . . . . . . . . . . . . . . . . . . . . . . .. -. . . . 27 36 30 82
4 Length of furnace, in . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . 36.5 30 diam 38 22 diam
5 Width “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23 24 . . . . - . . ..
6 Height “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 .875 30 36 23
7 Grate surface, sq. ft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.75 4.59 6.32 2.5
8 Thickness of shell, in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 .25 .25 .26
9 “ of crown-sheet, in . . . . . . . . . . . . . . . . . . . . . .. .25 .3125 .3125 .3125
10 “ of tube-heads. in . . . . . . . . . . . . . . . . . . . . . . .. .375 .3125 .375 .3125
1.1 Diameter of stay-bolts, in . . . . . . . . . . . . . . . . . . . . . . . . . . .875 .7 5 .875 . . . . . . . . . .
12 Distance between centres of stay-bolts, in . . . . . . . . . .. 4.5 10 5.5 . . . . . . . . . .
13 Number of tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 52 22 24
14 External diameter of tubes, in . . . . . . . . . . . . . . . . . . . . . . 2.25 2 .25 3 2
'15 Length of tubes, in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . r 54 78 18
16 Tube calorimeter, sq. ft . . . . . . . . . . . . . . . . . . . . . . . . . . . . .671 1.2 .929 .429
17 Heating surface in fire-box, sq. ft . . . . . . . . . . . . . . . . . .. 28 24.5 30 . . . . . . . . . ..
18 Total heating surface, sq. ft . . . . . . . . . . . . . . . . . . . . . . . . 108 156 120 58
19 Draught area through ash-pit doors, sq. it . . . . . . . . . 1 .28 .486 .59 . . . . . . . . . .
20 “ “ “ grate bars, sq. it . . . . . . . . . . . . . 1.92 2.43 . . . . . . . . . . . . . . . . . . ..
21 “ “ “ holes in furnace door, sq. in. .. 0 0 . . . . . . . . . . ~ . . . . . . . . ..
22 Cross'section of chimney, sq. ft . . . . . . . . . . . . . . . . . . . .. .545 .55 1.07 .349
23 Ratio of heating to grate surface . . . . . . . . . . . . . . . . . . . 18.8 34 19 .2
24 “ of tube calorimeter to grate surface . . . . . . . . . . . .117 .261 .169 .172
25 Water space, cub. ft . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . 11.2 18 . . . . . . . . . . 5.25
26 Steam “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7.5 11 . . . . . . . . .. 5.1
27 Diameter of feed-pipe, in . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 5 1 1 1
28 “ of blow-off pipe, in . . . _ . . . . . . . . . . . . . . . . . .. 1 1 1.5 .7 5
29 “ of steam-pipe, in . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 1 .5 1.5 . . . . . . . . . .
30 “ of safety-valve, in . . . . . . . . . . . . . . . . . . . . . . . . 2 ' 1.5 2 1
31 “ of exhaust-nozzle, in . . . . . . . . . . . . . . . . . . . . . . 2 2 . . . . . . . . . . .7 5
32 Engine horizontal or vertical . . . . . . . . . . . . . . . . . . . . . . . Horizontal. Vertical Horizontal. Vertical
33 “ attached to boiler or independent . . . . . . . . . .. Attached. [nd’t. Attached. Attached
34 Arrangement of cut-off . . . . . . . . . . . . . . . . . . . . . . . . . . .. Controlled by gov. Fixed Fixed. Fixed.
85 Diameter of c linder, in . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 .5 7 7 5
36 Length of stro e, in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7 10 5
87 Area of steam-port, sq. in.. .. . . . . . . . . . . . . . . . . . . . . . . . 3 .93 3.5 4 1
38 “ of exhaust-port, sq. in . . . . . . . . . . . . . . . . . . . . . . .. 4.18 3.5 7 .625 1.75
39 Clearance in per cent. of piston displacement . . . . . . .. 10 8 6.25 6.6
40 Kind of valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Piston. Piston Slide. Slide.
41 Diameter of valve-stem, in . . . . . . . . . . . . . . . . . . . . . . . .. . 625 .5 .151 .625
42 Stroke of valve, in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1;}, to 23,5 2.5 2.25 1
43 Diameter of piston-rod, in . . . . . . . . . . . . . . . . . . . . . . . . . . 1.25 1.375 1 .1875 .875
44 of exhaust-pipe, in . . . . . . . . . . . . . . . . . . . . . .. 2 x 2 2 1.5
45 “ of feed-pump, in . . . . . . . . . . . . . . . . . . . . . . . . . .875 1.75 1.125 1
46 Stroke “ “ “ . . . . . . . . . . . . . . . . . . . . . . . .. 10 8 10 1 .5
47 Number of fly-wheels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1 2 2
48 Diameter “ “ in . . . . . . . . . . . . . . . . . . . . . . .. . . . . 36 and 48 42 30 and 44 24 and 14
49 Face “ “ in . . . . . . . . . . - . . . . . . . . . . . . . . .. 9and 7 8 8.5and 10.5 6.5and5
50 Weight “ “ lbs . . . . . . . . . . . . . . . . . . . . . . . . .. 150 each. 650 120 and 350 48 and 160
51 Diameter of truck wheels, in . . . . . . . . . . . . . . . . . . . . . .. 42 and 54. . . . . . . . . 44 and 54 . . . . . . . . ..
52 Weight, light, lbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7505 5480 6000 - 8100
53 “ with water and coal, lbs . . . . . . . . . . . . . . . . . .. 8202 6600 6500 3400
54 Length, in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 84 144 42
55 Width, in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 48 72 42
56 Height, in . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 114 90 90
57 Working pressure, lbs. per sq. in . . . . . . . . . . . . . . . . . .. 120 60 . . . . . . . . . . 70
58 Revolutions per minute . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 220 175 240
59 Gut-off, from commencement of stroke, in . . . . . . . . .. 1 .7 4.3 . . . . . . . . . . 3.5
60 Effective horse-power . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 14.5 10








tubular boilers, and engines, either vertical or horizontal, attached to the casting on which the boiler
rests, but not connected to the boiler, except by the steam-pipe. In some instances, however, as in
the case of the Baxter engine, Fig. 1436, and some other varieties, the engine is attached to the
boiler. In the Baxter engine, the cylinder is secured in the steam-space of the boiler. The illustra-
tion of this well-known engine is so complete as to need no further description.
The semi-portable engine manufactured by the New York Safety Steam-Power Company, Fig.
1437, is a good example of the most ordinary variety of this class—an example that has been cop-
ied, with more or less success, by many other builders.
The Eclipse Sent-Portable Engine, Fig. 1438.—The frame or bed comprises the one cylinder-head,
guides for cross-head, and the two bearings for crank-shaft, all in one solid casting, the object being
to prevent the working parts of the engine from getting out of line. The shape of this bed is the
half of a hollow cylinder, except a small portion of one end, which is an entire hollow cylinder,
with its one end closed by the formation of a flange or cylinder-head, to which are bolted the cylin-
der and steam~chest, which is also one solid casting. All the exposed parts of the cylinder are
jacketed to prevent loss of heat by radiation. By this plan of constructing the bed-plate the work-
ing strain is directly through the centre of cylinder and pillow-blocks, thereby making a very strong
engine with little material. The heater is formed by a separate cast-iron pipe bolted near its one
end to the steam-cylinder, and supported at the other end by a bracket over the bed-plate. The
ENGINES, STEAM, PORTABLE AND SEMI-PORTABLE. 629

Dimensions of Portable and Semi-portable Engines (continued).

















Sample, New York 1 ,
Whitman 61 Gear, Scott Lane 8: 51121; Tool , Snyder’s ,
Burroll. a 00. Lida” Sgfzrs‘gf“ Bodley. Works. Em“? w" Mm" Little Giant. 2°“
Horizontal. Horizontal. Vertical. Vertical. Horizontal. 1 Vertical. Horizontal. Vertical 1
8.5 8.42 5.5 6.25 8.56 I 5 9.11 4 2
30 27.5 35 28 30 19 10 3
30 32 25 diam 30 diam 37 l 25.5diam. 16 15 diam 4
24 23.5 . . . . . . . . . . . . . . .. 17.75 . . . . . . . . . .. 27.5 . . . . . . . . .. 5
20 34 30 21 28.75 22 27 . . . . . . . . . . 6
5 5.29 3.4 4.9 4.56 3.48 3 .917 7
.25 .25 25 .3125 .25 .25 .25 .3125 8 .
.3125 .3125 .375 .375 .25 .3125 .25 .375 9
.3125 .375 .375 .375 .3155 3125 .3125 . . . . . . . . . . 10
'.625 .875 .875 .75 .75 ' . . . . . . . . .. .75 . . . . . . . . .. 11
6 5 9 9 6.75 x 5 5 . . . . . . . . .. 3.5 . . . . . . . . .. 12
15 27 37 l 64 30 5 40 31 2 13
3 2.5 2 2 2.25 2.75 . 1.5 1.0625 14
89 54 36 48 49.625 ,1 30 ;. 66 15
. .767 .661 1.144 .694 l 1.4 g .301 . . . . . . . . .. 16
10 20 17.2 19.2 24.3 i 13.9 i 18 . . . . . . . . .. 17
120v 85.7 69.5 153.1 5.1 I 82.6 86 14 , 18
.521 .563 .375 1.24 1.24 .66 1 .122 . 19
1.77 1.85 .792 2.45 1.86 1.16 1.56 .458 1, 20
4 4 2.2 0 0 0 g 21
417 .545 .785 .78 .327 .54 .087 .165 ,' 22
16.2 20.4 31.1 20.8 1 23.4 28.7 15.3 23
.127 .145 .194 .234 .152 .402 .1 , ........ .. ; 24
15.125 15.97 7.25 19.53 17.58 6.29 8 1‘ .902 g 25
8.75 7.27 5.2 2.68 6.67 3.78 4 .455 26
1 .75 .75 .75 1 .5 1 1 .375 I 27
1 1.5 1.5 1.25 1 1 .75 1 1 .375 1 28
1.25 1.5 1.25 1.25 2 1.25 1.75 ’ .5 29
1.25 1.5 1.5 2 1.5 2.5 ._ 1.25 5 g 30
1.5 1.125 1 1.5 .15 1.25 5 1.25 , .15 ,1 s1
Horizontal. Horizontal. Vertical Vertical. Horizontal . Herizontal. Horizontal. i Horizontal 32
Attached. Attached. lnd‘t. Ind‘t. Attached. Ind't. 1 Attached. i nd‘t. l 33
Adjustable. Fixed. ed. Fixed. Fixed Fixed. Controlled by gov. 2 Fixed 1 34
7 6.5 5 7 7 5 i 6 l 2.75 1 35
10 13 6 9 12 i 6 l 4.5 . 36
3.75 3 2.5 3.125 3.62 1.25 4.1 ‘ .475 37
’15 6.5 5 5 1 6.87 2 3 11 .159 i 38
9 9.23 19.5 6.86 1 9.07 3.86 11.75 .767 I 39
Slide. Slide. Slide. Slide. Slide. Slide. ; Piston Slide 1 40
.9375 .875 .5625 .75 .9375 .625 .5 .5 i 41
. . . . . . . .. 2.25 1.75 2.5 1.875 1.25 z 3.5 max 625 j 42
1.0625 1.25 .9375 2.125 , 1 .3125 1 875 f 43
1.5 2 1.5 , 1.8125 1.5 2 a . . . . . . . . .. i 44
2 .75 1.625 1.75 .75 1.7' 1.625 1 1 45
. . . . . . . . .. 13 2.5 l 12 1.5 1 . 546
1 1 1 1 2 1 1 2 47
48 42 26 42 40 8.: 15.9375 24 36 16 and 6 48
8.25 8 6.5 7. 7.875 854375 6. 6 1.75 and 2 49
320 370 200 565 i 345 and s5 1 22s 260 I 35 so
36 and 48 40 and 48 . . . . . . . . . . . . . . . 3.3125 and 41 ‘ . . . . . . . . . . 39 and 43 I . . . . . . . . . . 51
00 5225 2400 3542 i 5514 2700 4250 535 52
5560 6110 2900 4802 i 6600 3200 4850 630 53
126 127 55 77 148 129 50 54
69 78 36 42 79 .5 62.5 54 55
108 84 87 126 80.5 65.5 86 l 48 56
75 60 100 45 75 60 100 l 60 57
140 190 400 160 200 225 250 l 300 as
5.25 8.67 3.5 5.25 4.9 5.25 4.5 l 1.38 59
12 10 6 10 15 7 10 1 60 ',
E




water-pipe passes several times through this heater, and is of sufficient length to heat the water
nearly to the boiling-point before it enters the boiler. The boiler is of the locomotive pattern, with
the water-space extending entirely around the bottom, forming a mud drum. The boiler-front is
made of cast-iron in sections, and so-arranged that the draught in passing to the furnace passes over
the inside lining of the front, thereby keeping it cool and less liable to crack or burn out. The
machine can very easily be dismounted from the boiler and used as a stationary engine.
The Hasleins Engine, Fig. 1439, is selected as an example of a class of engines that have been
received with considerable favor, for powers of from 10 to 50 horse-power.
The Little Giant Engine, Fig. 1440.—The chief peculiarity of this machine, which is constructed
of from 1 horse-power up, is the boiler. The body is made of tubing 10 inches in diameter, and is
closed below with a cast-iron cap D, and above by the head A ; 29 water-tubes O, 15 inches long,
project into the fire. The couplings E and F are for connecting the feed and blow-off pipes. The
engine is of the ordinary horizontal form, with plain slide-valve.
Data of Portable and Semi-portable Engines—The particulars in the preceding table are both
interesting and valuable, as representing the practice of some of the most experienced engine-build-
ers in this country. The data have in all cases been furnished by the manufacturers, and are there
fore very reliable.
For works of reference, see ENGINES, HEAT. R. H. B.
630 ENGINES, “STEAM, STATIONARY (RECIPROCATING).

ENGINES, STEAM, STATIONARY (REGIPROGATIN G). Under this head are included engines
resting on foundations of brick or stone, to which they are secured by bolts. A stationary steam-
engine, in distinction from a portable or semi-portable engine, is unconnected with the boiler which
furnishes it with steam, with the exception of the steam-pipe connection; and it is not uncommon,
in the case of large stationary engines, for one manufacturer .to furnish the‘engine and another the
boiler. Such engines may be either condensing or non-condensing, but the majority of stationary
engines used in the United States do not have condensers.
A horizontal engine, with plain slide-valve, the speed being controlled by the action of the governor
on the throttle-valve, probably represents the most common type of stationary engine that has been
and is still used in this country. A good example of this form of engine, as built by Lane 82
Bodley, is shown in Figs. 1441 and 1442. At the side of the engine frame, in Fig. 1441, is the feed-
water heater, containing a coil of tubes through which the feed-water circulates, and around which
1441.



























F U
the exhaust-steam passes before being discharged into the atmosphere. The action of the governor
in such an engine is, of course, to reduce the pressure of the steam admitted into the cylinder, when-
ever the speed of the engine tends to increase in consequence of the reduction of the load; or, in
other words, to reduce the mean pressure in the cylinder by throttling or wiredrawing the steam.
NVliere the load on an engine is practically constant, there is no particular objection to this arrange“
ment, if the point of cut-off is so adjusted as to give the most economical result. But when the load
varies greatly, there will obviously be a frequent reduction in the boiler pressure before its admission
into the cylinder, with the consequent objection of subjecting the boiler to a considerable strain,
without the resulting advantages of the high pressure produced. For this reason, many manufac-
turers have designed what are known as automatic cut-off engines, in which the governor controls
the cut-ofi mechanism, and varies the mean pressure in the cylinder by changing the point of cut-off,
while the initial pressure of the steam is unaltered. As ordinarily constructed, such arrangements
are also more sensitive than the regulation by throttle, so that the variation of speed under varying
load is much less. This is not a necessary distinction between the two methods of regulation, but
it is one that usually obtains in practice. An automatic cut-off engine, also, is usually designed with
greater attention to the distribution of steam, and frequently with many improvements in workman-
ship and minor details; so that it is almost invariably more economical than an engine regulated by
throttle, under circumstances otherwise similar. It is doubtful if this is necessarily the case; that
is, whether if the latter form of engine were as carefully designed as the other, it would not be about
as economical. In practice, however, as already remarked, the automatic cut-off engine is generally
superior to its rival, both in regard to its capacity for controlling the speed, and in economical per-
formance. Until a recent period, the engine regulated by throttle possessed the advantages of cheap-
ness and simplicity; but, with improved methods of construction, it is believed that at present the
difference in first cost is almost the only advantage it can claim.
The best point of cut-off, under given conditions, has not been ascertained with precision; but for
average conditions, with from 60 to 80 lbs. steam-pressure, it is probably between one-third and one-
half stroke. The cutoff can be shortened considerably without much change in the economy; but,
of course, the shorter the cutoff, the larger will be the cylinder that is required for a given power ;
and the most economical engine, all things considered, is the one that gives the most power for about
the minimum number of pounds of steam per horse-power per hour. A series of experiments to
determine the best point of cut-off for various sizes of cylinders, and different steam-pressures and
piston-speeds, would be of immense advantage to all who are engaged in the designing and construc-
tion of engines. The most extensive tests ever conducted in relation to this matter were the U. S.
Government expansion experiments, which were undertaken to settle some controverted questions in
regard to the benefits to be derived from expansion. These experiments were never completed so
as to include a high range of steam-pressures and piston-speeds; but there were several series, under


ENGINES, STEAM, STATIONARY (RECIPROCATING). 631

certain conditions, that are quite complete. Their results have never before been made public; but,
by the kindness of Chief Engineer B. F. Isherwood, a summary of results has been made up from the
official records, and is given in the following table and in that on pages 684 and 685. They are
worthy of the careful attention of all who are interested in the subject. ‘
Principal Dimensions of Cylindm's used in U. 8. Expansion Experiments.










. Net Displace- .
NUMBER OF CYLINDER. Diameter. Stroke. Clearances. gimm’ °f ment of Piston Fmm’“
listen-rod. Pressure.
per Stroke.
Inches. Inches. Cubic Inches. Inches. Cubic Inches. Lbs. per Sq. In.
1 . . . . . . . . . . . . . . . . . . . . .. 12.26 20.08 291 2.5 ,272 5.1
2 . . . . . . . . . . . . . . . . . . . . . . 12 26 20.08 283 2,48 2,274 5.1
8 . . . . . . . . . . . . . . . . . . .. 12 4 20.08 200 2.48 2,828 5.1
4 . . . . . . . . . . . . . . . . . . . . . . 12 4 20.08 268 2.48 2,328 5.1
5 . . . . . . . . . . . . . . . . . . . . . . 13 77 20.08 499 2.5 2,892 3.1
6 . . . . . . . . . . . . . . . . . . . . . . 13 77 20.08 476 2.48 2.893 3.1
7 . . . . . . . . . . . . . . . . . . . . . . 15 66 20.08 1,350 2-5 3,769 3.0
8 . . . . . . . . . . . . . . . . . 15 67 20.08 1,279 2.48 3,776 3.0
9 . . . . . . . . . . . . . . . . . . . . . . 21 52 20.08 724 2.5 7.205 2.4
10 . . . . . . . . . . . . . . . . . . . . . . 21 52 20.08 1 066 2.48 7,206 2.4
11 ................. .. 30 02 20.08 2,619 5 13,818 1.5

The' experiments detailed in these tables were made, for the most part, at the Novelty Iron
Works in New York; and on their suspension, a supplementary series was conducted by the proprie-
tors of those works, for the purpose of obtaining data for the construction of stationary engines.
As the result of these experiments, a pamphlet was prepared, containing tables showing the various
sizes of engines required for different horse-powers under varying conditions, and the effect on the
. economy of varying those conditions. This pamphlet was not issued at the time of its preparation,
in consequence of the suspension of the works; but it has since been published, with additions,
under the title of “Tables and Diagrams relating to Non-condensing Engines and Boilers,” by W.
p P. Trowbridge (New York, 1872). The results of these tables are to be received, perhaps, with some
caution; but they are much more accurate than the estimates of power and economy usually given
in trade catalogues. A compilation made from this work, showing the sizes of engines especially
recommended by the Novelty Iron Works for various powers, is given in the table on page 686,
which will be found useful in practice.
The earliest form of cut-off introduced into this country, and in use on many engines at the pres-
ent time, is believed to have been the one known as Boyden’s cut-off, invented by that ingenious
mechanic Seth Boyden, and illustrated in Fig. 1443. There are two cut-off valves, B B, on the back
1448.






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a
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of the main valve A, sliding with it, and uncovering the openings for the admission of steam, until
the lug O', on either of them, strikes the piece D, when the admission of steam is instantly cut off.
The instant at which the cut-ofi occurs is determined by the position of the pieces D D, which is
regulated by a rod F, connected at one end with the lever E, and at the other end with the governor.
As the cut-off valve must close while the steam-valve is opening, it is evident that this cut-01f can
only operate up to half stroke.
Fig. 1444 represents the variable expansion-gear of Gonzenbaeh. It consists of an ordinary short
slide-valve and easing, with ports in the back, upon which another slide-valve and easing are im-
632‘
ENGINES, STEAM, STATIONARY (RECIPROCATING).

Summary of U. 8’. Expansion Experiments made at New York, 1865-1867.





















































H
g I PRESSURE IN POUNDS PER SQUARE INCH.
i=1
g D Fraction
uration
of Of Revohb ABOVE THE ATMOSPHERE.
9: . Stroke
9: Experi- tions
0 ment, com- Per M01111
h, in plated Minute Buck, Vacuum Mean Mean Mean
,2 Hours. at ' At End above ' Total. Indicated. N at.
g cut'om Initial. At Terminal. of zero-
? cut'om Cushion.
D
Z
1 2 3 4 5 6 7 8 9 10 11 12 13
1 72 .917 50.6 40.2 32.7 29.7 14.2 16 ' non-con- }53.5 37.5 82.4
2 96 .913 50.6 39.8 83.7 30 13 15.91 densing. 53.4 37.5 82.4
3 96 .863 50.8 25.5 22.8 17.7 —8.1 4.1 10.7 39 34.9 29.8
4 72 .862 51 28.9 18.3 13.9 -—8.9 3.6 11.1 36.3 32.7 27.6
5 72 .861 48.9 9.5 7.7 4.2 ——8.5 4.5 10.2 ' 23.3 18.8 13.7
6 72 .855 49.5 4.4 2.8 —0.1 -—8.4 3.9 10.7 18.2 14.3 9.2
7 48 .791 47.8 45.7 38.8 29 —7.9 2.7 12.1 57 54.3 49.2
8' 48 .7 49.3 45.2 38.7 24 —7 3.6 11.2 54.6 51 45.5
9 48 .6 48.1 44.8 37.8 18.7 -—7.3 2.5 12.3 51.8 48.8 43.7
10 20 .6 49.3 45.3 38.7 18.3 —7 3.3 11.4 51.3 48 42.9
11 48 .5 48.2 44.6 37.3 13.5 —7.6 2.5 12.2 47.4 ' 44.9 39.8
12 48 .409 48 44.5 38.1 9.2 —7.3 2.2 12.4 43.1 40.9 35.8
13 43 ,301 49,4 44,2 see 4.7 —8.4 2.1 12.5 87.5 85.4 80.3
14 48 .203 47.5 44.5 39.6 —0.2 -—-8.4 2.1 12.6 30.3 28.2 23.1
15 48 .292 51.2 44.6 39.5 4.5 —6.9 2.4 12.1 87.4 35 29.9
16 4S .2 50.7 44.8 39.3 —0.1 —7.5 2.4 12.4 30.8 28.4 23.3
17 48 .204 49.2 44.7 41.2 0.5 ——9.1 1.9 12.6 31.1 29.2 24.1
18 48 .054 46.7 44.3 40.6 —6.6 —8.6 2.4 12.4 16.8 14.4 9.3
19 48 .1 49 44.9 41.3 —4.7 —-9.4 1.9 12.7 21.5 19.6 14.5
20 72 .792 51.4 39. 28.3 20.2 16 16.7 non-con- 49.9 33.2 28.1
21 72 .746 50.9 39.5 30.6 19 13.7 16.31 (lensing. 148.9 82.6 29.5
22 72 .789 51.1 4.9 2.2 —2.2 —8.8 4.2 10.6 17.6 13.4 10.8
28 72 .739 50.2 9.9 6.8 1 —-8.4 4.2 10.6 22.4 18.2 15.1
24 72 .739 51 32.3 18.4 10-1 -—8-2 3.4 11.4 36.8 33.4 30.3
25 96 .738 51 25.1 21.1 12 *7-2 3.8 10.9 36.8 33 29.9
26 72 .603 52.1 31.8 18.8 6.8 —-7.4 3.9 10.9 34.9 31 27.9
27 72 .599 51.5 4.4 0.7 —4-8 —8-1 4 10.7 15.5 11.5 8.4
25 72 .589 52.1 25.2 19.4 6 ——6.5 4.4 10.4 33.3 28.9 25.8
29 72 .586 50.1 9.7 5.2 -—-2.8 —7.3 4.1 10.7 20.1 16 12.9
30 71 .501 49.7 24.9 17.8 2-3 -6-6 4 10.9 30.6 26.6 23.5
31 72 .5 49.9 9.7 6.4 —3.3 —7 4.2 10.6 19.2 15 11.9
32 72 '5 50.1 29.1 16.6 2.3 —6.8 4 10.9 30 26 22.9
33 72 .498 49.9 24.4 17.7 2-7 '—6-6 3.7 11.1 30 26.3 28.2
34 72 .487 50.2 4.3 0.8 ——5.9 -—7.7 8.9 10.7 14.3 10.4 7.8
35 72 .747 50.8 24.4 18.7 11.9 7.5 15.4 36.1 20.7 17.4
36 72 .499 50 37.5 31.1 13.1 7-9 15.3 non-con- 42.8 27.5 24.5
37 72 .243 50.4 56.8 52.4 10.6 8.5 15.4 (lensing. 45.6 80.2 27.2
38 72 .122 50.4 83.8 80.2 9.8 9 15.1 46.8 31.7 28.7
89 96 .479 50.0 24.7 19.6 5.8 -s.1 4 10.6 91.2 27.2 24.2
40 72 .475 50.4 4 1.4 -5 -9.2 9.9 11 14.9 11.1 8.1
41 72 .475 50.7 25.9 18.1 4.9 -s.0 9.5 11.2 90.7 27.2 24.2
42 31 .474 51.1 25.7 17.9 4.9 —8.9 3.1 11.3 30.2 27.1 24.1
43 55 .472 51.3 8.8 5.7 —2.7 —-8.4 4.1 11 19 14.9 11.9
44 5' .472 51.5 9.1 6.2 —2.2 .3 3.9 10.8 19 15.1 12.1
45 72 .471 49.9 8.8 5.7 —2.7 —8.7 4 10.7 18.6 14.6 11.6
46 72 .329 49.5 23.9 19.2 0.4 -—8.1 ' 4.3 10.4 26.2 21.9 18.9
47 72 .319 49.6 32.8 22.1 3 21 17 { non-con- 30.3 13.3 10.9
48 29 .292 48.6 37.7 29 3.8 22 16.5 densing. 132.5 16 13.6
49 43 .187 53.2 35 28.3 —4 4.2 5.4 9.4 24.1 18.7 16.3
50 96 .256 51.5 23.5 16.9 —5.1 0.5 4 10.7 20.5 16.5 14.1
51 24 .255 51.4 23.4 17.6 —4.3 —1 3.6 11 20.6 17 14.6
52 72 .25 49.9 8.1 4.2 ——8.4 —-3.7 4 10.7 12.6 8.6 6.2
53 63 .25 53.1 23.7 17.8 ——4.9 -—9.3 4.4 10.4 22.2 17.8 15.4
54 72 .247 48 3.4 0.4 —-9.2 —4.5 4 10.8 10.3 6.3 8.9
55 72.1 .239 50.6 21.4 16.7 -5.2 -—0.5 4.3 10.4 19.8 15.5 13.1
56 72 .237 49.7 7.6 4.1 ~8.4 —3.2 4.2 10.6 12.3 8.1 5.7
57 96 l .237 51 21.4 16.7 —-5.2 —0.8 4.4 10.4 19.9 15.5 13.1
58 72 _ .228 50.9 2.7 -—0.1 -—9.7 -—5.2 3.6 11.1 9.5 5.9 3.5
59 72 .123 51.2 —0.6 -—2.7 ——10.5 —8.7 3.4 11.4 6.7 3.3 1.8
60 96 .116 51.6 15.7 12.7 —7.8 --7.4 3.7 11 12.6 8.9 7.4
61 72 .11 49.9 4.7 2.4 —-9.7 —7.7 3.5 11.2 8.4 4.9 3.4


ENGINES, STEAM, STATIONARY (REGIPROCATING).
683

Swnmary of U. 8. Expansion Experiments made at New York, 1865—1867 (continued).





























H
POUNDS 01" WATER TEMPERATURE, IN 0
HOBBE'POWR' PER 1101112.. rmazuum'r DEGREES. Z;
M 5
Height 5
of Number 9"
Barometer of F5
Per Per 2 _ 0
Per Net _ in Cylmder. {a
1600. 11111108966- Net. 116m. Air. Feed. Effie Inches. .5
power. ' 15
power power. a
lfi
D
Z
14 15 16 17 18 19 20 21 22 23 24 i 25
l
81.01 21.73 18.8 45.7 65.3 75.3 58.8 56.7 72.3 29.9 1 1
81.01 21.77 18.82 45.9 65.3 75.7 50.2 52.8 72.4 29.92 ‘ 2
22.78 20.37 17.88 46.3 51.7 60.6 87.8 86.6 58.2 80.2 3
21.3 19.18 16.17 46 51 60.5 37.8 88.1 66.8 29.96 2 5 4
18.08 10.57 7.7 59.1 73.1 101 48.7 40.4 70.6 29.82 5
10.87 8.13 5.23 64.2 82.2 128 49.9 48.1 71.8 29.81 ; 6
82.01 80.48 27.63 86.6 38.4 42.4 67.8 69 78.6 80.2 ‘ 7
31.65 29.56 26.87 85 37.5 42 76.6 69 86.8 80.08 i 6
29.01 27.61 24.72 33.8 35.5 89.7 62.8 68.1 78.8 30.01 9
29.72 27.79 24.86 34.4 86.8 41.1 73.4 69 85.7 29.94 3 g 10
26.8 25.4 22.54 33 34.9 39.2 61.2 67.8 77.9 29.94 11
24.35 28.12 20.22 33 84.8 39.8 65 67.5 78 29.78 5 12
21.75 20.54 17.59 31.9 33.9 39.5 64.8 65.8 82.5 29.73 i 13
16.92 15.77 12.9 38.3 85.6 43.6 57.4 64.3 75.6 29.94 ,1 14
22.52 21.05 17.99 60.2 62.2 87.7 56.5 56 80.1 29.62 f 15
18.87 16.92 13.88 30.9 33.7 40.9 50.9 60.3 79.2 30.32 5 16
18.11 17 14.04 80.6 32.5 89.5 61.9 63 80.8 29.62 4 i 17
9.19 7.89 5.11 88.5 44.9 69.2 59.8 62.5 81.3 80.07 § 18
12.35 11.27 8.35 33.6 36.8 49.9 55.7 62.6 79.1 29.74 i; 19
3
37 .47 24.92 21 .1 38.9 58.5 69.1 78.4 68.8 80 .7 80 .25 5 20
36.35 24.21 21.95 38.2 57.4 63.4 71.8 60.2 80.6 30.5 21
13.14 10.04 7.67 53.8 69.9 91.9 50.1 50.8 66.5 30.06 22
16.44 13.38 11.08 49.1 60.5 72.5 51.6 52.6 67 30.18 2‘3
27.4 24.86 22.56 40 44 48.5 49.9 57.2 67.4 30.2 24
27.41 24.56 22.27 41.6 46.4 51.1 60.8 59 72.9 30.09 25
26.55 23.57 21.22 38.5 43.4 48.8 28.8 40.6 57.4 30.03 26
11.66 8.67 6.32 50.5 63.2 93.5 48 51.3 68.2 29.93 ~.
25.83 21.98 19.62 39 44.8 50.3 48-6 45.3 69.5 80.16 6 28
14.72 11.69 9.45 46.3 58.1 72 49.1 47.5 68.5 30.2 29
22.23 19.29 17.07 89.4 45.3 51.1 26.6 38.6 57.5 30.27 30
14.01 10.98 8.66 46.8 50.1 75.6 34.9 48.7 61.2 30.14 31
21.96 19.05 16.76 39.1 45.1 51.3 25.5 35.1 60.1 80.18 32
21.87 19.18 16.92 39.6 45.2 51.3 24.6 35.1 54.2 80.09 33
10.49 7.62 5.36 49.2 67.8 96.5 47.4 51.3 68.9 29.8 84
84.89 20.02 16.66 42 73.1 66.6 77.7 72.3 69.6 90.21 95
40.76 26.2 23.32 86.6 57 64.1 76.4 73.2 88.8 29.95 .7 36
43.73 28.99 26.07 82.5 48.9 54.3 70.8 75 80.8 30.07 37
44.86 30.37 27.53 81.2 46 50.9 65 72.7 76 30.15 38
80.13 26.24 23.37 39.2 45 50.4 29.3 85 68.7 30.03 89
14.36 10.68 7.78 46.4 62.4 85.9 85.4 36.7 63.9 80.81 40
29.67 26.27 23.42 88 42.9 48.3 39.3 85.7 68.7 30.08 41
29.43 26.37 28.46 38 42.8 47.5 39.2 35.8 66.8 29.48 8 42
18.54 14.56 11.65 44.2 56 69.8 83 86 66.1 30.65 43
18:68 14.81 11.88 43.9 55.2 68.7 37.9 36 66.9 29.85 44
17.73 13.9 11.04 44.4 56.5 71.6 33.7 36.5 59.5 80.09 45
24.66 20.64 17.85 40.2 4‘2 55.4 35.1 86.7 63.7 29.85 46
54.75 ' 23.97 19.69 25 57.2 69.7 43.9 49.2 60.2 30.41 47
57.37 28.2 24.03 25 50.9 59.8 41.8 48 58.9 29.61 9 48
46.65 36.24 31.56 33.5 48.2 49.5 34.5 69 86.4 80.5 49
38.45 30.98 26.45 28.4 35.8 41.2 56.4 52.9 77.9 29.91 50
38.53 31.74 27.31 29.5 35.8 41.6 55 55 75.4 29.73 51
22.74 15.55 .27 38.3 48.4 66.8 50.1 52.6 73.6 29.94 52
43.04 84.44 29.78 30.6 38.2 44.1 69.8 63.2 82.8 80.18 53
17.96 10.98 6.81 34.7 57.3 91.6 48.4 52.1 69.3 30.18 10 54
86.48 28.66 24.14 30.7 39 46.5 64.5 69.6 74.2 30.03 55
22.24 14.61 10.81 32.8 49.9 70.8 63.8 70 70.8 30.19 56
36.92 28.68 24.3 30 38.6 45.6 68.1 67.6 74.2 30.16 57
17.61 10.95 6.49 34.8 54.9 94.4 72 71.3 78.9 29.93 58
24.02 11.78 6.45 32.7 66.5 122 75.4 69.8 81.1 29.99 59
45.83 81.87 26.62 30.3 48 51.5 72.4 71.5 79.9 80 11 60
29.26 17.06 11.84 32.5 55.7 80.8 66.6 70.1 75.3 29.9 61













634
ENGINES, STEAM, STATIONARY (RECIPROCATING).













































































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I ENGINES, STEAM, STATIONARY (RECIPROCATING).
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posed. The ordinary valve is worked in the usual manner; but the travel of the supplementary
valve may be lengthened or shortened, so as to cut oil2 the steam at any part of the stroke. A IS the
common valve, and F the valve-chest. B is the supplementary
valve, which is a solid block with two perforations, which, when
opposite the ports in the cover E admit steam from the sup-
plementary valve-chest K. The starting-handle is connected
with the shaft 9, upon which a lever is fixed, and so connected
by links with the extremities of the eccentric-rods D and (I,
that when one eccentric-gab is in gear with the pin e' upon
the valve-lever, the other shall be disengaged. In the figure
the engine is in gear for going ahead, and the reversing eccen-
tric-rod D is disengaged from the ordinary valve, and in gear
with the supplementary valve, by means of a second gab f,
which receives a pin upon the expansion-valve lever G. In
this lever there is a long slot, in which a pin G, fixed on the
valve-link H, may be moved to a greater or less distance from
the centre of the expansion-valve shaft, by means of a handle
t; and the eifective length of the valve-lever being thus varied,
the travel of the valve receives a corresponding variation. The
expansion-valve thus receives the reversing motion while the
slide-valve is receiving the forward motion.
Fig. 1445 represents the variable expansion gear of Mayer.
It consists of an ordinary valve, with the addition of perfo-
rations through the top and bottom faces, each of which is
covered by a supplementary valve upon the back of the first,
consiSting of two solid blocks, into which a valve-rod is screwed,
having a right-handed screw where it penetrates the one block,
and a left-handed screw where it penetrates the other; so that
the blocks will be set closer or farther apart, according to the
direction in which the rod is turned. The ordinary valve re-
ceives its motion in the usual way, and the expansion-valve is
moved by means of a pin attached to the piston-rod, which
works in a slotted lever, to which the expansion-valve rod-is
attached. The motion of the two valves is, therefore, at right
angles, and the expansion-valve is about one-fourth of a revo,
lution in advance of the steam-valve. In Fig. 1445, A is the
steam-valve; B, the expansion-valve; T, the valve-rod, with
right- and left-handed screw; G, a wheel attached to the valve-
rod, over which a pitch-chain passes, by means of which the
valve-rod is turned, and the blocks are altered so as to give
the requisite amount of expansion; D, the valve-shaft, and
CE, the valve-lever; F, the pin attached to the piston-rod.
In all cases in which the motion of the expansion-valve is the
same as that of the piston, the Slide-valve must be provided
with lap.
The general arrangement of Watt’s and Phelps’s variable
cut-01f is represented in Figs. 1446 to 1448. The following
description is from the Scientific American for Jan. 21, 1871 :
“The controlling power of the governor is transmitted through
the connecting-rod A, Fig. 1446, the sector B, the connecting-
rod C, and the toothed sector 1), to a cylindrical rack turned
on the sleeve E. The sleeve Eis feathered'to the Shaft F,
and slides longitudinally when acted upon by the parts A, B,
C, and D, while turning with the Shaft F, the rotation of the
latter being accomplished through a system of gearing from
the crank-shaft. The sleeve E also carries two cams, shown
in section in Fig. 1448, at G, which, turning under the toes of
tappet-arms H, Figs. 1446 and 1448, attached to the vertical
stems I, Fig. 1448, of the cut-ofi valves J, Figs. 1447 and 1448,
raise the valves and let them fall abruptly at the proper point
of cut-01f to which they are adjusted. The cut-oif valves are
of the ‘grid ’ variety, and Slide on the backs of the principal













636 ENGINES, STEAM, STATIONARY (RECIPROCATI N G) .
I

valves, which latter are actuated in the usual way from an eccentric on the crank-shaft. The sliding
of the sleeve E on the shaft F causes the cams to let the cut-ofl“ valves fall earlier or later in the
stroke, according as varying velocity affects the governor. If the belt breaks, or any other derange-
ment of the governor occurs, the travel of the Sleeve, being a little more than the length of the cam,
allows the toes of the tappet-arms to drop off the cam on to the shaft, closing the cut-off valve ports
and instantly stopping the engine. In starting the engine, a lever and cam, K, Figs. 1446 and 1448,
is used to raise the cut-01f valve and open the port. The motion of the engine then, operating on
I 1446.


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the governor, draws the sleeve along so as to bring the cams under the tappets, and thenceforward
the gear works automatically. It will be seen that this gear can be made to cut oif from zero to
any part of the stroke desired.”
The principle of Sickels’s cut-off is to detach the main valve from the stem at any desired point,
and close it by springs or weights. As originally applied to puppet-valves, the valVe was detached
from the stem as it was rising, and allowed to seat by its own weight, being cushioned in its descent
by a dash-pot containing air or water. In later forms of the cut-off, the valve was detached from the
stem by a sliding or vibrating arm having motion coincident with that of the piston, so that the cut-
ofi was effected at any desired point of the stroke. Many other cut-offs have been constructed on
this principle, prominent among which is the Corliss cut-0E.
The original form of the Corliss engine, on its introduction, is Shown in the full-page illustration.
- 1447. -
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Its chief peculiarities lie in the method of working the valves, and in controlling the valve motion
by the governor, so as to regulate the motion of the engine and use the steam to the best advantage
under all conditions. The valves employed are rotary sliding valves. Their motion is similar to that
of the common plug-cock or faucet, but the form adopted is such that they fill a portion only of the
cylindrical cavities in which they are mounted. The connection of each valve to its spindle or stem
is such that it is free ,to. adapt itself to all conditions. It works freely and yet remains tight, pre-
cisely like an ordinary slide-valve. There are two steam-valves and two exhaust-valves, all worked
ENGINES, STEAM, STATIONARY (RECIPROCATING). 637

independently, yet by simple mechanism. The exhaust-valves are held open during the whole stroke
of the piston, but the steam-valves are opened at the proper time and allowed to shut automatically
at some point in the early part of the stroke. The precise point at which this shutting of the steam-

1449.












II
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\

valve occurs, and consequently the volume of steam admitted into the cylinder in any given stroke,
depends on the position of the governor-balls, and the speed of the engine is regulated by the varia-
tions in the quantity of steam thus admitted.
The invention of the Corliss engine marks an era in steam-engine construction, and the history of
its introduction bears a striking analogy to that of the pumping engine invented by Watt. Like

4_J

















Watt, Mr. Corliss was contented to displace the older forms of engines by his more perfect device,
and take in payment the value of a portion of the coal saved; and like Watt, he soon found that
proprietors of mills were unwilling to render him true accounts of the saving effected. Now that
638 ENGINES, STEAM, STATIONARY (RECIPROCATING).
ii

the patent has expired, the Corliss engine, or some modification, has been largely adopted as the
standard design by engine-builders in this country; and it has displaced almost all other styles
abroad. No device for regulating the distribution of the steam in stationary engines has been in-
vented that successfully supersedes the Corliss wrist-motion; and this attachment, together with
improved construction and increased pis-
ton-speed, has increased the efficiency of
the stationary engine quite as much as 100
‘ per cent. '
The action of the Corliss wrist-motion
is plainly illustrated in Fig. 1449, which
shows the valves at one end of the cylin-
der, in the two extreme and middle posi-.
tions. The Sketch will repay study, show-
ing in an admirable manner the effect of
the peculiar mode of connection. The ex-
ample is from the Corliss engine as built
by Watts, Campbell & Co. ;' and Fig. 1450
is from a working drawing of one of their
cylinders, Showing valve-motion, and de-
vice for tripping the steam-valves by the
rod connected to the governor. The valve,
when tripped, is closed eitherby weights
or springs, dash-pots being ordinarily used
in connection with weights. Fig. 1451 rep-
resents the main bearing used by Watts,
Campbell & Co. on their engines; the top
and bottom brasses not being fitted, but having a little play allowed, any adjustment required being
made on the centre brasses, as Shown.
One of the finest examples of the Corliss engine ever constructed was the pair of engines
by Mr. Corliss for use in Machinery Hall at the Centennial Exhibition.
in a full-page engraving, and the principal dimensions are appended:



built
These engines are illustrated
Diameter of cylinder, inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Stroke of piston, feet.. 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Diameter of air-pump, inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Stroke “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Diameter of piston-rod (steel), inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.25
Length of beam between centres, feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Depth of beam at centres, feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
“(eight of beam, lbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22,000
Length of crank-shaft, feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Diameter of “ inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
“ “ “ bearings, inches . . . . . . . . . . . . . . . . . . . . . . . . ._ . . . . . . . . . . . 18
Length “ “ “ “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Diameter of fly-wheel at pitch-line, feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.7
Pitch of teeth, inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.183
Face of fly-wheel, inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Weight of fiy-wheel, lbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112,000
Number of teeth in fiy-wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Diameterof pinion at pitch-line, feet.. . . .. . . .. .. . . . . .. . . .. .. . . 9.9
Weight of pinion, lbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17,000
Revolutions of engines per minute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Total revolutions during the Exhibition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,355,300
These engines were let by Mr. Corliss, during the Exhibition, for $77,000, the Board of Finance
building the boiler-house, making the necessary excavations, and furnishing the fuel—thus bringing
the whole cost up'to $142,374. According to a statement made by Mr. Corliss, his expenditures
were in excess of his receipts by $40,788.10.
The Harm's-Corliss Engine—Fig. 1452 represents a modified form of the Corlissengine largely
used in the United States. Fig. 1453 is a longitudinal section of the cylinder, steam-chest, and ex-
haust-passage, with cross-sections of the valves. At A is shown one steam-port open, and at B~ the
other steam-port closed; 0 is one exhaust open full area of port, and D the other exhaust closed.
It will be noticed in Fig. 1453 that the piston has traveled a very small part of the stroke while the
steam- and exhaust-valves .4 and C have been opening the full area of their ports. Fig. 1454 shows
the method of packing the valve-stems so as to obviate the use of stuffing-boxes and to cause the
thrust-collar to bear directly against the bonnet E. D is the valve-stem, on which is shrunk the
collar F, which fits in a recess a of the bonnet. The opposing faces are finely scraped so that they
approximate very closely, and are packed by the steam itself acting outward on an area equal to the
section of the valve-stem D. In the hollow space in the bonnet all drip enters, and is carried off by
the pipes G, which extend from bonnet to bonnet. (See “ Economy Trials of an Automatic Engine,”
by John W. Hill, M. E., in Van .Nostmnd’s Engineering Magazine, December, 187 7.)
The Wheelock Engine—An elevation of this engine, and a modification of the Corliss valve-gear
patented by Jerome Wheelock, are shown in Figs. 1455 and 1456. In this arrangement there
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ENGINES, STEAM, STATIONARY (RECIPROCATING). 639

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640 ENGINES, STEAM, STATIONARY (RECIPROCATING).

is only one port in each end of the cylinder, an independent cut-off valve regulating the admission
of steam. The cut-off valve is of such a form as to allow a double admission and cut-ofli', which is
an arrangement very favorable to the distribution for a given port area. The valves rotate on hard-
ened steel bushings, which are adjustable endwise, and no stuffing-boxes are used.
The lWight Automatic Cut-of Engine is the invention of Mr. William \V right of N cwburgh, N. Y.
Fig. 1457 shows the steam side with the cut-off valve gear, and Fig. 1458 the exhaust side: There
7.
145
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are four gridiron slide-valves, which work vertically in chests cast with the cylinder, two upon
one side of the cylinder being for induction, or cut-off, and two upon the opposite side being for
eduction, or exhaust steam. All valve-motion is derived from a single eccentric, which operates
levers, so arranged as to give a quick movement to valves when opening, and also a very slow
movement when valves are lapped. The location of all these valve-faces close to the bore of the cylin-
der insures the least possible amount of clearances. The steam valve-stems are fastened in yokes,
which have at their lower ends plungers fitted in dash-pots, the same acting as guides; the yokes are
operated by steel slides fitted through the end of hollow rocker-arms, and which act upon the swing-
ing toes held in the yokes, the said slides having a diagonal slot in which works a feather, this feath-
1458.


er being made on a rod which has a longitudinal movement through the hollow rocker-arm, and to
which the governor is connected. By this longitudinal motion, and through the diagonal feather and
slot, the slide is automatically set, to engage more or less with the swinging toes, and which gives
the valve its proper lift, and liberates upOn the chord of the arc. The governor itself stands on a
bracket or shelf, east on the slide part of the bed-plate, and the governor-rod is connected to a lever,
which is fastened to the governor-shaft. This same shaft carries two forked arms which take hold
ENGINES, STEAM, STATIONARY (RECIPROCATING). 641

of the small rods running through the hollow rocker-shafts. The rods are enlarged at their other
ends, Where they carry the adjustable slides mentioned before. The advantages in this arrangement
of valves and valvagearing are easy accessibility to each valve, by the simple removal of a bonnet,
and that the whole of the valve-gear and governor connections is outside of the steam-chests, where
any derangement can be at once seen and rectified.
The Greene Engine, manufactured by the Providence Steam-Engine Company, of Providence, R. L,





is represented in Figs. 1459, 1460, and 1461. There are four flat slide-valves, one (as shown on the
left of Fig. 1460) at each end on the top to admit the steam, and one (as shown on the right of Fig.
1460) to let out the exhaust. The working of the valve-gear is as follows: The induction-valves
are connected with the rock-lever shafts A, Fig. 1459, by arms B working in slots in the valve-
stems 0. Below the rock-levers D D is a sliding bar E, receiving a reciprocating motion from an
eccentric on the main shaft. Behind the sliding bar is a gauge-bar F, Fig. 1461, connected with the
governor, which bar receives an up-and-down motion from a corresponding movement of the governor-
balls. The adjustable tappets G G, Fig. 1461, in the sliding bar, are kept up in contact with the
gauge-bar F, and are made to move up and down in unison with it by the springs H H. As the
1460. O O
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sliding bar moves in the direction of the arrow, one of the tappets is brought in contact with
the inner face of the toe on the rock-lever, causing it to turn on its axis, thereby opening the
steam-valve at one end of the cylinder, the other tappet meanwhile passing under the other rock-
lever without moving it. The toe and tappet are so beveled that the tappet will be forced down
against the action of this spring until it has passed by the toe, when the spring causes it to fly up to
its original position, ready to open the induction-valve at the opposite end. As a result of this
motion, the two tappets always open the steam-valves at the same period; but, the tappet moving in
a straight line while the toe describes the arc of a circle, the tappet will pass by, liberating the toe,
41
642 ENGINES, STEAM, STATIONARY (RECIPROOATING).

which is brought back to its original position by a weight I, Fig. 1459, the steam-pressure on the
valve-stem thus closing the valve and cutting off the steam. This liberation will take place sooner
or later, according to the elevation of the tappets; that is, the lower the tappets are the sooner the
toes will be liberated, and vice 'versa ,' and so, by sim-
1462' ply elevating or depressing the gauge-bar .F, Fig. 1461,
the period of closing the valves can be changed while
the period of opening them remains the same. The
adjustment of the gauge-bar is effected by the gov-
ernor, and the steam is cut off sooner or later accord-
ing to the amount of load. The exhaust-valves J, Fig.
1459, which lie in the bottom of the cylinder, are con-
nected at their outer ends by parallel rods K, which
are tied together by a cross-bar on the inside. The
exhaust rock-shaft arm L is a jaw, as shown in Fig.
1459, just under the cylinder. One side of this jaw
comes in contact with a lug it! on the cross-bar, and
moves both the exhaust-valves simultaneously, open-
ing one and closing the other. While the exhaust-
eccentric is taking up the lost motion between the sides
of the jaw, the exhaust-valves remain at rest. The
other side of the jaw coming in contact with the cross-
bar, the exhaust-valves receive a reverse motion. The
lug on the cross-bar is so shaped that it receives no
blow from the jaw L, but takes a gradually acceler-
ated motion.
Wintei"s Cut-ofl; Fig. 1462.—-In this the shaft D
receives a rotary motion from the eccentric-rod, the
D . latter being pivoted to a lever between its points of
attachment to the eccentric and shaft D. A cam on
this revolving shaft acts on the lifter F to open the valve, through the piece E; the duration of con-
tact, or the point of cut-ofi, being regulated by the position of the piece E, which can be adjusted
as shown.
The Brown Engine, Fig. 1463.—The cut-off mechanism in this engine is the invention of Mr. C. H.
Brown of Fitchhurg, Mass. Its arrangement is as follows: The cut gear-wheels shown impart a
rotary motion to the shaft A, which operates the governor and communicates rotary motion to the
valve-shaft B. Between these two shafts is a friction device 0, which is so constructed as to permit
the shaft B to be operated by hand independently of the shaft A. Upon the shaft B are the eccen-
trics, the ends of the straps of which connect with the horizontal lever E; and the latter extends
into the square slot in the slide-spindle guide to the catch of the tongue. As the shaft B revolves,
the lever B reciprocates vertically in the said square slot. The valve-stem is attached to the guide
F, and in the slot shown in the latter is pivoted a tongue G. The upper end of this tongue has a
projecting catch upon it, and beneath this catch stands the end of the arm E. The induction-valve,
is closed when at the bottom of its travel, and the weight of the valve and stem and the pressure of
the steam (acting on an area equal to the area of the valve-stem) are, combined, always acting to




















keep the valve at the bottom of its travel, that is, in its normal position ; and there it remains until
lifted for the admission of steam. The manner of efiecting this admission is as follows: The end
of the arm E, acting against the catch on the upper end of the tongue in the slot, lifts the valve and
ENGINES, STEAM, STATIONARY (RECIPROCATING).
643



. iiil ..llHdllLh





v644 ENGINES, STEAM, STATIONARY (RECIPROOATING).

holds it open so long as the tongue is not tripped. The instant, however, that the latter action takes
place, the valve, from its weight and the action of the steam upon the area above mentioned, closes,
the movement being cushioned after the valve is completely closed by means of the small dash-pot
shown beneath. By regulating the eccentrics, the valve may be given any desired amount of lead,
and the duration of the period of admission may be varied by tripping the tongue before referred to ;
and this is accomplished by the engine governor in the following manner: The governor communi-
cates with the rod N. Upon this red, and immediately behind the induction-valve spindle-guide I",
1465.
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is an arm standing vertically, and carrying a pin H standing horizontally. The tongue, which at
one end acts as a catch to the eccentric arm at the other end, protrudes from the back of the slide-
spindle guide, and stands directly beneath the above-mentioned pin; so that, when the rod E lifts
(through the medium of the tongue-catch) the induction-valve, the latter continues to lift until the
tail of the catch G, coming in contact with the pin H, trips the tongue, and the valve instantly
closes, returning to its normal position. The exhaust~valves lie horizontally, and are operated as
follows : Upon the shaft D are the disks J, which are provided with cam-grooves. The rocker-arm
K carries a friction-roller extending into the cam-groove, the upper arm L being attached to the
exhaust-valve spindle. To compensate for the circular motion of the arm and the vertical move-
ment of the valve-spindle, the connection between the two is made by the eye of the spindle, contain-
ing a slot, in which is fitted a sliding die to which the pin of the arm is fitted. To regulate the
amount of compression, it is merely necessary to adjust the position of the disk. The governor is
of the ordinary fly-belt type, and is inclosed in a polished casing. ' j
The Buckeye Automatic Out-of Engine is represented in elevation in Fig. 1464. Fig. 1465 is a
section of the cylinder, and Fig. 1465 A shows the construction of the governor used. By reference to
Fig. 1465, the main valve is seen to be a hollow box, taking steam on the inside, balanced by the
exclusion of steam-pressure from the back, and driven in the usual way by an eccentric fast on the
shaft. Steam is admitted from the inside of the valve to the cylinder and exhausted into the chest,
the reverse of the ordinary operation. The, valves are fitted up under steam at 80 lbs., insuring
freedom from leakage or cutting from distortion caused by expansion under heat or pressure. The
cut-ofi mechanism consists of a light cut-off valve, working on the inner face of the main valve, the
stem passing out through the hollow steel stem of the main valve, and being driven from a loose
eccentric on the shaft with a special motion derived from the compound rock-shaft. This loose
eccentric is controlled by the governor, Fig. 1465 A, which is a shell fast upon the shaft and revolving'
with it. In this shell are pivoted two weighted levers, the outer ends of which are linked to the
1465 A. m h
[1 ,f 1466.



}









flange on the elongated sleeve of the loose eccentric. The centrifugal force developed in the weights
throws them outward, and two well-tempered steel coil springs furnish the centripetal force. The
system being coupled is independent of gravity, and it is readily seen that the speed determines the
position of the weighted arms, which in turn determines the angular advance of the eccentric and the
consequent point of cut-off, the range of which is, we are informed, from zero to nearly three»-
quarters of the stroke. '
ENGINES, STEAM, STATIONARY (RECIPROCATING). 645

Fig. 1466 represents an indicator diagram taken from one end of the cylinder of a Buckeye auto-
matic cut-off engine; and the following data, in relation to the engine from which the diagram was
taken, were furnished by the Buckeye Engine Company:
Scale of indicator spring, 31;; diameter of cylinder, 18 inches; length of stroke, 36 inches; clear-
ance in cylinder and ports at ,each end of cylinder, 2 per cent. of piston displacement per stroke;
diameter of piston-rod, 3 inches; extreme length of cylinder between heads, 44% inches; length of
steam-port, 17 inches; width of steam-port, 11} inch; revolutions of engine per minute, 98.
Data obtained from the Diagram—Draw perpendiculars to the atmospheric line a b, at the extrem-
14.7
ities of the diagrams, produce them below this line a distance equal to z 0.37 inch, and draw
the perfect vacuum Zine ccl parallel to ab. Next select a point near one end of the diagram, a
little before release, and another point near the other end, a little beyond exhaust closure. In the
- diagram under consideration, these points are taken at 0.95 of the forward and return strokes re-
spectively. The length of the diagram is 3.73 inches, so that c n is 0.95 x 3.73 = 3.54 inches, as is
also di. Erect perpendiculars to ed at the points at and i, and draw also the perpendicular k j
through f, at which point cut-of has apparently occurred. Make cl equal to 0.02 x 3.73 : 0.07
inch, and draw the perpendicular Z m, thus increasing the length of the diagram in accordance with
the clearance. By measuring the lengths of these several perpendiculars, the absolute pressures in
pounds per square inch in the cylinder at the various points can be determined : Initial pressure, c c,
2.44 x 40 = 97.6; pressure at point of cut-elf, k f, 2.28 x 40 : 91.2; pressure at 0.95 of forward
stroke, n g, 0.42 x 40 = 16.8; pressure at 0.95 of return stroke, i h, 0.44 x 40 = 17.6. The diagram
_ _ _ c k 0.63 lic 0.70
also gives the cut-OE 1n fractlon of stroke, —— = -— = 0.169, and the real cut-off, * = —- = 0.188.
c d 3.73 Zcl 3.80
An annular planimcter was used for calculating the diagram, Fig. 1466. This gave the total mean
_ _ area efgbdc 4.33
pressure 1n pounds per square inch : -———-—--— x 40 : —’_— x 40 = 46.43; the mean total back
areaehbdc 1.60 ad 3-‘3 _ area efgbh
pressure = —-——-—d—-—— x 0: 5-7—3 x 40 = 17.16; the mean effective pressure =-—-—T— x
c c
40 :46.43 — 17.16 = 29.27 i; and the fraction of the total work that is due to expansion:
areafgbdk _ 2.84 __ 0656
areaefgbdc 433
The only other data needed in the calculations can be obtained from table I. in the article
EXPANSION 0F STEAM AND GASES. Thus, from column 10, by interpolation, it is found that the
weight of a cubic foot of steam at a pressure of 16.8 lbs. per square inch, represented on the dia-
gram by n g, is 0.04304 1b.; that the weight at a pressure of 17.6 lbs. per square inch, represented
by ih, is 0.04496 lb. ; and by column 6, that the latent heat in a pound of steam, at a pressure of
16.8 lbs. per square inch, is 961.3 units.
Calculations from the foregoing Data—The effective area of piston is 250.94 square inches.
The horse-power of the engine, for 1 lb. per square inch mean pressure, and one revolution per
250.94 x 6
and the indicfiehohorse-power, 0.045626 x 98 x 29.27 = 130.87. The displacement of the piston in
cubic feet per revolution, to 0.95 stroke, including clearance, is w x 0.99 : 10.35128; so
hat the number of pounds of steam used per hour, as calculated bylpgessure near termination of
forward stroke, is 10.35128 x 98 x 60 x 0.04304 2 2,620. The steam saved in cushion space in
cubic feet per revolution, including clearance, is x 0.09 : 0.94103; so that the number
minute, is = 0.045626; so that the total horse-power is 0.045626 x 98 x 46.43 = 207.6 ;
of pounds of steam saved per hour by cushion is 0.94103 x 98 x 60 x 0.04496 = 249. The number of
207.6 x 0.656 x 1,9s0,coo
772 X 961.3 _
363. From this it appears that the least possible consumption of steam in pounds per hour by the
pounds of steam condensed per hour for the total work due to expansion is

a e 2 engine = 2,734; corresponding to a consumption, in pounds per hour, of 667—6 : 13.17 per total
2 734 ~ 0
9
lno 877 = 20.89 per indicated horse-power. The condensing surface in the engine
0 -
under consideration is approximately 28.7 square feet, viz.: in cylinder sides, 17.5; in cylinder
heads and 2 sides of piston, 7.1; in piston-rod, 2.4; in ports, 1.7. Internal condensation may be
assumed at the rate of 20 lbs. per square foot of condensing surface per hour, making the total
condensation 28.7 x 20: 574 lbs. This will give, as the probable number of pounds of steam
308

horse-power, and
3
consumed by the engine per hour, 2,734 x 574 =- 3,308 ; or at the rate, in pounds per hour, of 5,07- 6
3 308
= 15.93 per total horse-power, and = 25.28 per indicated horse-power. Dividing the water
used per horse-power per hour by 9, it appears that the number of pounds of coal used per hour, in
a boiler capable of evaporating 9 lbs. of water per pound of coal, is: least possible, per total horse-
power, 1.46; prohable, per total horse-power, 1.77 ; least possible, per indicated horse-power, 2.32;
. probable, per indicated horse-power, 2.81.
646 ENGINES, STEAM, STATIONARY (RECIPROOATING).

The BMW Engine, Fig. 1467.—-In short-stroke engines of this class, where the ordinary three-ported
valve is generally in use, the main slide-valve is, in its action and in the 'lToi-m of its face side, simi~
lar to that of the well-known slide-valve, with the exception that its ends are lengthened to admit of
I steam-ports or openings being formed outside of the
1467- valve proper. These openings or ports are, on the
face side of the valve, rectilinear and rectangular to
the motion of the valve; that. is, they run parallel
with the ports in the cylinder, or disposed square
across the valve-seat. 0n the back of this main
valve, where the cut-oif valve is fitted, these steam-
ports are oblique, and at opposite angles to each
other, the use of which will be presently explained.
The cut-ofi valve is a sector of a cylinder, with its
ends cut off obliquely in opposite directions, so that
the extremities or acting ends of the cut-ofi valve
respectively conform to the lines of a right- and left-
hand screw of high pitch, corresponding to the obli-
quity or angle of the steam-ports in the back of the
main slide-valve. This cut-off valve just described




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1468.



is fitted into a semi-cylindrical recess in the back of
the main slide-valve, and between the spiral open-
ings. It is operated lengthwise by a separate eccen-
tric, to which it is attached in the usual manner, ex»
cepting that it has a swivel-joint to permit its partial
rotation. A portion of the valve-stem is made square,
or sometimes arranged with a “feather,” and at this
place on the valve-stem is fitted a sector, engaging a rack on the lower portion of the governor-spin-
dle, so that as the governor rises or falls the cut-off valve will partly rotate. Thus the cut-off valve is
moved lengthwise by the eccentric, and at the same time has imparted to it by the governor an ad-
justing motion on its axis. As a consequence of the radial motion, imparted by the governor, and
the spiral form of the steam-ports and acting ends of the cut-ofi valve, the distance between the
openings and the ends of the valve is varied withinvery wide limits, the eifect being to cut oil’ the
steam at any point of the stroke. The arrangement may be compared to a right- and left~hand













screw, formed by the shape of the valve ends and the openings. This device is extremely sensitive
to the action of the governor, as the rectilinear motion of the eccentric causes the radial or axial
movement of the cut-off valve to be efl’ected by the least possible amount of force. This compound
motion also highly favors the perfection and durability of the service. In engines of a larger size,
where it is desirable to have short steam-passages, the main and cut-off valves are divided through
the centre, and each end carried outward (Fig. 1468) to act on the steam-ports of the cylinder at its
ends, as is usual with the ordinary slide-valves as commonly constructed.
The engine illustrated in Fig. 1469 possesses no striking peculiarities, but is a good example of
that class of stationary engines in which the cut-off is regulated by hand. There are two cut—ofl’


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THE PORTER—ALLEN STEAM-ENGIN E.
ENGINES, STEAM, STATIONARY (RECIPROCATING). 647

valves on the back of the main valve, actuated by an eccentric having motion coincident with that of
the piston; and they are connected to the valve-stem by right- and left-hand screws respectively, so
that they can be brought closer together or the reverse by the movement of the hand-wheel shown
inthe fi re.
Fig. {2:79 represents a good form of engine built by Messrs. Prescott, Scott 8t (30., of San Francisco.
This engine is provided with the O’Neil valve-motion and cut-ofi'. It will be noticed that the admis-
sion of live steam to and the emission of exhaust steam from the steam-cylinder are accomplished
by four double-shell valves A, resting on the seats B, with which both the outer and inner rings have
1470.


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two points of contact. Four circular openings are thus secured when the valves are raised from
their seats. The valves are raised by the bar 0, carried by the rollers D D, and worked backward
and forward by an eccentric on the crank-shaft of the engine. This bar, which has four inclined
planes cut in its upper surface, passes through the slotted valve-stems, which are furnished each with
loose rollers G G. The reciprocating motion of the bar raises these rollers alternately to the top of
the incline, and with them the segments J that suspend the valves. Thus at the proper points in
the stroke of the engine the four valves are opened. They are reseated by the springs E E, while
the dash-pots F F cushion the valves at the instant of cut-ofi. The cut-off is operated by the rod
H connected to the arms I, which are attached to the segments J, which are oscillated in the
slotted valve-stems by an independent eccentric, and supported by the rollers G G. When by their
oscillation these segments pass the rollers, they lose their support, and with stems and valves sud-
denly drop. The cut-off is adjusted to any point of the stroke by a hand-wheel K, and by the right-
and left-hand screws on the cut-ofi bar, which change the relative position of the segments. By a
simple device the whole can be controlled automatically by Scott 8: Eckart’s governor. The advan-
tages claimed for the O‘Neil patents are: 1. The lift of the valves is so light that but little power is
required to open them. 2. They drop instantly when the cut-off acts, and reseat themselves without
pounding. 3. The construction throughout is the simplest possible. 4. Adjustment can be made
while the engine is in motion. 5. A much better duty is secured.
The Porter-Allen Engine possesses many features of unusual interest, and occupies a deservedly
high place among automatic cut-off engines. This engine is illustrated in a full-page engraving and
in Figs. 1471 to 1479. All of these figures are reduced from working drawings furnished by Mr.
Porter, who gives the followingr description of the engine: '
“This belongs to the class of automatic variable expansion engines ; but it is distinguished in this,
that all its' valves have positive movements, which are given by a single eccentric. The valves may
be operated with any degree of rapidity, and these engines are designed for a high rate of piston
speed, with moderate length of stroke. In this system of valve-gear, invented by John F. Allen, the
eccentric is set on the shaft in the same position with the crank, or so as to reach the termination of
its throw when the crank arrives at the line of centres; and the connection of the link is such that
its central point, on which it is pivoted, has a motion coincident with that of the piston of the engine
—-the angular vibration of the line connecting the pivot of the link and the centre of the eccentric
coinciding in time and degree with that of the connectingrod. The openings for admission of steam
at the opposite ends of the cylinder are given, as in the ordinary link, by the tip of the link, in oppo-
site directions alternately, beyond the lead-lines, but these are separated by a distance equal to the
throw of the eccentric. This link is thus merely a right-angled lever, pivoted on a vibrating ful_
~ erum, with one arm of variable length. When the two arms are of equal length, the cut-off takes
648' ENGINES, STEAM, STATIONARY (RECIPROOATING).

place at the mid-stroke. The release of the steam is, in an engine intended to run in one direction
only, efiected by separate valves, driven from a fixed point at the extremity of the link. The motion
of the link at this point is favorable to the proper action of the valves. The release and compression
take place at points near to the terminations of the forward and return strokes, and the movements
HORIZONTAL 5 ECTI O H
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given to the valves in opening and closing are rapid. The governor adjusts automatically the posi-
tion of the block from which the admission valves are driven, according to the resistance to be over-
come, from the mid-point, at which the port is not opened except by the lead given to the valves, to
the point at which the steam is cut off at five-eighths of the stroke. Lead is given to the valves by
j ENGiNEs, STEAM, STATIONARY (RECIPROGATING). e49

adjusting their position on the stem. The admission of the full pressure of steam, and maintaining
it up to the point of cut-off, and its proper discharge, require, in a high-speed engine, corresponding
amplitude in the openings. Each valve in these engines opens four passages simultaneously for
admission and release. ' The openings made by the admission valves are further enlarged, and at the
same time the idle travel of the valves while their ports are covered is reduced, both in a consider-
able degree, by the employment of the wrist-motion first applied to slide-valves by Mr. Corliss. The



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motion of the exhaust-valves, which is invariable, gives the full opening when the piston reaches the
termination of the stroke, and maintains this (their further motions and return merely enlarging two
passages while contracting the other two) until near the end of the return stroke, when the port is
650 ENGINES, STEAM, STATIONARY (RECIPROCATING).

closed by an accelerated movement. The admission valves move in equilibrium between opposite
parallel seats. Those at the back of the valve are made adjustable, to compensate for wear, in a
manner fully shown in the sectional views of the cylinder. The exhaust-valves work under the
pressure in the cylinder. Their seats, the cover of the chamber, and the discharge nozzle are formed
in one piece. The principle which is regarded as fundamental in the working of these engines is the
action of the reciprocating parts, the piston, cross~head, and connecting-rod, in absorbing the force
of the steam at the commencement of each stroke, and giving it out to the crank at its termination.
This is founded on the fact that the force required to impart and to arrest the motion of these parts







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is greatest when the piston is on the line of centres, and diminishes from this point to the mid-stroke
(as illustrated on page 434). The force varies directly as the weight of the parts, and as the length
of the stroke, and as the square of the revolutions per minute; and, while in an engine moving at a
moderate speed, with reciprocating parts of ordinary weight. it is quite small, by employing heavy
reciprocating parts and high speed, with strokes of moderate length, it becomes easy to absorb, in
putting them in motion at the commencement of each stroke, a large proportion of the force of the
steam, which is then given out by them to the crank at its termination. This action is 'of importance
chiefly in engines working expansively, tending to equalize throughout the stroke the pressure on
the crank which otherwise would be almost wholly applied to it at and near the commencement.
These parts of the engine thus perform an office similar to that of the fiy-wheel, and, besides partially
1479.











MMN BEARlNB
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relieving the crank from the impact of the steam on the centres, contribute largely to the remarkable
uniformity of rotation which this engine exhibits, and which the small fly-wheels employed would
alone seem insufficient to maintain.” ,
The following summary of tests of portable and stationary engines will give a good idea of the
best as well as of average results obtained in modern practice. It is proper to remark, with regard
to the tests of English portable engines, that they were made with “ racing engines,” that is, engines
constructed especially for the trial, and much superior to the commercial engines furnished by the
same makers, and that the firing was done by trained experts; while the other engines were of the
ordinary commercial type, and generally managed by attendants of only average skill.


L___--____ ____._...1







Summary of Tests of Portable and Stationary Engines.


POUNDS OF WATER




































g p 5 t f PRESSURE IN Poms POUNDS or COAL '
g 0 Duration 12:1fisgggslgn' Revel“- 8.17.0; PER SQUARE INGH. HORSE'POWER' PER HOUR. PER HOUR. egg
‘7 E NAME. °-f. 1480111381 am from cm?“ ABOVE THE Ratio of Per 1.," Pet Net "5 E3
o @ Tm, PET mum t ATMOSPHERE. Mean .. . Per Net Indlcated ' o a
a g in Houm Manta. of Stroke, _-____._____ Efiecflve‘ Inmcated... Net. Net to Indxoated Horwpoweh Hem Horse- 2 a
m Diameter.I Stroke. in Inc]... In Boiler. 11mm. Indiwwd- Howpower- PM“ WW- I:
I I
PORTABLE ENGINES AT ROYAL AGnIcIILTImAL SOOIETY’s Snow, CARDIFF, 1872.
1 Marshall, Sons & CO . . . . . . . . . . . . . . . . . 4.15 8.5 12 168.8 2.04 80 77 81.25 18 14.8 .797 28.89 80.11 2.62 8.8 1
2 Clayton &Shuttleworth . . . . . . . . . . . .. 4.84 9 12 118.9 2.76 80 71.5 82.1 14.8‘ .... .. 27.49 2.84 2
8 E. Hayes . . . . . . . . . . . . . . . . . . . . . . . . .. 1.48 9 12 122.6 7.2 68 41.6 19.6 9.1 7.6 .828 22.27 26.85 8.8 10 8
4 Davey, Paxman & Co . . . . . . . . . . . . . . .. 4.88 8.6 12 114.2 1.92 80 78' 88.9 18.6 11.9 .878 28.44 82.4 2.85 8.25 4
5 Brown & May _ . . . . . . . . . . . . . . . . . . . . . 4.18 7.8 12 189.1 2.7 80.5 78 29.2 10.1 9.8 .92 27.55 29.97 8.02 8.29 5
6 Tasker & Sons . . . . . . . . . . . . . . . . . . . . . . 2.75 9. 12 128.7 4.56 59.5 52 29 .72 14 12.4 .88 34.16 88.66 4.86 4.94 6
7 Reading Iron Works.. . . . . . . . . . . . . . . . 4.98 8.5 14 188.2 8.52 80.8 72.5 87 20.8 16.8 .826 28.59 28.49 2.88 2.88 7
8 E. R. & F. Turner . . . . . . . . . . . . . . . . .. 8.87 9 12 179.2 8.84 . 80 77.2 86.24 24.8 20 .808 24.07 29.85 2.9 8.68 8
9 Barrows&8tewart.................. 2.5 9.5 18 116.1 7.8 7 47.2 25.8 18.8 11.6 .84 84.64 41.1 4.87 5.78 9
10 Ashby, Jeffery & Luke . . . . . . . . . . . . . . 1.8 9.5 14 125 2.24 80 68 20.4 12.6 8.8 .66 40.56 61.86 4.94 7.47 ' 10
PORTABLE ENGINES AT CINCINNATI INDUSTRIAL ExrosITION, 1875.
11 Lane&.BOd1ey . . . . . . . . . . . . . . . 5 7 12 203.8 72.8 . . . . .. 18.5 15.1 .816 40.81 50.01 6.56 8.04 11
12 Woodsum Machine CO . . . . . . . . . . . . . .. 5 6.5 12.5 208.8 75.8 12.5 10.5 .886 71.46 85.52 11.48 18.67 12
13 Robinson Machine Works . . . . . . . . . . .. 5 615 12 205.8 74.6 . . . . . .. 15 11.6 .775 58.18 68.7 9.22 11.9 13
14 Gaar, Scott & CO . . . . . . . . . . . . . . . . . . .. 5- 6.5 18 188.4 74.4 15.4 12.8 .808 64.6 68.01 8.89 11.07 14
15 Browne118z Kielmeier Manufact‘g Co. 5 6 10 197.6 74.2 . . . . . . . 9.9 ‘ 8.3 .845 61 .1 72.8 9.99 11.82, 15
, PORTABLE ENGINE AT CENTENNIAL EXPOBITION, 1876.
16 J. C. Hoadley 00.... . . . . . . . . . . . . . . .. 6.08 14.6 I 20 | 126 | 8.58 | 120 | 117.6 | 88.49 | 80.8 | 72.7 | .905 | 25.61 I 28.27 | 8.85 | 8.69 16
PORTABLE ENGINES AT NEW YOIIK STATE AGRICULTURAL FAIR, 1877.
17 Porter Manufacturing 00., limited. . . . 4 7 10 141.8 72.4 . . . . . . 7.4 . . . . . . 70.16 . 18.02 17
18 “ “ “ “ 4 7 10 188.4 79.1 . . . . .. 9.8 . . . . .. 43.22 .. 5.54 18
19 “ “ “ “ 2 5.5 7 190.9 918 5.2 . . . . .. 61.61 .. 10.06 19
20 Fishkill Landing Machine CO . . . . . . . .. 4 6 6 288.6 119.1 . . . . .. 8.9 . .. 45.1 .. 6.88 20
21 Mansfield Machine Works . . . . . . . . . . .. 4 7 10 162.9 59 .9 . . . . . . 7.4 . . . . . . 76.61 . . 12.69 ' 21
22 G. Westinghouse & C0 . . . . . . . . . . . . . . . 4 6 7 260.1 69.9 . . . . . . 8 . . . . . . 68.78 . . 9.02 22
28 E. M. Birdsall & CO . . . . . . . . . . . . . . . .. 4 7 9 204.4 65.8 . 8.8 .. . . . . . . 68.81 . . 10.04 28
24 Watertown Steam-Engine CO . . . . . . . . 4 6 12 184.4 89.6 . . . . .. 7.1 .. . . . . . . 62.45 . . 9.28 24
25 Frick&(.‘o. . . . . . . . . . . . . . . . . . 4 7 10 178.5 89.5 . . . . .. 6.8 . . . . . .. 70.82 . . 9.68 25
26 Oneida Iron Works . . . . . . . . . . . . . . . . . . 4 7 10 182.8 85.8 . . . . . . 6. 6 . . . . . . . . . . 76.18 . 10.51 26
27 B.W.Payne&80ns . . . . . . . . . . . 2 4 5 227.1 91.1 . . . . .. 3.3 . . . . .. 61.26 . 7.66 27
AUTOMATIC CUT-OFF ENGINES AT AMERICAN INsTITIITn EXHIBITION, 1869.
28 Babcock &Wilcox . . . . . . . . . . . . . . . . . .. 8 16 42 I 60.8 I 7.94 81.7 76.1 81.06 I 78.8 68.7 .872 25.48 29.28 I I 28
29 Harris-Corliss . . . . . . . . . . . . . . . . . . . . .. 8 16.1 42 60.8 9 .49 80.5 70.9 29.78 76.6 69.1 .901 26.06 28.88 . . .. 29
AUTOMATIC CUT-OFF ENGINns AT CINCINNATI INDUSTRIAL EXPOBITION, 1874.
80 Harris-Corliss . . . . . . . . . . . . . . . . . . . . . .. 8 16.1 48 I 60.1 I 9.94 70.5 I 69.8 25.88 74.9 65.9 .879 29.18 88.19 I I 80
81 John Cooper Engine Manui'act’g Co. . 8 16 80 84.8 7.88 70.8 70.1 29.18 74.9 66.6 .889 80.56 88.95 .. .. 81
SLIDE-VALVE ENGINES, REGULATED BY THROTTLE AT CINCINNATI lNnusTnIAI. EXPOSITION, 1875.
82 Buckeye . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 10 14 209.8 8.75 79 58.4 85.15 41 86.7 .896 48.15 I 48.16 I .. . I 82
88 Lane&Bodley....., . . . . . . . . . . . . . . .. 5 9 15.6 194.7 18.57 77.9 58.9 89.06 88.1 88.8 .885 44.86 50.67 88







'(QMILVOOIMIOHH) AHVNOILVIS 51111219. 8511615115»
199
652 ENGINES, STEAM, STATIONARY (ROTARY).

Although it has been impossible in the preceding notice to include all the prominent forms of
automatic expansion-gear in the market, the distinguishing characteristics of nearly all important
varieties have been given. In the accompanying table will be found the principal dimensions of
some of the best varieties of stationary engines, which will doubtless be of interest and value to
steam-engine users and manufacturers:
\
Dzmenscons of Horizontal Stationary Engines.

















No. DETAILS. Erie City Iron Works. Jerome Wheelock. Lane & Bodley.
1 Arrangement of cut-off. . . . . . . . . . . . . . . . . . . . . Fixed Controlled by gov. Fixed
2 Diameter of cylinder, inches . . . . . . . . . . . . . . .. 14 14 9
i kengtl} of stroke, inches . . . . . . . . . . . . . . . . . . .. q? 42 15.6
rea o steam- ort, square inches . . . . . . . . . .. .- 5 - \ 6.2
5 Area of exhausIt-port, square inches . . . . . . . . . 14.625 in; (both m One/j; 11.5
6 Clearance in per cent. of piston displacement. 5.56 .98 6.25
7 Kind of valve . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . Slide Modified Corliss Slide
8 Diameter of valve-stem, inches . . . . . . . . . . . . . . 1 .25 . " .9?
9 Stroke of valve, inches. . . . . . . . .. . . . . . . . . . .. 4.125 10, on 8-inch crank 2.25
10 Diameter of piston-rod, inches. . . . . . . . . . . . . . 2 125 2.5 1 .563
11 “ of steam-pipe, inches . . . . . . . . . . . . . 3 .5 4.5 8
12 “ of exhaust-pipe, inches . . . . . . . . . . . . 5 6 4
18 “ of fly-wheel, inches . . . . . . . . . . . . . .. " 110 144 79
14 Face of fly—wheel, inches . . . . . . . . . . . . . . . . . . .. 7 24 4.5
15 Weight of fly-wheel, lbs . . . . . . . . . . . . . . . . . . . . 2,500 10.000 1,882
16 Length of engine, inches . . . . . . . . . . . . . . . . . . . . 128 264 110
17 Width of engine, inches . . . . . . . . . . . . . . . . . . . . . 24 120 25
18 Height of engine, inches . . . . . . . . . . . . . . . . . . .. 82 120 . 28 .-
19 Weight of engine, lbs . . . . . . . . . . . . . . . . . . . . . . . 9,500 20,000 8,592
20 Working pressure, lbs. per square inch . . . . . . . . . . . . .. 60 61
21 Revolutions per minute . . . . . . . . . . . . . . . . . . . . 125 75 200
22 Cut-off from commencement of stroke, inches . . . . . . . . . . . . . . . . 10 .9
28 Effective horse-power . . . . . . . . . . . . . . . . . . . . . . . 50 75 84
No. DETAILS. 8,6822%?“ Porter—Allen. was, Campbell a CO.
1 Arrangement of cut-off . . . . . . . . . . . . . . . . . . . . . Controlled by gov. Controlled by gov. Controlled by gov.
2 Diameter of cylinder, inches . . . . . . . . . . . . . . .. 26 18 20
8 Length of stroke, inches . . . . . . . . . . . . . . . . . . .. 48 8O 48
4 Area of steam-port, square inches . . . . . . . . . .. 85 17.5 20.81
5 Area of exhaust-port, square inches . . . . . . . . . 40.5 24.75 81.5
6 Clearance in per cent. of piston displacement. 2.7 6.67 2.08
7 Kind of valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 slides s . Allen Corliss ,
. . team, 2, each i '
8 Diameter of valve-stems, inches... . . . . . . . . .. 2 and 1 { exhaust, 1. ’ } 1.875
9 Stroke of valve, inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10 Diameter of piston-rod,_inches . . . . . . . . . . . . . . 8.75 2.625 . . . . . . . .
11 “ of steam-pipe, inches . . . . . . . . . . . . . . 7 7 5
12 “ of exhaust-pipe, inches . . . . . . . . . . . . 8 7 6.5
18 “ of fly-wheel, inches . . . . . . . . . . . . . .. 216 108 192
14 Face of fly-wheel, inches . . . . . . . . . . . . . . . . . . .. 82 80 80
15 Weight of fly-wheel, lbs . . . . . . . . . . . . ._ . . . . . . . 28,000 5,000 20,000
16 Length of engine, inches . . . . . . . . . . . . . . . . . . .. 854 287 845
17 Width of engine, inches . . . . . . . . . . . . . . . . . . . . 156 110 144
18 Height of engine, inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
19 Weight of engine, lbs . . . . . . . . . . . . . . . . . . . . . . . 56,000 17,000 26,915
20 Working pressure, lbs. per square inch . . . . . . . . . . . . . . 80 80
21 Revolutions per minute . . . . . . . . . . . . . . . . . . .. 65 140 65
22 Cut-off from commencement of stroke, inches: . . . . . . . . 7 .5 12
28 Effective horse-power . . . . . . . . . . . . . . . . . . . . . . 225 200 165 ,
For works of reference see ENGINES, HEAT. R. H. B.
ENGINES, STEAM, STATIONARY (ROTARY).——It has been said that there is scarcely an engi-
neer of much experience who has not designed at least one rotary engine and one balanced valve,
both of which he has afterward abandoned. The number and variety of rotary engines that have
been invented is already so great that but few novelties are introduced at present, most modern de-
signs being reinventions. The life of the average rotary engine is so short before it passes into the
scrap heap, that but little is known of their performance and capabilities, even when new. An
' account of almost the only test of rotary engines that was ever published may be found in figmen-
ing for "J an. 1, 1875 ; and although this test has been very severely criticised as being too favorable
to the engines, the results are not very flattering to the different designers—the best engine, entirely
new, and supplied with unlimited oil, requiring 108 lbs. of steam per net horse-power per hour, and
the .least economical 398. The ephemeral character of rotary engines is due generally, even when
they are well constructed, to mechanical difliculties, which may be summed up in the statement that,
so far, no means have been found of packing the pistons so that they shall work without excessive
friction, be steam-tight, and durable. There have been numerous projects for overcoming these dif-
ficulties, and the literature of the subject is extensive. At present, however, these projects have not
assumed tangible form. The reader is referred to Galloway’s “History of the Steam-Engine ” and
Reuleaux’s “ Kinematics of Machinery,” for descriptions and illustrations of nearly every form of
rotary engine that has been invented. .
It seems proper, however, to call attention to one example, which diifers in many important
ENGINES, STEAM,



respects from the general form of rotary engine, the differences being of such a character as to
overcome many of the practical difficulties ordinarily experienced. Reference is made to Dudgeon’s
engine, illustrated in Figs. 1480 to 1482,
and described as follows in Engineering
for Nov. 14, 1878:
“The principle of the engine and its
mode of action will be readily under-
stood if we consider the action of a pair
of spur-wheels, such as is shown in Fig.
1481. When such a pair of wheels are
working, it is evident that the space in-
closed between any given teeth, when
Situated on the line of centres, is very
small, but that as the wheels rotate this
space gradually enlarges in capacity, un-
til it becomes thrown open on one side
by the teeth falling out of gear. If,
then, steam or any other elastic fluid
was admitted into the space between
any given teeth (escape at the end of the
teeth being prevented) when on the line
of centres, it would, as the wheels ro-
tated, be expanded, and ultimately be
discharged into the air, or into the casing
in which the wheels might be inclosed.
Practically, this is what occurs in Mr.
Dudgeon’s rotary engine. Referring to
the annexed illustrations, it will be seen
that the engine consists of a simple cast-
iron casing, formed in two parts, the
lower part being fitted with bearings for
a couple of shafts, on which a pair of
spur-wheels are mounted. These wheels
are turned up true on their edges, and
those parts of them which are in gear
work between a. couple of true surfaces,
one of these surfaces being formed at the
end of a circular plug inserted through


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654 ENGINES, STEAM, UNUSUAL FORMS OF.

one side of the casing, while the other surface is that of a disk cast in one piece with an eccentric
axis, which passes through a loose piece in the side of the casing, as shown in Fig. 148]. It will be
seen that the eccentric axis is hollow, and that it communicates with a passage east in the disk itself,
the opening of this passage being situated so that it can discharge steam between the teeth which
are in gear. By turning the eccentric axis of the disk, the admission-port can evidently be varied
in position, so as to discharge the steam either directly on the line of centres, or within a certain
distance above or below that line. We are thus provided with a most simple reversing arrangement;
or, if desired, the movement of the disk may be so regulated that the admission-port is always on
one side (either above or below) of the line of centres, in which case the movement will vary the
degree of expansion. This latter arrangement is that adopted in the particular engine illustrated,
a lever on the axis of the eccentric disk being connected to the governor, so that the rise or fall of
the governor balls brings the admission-port in the disk-closer to or farther from the line of centres.
“ It will be noticed, on reference to Fig. 1481, that the teeth there shown are of somewhat pecu-
liar form, and that they are different on the two wheels. The fact is that they are ordinary epicy-
cloidal teeth, except that those on one wheel are minus the points, and those on the other minus
most of the roots or inner portions of the teeth lying within the pitch-circle. The original object
of Mr. Dudgeon in adopting this arrangement, instead of having complete epicycloidal teeth on each
wheel, was to reduce the spaces inclosed between the teeth when on the line of centres; or, in other
words, to reduce clearance. A further investigation of the subject has Shown, however, that these
spaces are filled by the cushioning of the exhaust-steam; for, the casing in which the wheels revolve
being filled with this steam, each pair of wheels as they come into gear inclose a portion, and as the
rotation of the wheels continues, the steam thus inclosed is compressed, until by the time it arrives
at the line of centres it has reached nearly or quite boiler pressure. This being the case, Mr. Dud-
geon is now using complete epicycloidal teeth on both wheels.
“ The engine now working at Millwall has been running over three years without repairs of any
kind. Even the side wear has proved to be imperceptible. The engine, it will be noticed, has not a
single packed joint about it.”
See works for reference under ENGINES, HEAT. R. H. B.
ENGINES, STEAM, UNUSUAL FORMS OF. A great amount of inventive ingenuity has been
expended in the devising of steam motors which, either from their uniqueness of form or peculiar
mode of action, cannot be strictly classified with ordinary accepted types. Regarding these machines
generally, it may be stated that their employment is rarely more than ephemeral, or at best becomes
restricted to special uses. The reader interested in them will find scores depicted and described in
the United States Patent Office Reports. Among the few instances which exist of engines of this
class proving of superior value and utility may be noted those of the W'illan and Brotherhood forms
of three-cylinder machine. These will be found described under ENGINES, STEAM, MARINE, as their
chief application is to the propulsion of small vessels. The engines which are represented in the
following engravings have all given reasonably fair results under trial, and they will serve to exhibit
some of the best of the unusual forms.
The Allen Double-Expansion Engine—Fig. 1483 shows a section of the cylinder and valves of
this machine. The cylinder is made double the length of the stroke, and has a division A in the
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centre, through which the trunk B passes. On the ends of the trunk are covers C D, held together
by the piston-rod. Steam enters first through the port K into the annular space E. It escapes at
the end of the stroke through the port K, passes through the passage ill in the valve and into the
port 0, and so to the end G of the cylinder, where it expands. Upon the stroke being again com-
menced, the steam in G passes out through the port 0 into the valve Q, being exhausted at S. The
action at the other end of the cylinder is precisely the same. The division A is packed the same as
a piston, the rings, however, having a spring inward instead of outward. The valves are balanced by
cast-iron rings T and U, being placed on their backs and kept to the face of the chest by light springs.
The tubular openings Vand W communicate with the atmosphere, and are always open. This en-
gine was built in England in 1864. The cylinder was 20 inches in diameter and 80 inches stroke.
The trunks were 16 inches in diameter. About 50 revolutions were made per minute, and expansron
was carried down to atmospheric line. (See Scientific American, xi., 100.)
Randall’s Engine, Fig. 1484, has a dividing plate I), which divides the cylinder A into two cham-
bers, in each of which is a piston 0, having rods cl which work separate cranks f and f’. Between
, ENGINES, STEAM, UNUSUAL FORMS OF. 655

the gear-wheels p and g on the crank-shafts is arranged a third wheelfm, which meshes into the two
driving-wheels and is carried by them. It is “ suspended by the teeth and rotated from both sides,
maintaining its position almost independently of its bearings, and producing a uniform and steady
motion without the use of a balance-wheel.” The valves and rods are shown at k and l.
Hurlbut’s Spiral-(Jam Engine, Fig. 1485, embodies a curious device for the conversion of recipro-







Millie-,5


eating into rotary motion. A is the cylinder, B the steam-chest, C’ the cross-head, and D the spiral
cam. From the lower surface of the cross-head project two pins E, which engage with the sides of
the cam flanges and impart a rotary motion to the shaft on which the cam is mounted, and through
the pulley F to the machinery. "
Runlcel’s Oscillating-Piston Engine, Fig. 1486.—This consists of a short cylinder L, the central
portion of which is occupied by a wheel performing the office of a piston, which makes about half a


revolution in one direction and then stops and turns back the other way, thus oscillating back and
forth. The crank or arm on the end of the axle is made of a proper length in relation to the
length of the crank on the fly-wheel shaft to cause a revolution of the latter to each oscillation of
the former. The piston-wheel has two rings fastened securely upon it, extending to the inner surface
of the cylinder. Two abutments are secured rigidly to the latter and project into the wheel, which
revolves against them steam-tight. When steam is admitted the wings are carried nearly against the


abutments. The valves are then changed so as to admit the steam through the ports from which it
had previously been exhausted, and the motion of the piston is reversed.
The Billings ill/[ultieglincler Engine, 1487, operates in a manner the reverse of that of ordinary
motors, inasmuch as it is the engine that revolves while the shaft and crank are stationary. Instead
of one, or even three cylinders being employed, as many may be used as can be grouped around the
rim of the fly-wheel without causing too great complication of parts. Dead-centres are, therefore,
656 ENGINES, TRACTION.

non-existent; and the machine, paradoxical as it may seem, reduces itself to a self-rotating pulley-
wheel. A is the stationary crank, O is a light wheel, and the three cylinders grouped symmetrically
about the latter furnish the necessary weight at the rim; the cylinders take steam at the rear end
only, B being the steam-port, and the dotted lines indicating the steam-passages. -
The Camber Rotary Engine.—Fig. 1488 represents a curious form of engine devised by Mr. W.
A. Comber of Birmingham, England. The action consists in each end of the piston. being alternate-


ly propelled down an inclined plane, the curve of which, it is claimed, causes the force of the steam
to be almost constant during the whole of the stroke. The cylinder-ports, which serve the double
purpose of inlet and outlet, are prolonged into a hollow solid-ended trunnion, turned slightly taper,
and surrounded by a divided chamber communicating with the steam-pipe on one side and the exhaust-
pipe on the other, and so arranged that the revolution of the cylinder causes the ports to be changed
alternately from steam to exhaust at the end of each stroke, any proportion of cut-off being attaina-
ble. This chamber, which also serves as a bearing, is held by two brackets surrounding its two pipe
branches, which are capable of adjustment in all directions. A horizontal spring governor (not
shown) may be attached to the trunnion end and work a governor-valve attached to the steam-inlet
flange. A trunnion or flange is cast on the other side of the cylinder, to which is attached a wrought-
iron shaft turning in an ordinary bearing for taking off power. '
ENGINES, TRACTION. See ENGINES, STEAM, PORTABLE AND SEMI-PORTABLE.
ENGINES, 'WATER—PRESSURE. In a motor of this class, water under pressure is admitted to
a cylinder, and moves the piston, being allowed to escape on the completion of the stroke. Such
engines may be either single- or double-acting. In the single-acting water-pressure engine, the water
moves the piston only in one direction, and it is caused to make the return stroke by its own weight,



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or some added weight if necessary; while in the double-acting engine the water is admitted on both
sides of the piston alternately. The pistons of water-pressure engines are generally packed with
leather rings, so arranged as to be forced out against the sides of the cylinder by the pressure. The
principal parts of the water-pressure engine are, as may be seen from Fig. 1489, the following: A
is the reservoir or supply-cistern, A B the supply-pipe; O is the working cylinder, in which ‘the
water performs its work by forcing upward the loaded driving-piston K; and H D is the discharge-
ENGINES, WATER-PRESSURE. 657

pipe. In the connecting-pipe B O, which joins the working cylinder with the supply-pipe, is situated
thereguilator, which in this case is a cock with a T-shaped channel, which serves to unite or to dis-
connect the supply-pipe and the working cylinder. In the first case, the Water forces the piston,
with its load P1, upward, and in the second case the water beneath the piston, cut off from the
supply-pipe, returns through the cock and is discharged by the pipe H D, while the piston, now
unloaded, descends. ' There are single and double-acting engines, and also engines with one and
with two cylinders. In the single-acting engine which is shown in Fig. 1489, the piston is moved
by the water in one direction only; in the opposite direction its own weight, or an added weight P2,
is- the moving force. In the double~acting engine, on the contrary, the downward as well as the
upward motion is occasioned by the force of the water. Fig. 1490, I. and II., shows the arrange-
ment of such an engine. From this figure is~ to be seen how the motive water passes first (1.)
1 490.
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through A B C, forces the piston K downward, and thus drives the water beneath through the
passage 01 B1 D1,. and second (IL) through A31 C1, forcing the piston upward, and the water
above out through 0 B D.
The water-pressure engines thus far described have but one cylinder. Fig. 1491 represents an
engine with two cylinders. Here, while the motive water A B C forces the piston K upward (1.),
the piston K1 descends, and the dead water beneath passes off through the passage 01 B; D; and,
again (II.), while the motive water causes K, to ascend, K descends, and the dead water passes off
through the discharge-pipe D. I
Regulato1'.-—The regulator is, as it were, the soul of a water-pressure engine; by it the machine is
enabled to perform its work without interruption. It is composed essentially of two principal parts,
one of which alternately shuts the water from or admits it to the working cylinder, and the other is
1431.


necessary to connect the first with the engine proper (with the piston-rod), so that no outside force
will be necessary to work it. “Is can very well call the first mechanism the inner and the second
the outer gear or regulator. As regards the inner regulator of a water-pressure engine, we have to
speak especially of the piston regulator. Fig. 1492, I. and II., shows the arrangement of a piston
regulator for a single-acting, single-cylinder engine. A is the supply-pipe, O the working cylin-
der, .8 the cylinder inclosing the regulator-piston or the regulator-cylinder, l) the discharge-pipe,
K the regulator-piston, and L the so-called counter-piston, which only serves, by creating a coun-
ter-pressure, to make the movement of the regulator-piston or red easier. When the regulator-
piston K is in its lowest position (1.), the working cylinder is in connection with the supply-pipe,
and the driving-piston can only ascend. When, on the contrary, it is in its highest position (II.),
the regulator-piston 11’ 1 shuts ofi the water in the supply-pipe, and that which is beneath the piston
is forced out at D.
The arrangement of the regulator-piston for a deublc-acting or for a double-cylinder engine may be
seen from Fig. .1493, I. and II. Here A is the supply~pipe, O the connecting pipe for one cylinder
4.21 -.
css ENGINES, WATER-PRESSURE.

and 01 (1.) that for the other, D the discharge-pipe for the one and D1 that for the second. It is
seen from 1. how the piston, in its upper position, admits the water to C7, and the dead water from 01
flows through D1 into E ; whereas, at the lower position of the piston, the water is turned into Cl,
and the water shut ofi in 0 may flow through 1) into E. .
Kinds of Regulators.~—1n single-acting engines, and especially in those which have only a recti-
linear motion, it is not possible to connect the regulator directly with the motive mechanism, or to
make the motion of the regulator-piston rod depend directly upon that 'of the driving-piston rod,
since then, at the moment when the rcgulator~piston or valve closes the connection between the
working and the regulator-cylinders, not only the driving-piston, but also the regulator-piston connect-
ed with it, come to a state of rest. In order that the regulator-piston may be enabled to move
through the rest of its stroke after the driving-piston has stopped, it is necessary to use an inter-
mediary apparatus, which only acts upon the regulator-piston when the driving-piston is at rest.
1492.


This apparatus may consist of the following essentials: (1) of a weight, which is raised by the driv-
ing-piston during its up-stroke, and is let fall at the moment it stops, after making the stroke; or,
(2) of a spring, which is brought into tension during the movement of the driving-piston, and let go
at the end thereof ; or, finally, (3) of a second or auxiliary water-pressure engine, which is regulated
directly by the motive mechanism, and whose driving-piston moves the regulator-piston rod of the
principal machine, while the driving-piston of the latter is traversing the last portion of its stroke
and for a short time comes to rest. We have, therefore, to distinguish from each other the weight
regulator, the spring regulator, and the water-pressure regulator.
The weight regulator consists chiefly of a mechanism by means of which the motive engine during
its movement raises a weight, which, by falling at the moment when the working cylinder is closed
by the regulator cock or piston, etc., moves this regulator through the second part of its prescribed
stroke, and completes in this way the regulation. The weight regulator is used in the older and im-
[_ A 1493.


D1
perfect water-pressure engines under the names drop, hammer, balance, pendulum regulator, etc.
In modern times, weights are also used with valve regulators, in such a manner that the motive en-
gine opens the one while the falling weight closes the other valve. The arrangement of such a
weight regulator is quite the same. as in the ease of steam-engines with valve regulators. This sys-
tem consists essentially of several levers in combination with a pawl or ratchet, whence it is also
sometimes called a lever or spring-catch regulator. , .
Regulator- Qz/Ze'mler.--1n the larger machines of modern construction, the regulator and counter pis-
tons of the principal engine, and the driving-piston of the auxiliary engine, are placed in one and
the same pipe, the so-called regulator-cylinder, after the pattern of Reichenbach’s engine in Bavaria;
and in some machines, even, the counter-piston performs the function of driving-piston of the aux-
iliary engine, which is a great simplification. The simplest construction is that shown in Fig. 1494,
and used in several Freiberg machines. 8 is the main regulator, and G the counter and auxiliary
driving-piston; C the connection with the principal working cylinder, and E that with the supply- .
pipe, and A the discharge opening for the motive water; finally, at e is the connection with the regu-
" ENGINES, vWATER-PRESSUBE. 659

later of the auxiliary machine, which here consists of a cock. The piston G is larger than 8;
therefore the regulating mechanism 8 G descends as soon as the motive water is admitted through
0 ,' and, on the contrary, it ascends, under the action of the upward force on S, as soon as e is closed.
By this a certain quantity of regulating water is consumed for each stroke from the motive water,
which quantity depends on the space traversed by G in its ascent or descent, and which for this con-
struction is not very small, since the piston G should have a section at least as large again as that
of the piston S, which again is not made smaller than the supply or connecting pipes.
In the regulator of the machine at Clausthal, shown in Fig. 1495, this consumption of regulating
water is smaller, as here there are three pistons: the main regulator-piston S, the counter-piston G,
and the auxiliary driving or reversing piston H, the last being smaller than the first. The regulating
water is here brought into the regulatOr-cylinder by the pipe e, and the regulation of this water is
effected by "a small cock, through which the water passes before reaching e, and through which it is
also drawn off after the complete revolution. The movement of this cock is brought about by a
1495.


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plate fastened to the driving-piston rod, which turns now to the one side, now to the other, by means
of two curved knee-formed arms, an arbor connected with the cook. The water-pressure engine at
Clausthal has a fall of 630 feet, a piston diameter of 17 inches, and a length of stroke of 6.21 feet,
and makes four strokes per minute.
Double- C(z/lz'nder I'Vater-Pressure Engine—The arrangement and working of a double-cylinder
water-pressure engine is shown clearly in Fig. 1496, which is a vertical section of the machine at the
“ Alte Mordgrube ” in Freiberg. Here Ov K and Cl K1 are the two working cylinders, K and K1
the driving-pistons, S and T the two regulator-pistons, and W the reversing or auxiliary piston.
5'1, T1, and W1 denote the positions which these pistons assume at the change of the motion of the
driving-pistons. Further, E is the opening of the supply-pipe E1 E into the regulator-cylinder, C S
the connecting pipe for the first and 01 T that for the second, A the discharge opening for the first
and A1 (almost hidden by the regulator-piston rod) that for the second working cylinder. The two
piston-rods B K and B1 K1 are connected by an equal-armed lever or so-called walking-beam (not
660 ENGINES, VVATER—‘PRESSURE.

@
shown in the figure), so that the ascent of one causes the descent of the other. It is easily seen,
therefore, that at the lower position of to regulator-piston, as represented, the motive water passes
through E SI 0 and drives the piston R upward ; the piston K1, on the contrary, descends, and the
dead water passes out through 01 T, A 1. - ‘
i The regulation of the auxiliary machine is effected by the cock with double bore, already described,
which is represented at h in Fig. 1497, in elevation in I. and in section in 11. This cock is in con-
nection with the supply-pipe by the pipe 0 el, and with the rcgulator-cylindcr by the pipe g h. At one
position of the cock hi, the motive water passes through E e1 0 h g IV, and presses the reversing pis-
ton W downward; and at the opposite position the motive water is shut off from W, and therefore
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the ascent of W, the return of the regulation water through g h, and its discharge through a a, are
possible. In order that, during the shutting off of the motive water from W, the regulator-piston
and connection may ascend and descend when it is again admitted, it is necessary, however, that the
regulator-piston T, upon which the water acts from below,‘shall have a greater area than thepiston
8, upon which the water presses downward, and that the reversing piston W shall have a large
enough cross-section, so that the water-pressures on W and S together shall be greater than the
opposite pressure upon T.
Finally, for the outer regulator of this machine, we have the following mechanism: r is a regula-
tor-wheel having four teeth, r h a ratchet, k l a rod, 1 c f an angle-lever with the friction-wheel f
(see Fig. 1496), and m and ml (the last not shown in the figure) are two oppositely-placed wedges
ENGINES, WATER-PRESSURE. 661

fastened to the driving-piston rod B K. The ratchet r k is, moreover, connected with the axis of
the cock by arms, and is supported in the teeth of the little wheel r by a small counterpoise 9.
Single- Cylinder Water-l'ressure Engine.-—One of the finest and most complete water-pressure
engines is stated by Weisbach to be that at Huelgoat, in Brittany. It is a single-acting, single-cyl-
inder engine, but beside it stands another machine exactly similar. From Fig. 1498 the arrange-
ment and manner of working may be seen. 0 (71 is the working cylinder, K K I the driving-piston,
and B B; the driving-piston rod, which passes through the stuffing-box 6. While in the previously
described machine the packing consists of one broad piece of leather, in this one, as may be seen in
the figure, a piece of leather is inserted in the piston and another piece also screwed on. The regu-
lator-cylinder A S G, at one side, is connected with the working cylinder by the connecting pipe
0 D ,' the supply-pipe enters it at E, and the discharge-pipe leads out of. it at A. The regulator-
piston 5', shown in the middle position of the down stroke, is connected with the larger piston T by
the rod S T; the whole apparatus, therefore, is forced upward by the extra pressure of the motive
water on T, unless ,a third force prevents. This third 'force is obtained by introducing the motive
water above the piston T, through the pipe 0, cf; but in order to make the use of only a small
quantity of water necessary during the descent of the mechanism occasioned thereby, the hollow
L 1497. IL



cylinder G H is added to the piston T ; this hollow cylinder goes through the stuffing-box at H, and
renders necessary the use of only enough water to fill the ring-shaped space g.
The alternate admission of the motive water to and shutting it off from the space g is effected
by an auxiliar ' regulator, which is altogether similar to the main regulator, and like this c'msists of
the regulator-piston s, the counter-piston t, and the thick piston-rod passing through the stnfi'ing-box h.
At the position 8 t h, shown in the figure, the motive water can pass unhindered through the pas-
sage e finto the space g ,' but if s t h. is raised so that s stands overf, the connection is interrupted,
and at the same time a passage a a1 is opened, through which the water in g g may flow out as the
piston T ascends. Finally, to connect the auxiliary regulator apparatus 8 t h with the working engine,
a rod is affixed to the driving-piston K K, ; this red moves in a guide above, and is furnished with
a series of holes into which the tappets X1 and .11. may be placed on oppdsite sides of the rod.
The red I) h. is attached to two levers, movable about 0 and o, and connected with each other by the
piece I ,' one of these levers ends in a circular piece. which carries two knobs Y] and Y9. Toward
the end of the up stroke of the driving-piston, A", strikes Y1, and s t h is thus carried to its highest
position; toWard the end of the down stroke, on the contrary, 11’; strikes the knob Y2, and the rod
8 t h is carried back by the lever to its lowest position. The regulation of the machine is thus
effected by S T, and the piston K K1 ascends and descends with regularity. -
Figs. 1499, 1500, and 1501 represent a water-pressure engine erected at the Alpert mines in Der-
byshire, England, in 1845. Fig. 1499 is a front elevation of the combined cylinder engine; Fig
662 ENGINES, WATER-PRESSURE.

1500 is a sectional view, and Fig. 1501 is a general plan. P0 is the bottom of the pressure column,
130 feet high and 24 inches internal diameter. C 0 are the combined cylinders, each 24- inches
diameter, open at top, with hemp-packed pistons a, Fig. 1500, and piston-rods m, combined by a
1498. I.
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cross-head n, Fig. 1409, working between guides in a strong frame. The admission throttle-valve is
a sl'uice‘valve, shown at 0, Fig. 1499, and between the letters I) and c in Fig. 1501. The main or work-
ing valve is a piston g, 18 inches in diameter, Fig. 1500, with its counter or equilibrium piston above.
The orifice for the admission of the pressure water is between the two pistons. The intermediate
pipe a is a flat pipe, into which numerous apertures lead from the valve-cylinder, seen immediately7
under g, Fig. 1500. The valve-piston is in the position for discharging the water from the cylinders
through the pipe 6, Fig. 1501, by'the sluice-valve k.
The valve-gear is worked by an auxiliary engine h, Fig. 1500, by means of the lever 21. The aux-
iliary engine-valves are piston-valves in the valve-cylinder 71, Figs. 1499 and 1500, communicating
with the pressure-pipes by a small pipe, provided with cocks, as shown in Fig. 1501. The motion
of the auxiliary engine-valves is effected by a pair of tappets t' t", Fig. 1499, set on a vertical rod
attached to the cross-head 72. These tappets move the fall-bob B by means of the cantilever t,
Fig. 1501, the other end of the lever being linked to the rod s, which again is linked to the auxiliary
piston-valve rod. _
The play of the machine is now manifest. It is‘in every respect analogous to the Hartz and Huel-
" " ENGINES, WATER-PRESSURE. ses
oat engines, described'by‘Weisbach. The average speed of the engine is 140 feet per minute, or
gadouble strokes per minute. This requires a velocity of something less than 2% feet per second of
the water in the pressure-pipes; and as all the valve apertures are large, the hydraulic resistances
must be very small. The engine is direct-acting, drawing water from a depth of 135 feet, by means
of the spear w w, Figs. 1501 and 1502. The “ box ” or bucket of the pump is 28 inches in diam-
eter, so that the discharge is 266 gallons per stroke, or, when working full speed, 1,862 gallons per
minute. The mechanical efl’ect due to the fall and quantity of water consumed is nearly 140 horse-
power. The mechanical eifect involved in the discharge of the last-named quantity of water is
1500. 1501.










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nearly'74 horse-power, so that, supposing the efficiency of the engine and pumps to be on a par
with each other, the efficiency of the two being 171 = 71.15, the etficiency of the engine alone n ::
1+fl1 2 _-——2-—--.85.
Evidency of the foregoing YII/pes of Famine—According to Weisbach, no exhaustive experiments
have been made upon the performance of the water-pressure engines above described. They are

664 ENGINES, WATER—PRESSURE.
used generally only to raise water from mines by the aid of pumps ; and the experiments that have
been made bear only upon the apparatus of pumps and pressure engines as a whole. Full calcula-
tions as to the efficiency of the engines will, however, be found in the work already quoted. Oom-
paring watenpressure engines with water-wheels, the same authority states that “ water-wheels have
the advantage of simplicity and cheapness;
and on this account, where they can be used,
or with a fall of about 60 feet an overshot
wheel, or two overshot wheels where the fall
is 100 feet, give better results than a water-
pressure engine. If the fall, however, is
more than the height of two of the largest
wheels, a water-pressure engine is to be pre-
ferred to a system of wheels, the first cost
and maintenance of which will probably be
the greater. With great falls, however, hori-
zontal water-wheels can also be used, and in
point of simplicity and cheapness these have
the advantage. But it is quite otherwise as
regards the duty and efficiency of the ma-
chines. With great heads, the highest per-
centage attainable with a turbine or reaction
wheel is 0.70, while water-pressure engines
give a percentage of 0.80. Consequently,
where with a great head it is necessary to
‘ utilize all the power, a water-pressure engine
should be used; but where there is no lack of power and it is desired to economize the cost, the
turbines have the advantage.”
Full information with bibliographical references relative to the above-described forms of water-
pressure engines will be found in 'Weisbach’s “Manual of the Mechanics of Engineering and of the
Construction of Machines,” translated by Dubois, New York, 1878 (Vol. II., Section 11.).
l/Vater-Po'essure Engines as General Jilotors are either reciprocating or rotary, and all quite simple
in construction. In this country, in cities where such a use of the water-supply is permissible,
they are frequently driven from the town mains. Various projects have from time to time been sug-
gested for constructing water-towers where there are no regular water-works, and distributing from
these water under pressure to afford power for small nlanufactories. Where power is taken from
the regular mains, it is often found that the pressure varies, being always highest in the mornings
and evenings, and lowest during the middle of the day when most required. An engineer has there-
fore to construct an engine of sufficient power to perform the requisite amount of work at the low-
est usual pressure in the main; and‘thus at the period when the pressure is highest a greater
power is exerted, and consequently a larger quantity of water is used than is necessary; for the cyl-
inder must be completely filled with water at every stroke, whether the power is required or not. .
When these two disadvantages are taken into account, there is often a loss of water to the extent of
from 60 to 70 per cent.
The Hastie Economic i'i’aler-Pressm'e Engine—It is claimed that in this machine, the invention of
Mr. John I-Iastie of Greenock, the above-mentioned difficulty has been obviated. W 0 take the fol~
lowing description and illustrations from Engineering, xxvi., 371 :
“Figs. 1503 to 1507 give details of a hydraulic engine (in this case with two cylinders) constructed














1503. “i504.


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for the lower pressures, and the working of which will be understood from the following descrip-
tion: A is the inlet-pipe, which,by means of passages in the frame of engine B, conveys the water
to the oscillating cylinders C and D; each of these is fitted with long trunnidns G, which contain
the admission-ports, and which during their oscillation act as valves; the outlet for the water is by
ENGINES, WATER—PRESSURE. 065

...
similar passages leading to a pipe in the opposite side of framing from A. The ends of the piston-
rods E and Fact direct on the crank-pin H; this pin is formed on a sliding frame I, which frame
effects the necessary adjustment of stroke; it is formed in two pieces, an outer and an inner, bolted
1504.


together at the ends, and between which is a space in which the double cam K works. The outer
plate has a small steel roller L working on outer half of cam, and the inner plate a similar roller .51
working on inner half of cam. The disk N is keyed on the hollow shaft 0 and the cam 11’ on shaft
P, reduced to pass through centre of shaft
0. This latter shaft 0 has two snugs
formed on it, to which chains R are at-
tached; the shaft P has the spring case
S keyed on it, which contains the two
springs T. The action of this part of the
arrangement is as follows: \Vhcn the en-
gine is at rest the springs have just as
much pressure on them as holds the roller
against the inner part of the curve of cam ;
this pressure is also sufficient to prevent
any change in position of the crank-pin
should the engine be running without load;
when the load is thrown on, the springs
become compressed in proportion to the
amount of load; the compression of the
springs alters the relative positions of the
shafts 0 and P, which causes the roller L
to move along the curve of cam, at the
same time shifting position of sliding frame
1, and giving an increased stroke in pro-
portion to the work being done. On the
weight being removed the pressure on the
springs causes the roller 1]! working on the
cam to bring the frame and crank-pin hack
to the inner position, and through this an-
tomatic variation of the stroke the water
required is in proportion to the work done.
When a very high pressure of water is em-
ployed, such as is obtained with the ac-
cumulator, the springs are dispensed with,
and an arrangement shown in Fig. 1504 employed. In this arrangement two water-
rams U occupy the place of the springs;
these are connected through centre of shaft
P with the Supply-pipe, and are therefore
under the same pressure as is employed to
work the engine. The chains R are employed in a similar manner as in connection with the springs,
but, instead of being wound directly on the body of shaft 0, they are wound on cams V ,' in this way
increased power is required to force hack the rams in proportion to the distance from the centre of
shaft at which the chain R acts, and the effect is identical with that obtained from the SlfH‘lIlgS.”
The following data have been derived from experiments with this engine, the lift being 2:3 feet:


Weight lifted, Average Water used Weight lifted. Average Water used
Lbs. each Lift, Gallons. Lbs. each Lift, Gallons.
382.... . . . . . . . . . ..10 867......“~... . . . . . . . . ..20
567... .......... ..... 14 | 967......~............. 21
667 . . . . . . 16 1,067........ . . . . . .......22
17
666 ENVELOPE MACHINERY.

Rotary Water-Pressure Engine—An example of the rotary form of water-pressure engine, a type
used to considerable extent in this country for running light elevators, lathes, printing-presses, blow-
ers, sewing-machines, organs, coffee-masters, spinning-mills, sausage-mills, etc., etc., or for use in
hotels, laundries, forges, etc., is represented in Fig. 1507, and is the invention of Mr. James Talley,
Jr., of Missouri. The buckets on the wheel A are set sloping at an angle of about 30° with the
radial lines of the wheel, and between each pair the flanges are scalloped out, as shown. On the
face of the wheel are formed annular flanges B, which bear against the inner faces of the casing,
preventing side play of the water. The wheel is placed eccentrically in the casing so. as to touch or
nearly touch the latter on the inlet side, and to leave a large waterway on the outlet side. The in-
duction-pipe O terminates on the inner face of the casing in a wave-line chute .D. The width of
this aperture is greatest at E, where the stream is first discharged upon the wheel, and from that
point it gradually diminishes as shown, having the greatest weight of water at E, at the other (on the
blow-pipe principle) the greatest force. The distance over which this diminution takes place may
be varied so as to deliver the water upon one or more buckets of the wheel. Two outlets are pro-
vided for the escape of the spent water. The first of these, at F, is used to discharge the water
from the casing at the bottom when the ma-
1508. g chine is used in a vertical position. The
"' other is formed on the side which becomes
the bottom when the machine is placed hori-
zontally or in turbine position. A screw-cap
G is placed upon either outlet when not in
use. A slide or gate H is arranged in the
casing so as to close the orifice F when not
in use. By the wave-line chute it is claimed
that the water is given in one continuous
sheet and not by periodical jets. The work-
ing side of the wheel thus becomes a lever,
and there is no waste until the outlet is
reached. A tapering duct I is formed on
the side piece, and gradually widens to a
point diametrically opposite that where the
' width of said duct is about equal to the
diameter of the orifice G. From the large end of this duct there is a passage to the discharge out-
let, which passage is so formed as to relieve the wheel from back pressure of spent water. It is
stated that a 5-inch wheel of this type, with 70 lbs. pressure of water and less than threesixteenths
of an inch inlet, has driven a half-horse power 14-inch metal-turning lathe.
Root’s Hydraulic Engine, represented in Fig. 1508, is constructed on the principle of the Root
blower (see BLOWERs), and has proved advantageous for furnishing light power, especially for oper-
ating the bellows of large organs.
d,—
_ “1’?” I:‘\_


Table showing Dimensions, Bower, etc., of Root’s Hydraulic Engine.












DETAILS. No. 1. ' No. 3. I No. 4. - No. 7. N0. 10. No. 11. No. 12.
Diameter of gears, inches . . . . . . . . . . . . 2% 5% 5 5 f} 6% {‘1}
Face of piston, inches . . . . . . . . . . . . . .. 11} 2% 1} 1% 2 4
Diameter of supply-pipe, inches. . .. 1 1% ' 11- 2 21} 3 8}
“ of discharge-pipe. inches... 11- 1% 1 2% 3 3g- 4
Length of engine, inches . . . . . . . . . . .. 12 13 221,- 2ti} 3E} 40;- 4‘ %
Width of engine, inches . . . . . . . . . . . .. 8 8 11 154- 20 20 20
Height of engine, inches . . . . . . . . . . .. 8 ~ 8 13 161} 221} 22.1} 22%-
Cubic inches of water per revolution. 12.7 21.2 34. 6 69.6 159.2 318.3 41 7 .8
Revolutions per minute . . . . . . . . . . . . . 250 200 180 150 120 100 85
Horse-power at 60 lbs. per square inch 0 .25 0 .45 0 . 5 1 . 1 2 .5 8 .5 4. 5J
Water-Pressure Engines for Hydraulic Cranes.-—A novel application of the hydraulic engine is to
the moving of the bridge of a travelling crane along its track. The construction embodies two cylinders
with rains, which are duplicates of each other, both being provided with wire-rope wheels. The
most convenient location for these is in the opposite ends of the building and near one corner. The
ropes, after passing about wheels on cylinders and rams, lead to and are secured at opposite sides of
the bridge; the lengths of these ropes are so adjusted that, with the bridge in the middle of its travel,
the rams are at half-stroke. The length of rams and combination of coils are such that one stroke
hauls in a length of rope equal to the travel required of the bridge. With rams arranged as shown,
and pressure-water admitted to both cylinders, the maximum strain will be put upon the ropes; but
as this pull is equal, and in opposite directions, there is no effect in the way of moving the bridge.
Suppose, now, that by means of a valve the pressure is cut off from the cylinder A, the pressure con-
nection with cylinder B still remaining open, this will produce no motion; but go a step farther, and
permit water to escape from cylinder A : it is evident that the holding force acting on the bridge
through the ropes about A is released, and that the pulling force from the cylinder B will produce a
motion to the bridge in that direction; also, that there will still be a strain upon the ropes from A
equal to that from B, less the pull consumed in moving the bridge. B-y reversing this operation,
motion to the bridge in the opposite direction is produced. ,
ENVELOPE MACHINERY.-—In the earliest stages of invention the paper blanks were cut out, and
the subsequent folding performed entirely by hand. Then came an improved paper-cutting machine, and
ENVELOPE MACHINERY. ’ 667
a plan for cutting out the blanks. Many envelopemakers use this machine now; but others employ
a hollow cutting-die, cutting through about 250 sheets of paper at once.
Fig. 1525 is a sectional elevation of the die, and Fig. 1526 a plan. It is simply a knife shaped to
the contour of the envelope blank, A being the sharp edge. This is forced through a thick pile of
7 sheets by a convenient press, so as to produce blanks agreeing in shape to the_interior of the two
= lines in Fig. 1526. This shape, it will be observed, is not one now in common use, but it serves as an
example of. some of the attempts which have been made to give additional security, and probably a
greater appearance of style. The cut pieces are gummed on one side, at the ends of each flap ; and
when folded, as indicated by the dotted lines in the plan of the cutter, the long narrow part adheres
1526.


to one end of its counterpart, forming the back, and the remaining pair of flaps fold down upon it.
This shape of envelope has, for many reasons, never come into ordinary use.
Figs. 1527, 1528, and 1529 exhibit, in elevation and detail, an improved folding-machine, patented
in France by M. Rémond. In this machine some ingenious appliances are introduced, whereby
atmospheric pressure is employed to facilitate the feeding in of the blanks to the folding apparatus,
and the secondary folding action of the flaps in connection with the creasing plunger.
Fig. 1527 is a side elevation of the machine, partially in section. Fig. 1528 is a vertical section
1527.















of a portion of the machinery, taken at the dotted line A B in Fig. 1527. Fig. 1529 is a horizontal
view or plan of the folding-table, with the details of the apparatus for receiving the blanks prepara-
tory to folding. Fig. 1530 is a transverse section, taken at the dotted line 01) in Fig. 1527. Fig.
1531 is a plan of the feeding-slide N in 1527. .
The arrangement of the mechanism is such that, a quantity of blanks of the required size being
placed on the feeding-table, each will be taken up singly from the pile, and fed into the folding ap-
paratus by means of an instrument, in which, at proper intervals, a partial vacuum is formed, where-
by each sheet is sucked up against the surface of the fingers for conveyance to the folder.
As the first step of the process of folding, the flaps of the blanks are bent to a right angle by
simple devices; but a novel arrangement is introduced for the performance of the secondary fold.
The bottom of the creasing frame or box is perforated, so that the passing back of the plunger
668 ENVELOPE MACHINERY.

leaves the blank within the recess, with its four flaps standing upright; and here the second ap-
plication of the atmospheric action comes into play, for the purpose of giving the flaps a prelimi-
nary inclination inward, in order to fit them "for receiving the flat folding. pressure of the return
stroke of the plunger. To this end the sides of the folding-box are perforated, so as to allow
streams of atmospheric air to be forced against the outsides of the flaps; so that, on the descent
of the plunger, they will all be folded down at once, the interior and under surface of the plunger
being suitably formed to cause the flaps to succeed each other in their proper order. In addition
to this, certain contrivanees are adapted for stamping the outer flaps with an embossed or perforated
device, and also for gumming the lowest flap as a fastening for the completed envelope.
B, Fig. 1528, is the folding-box, or recess, in which the folding process is performed. It consists of
1528. I 1529.
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4 side-pieces, at the angles of which are projections between which the blanks are successively fed
so that they may be correctly placed, and held during the action of the plunger. D is the door or
movable bottom of the box, hinged at one end, so that, when an envelope has been folded in the box,
it may be discharged below; it is perforated with numerous holes for the escape of the air, as the
blank is forced down, and is kept closed by means of a lever E, which is actuated at the proper in-
tervals of time by means of the cam on the main shaft, giving motion to a slide. The feeder N, Fig.
1527, is carried upon a slide, having dovetailed edges, moving between fixed guiding dovetails. It
consists of two hollow fingers, each having an opening on the under side; the interior of the fingers
opens into the hollow portion of the slide, allowing of a partial vacuum being obtained within the _
fingers when the exhaust movement comes into use. A flexible tube Q, of vulcanized India-rubber,
is attached to the under side of the slide, the opposite end being connected with the bellows R.
When the under side of the fingers comes upon the top of the pile of blanks, the exhausting action
is brought into play, and the top sheet is carried over to the top of the box B for deposit. At the
termination of the outward stroke of the bellows, the sheet is separated from them by the action of
a valve in the bellows, opening outward at the commencement of the return stroke.
As the blanks are fed into proper position, the folding plunger 9, Fig. 1528, comes into action. It
is a hollow rectangular metal frame, having in its interior a set of three projections, which, in the
secondary movement, act on the separate flaps, folding them all down at once, when they are held in
the required inclined position by the atmospheric side currents, as previously detailed. The inclined
projections are essentially necessary, in order that the flaps may be folded down in their proper relative
positions; the projection Z, pressing on one of the side flaps, causes it to be folded first; afterward
the projection m acts upon one of the ends, while the third, 72, carries down the opposite one, the




























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final folding being completed by the under edges of the plunger, which gives a sharp pressure to the
initiatory fold of the whole series. By suitably setting these projections, any order may be given to
the flaps ; thus, if the two end ones do not overlap each other, they may be folded down together by
equal projections. '
The necessary atmospheric side pressure on the flaps is obtained from the inclined air-pump p, the
' ~ ENVELOPE MACHINERY. 669

piston of which is driven by a crank-pin on the fly-wheel; and a tube 9 conveys the forced air from
the bottom of the pump to a hollow channel passing all round the edges of the folding-box, as dotted
in the plan, Fig. 1529, whence the orifices, already pointed out, open inward to the box. For the
application of gum or other cementing fluid to the lowest flap, to secure the three stationary ones,
a fountain is placed at 9', from the bottom of which two tubes 8 s branch out to- the two flat tubular
receptacles tt inclosed in a vessel u, the supply being regulated by a stop-cock before the junction of
the two supply branches. The gumming action is performed by pieces of sponge placed in the upper
ends of the flat tubes it, which stand slightly above their upper edges; the presser v, descending
just before the plunger, presses the edges of the lowest flap upon the sponge, as clearly illustrated
in the plan view. This presser receives its motion from the cam 20 acting on the slide 2:, to which
the presser is attached. If it is intended to stamp or emboss the outer flap with an embossed or
perforated device, dies are applied as at yz. The die y being attached to a slide 1, acted on by the
external-cam 2, the stamping action takes place just before the descent of the plunger,
. This machine is said to have produced easily 60 envelopes per minute, or 36,000 per day, com-
pleted, gummed, and stamped, and might probably be worked faster.
Since the first anticipations of the value of the envelope for general consumption, many modifica-
tions have been introduced. In 1844 Mr. Wilson, the inventor of the cutting machine, hit upon the
ingeniously simple mode of economizing the paper in cutting out the blanks. by cutting the original
web of paper diagonally across its width. Formerly, when the web was divided longitudinally, and
then by transverse cuts at 'right angles, the rectangular sheet thus formed, when out up into diamond
pieces for the envelopes, suffered considerable loss in the reduction. By Mr. Wilson’s plan this was
avoided, as, the transverse cuts being all made diagonally, each blank fitted exactly to its neighbor,
and this source of loss was removed. In 1846, again, Mr. Charles Chinnoek obtained a patent for
some contrivances for the obtainment of greater security of inclosure, by applying the ordinary
postage-stamp, or other adhesive labels, so as to become a fastener for the edges of the paper form-
ing the envelope. In one of his arrangements, a small hole, somewhat less than the area of a post-
age-stamp, is punched at the right-hand corner of the address side, so that, when the stamp is put
on, it adheres not only to the edges of the hole, but also to the turned-in edge produced in the end
fold of the envelope, as well as partially to the inclosed note. Thus the inclosure cannot be re-

l.
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moved without leaving detective marks. According to another mode, the patentee punches holes of
various sizes through the parts of the envelope where the seal is placed—in some cases placing a bit
of blotting-paper beneath, this being fer the purpose of securing the whole by the seal. In another ‘
arrangement, the envelope is the same shape as that now generally used, having four triangular flaps,
meeting in the centre for the seal. In the ends of three of these flaps are small holes, each one a
little different in size, so that when folded thesmallcst hole is the lowest, and the largest the third
6’70 ENVELOPE MACHINERY.

in the layers, while the fourth is blank, the wax below which not only secures all the flaps, but
adheres also to the inclosure. When a piece of blotting-paper is placed below the holes, as in an-
other modifieation, any attempt to open the letter would involve a tear. .
In Figs. 1532 and 1533 are represented two views of the envelope machine devised by T. V. Way-
mouth, and manufactured by Berlin 8t Jones of New York.
A represents the bed of the machine, supported on suitable legs, B. The table A’, which supports
the blanks, is detached from the main portion of the bed, and is connected to it so that it can be
turned in or out. From this table A’ rises a curved guide T, against which the edges of the blanks
abut, so that such blanks can readily be brought into the desired position without bending up their
edges. Above such table rise the pickers or gummers C' C’, which serve to apply the gum to the
blanks, and to lift one after another to be carried to the folding-machine. The gummer 0’ applies
the gum to the seal-flap, and the gummer C to the back flap of the. envelope-blank.
The gummers or pickers O 0’ are suspended from an arm D, extending from a slide, to which a
rising and falling motion is imparted by a cam. The gummers are supplied with gum by the rollers













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c c, which have their bearings in a reciprocating carriage d, by which they are alternately brought
in contact with rollers e e, which revolve in the gum-boxes ff, and then are carried under the gum-
mers. By'these means the seal and back flaps of the envelope-blank are gummed at or about the
same time, after the blank is put into the machine.
After the gummers have descended upon the blanks they rise again, carrying up with them the up-
permost blank, which adheres to them, by reason of the nature of the gum, until such blank comes
in contact with the under surface of the platform supporting the gum-box, when the blank is disen-
gaged from the gummers or pickers and deposited on the carriers G’, to which a reciprocating motion
is imparted by the action of an arm H, mounted on a rock-shaft h’, which rock-shaft receives an os-
_ cillating motion by means of an eccentric 71', mounted on the driving-shaft j, and connecting with
such, rock-shaft by a strap k and arm Z.
By the carriers G' the blank is brought under the creasing-plunger I, which is secured to an arm
K, extending from a slide L, to which a rising and falling motion is imparted by the action of a
cam. The plunger I forces the blank down through an aperture n in the creasingplatform N, the
blank being disengaged from the carriers, and deposited on the creasing-platform before the plunger
descends, by the, action of a forked lever 0. To one of the arms of such lever is attached a die 0,
which, when brought down upon the blank while it rests upon the creasing-platform N, produces
upon the seal-flap any mark or figure desired, as an initial letter, monogram, etc. By the descent of
the plunger I through the aperture 9?. the blank is creased, and in this condition it is brought down
upon the folding-table P. By engraving or otherwise producing on this table, or in the face of the
creasing-plunger, or in both, a suitable or desired design or die, the body of the envelope can be
embossed or stamped with any desired character or pattern.
As soon as the plunger has ascended a sufficient distance from the platform P, the folding-wings
' ENVELOPE MACHINERY. 671

f’ g’ h’ i’ turn down in quick succession, the wings g’ i' turning down first, and folding down the
end flaps; then the wing h', folding the back flap; and lastly the wing f ', which folds the seal-flap.
The wings g', i’, and h’, after having been turned down, remain stationary until the seal-flap is turned
down, and such wings are so shaped that the gummed part or edge of the seal-flap will not be allowed
to come in contact with any of the other flaps, and consequently such seal-flap will be prevented
from adhering to the other part of the envelope.
After the operation of folding a blank has been completed, as before described, the folding-wings
turn back to their original position, and the foldingtable P is tilted, causing the folded envelopes to
slide from ofi such table, and drop one by one into or between two of the radiating arms or plates
j', which project from an endless apron Q. The envelopes, on being discharged from the apron,
drop into a receiving-box R, which is provided with a follower S, by which they are slightly com-
pressed, so as to be ready to be put into bundles or packages. -
The endless apron on which the envelopes pass is usually made longer than is here represented,
and is provided with a small blower beneath it, which creates an air-blast to dry the paste of the
envelopes during their passage. An ingenious arrangement 'of fingers has also been contrived to
take the envelopes one at a time from the apron, and place them in .piles. This machine is capable
of folding and pasting envelopes at the rate of about one a second.
The Reay Envelope-Folding Machine (Fig. 1533 A).--The envelope-blanks, which are previously cut
out by a suitable knife and hand-gummed on the seal-flap, are laid in lots of about 500 at a time on
the sliding feed-board, which is pushed back in its place and locked by an automatic catch. A gum-
box filled with liquid gum, placed on a table above the feed-board and pile of blanks, contains a
1533 A.
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roller, driven by a belt from the cam-shaft, which roller imparts gum to a distributing-roller made
of the same material as printers’ rollers, and covered with a thin hose or tube of India-rubber,
mounted on a reciprocating carriage, which passes under the lifting-pickers and deposits gum on the ‘
lower surface of them. The pickers descend on the pile of blanks, pick and lift up one blank at a
672 , ESCAPEMENT.

time, and leave it on a pair of reciprocating slides which are mounted on the folding-box. These
slides are provided with a pair of adjustable hooks on their foremost end, and carry the blank over
the folding-box. The plunger or former is now on its downward stroke, takes the blank with it into
the folding-box, leaves it with the four flaps bent up at right angles, and returns to its highest posi-
tion, while the foundation or bottom comes up from underneath, the folding fingers or flaps begin to
push one after the other against the flaps of the envelope-blanks and fold them down flat. The
plunger descends again with another blank, the flaps withdraw from under the plunger, which drops
till it meets the bottom, when a pair of pressurecranks passing over the plunger-rollers, which are
riding on the plunger-cams, give the required pressure to stick the flaps of: the envelopes permanently
together. Now the bottom drops and discharges the finished envelope on the work-table in a suitable
trough, from where it is pushed out by a swinging wing over a couple of flanges, one by one, until
the trough on the work-table is filled, when they are ready to be taken out to be banded, twenty-five
in a pack, and put away in boxes.
ESCAPEMENT. A wheel fitted with teeth which are made to act upon two distinct pieces or
pallets attached to a reciprocating frame, so arranged that when'one tooth escapes, or ceases to drive
' _ , a pallet, the other shall begin its action. One of the
1584. most simple forms is shown in Fig. 1534. A sliding
frame, A B, is furnished with two projecting pieces at C
and D, and within it is centered a wheel possessing three
teeth, P, Q, and R, which tends always to turn in the
direction indicated by the arrow. The upper tooth, .P, is
represented as pressing upon the projection D, and driv-
ing the frame to the right hand: when the tooth P es-
capes, the action of Q commences upon the other side
of the frame, and the projection O is driven to the left hand. Thus the rotation of the wheel causes
a reciprocating movement in the sliding piece A B. It is clear that the wheel must have 1, 3, 5, or
some odd number of teeth upon its circumference.
The crown-wheel cscapement is a circular band, with large saw-shaped teeth cut upon one edge;
the vibrating axis A B, Fig.11535, carries two flat pieces of steel, a 6, called pallets, which project
from the axis in directions at right angles to each other, and engage alternately with teeth upon the
opposite sides of the wheel. Suppose the wheel to turn in the direction toward which the teeth in-
cline, and let one of its teeth encounter the pallet b and push it out of the way; as soon as b escapes,
a tooth on the opposite side meets the pallet a, and tends to bring the axis A E back again; thus a
reciprOcating action is caused. '
In the anchor cvcqnemcnt a wheel centered at E is provided with a number of teeth, and tends
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always to turn in the direction indicated by the arrow. A portion of this wheel is embraced by an
anchor, A (1B, Fig. 1536, centered at O, the extreme ends of which are formed into pallets, A m
and Ba : these pallets may be flat or slightly convex, but they are subject to the condition that the
perpendicular to A m shall pass above 0, and the perpendicular to Bn shall pass between 0 and E.
The point of a tooth is represented as having escaped from the pallet Bn after driving the anchor
to the right hand ; and the point g, by pressing against A m, is supposed to have already pushed the
anchor a little to the left hand, and thus the wheel can only proceed by causing a vibratory motion
in the anchor, A C B. (See “Elements of Mechanism,” Goodeve, New York, 187 7.)
EVENER. See COTTON-SPINNING MACHINERY. ,
EXCAVATING MACHINES. Hand-labor is now becoming supplanted by steam-machinery for
all kinds of excavating and the rehandling of material. The modern excavating apparatus is em-
ployed for loading cars, for balla-sting, trestle-filling, or for widening cuts or embankments, cutting
down grades, cleaning ditches, draining swamp-lands either by open ditch or tile drainage, dredging
streams and harbors, digging canals, building up railroad embankments, reclaiming marshes, and so
on, through a constantly multiplying variety of uses. The type .ofmachine used in railroad-building
usually consists of a supporting car heavily framed, provided with a crane and dipper, and a steam-
engine for actuating the latter. A new form of this apparatus is thus described: I . .
EXCAVATIN G MACHINES. 673

“It will work from'either side and make a ditch any desired shape required; will widen a cut of
sufficient width to lay down a double track; will fill a. car of 18 or 20 yards and run it out to
the embankment and dump it, and back to its cut, every 15 minutes; and it will handle any kind
of soft, slushy, running mud that men could not handle. It can clean out ditches between two
tracks and dump into cars on either track. It will swing to the centre of the car upon which it
stands, and run through any bridge or tunnel where a passenger-car will pass. It is self-propelling,
and runs its own car out and in. The crane can be taken off and the machinery used as a pile-
driver. It can also be used as a dredge or hoisting machine, and will make any required shape of
ditch as to depth or widt .”
In a new form of steam-shovel made by the Bueyrus (Ohio) Steam-Shovel and Dredge Co., steel is
mainly used throughout the machine, and a thrust-motion is provided for feeding the bucket outward
as the bank is dug away, so that less frequent advances have to be made. The machine can dig 26
ft. from the centre of the track at 8 ft. elevation, making a through cut 52 ft. wide.
The quantity of material to be removed is of course found by calculation. The ordinary
method of ascertaining the nature of the material to be excavated, previous to the undertaking
' of any piece of earthwork, is by boring a vertical hole of about 31} to 4 inches diameter in the ground,
and bringing up specimens of the materials pierced through at difierent depths. For this examina-
tion, when made in rocky ground, the diamond drill is largely employed, as is explained under
ROCK-DRILLS. The best method is to combine shafts with boring by sinking at least one shaft,
which should be at the point of greatest depth, and then making the borings at least 200 or 300
yards apart. Boring-tools for earth will be found described under WELL-BORING. See also TUNNEL-
ING. A cutting is usually commenced by making a' “gullet” or vertical-sided excavation, wide
enough to contain one or more lines of temporary rails for the passage of cars. The widening of
the cutting to its full width, and the formation of the slope, should be carried on so as never to be
far behind the head or most advanced end of the gullet; for the strain thrown on a mass of earth
by standing for a time with a vertical face has a tendency to produce cracks, which may extend
beyond the position of the intended slopes, and so render the sides of the cutting liable to slip
after they have been finished. The advanced end of a cutting of considerable depth, and the
parts of its sides whose slopes have not been finished, consist, while the work is in progress, of
a series of steps or stages called “lifts,” rising one above another by 6 or 8 feet, or thereabouts,
the excavators working at the faces of these lifts so as to carry them on together. From faces at
the end or sides of the gullet, the earth is shoveled directly into the carts or cars. From the other
faces of the cutting the earth is wheeled in barrows along planks to points from which it can be
tipped into the wagons. The labor of excavating or getting the earth depends mainly upon its ad-
hesion. Loose sand and gravel, soft vegetable mould, and peat can be dug with the shovel or the
spade alone; stiffer kinds of earth require to be loosened with the pick before being shoveled into
barrows, and in some cases with crowbars, wedges, or stakes; the softest kinds of rock can be
broken up with pick or crowbar; harder kinds require the action of wedges; harder still, especially
if free from natural fissures, need blasting by gunpowder or other explosives.*
The loosening of the material in shallow cuttings and in light soils is best done by the plough. In
deep cuttings, the earth, being undermined at the ends, falls by itself. For short distances, 10 to 20
feet, the earth, if loose and dry, may be moved by shovels; from 20 to 200 feet, barrows may be em-
ployed running over a plank; for over 200 feet, carts will be found more economical; and for hauls
over 500 feet, where a large amount of work is to be done, a track, with cars drawn by horses, will
be found profitablesl
Very complete data on the subject of cost of earthwork, etc., will be found in papers on the sub-
ject by Mr. Ellwood Morris in the Journal of the Franklin Institute, vol. ii., 3d series, page 164;
also in “A New Method of Calculating the Cubic Contents of Excavations and Embankments by the
Aid of Diagrams,” by J. C. Trautwine, C. E. See also the works of Rankine and Vose, previously
quoted.
In order to execute an excavation with speed and economy, it is necessary to fix correctly both the
absolute and the proportionate numbers of pickmen, shovelers, and barrowmen, so that all shall be
constantly employed. The only method of doing this exactly is by trial on the spot. Approxi-
mately one excavator to 5 or 6 feet of breadth of face is about as close as the men can be placed
without getting in each other’s way. The proportion of wheelers to shovelers may be estimated ap-
proximately by the fact that a shoveler takes about as long to fill an ordinary barrow with earth as
a wheeler takes to wheel a full barrow about 100 or 120 feet on a horizontal plank, and return with
the empty barrow. The number of barrows required for each shoveler is one more than the number
of wheelers. The proportion of pickmen to shovelers (in a single rank) depends on the stiffness of
the earth; hard clay requires 2 pickmen to 1 shoveler. An earth wagon holds about as much as 50
wheelbarrows. The transverse slopes of cuttings and embankments depend upon the nature of the
soil in which the work is carried on. Gravel will stand at a slope of 1%- horizontal to 1 vertical, and
in some cases at 1:1- to 1. Clay, though remaining at a high angle when first cut, finally assumes a
very flat slope, even as low as 4 to 1. The manner in which slips occur upon high slopes of clay or
clayey earths suggests that the proper form to be given to the cross-section of the cutting is that of
a parabola, flatter toward the bottom of the slope, where the pressure is greatest, and steeper above.
Carp should in all cases be taken to secure good drainage and to protect the slopes of the earth-
wor i.
Fig. 1549 represents the New Jersey excavator, which is designed to excavate earth, gravel, peat,
and marl; also to dig large trenches, levees, and canals for irrigating and other purposes. It is
claimed to be able to dig a trench 4 to 6 feet wide and 3 feet deep, and from 400 to 600 feet long,

* Rankine‘s “ Civil Engineering " ‘S Vose‘s “ Manual for Railroad Engineers.”
43 ‘ '
6'74 EXCAVATIN G MACHINES.

or to remove a proportionate amount of earth from a bank, in‘ one day, at a cost for labor and fuel
of not over $36. It is also claimed to excavate 1 cubic yard of earth per minute from a. 4-foot trench.
It was patented in 1876 by Mr. J. P. Bonnell. The engraving is explained by the following refer-
ences: A, the frame; BB, propelling traction-wheels; 0, caster-wheel, for guiding the machine
when traveling, to which is attached screw H ; D, three rows of buckets faced with cast-steel
knives; E, the four chains to which the buckets are attached; FF, upper and lower chain-wheels,
over which the bucket-chains revolve, the upper of which are provided with lugs cast upon their
periphery in order to give a positive motion to the chains; G, ofi-bearer, an endless revolving apron
for depositing the earth to the side and at distance required; H, screw in connection with revolving
nut (not seen in the engraving), worked by brake-wheel adjoining, for regulating the grade; I, pinion,
in connection with gear J, for transmitting power to traction-wheels B B ; K, rotary engine; L, boiler.
The excavator is represented in the act of entering the ground. The rear end of frame A is
raised by screw H at an angle sufficient to lower the forward or digging end (which is suspended) to
a contact with the ground; but a few feet advance is required to attain the necessary depth; the
rear of frame is then lowered until the bottom of the trench is made parallel with the surface of the
ground. The machine may be permitted to dig itself up on to the surface by a further lowering of
the rear end of frame. The digging is performed by the buckets D attached to chains E revolving
around the upper and lower chain-wheels FF. At the lower or digging point the concave backs of
the buckets firmly rest, while working in the earth, against the periphery of the lower chain-wheels;





they then pass up, performing merely the functions of elevators, carrying the earth to the upper
chain-wheels, at which point, in passing to return, they deposit their lead upon the off-bearer G,
which carries it to the side at any desired distance from the machine, dropping it upon the bank into
cars or carts. The machine is carried forward to its work by means of the traction-wheels BB, in
connection with the pinion I and gear J: The excavation made is sufficiently wide to permit the
machine to pass through.
Fig. 1550 represents Dunbar & Ruston’s steam navvy, which is used in connection with wagon
roads on each side. This is one of the most recently improved forms of this machine. As the
machine advances, excavating its own gullet, it fills alternately, first on the one side and then on
the other, one of the empty wagons in position for being filled. The lines of rails are arranged
for the wagons so that there is always 'a train of empty wagons standing on a central road behind
the navvy, and from-whence they are drawn over a short jump-road into position on the side roads
for filling, while the filled wagons run back from the machine on the side roads. The navvy is ca-
pable of excavating and filling into wagons at the rate of 60 cubic yards per hour, two men and one
boy being required to work it. '
This machine, as will be seen on reference to the detailed drawings, is constructed mainly of
wrought-iron, so as to withstand the heavy work that it has to encounter. The mode of working it
may be briefly described as follows: The engine-driver, who has the control of all the moving parts,
is directed by the man who has charge of the scoop, and who stands on the circular platform at foot
of the jib in front of the machine. When the jib is swung to the position required, the scoop is
EXCAVATI N G MACHINES. 675

lowered till the mouth of it rests upon the ground. The man on the circular platform, by means of
a foot-brake and gear, holds the scoop in that position, so fixing the length of the scoop-handle from
a pivot or point on the jib. The scoop is now drawn forward by means of a chain and winding-
drum, thereby cutting all before it, according to the radius described by the length of the scoop-
handle. As soon as the scoop is filled, the man who has charge of it eases the foot-brake, allowing
it to come out of its cut. When lifted high enough, the jib is then swung round until the scoop is
brought over the wagon to be filled; the attendant now, by means of a trigger-line, draws the spring
catch-bolt, allowing the hinged bettom to drop down, discharging its contents into the wagon. The
jib is then swung round again, the scoop lowered, and the operation repeated.
After the.machine has excavated all that is within its reach, the anchor-screws are slackened
off, extra sleepers with a short length of rails are laid down in front of it, and by means of the
propelling gear it is moved forward the required distance. The anchor-screws are then screwed
down in order to prevent the machine from slipping back when at work.
For submarine excavation, see Dasneme.
A steam digger and excavator, the invention of Mr. Otis of New York, is illustrated in the
annexed figures, which present the principal side elevation (Fig. 1551) of the machine, which brings
all the working parts sufficiently into view; Fig. 1552 is a plan of the horse-shoe pulley and crane top,
the dotted lines showing the position of the lower framing or stage and boiler; Fig. 1553 shows the
crank-shaft and gearing; Fig. 1554, the main drum; Fig. 1555, the main drum for working the ex
cavator; and Fig. 1556, a plan of the excavator.
The machine consists of a strong horizontal wooden framing or stage A, mounted upon two pairs
of railway wheels 6, for locomotion, which run on temporary rails, laid down as may be required; on




l
I'll
n)




____






the one end of the stage is fixed a cylindrical boiler O, and the gearing for turning the crane round.
In the middle is placed the gearing for working one of the motions of the excavator D ; and at the
other end is placed the wooden crane E, in form similar to an ordinary timber crane, on the diagonal
brace of which is placed a platform f, on which an assistant stands, and gearing W for working
another motion of the excavator D. ,
The excavator or shovel D, Fig. 1551, is formed of stout boiler-plate, and is firmly riveted to-
gether; it is of a box shape, having one end open: on the lower edge are four tangs or points,
which serve to penetrate and loosen the soil; the other end is hung on swivel hinges, and fastened
by a spring (I, which may be set at liberty by means of the lever and rods a.
The machine is made to perform three distinct movements: 1, the digging movement; 2, the turn-
ing movement; 3, the locomotive movement.
The digging movement consists of two motions, one for drawing the excavator forward, and the
other for driving it into the ground, both of which are done simultaneously. The first motion is per-
formed in the following manner: On the horizontal stage A, and in front of the boiler C, is placed
a. small high-pressure engine (not shown in the engraving), the connecting-rod of which acts upon
the crank c, and gives a rotary motion to the shaft L, and with it the pinion I, Fig. 1553, which
works into the large wheel 11!, mounted on the shaft N, upon which is fixed a large channeled barrel
or drum n, Fig. 1551, round which the hauling-chain O is coiled; this chain passes upward through
the hollow crane-post, over the indented pulley P, to a double pulley fixed at the jib-head, thence
round the blocks R, to which the excavator is suspended, as the chain wound up draws the excavator
out of the ground both in a forward and upward direction, when driven into the ground by the
second motion. This last motion is communicated, by the chain traversing over the indented pulley
P, to another gearing. On the axle of the indented pulley P is fixed a beveled wheel a, Fig. 1552,
67 6 EXCAVATING MACHINES.

which works into a similar one a' mounted on to the upper end of the oblique shaft V, on the lower
end of which is a corresponding beveled wheel a", working into another '10, fixed upon the shaft W;
upon this shaft is a pinion 20’, which takes into the large spur-wheel u', mounted upon a shaft, upon
which is a channeled drum 2:, round which is coiled the/chain s, attached to the diagonal wooden arms








































' , :' .-
"_ ' ad
4.): v ' ' ’- ' :\ ::- '-
-v'--- -' .2:--. .
a...’ =.. I K
‘ u \.
\.
\\ I,
. \ . '
\ . 1'
. ~ \
l | \
‘ I .... \
\/ ‘ \
t
J \ I
Scans—3 inches = 16 feet.



EXHAUSTER. 677

S; on the lower end of these arms is fixed an iron yoke, to which is suspended on pivots the ex.
cavator. By this arrangement, as the main chain 0 passes over the pulley P, motion is communi-
cated to the shaft for the purpose of forcing downward in a diagonal direction the arms 8, and with
them the excavator into the ground. A man stands upon the stage f, for throwing in and out of
gear this apparatus, and to regulate the motion for lowering or raising the excavator.
The next motion to be described is for the purpose of turning the crane round either to the right
or to the left; this is effected by another gearing in the following manner: On the first crank-shaft
I is fixed a beveled wheel Z, Fig. 1553, which works into a similar wheel g, mounted on to the end
of a horizontal shaft G, upon which are placed loose two beveled wheels g 9”, either of which can
be thrown in or out of gear so as to work, as may be required, into the large beveled wheel h,
mounted upon the shaft H; upon this shaft is a pinion h’, which works into the wheel j, fixed on
the shaft J; upon this shaft is fixed an indented pulley j', round which the chain r is coiled, and
passes upward over pulleys .9, round either side of the horse-shoe pulley, to the ends of which it is
fixed by iron bolts; the horse-shoe pulley is fixed by means of strong iron stays to the crane, and
when it is made to revolve, the crane-jib is turned round on the stationary post i, either to the right
or to the left as may be required, and empties the contents of the excavator into a wagon or barrow.
The progressing motion is effected by placing on the hind-wheel axle a strong wheel, shown by a
circle 6, Fig. 1551, which communicates with a pinion b', on the shaft, as shown by a dotted circle;
motion being given to the shaft above by the bevel-gearing described in the last motion, a forward
or backward motion of the machine is obtained.
The Guam-cur Excavating Apparatus has been largely employed in Europe, chiefly in the important
work of regulating the bed of the river Danube and in the construction of the Belgian ship-canal.
On the Danube this machine consisted of a chain of buckets so arranged on a frame that the empty
buckets descended from above while the filled ones rose below. On reaching the emptying point
these vessels were discharged by automatic mechanism. Motive power was supplied by a 20-horse
engine, and the entire apparatus was mounted on a carriage running upon three rails, and propelled
by a 4-horse engine. The excavated material on leaving the buckets fell into a conduit, which led it
to transport-wagons running on a second and parallel railroad. (See Ezginem-ing, xxvi., 312.)
Useful Data—Mr. Elwood Morris has determined the following useful data relative to excavation
work: A horse with a loaded dirt-cart, employed in excavation or embarkment, will make 100 lineal
feet of trip, or 200 feet in distance, per minute while moving. The time lost in loading, dumping,
awaiting, etc., equals 4 minutes per load. A medium laborer will load with a cart in 10 hours, of the
following earths, measured in the bank : gravelly earth 10, loam 12, and sandy earth 14 cubic yards.
Carts are loaded as follows: descending hauling, one-eighth of a cubic yard in bank; level haul-
ing, two-scvenths of a cubic yard in bank ; ascending hauling, one-fourth of a cubic yard in
bank. In loam a 3-horse plough will loosen from 250 to 800 cubic yards per day of 10 hours.
A scoop-load will measure one-tenth of a cubic yard, measured in the excavation. The time lost in
loading, unloading, and turning per scoop-load is 1% minute. The time lost for every 70 feet of dis-
tance, from excavation to bank and returning, is 1 minute. In double scooping, the time lost in
loading, turning, etc., will be 1 minute; and in single scooping it will be 1% minute. The volume of
earth in embankment is less than in excavation, from greater compression, the proportion being as
follows: sand, one-seventh; clay, one-ninth; gravel, one-fourth.
Sec Rankine’s “ Civil Engineering; ” also BLASTING, TUNNELING, ROCK-DRILLS, QUARRYIXG MACHINE,
WELL-BORING, and MINE APPLIANCES.
EXHAUSTER. See GAS, ILLUMINATING, APPARATUS FOR MANUFACTURE OF.
EXPANSION OF STEAM AND GASES. General Data—The formulae and tables that follow
give, in a compact form, the principal data required in calculations relating to the ordinary forms of
heat-engines; and the explanations that accompany them, together with the illustrative examples,
are intended to render them intelligible to all who may have occasion to use them.
Table I. is compiled from the experiments of Regnault, such calculations as were required being
made in accordance with rules given in Prof. Rankine’s “ Treatise on the Steam-Engine.” Some few
remarks on the properties of steam may be appropriate in this connection.
Saturated steam is steam which is just sufficiently heated to continue in the form of vapor. If
cooled at all, a portion will be condensed; and if any additional heat is imparted, the steam becomes
superheated. There are three distinct phases in the change of water into steam. Suppose heat is
imparted to a pound of water at 32° F., and under mean atmospheric pressure. The temperature
of the water will gradually be increased until it reaches 212°, and in this process, as shown by col-
umn 3 of the table, it will receive 180.5 units of heat, or as much heat as would raise the tempera-
ture of 180.5 lbs. of water from 39° to 40°. It requires 180.5 units of heat to raise the tempera-
ture of a pound of water through a range of 180° (from 32° to 212°), because the specific heat of
water increases with the temperature. To raise the temperature of a pound of water from 32° to 7",
T— 32 + 0.000000103 x [(T— 39.1)3 + (7.1)3] units of heat must be imparted to it; and by this
formula the quantities in column 3 of the table can be computed. When the water has attained the
temperature of 212°, the process of vaporization commences; and heat is required to perform the
work of overcoming the resistance of the particles of the water to the repulsion incident to the
change into vapor, and also to do the work of expansion against the resistance of the atmosphere in
which it is formed, so that the whole expenditure of heat in changing a pound of water at 32° into
steam of 212°, as shown by column 7 of the table, is 1,146.6 units, or the sum of the quantities in
columns 3, 4, and 5. By column 6, the latent heat of a pound of steam at atmospheric pressure is
966.1 units; and as this is the quantity of heat in a pound of steam evaporated “from and at 212°,”
the quantities in column ’7 divided by 966.1 give the total heat in units of evaporation, or pounds of
equivalent evaporation “ from and at 212°,” as shown in column 8. The other columns of this table
need no particular explanation.
678 EXPANSION OF STEAM AND GASES.
























TABLE 1., showing the Properties of Saturated Steam.
I,“ QUANTITY or near run room), IN nnrrisu ~
g m THERMAL UNITS. Tom Relative Ea
m . - v
((3 8‘ 5 Required Required to Vaporize the Water. Heat M 51:10,? a 8‘ g
in”: a E Temper- to "use Tom, Hum Vaporiza- Volume of a Weight of a that of my 9: a E
°‘ z a “‘““"F“h‘ 1115 Tem- To Over- To Over- of Vuporlza- 11°“ ., PM" °f Cm” F°°‘ 1111511 Water °* rs .
H D p: renheit emmm come come Latent Heat “on “have above 39 , Steam, in of Steam, in M th T E. p:
9‘ O <1 Scale. p - of Vaporiza- _° in Units Cubic Foot. Pounds. 0 em“ 0 ‘8
a ‘11 D of the Internal External t. s 32 —Sum f E _ perature of D 0-1 p
a 2 3’ Water Resistance Resistance 0;?léxl'mgg‘s of Columns oomt‘sg Maximum 8 z 53’
m H from 32° to Vapor- to Ex- 3 and 6. ‘ ' Dcnslt . N
‘4 to T. ization. pension. 4 and 5' 4 y g .
2 3 4 5 6 7 8 9 10 11 12
P T S I Z L E C W P I
Degrees. I
1 102.0 70.0 981.4 61.6 1,043.0 ' 1,113.0 1.152 330.4 .00303 20,623 1 '~
2 126.3 94.4 962 .0 64.1 1,026.1 1,120.5 1 .160 171.9 .00582 10,730 2
3 141.7 109 .8 949 .7 65. 7 1,015.4 1,125 .2 1.165 117 .3. 00552 7,325 3
4 153.1 121.3 940.6 66.8 1,007.4 1,128.7 1 .168 89.51 01117 5,588 4
2 9:9 51 191 212 .99 . . . . . o; , . . . ,
7 176 .9 145.2 921.7 69 .0 990.7 1,135.9 1.176 52.89 01891 3,302, 7
8 183.0 151.3 916.9 69 .6 986.5 1,137.8 1.178 46.65 02144 2.912 8
9 188.4 156.7 912.6 I 70.1 982.7 1,139.4 1.179 41.77 02394 2,607 9
10 193.3 161.7 908 7 70.6 979.3 1,141.0 1.181 37.83 02644 2,361 10
11 197.8 166.2 905.1 71.0 976 .1 1,142 .3 1.182 34.59 02891 2,159 11
12 202.0 170.5 901.8 71.3 973.1 1,143.6 1.184 31.87 03138 1,990 12
13 200.9 174.4 898.7 71.7 970.4 1,144.8 1.185 29.56 03383 1,845 13
14 209.6 178.1 895. 8 72 .0 967 .8 1,145.9 1.186 27 .58 03626 1,721 14
14 .7 212 .0 180.5 893 .9 72 .2 966.1 1,146.6 1 .187 26.37 03793 1,646 14 .7
15 218.1 181.6 _ 893.0 72.3 905.9 1,145.9 1.187 25.85 08869 1,014 E5—
16 216.3 184.9 890.5 72.5 963.0 1,147.9 1.188 24.33 04111 1,519 16
17 219.5 188.1 888.0 72.8 960.8 1,148.9 1.189 22.98 04352 1,434 17
18 222 .4 191.1 885.7 73 .1 958.8 1,149.9 1.190 21.78 04592 1,359 18
19 225.3 193 .9 883.4 73.3 956.7 1,150.6 1.191 20.70 04831 1,292 19
20 228.0 196.7 881.3 73.5 954.8 1,151 .5 1 .192 19.73 05070 1,231 20
21 230.6 199.8 879.2 ° 73.": 952.9 1,152.2 1.192 18.84 05807 1,170 ' 21
22 233.1 201.8 877.3 73.9 951.2 1,153.0 1 .194 18 .04 05545 1,126 22
23 235 . 5 204 .3 875.4 74.1 949 .5 1,153 .8 1 .194 17 .30 05781 1.080 23
24 237.8 206.6 873.5 74.3 947.8 1,154.4 1.195 16.62 06017 1,038 24
25 240.1 208.9 871.8 74.5 916.3 1,155.2 1.196 16.00 06252 998.4 25
26 242.2 211.1 870.1 74.7 944.8 1,155.9 1.196 15.42 06487 962.3 26
27 244.3 213.2 868.4 74.8 943.2 1,156.4 1.197 14.88 06721 928.8 27
28 246.4 215.3 866.8 75.0 941.8 1,157.1 1 198 14.38 06955 897.6 28
29 248.4 217.3 865.2 75.2 940.4 1,157.7 1.198 13.91 07188 868.5 29
30 250 .3 219.3 863 .7 75.3 939.0 1,158 .3 1 .199 13 .48 07420 841.3 30
91 252.2 221.2 862.2 75.5 987.7 1,158.9 1.200 12.07 07652 815.8 81
32 254.0 223.0 860.8 75.6 936.4 1,159 .4 1.200 12.68 07884 791 .8 32
a 29 as 1191 3211 129 a
207.5 22 . 858.0 .. 1 . , . 1.2 1 . .
35 259 .2 228.3 856.7 76.0 932.7 1,161.0 1.202 11.66 08577 727.9 35
36 260.9 230.0 855.4 76.1 931.5 1,161.5 1.202 11.36 08807 708.8 36
37 262.5 231.7 854.1 76 .3 930 .4 1,162.1 1.203 11 .07 09036 690.8 37
38 264.1 233 .3 852.9 76.4 929 .3 1,162.6 1 .203 10.79 09266 673.7 38
39 265.6 234.8 851.6 76.5 928.1 1,162.9 1 204 10.53 .09495 657.5 39
40 267.2 236.4 850.4 76.6 927.0 1,163.4 1.204 10.28 .09723 642.0 40
° 41 268.7 237.9 849.3 76.7 926.0 1,163.9 1.205 10.05 .09951 627.3 41
42 270.1 239.4 848.1 76.8 924.9 1,164.3 1.205 9.826 10179 613.3 42
43 271.6 240.8 847.0 76.9 923.9 1,164.7 1.206 9.609 10407 599.9 43
44 273.0 242.3 845.9 77.0 922.9 1,165.2 1.206 9.403 10635 587.0 44
45 274.3 243.7 844.8 77.1 921.9 1,165.6 1.207 9.207 10862 574.7 45
46 275.7 245.1 843.7 77.2 920.9 1,166.0 1.207 9.018 11088 563.0 46
47 277.0 216.4 842.7 77.3 920.0 1.166.4- 1.207 9.838 11315 551.7 47
48 278.3 247.8 841.7 77.4 919 .1 1,166.9 1.208 8.665 11541 540.9 48
49 279.6 249.1 840.6 77.5 918.1 1,167.2 1.208 8.498 .11767 530.5 49
50 280.9 250.4 839.7 77.6 917.3 1,167.7 1.209 8.338 .11993 520.5 50
51 282.2 251.6 838.7 77.7 916.4 1,168.0 1.209 8.185 .12218 510.9 51
52 283.4 252.9 837.7 77.8 915.5 1.1684 1.209 8.037 .12443 501.7 52
222 12.9 291 192-1 191: as: as a
' o ' c' ' - 0 ' n )\ a ' , . l l
55 287.0 256.5 834.9 78.0 912.9 1:169.4 1.211 7.624 .13112 475.9 55
56 288.1 257.7 834.0 78.1 912.1 1,169.8 1.211 7.496 .13341 467.9 56
57 289.3 258.9 833.1 78.2 911.3 1,170.2 1.211 7.372 .13565 460.2 57
58 290.4 260.0 832.2 78.3 910.5 1,170.5 1.212 7.252 .13789 452.7 58
59 291.5 261 .1 831 .4 78.3 909 .7 1,170.8 1.212 7 .136 .14013 445.5 59
60 292.6 262.2 830.5 78.4 908.9 1,171.1 1.212 7.024 .14236 438.5 60
3 A 2"“ 333 33'; 3'3 “811 1133 1'53 3'31? 11133 21'; 3 *
294.7 .4 . . 9 . , . . . . .
a rs 113% 121 292 1992 112-1 ' 296.8 266.6 827.2 8. . 1 .. , ‘ . . . . . '
65 1297 . 8 267. 6 826.4 78 . 8 905 . 2 1,172 .8 1 . 214 6. 515 .15350 406. 6 '65














EXPANSION OF STEAM AND GASES.
679

TABLE I. (continued).











































5 QUANTITY OF HEAT PER POUND, 157 BRITISH l1 g~
' THERMAL UNITS. Relative , a:
5; E 5 Requlmd Required to Vaporize the Water. 58:18; 201mm or .7’ E 5
a 8 E Temper- “, min Total Heat Vaporiw Volume of a Weight of a thmgi; 2 g (a Z
n, * nture,Fah- _ _ _ _ tion Pound of Cubic Foot . - : a, 7'
é ‘71 reuheit “11:32 To 0‘2" Tocgver Latent Heat 03:82:13? above 32°, Steam, in of swam, in hue: wnm H g 2
E 0 <1 Scale, p9 09m me of Vupoflza— {on e 111 Units Cubic F test. Pounds. at t 8 Tem' E {5 o <
p, D of the Internal External 3! —--Sum . perature of 9- :3
’J a W m R l ta Resista “nu—sum of C lam 0f Evap‘ 1 "J a
o E "1 a r e' 1 nee n“ 0! Column: 0 m oration Maximum ‘ e Z m
g from 32° to Vapor~ to Ex- 4 d 5 3 and 6. ' DENNY . 22 h
4 to T. imflon. pansion. “1 ' ' <
l
1 2 a , 4 5 7 a 10 I 11 1 12
P T I l H w 1 v ‘ P
Degrees. .
66 298.8 268.6 825.6 78.8 ‘ 904,4 1,173.0 1.214 6.422 15572 400.8 66
67 299.8 269.7 824.8 78.9 903.7 1,173.4 1.215 6.332 .15794 315.2 67
68 300,8 270,7 824,1) 79,0 903_() 1,173.7 1.215 6.244 .16016 889.8 68
69 801.8 271.7 823.3 79.0 902.3 1,174.0 1.215 6.159 .1628? £84 .5 69
70 302.8 272.7 822.5 79.1 901.6 1,174.3 1 .216 6.076 .16458 879.3 70
71 303.7 273.6 821.8 79.2 901.0 1,174.6 1.216 5.995 16679 374.3 71
72 304.7 274.6 821.0 79.2 900.2 1,174.8 1 .216 5.917 16900 369.4 72
73 305.6 275.6 820.3 79.3 899.6 1,175.2 1.216 5.841 17121 314.6 73
74 806.5 276.5 819.6 79.3 898.9 1,175.4 1 .217 5.767 .17342 360.0 74
75 307.4 277.4 818.9 79.4 898.3 11175-7 1.217 5.694 17562 355.5 75
76 303.3 278.4 818.2 79.5 897.7 1.1761 1 .217 5.624 .17783 251.1 76
77 309.2 279.8 817.5 79.5 897.0 1,176.3 1.218 5.555 .18003 346.8 7
78 310.1 280.2 816.8 79.6 896.4 1.176.6 1 .218 5.458 .18228 $426 78
79 311.0 281.1 816.1 79.6 895.7 1,176.8 1.218 5.422 .15443 {38.5 79
80 811.9 282.0 815.4 79.7 895.1 1,177.1 1.218 5.358 .186C3 334 5 80
81 312.7 282.8 814.7 79.7 894.4 1177.2 1.219 5.296 .188 82 83 ,6 81
82 313.6 283.7 814.1 79.8 893.9 1,177.6 1.219 5.235 .19102 326.8 82
88 314.4 284.6 813.4 79.9 893.3 1,177.9 1 .219 5.176 19321 8178.1 83
84 315.3 285.4 812 8 79.9 892.7 1,178.1 1.220 5.118 19540 819.5 84
85 316.1 286.3 812.1 80.0 892.1 1.1784 1 .220 5.061 19759 315.9 85
86 316.9 237.1 811.5 80.0 891.5 1,178.6 1.220 5.006 19978 312.5 86
87 317.7 237.9 810.9 80.1 891 .0 1,178.9 1.220 4.951 20197 309.1 87
88 818.5 288.8 810.2 80.1 890.3 1,179.1 1.221 4.898 20416 805.8 88
89 819.3 289.6 809.6 80.2 839.8 1,179.4 1.221 4.846 20134 802.5 59
90 320.1 290.4 809.0 80.2 889.2 1,179.6 1 .221 4.796 20558 299.4 90
91 820.9 291.2 808.4 80.3 888.7 1,179.9 1 .221 4.746 21071 296.3 91
92 821.7 292.0 807.8 80.3 885.1 1.1801 1 .222 4.697 21289 29. 2 92
93 822.4 292.8 807.2 80.4 887.6 1,180.4 1 .222 4.0“ 21507 290:2 93
94 323.2 293.5 806.6 80.4 887.0 1,180.5 1 .222 4.603 21725 287.3 94
95 823.9 294.3 806.0 80.4 886.4 1,180.7 1 .222 4.557 21943 284.5 95
96 324.7 295.1 805.4 80.5 885.9 1,181.0 1.222 4.518 22160 251.7 96
97 325.4 295.8 804.8 80.5 835.3 1.181 .1 1 .223 4.469 22878 279 .0 97
98 326.2 296.6 804.2 80.6 ' 881.8 1,181.4 1 .223 4.426 .22595 276.3 98
99 326.9 297.4 803.7 80.6 884.3 1,181.7 1 .223 4 .384 .22812 273.7 99
100 327.6 298.1 803.1 80.7 888.8 1,181.9 1 .228 4.342 .29029 271.1 100
101 828.3 298.8 802.5 80.7 883.2 1,182.0 1.224 4.502 .23246 268.5 101
102 329.1 299.6 802.0 80.8 832.8 1,182.4 1.224 4.212 23463 266.0 102
103 329.8 300.3 801.4 80.8 832.2 1,182.5 1 .224 4.223 28680 263.6 1(3
104 330.5 301.0 800.9 89.8 881'7 1,182.7 1 .224 4.1%5 03597 261.2 104
105 331.2 301.7 800.3 80.9 881.2 1,182.9 1.225 4.147 24114 258.9 105
106 331.9 302.4 799.8 81.9 880.7 1,183.1 1.225 4.110 24330 256 6 106
107 332.6 303.2 799.3 81.0 889.3 1,183.5 1.22 4.074 24547 254:8 107
108 883.2 303.9 798.7 81.0 879.7 1188.6 1.225 4.138 24763 252.1 108
109 333.9 804.6 793.2 81.0 879.2 1,183.8 1.225 4.003 .24979 249.9 1(9
110 334.6 305.2 797.7 81.1 878.8 1,184.0 1.226 3.969 .25195 247.8 110
111 335.3 305.9 797.2 81.1 878.3 1,184.2 1 .226 3.935 .25-411 245.7 111
112 835.9 306.6 796.6 81.1 877.7 1,184.3 1.226 8.902 .25626 243.6 112
113 836.6 807.3 796.1 81.2 877.3 1,184.6 1.226 3.870 .25842 241.6 118
114 837.2 3 l8.0 795.6 81.2 876.8 1,184.8 1.226 3.338 .26158 289.6 114
115 337.9 308.6 795.1 81.3 876.4 1,185.0 1.227 3.506 £6273 287.6 115
116 338.5 309.3 794.6 81.3 875.9 1,185.2 1.227. 3.775 .26-459 235.7 116
117 839.2 309.9 794.1 81.8 875.4 1,185.3 1.227 ' 8.745 26704 253.8 117
118 839.8 810.6 793.6 81.4 875.0 1,185.6 1.227 3.715 26920 if .9 118
119 340.4 311.2 793.1 81.4 874.5 1,185.7 1.227 3.685 27135 130.1 119
120 341.1 311.9 792.6 81.4 874.0 1,185.9 1.228 8.656 2785 228.8 120
121 341.7 312.5 792.2 81.5 873.7 1,186.2 1.228 8.628 .27-565 226.5 121
122 342.3 313.2 791.7 81.5 873.2 1,186.4 1.228 3.600 .27780 224.7 122
123 342.9 313.8 791 .2 81.5 872.7 1,186.5 1.228 8.572 .27995 228.0 128
124 343.5 314.4 790.7 81.6 872.3 1,186.7 1.228 3.545 .25210 221 .3 124
125 844.1 315.1 790.2 81.6 871.8 1,186.9 1.229 8.518 .28424 219.6 125
126 344.7 315.7 789.8 81.6 871 .4 1,187.1 1.229 8.492 .28639 218.0 126
127 345.8 316.3 789.3 81.7 871.0 1,187.3 1.229 8.466 .28858 216.4 127
128 345.9 316.9 788.8 81.7 870.5 1,187.4 1.229 3.440 .29068 214.8 128
129 346.5 317.5 788.4 81.7 870.1 1,187.6 1 .229 3.415 29282 18.2 129
130 347.1 318.1 787.9 8%.8 869.7 1,187.8 1 .230 3.890 29496 211.6 130
140 852.8 324.0, 783.5 8 .1 865.6 1,189.6 1.231 8.161 31634 197.8 140
150 _ 858.2 329 . 6 779 .8 82 .4 861.7 1,191 .3 1.233 2 .962 33764 184 .9 150





680 EXPANSION OF STEAM AND GASES.

It seldom happens that the temperature of the feed-water is at 32°, and table II. contains correc-
tions for various temperatures from 32° to 212°. To illustrate its use, suppose it is required to find
the total heat in units of evaporation necessary to change a pound of water at 65° into steam having
a pressure of 100 lbs. per square inch. By column 8 in table I., it appears that the total heat in
units of evaporation from water at 32° is 1.223, and by table II. the correction is 0.034 ; so that the
required quantity is 1.223 —0.034 : 1.189 unit of evaporation.
TABLE 11., showing Correction for (Traits of Evaporation—Difermt Temperatures of Feed- W’ater.


l
3 Temperature 1 Temperature
of Food, O 1 2 3 4 5 6 7 8 9 of Feed,
Fahr. Degrees. 1 Fahr. Bag.
30 | .... .... .... .001 .002 .003 .004 .005 .000 007 30
40 i .008 .009 .010 .011 .012 .014 .015 .010 .017 018 40
50 f .019 .020 .021 .022 .023 .024 .025 .020 .027 028 50
00 i .029 .030 .031 .032 .033 .034 .035 .030 .037 038 00
70 .039 .010 .041 .042 .044 .045 .040 .047 .048 049 70
80 .050 .051 .052 .053 .054 055 .050 .057 .058 .059 80
90 .000 .001 .005 .003 .004 .005 .000 .007 .008 .009 90
100 .070 .071 .073 .074 .075 .070 .077 .078 .079 .080 100
110 .0*l .082 .083 .084 .085 .080 .087 .088 .089 .090 110
120 .091 .002 .093 .094 .095 .090 .097 .098 .099 .101 120
130 .102 .103 .101 .105 .100 .107 .108 .109 .110 .111 130
140 .112 .113 .114 115 .110 .117 .118 .119 .120 .121 140
150 122 .123 .124 .125 .120 .128 .129 .130 .131 .132 150
100 .133 .131 .135 .130 .137 .138 .139 .140 .141 .142 100
170 .143 .144 .145 .140 .147 .148 .149 .150 .151 .153 170
180 .15' .155 .150 .157 .158 .159 .100 .101 .102 .103 180
190 .104 .105 .100 .107 .108 .109 .170 .171 .172 .173 190
200 .174 .175 .170 .178 .179 .180 .181 .182 .183 .184 200
210 .185 .180 .187 .... .... .... .... .... .... .... 210














The weight and volume of water at different temperatures are frequently required in making cal-
culations ; and they can be deduced from the following formulae, which are taken from Watt’s
“ Dictionary of Chemistry,” and represent the results of experiments by Kopp, Matthiessen, Sorby,
and Rosetti:
Let V: ratio of a given volume of distilled water, at the temperature T on Fahrenheit’s scale,
to the volume of an equal weight at the temperature of maximum density. W: weight of a cubic
foot of distilled water, in pounds, at any temperature, Fahrenheit.
For temperatures from 32° to 70° F. : V: 1.00012—0.000033914 X (T-— 32) + 0.0000023822 x
(T— 32)‘2 - 0000000006103 (T— 32)“.
For temperatures above 70° F.: V: 0.99781 + 0.00006117 x (T— 32) + 0.000001059 x (T—-32)9.
W__ 62.425_

The table given below has been computed by the aid of these formulae. The experiments on the
expansion of water have not been carried beyond a temperature of 412° F., so that the results given
in the table for higher temperatures have not been verified. It is not probable, however, that they
are greatly in error. The highest temperature in the table corresponds to a pressure of saturated
steam of more than 1,000 lbs. per square inch. The successive increments of 10° F. give such
slight changes in the successive differences in relative weights and volumes as to render interpola-
tions by proportion sufficiently accurate for most purposes. The weights given in the tables are for
pure water, so that, when water contains foreign matter, it will be necessary to multiply the tabular
weight by the specific gravity of the water. For ordinary rain, spring, or river water, the correction
is generally so slight that it may be neglected. Below are given the specific gravities of waters from
different localities, the most of which have been taken from Professor Chandler’s lecture on “ Wa-
ter,” published in the thirty-first annual report of the American Institute:

Atlantic Ocean . . . . . . . . . . . . . . . . . . . . 1.0275 Delaware River . . . . . . . . . . . . . . . . . . . 1.000059
Dead Sea . . . . . . . . . . . . . . . . . . . . . . ..1.17205 LakeErie........................1.000107
Great Salt Lake . . . . . . . . . . . . . . . . . . . 1.17 Lake Michigan . . . . . . . . . . . . . . . . . . . 1.000113
Mississippi River. . . . . . . . . . . . . . . .. 1.00068 Genesec River. . . . . .. . . .. . . . . . . . . 1.000226
Croton (New York water-supply). . . . 1.00008 Passaic River . . . . . . . . . . .. . . .. -. . .. 1.000127
Ridgewood (Brooklyn water-supply). 1.000067 Thames, at London . . . . . . . . . . . . . . . 1.000279
Cochituate (Boston water-supply). . . . 1.000053 Seine, above Paris. . . .. . . . . .. . . . 1.000151
Schuylkill (Philadelphia water-supply) 1.00006
It will be seen from these figures that, for most cases, it will be sufficiently accurate to use the
weights given in the table. If the weight of a gallon of water at any temperature is desired, it
may be obtained by dividing the weight of a gallon of water at the temperature of maximum den-
sity (8.3389 lbs. for a United States gallon, and 10.001077 lbs. for an imperial gallon) by the relative
volume at the required temperature. It may also be obtained by multiplying the weight of a cubic
foot of water at the given temperature by 0.1335631 to find the weight of a United States gallon,
and by 0.1603412 to find the weight of an imperial gallon. When water contains foreign matter in
solution, its rate of expansion by heat is not exactly the same as in the case of distilled water; but
there have not been experiments enough to determine the law of the variation, and no great error
will arise from the assumption that the expansion is in accordance with the formulae given above.
With these explanations, the use of the following table will be rendered plain to the reader:
EXPANSION OF STEAM AND GASES.
681

TABLE 111., showing Volwme and Weight of Distilled lVater at Difl'erent Temperatures on the

















Fahrenheit Scale.
Tempera- Rutio of Volume to Tempere- Ratio of Volume to
ture, Volume of Equal Weight of a ture, Volume of Equal Weight of a
Fuhrem Weight at the Difl’erence. Cubic Foot Difl'erencai Fahreu- Weight at the Difference. Cubic Foot ‘Difl'erencea
helt Temperature of in Pounds. heft Temperature of in Pounds.
Degrees- Maximum Density. Degrees. Maximum Density. .
82 1 .000129 ..... . . 62.417 . . .. ‘ 290 1 .08405 .00596 57.585 .318
39 .2 1 .000129 02.425 .008 i 300 1 .09023 00618 57.259 .320
40 1.000004 .000004 02.423 .002 l 310 1 . 09001 00038 50.925 .334
50 1.000253 ' .000249 02 .409 .014 1 320 1 . 10323 .00002 50. 584 .341
00 1 .000929 .000070 02.307 .042 I 330 1 .11005 .00082 50.230 .348
70 1 .001981 .001052 02.302 .005 340 1 . 11700 .00701 55 . 583 .353
80 1 .00332 .001339 02.218 1 .084 350 1 .12431 .00725 55.523 .300
90 1 .00492 .0000 02.119 .099 300 1. 13175 .01-744 55.158 .305
100 1 .00080 .00194 02 .119 370 1 . 13942 .00707 54 .787 .371
110 1 . 00902 00210 01 . 807 .183 380 1 . 147 29 00787 54 .411 .370
120 1 . 01143 00241 01. 720 .147 890 1 .15538 008119 54 . 030 .381
130 1.01411 00208 01 . 550 .104 400 1 .16300 00828 53 . 045 .385
140 1 .01090 .00279 01 .388 .108 410 1.17218 00852 53 .255 .390
150 1 .01995 00305 01 .204 .184 420 1 .18090 00872 52 .802 .293
100 1 .0231'4 00329 01. 007 . 197 430 1 .18982 0( 892 52 .400 .390
170 1 02071 00347 00.801 .200 440 1 .19898 00910 52 .065 .401
180 1 . 03033 00302 00 . 5S7 . 214 450 1 . 20533 . 00935. 51 .602 . 403
190 1 .03411 00378 00 . 300 .221 400 1 .21790 .00957 51 .250 .400
200 1 .03807 00390 00 . 130 .230 470 1 .22707 009 77 50 . 848 .408
210 1.04220 00419 59 .894 . 242 480 1 . 23760 .00999 50 .438 .410
212 1.04312 00080 59 .707 .187 490 1 .247 .01019 50.020 .412
220 1 .04003 00350 59 . 041 .000 500 1 .25828 .01043 49 . 011 .415
230 1 . 05142 00474 59 .372 . “209 510 1 .26592 .01004 49 . 195 .410
240 1.05033 00491 59 .090 .270 520 1 .27975 .01083 48.778 .417
250 1 .00144 00511 58.812 .284 530 1 . 29080 .01105 48.300 .418
200 1 .00079 00535 58. 517 . 295 540 1.30204 .0112! 47 .941 . 419
270 1 .07233 . 00554 58.214 .303 550 1 .81354 .01150 47.521 .420
280 1 . 07809 . 00570 57 . 903 .311
i
A perfect gas is one in which the particles are absolutely frictionless in their mutual action.
There are no examples of perfect gases in nature, but gases which can only be solidified by extraor-
dinary means, such as air, nitrogen, oxygen, hydrogen, are commonly considered to follow perfect
gaseous laws.'* Table IV. contains the principal properties of such gases, as well as approximate
data for steam. The columns relating to perfect gases will be found very useful in calculations
relating to air-engines, while those referring to steam will be equally serviceable in computations
connected with steam-engines, as is fully explained in the illustrative examples that follow. The
quantities in this table have been calculated in the following manner: Calling any quantity in col-
1 I D Q I
umn 1 or 24, ~1 the correspondlng quantities 1n the other columns are:
2.
R

1 + liyp_._log. R

R
3451—2451 x (—
1 0.408
R)

R
1
. 17 x é—lG x
Err-les}?
R—l

2451 [1 (1 MOS]
" X - a) _
R--1

R
‘6 X 5719101
hyr- 12515
1

NJ
1 0.408
2.451 x [1— (__) 1
10. R

R

3. (Egg?
0.
4. (l)
R
5- er
a“
6.
29
408
1 1.-
16 x [1—(—>‘°]
11. - R
R
(1)0408
' R
1
oo

23.
- (19%
( 1>3.451
' R
1\6
. TU
l
R)

* Quite recently all the so-called permanent gases have been liquefied. the discovery being announced almost simul-
taneously by M
.Oaillctet and Pictet. To M. Cailletet, however, belongs the priority. See 1111- Nature, 1877,1878;
Journal of the Franklin Institute, cv., cvi. ; Scientific American, xxxviii., 147 ; Scientific American Supplement.
v., 1888; Engineemng, xxv., 324.
682
EXPANSION OF STEAM AND GASES.
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389
TABLE IV. (continued).


GIVEN RATIO: TEMPERATURE, PRESSURE,
OR VOLUME.





1













Ratio of Initial and Final Tempera- a-
Ratio of Mean to Initial Total Pressure, for given Ratio of tures: Absolute Temperature for Ratio of Initial and Final Absolute Ratio of Initial and Final a:
Volumes. Air ; Temperature on Fahrenheit’s ures. Volumes. 5?,
Scale + 100° for Steam. g
Ratio of Total Pressure at :5
Point of Cut-off to Portion of For given Ratio For given Ratio 7'
Rate of Mean Total Pressure of Tempera- of Tempera- hi
During whole Stroke during whole Stroke that turea: Absolute tures: Absolute g a
, . _ is due to Expansion, _ . For given Ratio _ Temperature Fcr 'ven Ratio Tem ture £-'
(aziPipposing ItnétinltPrtesénre and During Expansion on)» for given Ratio of Volumes. F0; QT? Ram of Absolute For gviwlm Ratio or for Air; Tem- ofgAbsolu‘e for AlwTem— g E
Inverse ressure 2e _ :11) 6:31 ut-o o 0 units. Pressures. o umes. perature on Pressums. pemme on E g
Baum to 1 en Fahrenheit’a Fahrenheit’s 2 >-
Scale + 100° Scale + 100° H g:
for Stem. for Steam. o
0
Air ex- Air 421- Air ex- Air ex- Air or Air ex- Air ex- Air or Air ex“ I:
Fade“ panding Pgiaect pending Palm pnnding panding Satm panding Sam_ pnnding Plum—7:115 sahb panding pending ssh” é
88’ Without. Saturated T ’ without Saturated Tum e’m_ without Saturated without ted without “d without Saturated without mud without Saturated without mi
Temper-a- Loss or Steam. empm- Loss or Steam. p Low or Steam. Loss or m Loss or m L Loss or Steam. Loss or Loss or Steam. Loss or m g
ture ture lure Steam. Steam. . Steam. . 31mm
Gain of Co mm. Gain of constant Gain of Gain 01‘ Gain of Gain of Gain of Gum of Gain of a
commit“ Heat, “8 Heat. Heat. Heat. Heat. Hunt. Heat. Heat. Heat. 6
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2O 21 22 23 24
3 . 846 .6102 . 5295 5959 4733 .8641 .4539 . 3502 . 2695 . 3359 . 5772 .788 . 6768 . 799 . 1501 . 2890 .010 .3841 .2814 . 037 . . . . .26
3 .7 04 .6235 . 5439 6094 4843 .3752 .4650 .3535 2739 .8394 . 5861 . 798 .6843 . 804 .1583 . 2488 .011 .8946 . 2916 .040 . . . . .27
3.571 . 6364 .5580 6226 4950 .3861 .4759 .3564 .2780 .8426 .5949 .798 . 6915 .809 .1666 .2586 .012 . . .4049 .8018 .044 . . . .28
3 .448 .6490 .5718 6355 5056 .3970 .4866 .3590 .2818 .8455 . 6035 .803 .6986 . 814 .1750 2684 .014 .4151 .3119 .048 . . . . .29
8.333 .6612 .5854 .6479 .5160 .4077 .4971 .3612 .2854 .8479 . 6119 .808 .7055 .818 .1836 .2783 .016 .4252 .3220 .052 . .30
3.226 .6731 .5986 .6601 .5262 .4183 .5074 .8631 .2886 .8501 .6201 .818 I .7122 .828 .1922 .2881 .018 .4353 .8321 .057 . .81
8 .125 .6846 .6116 .6719 .5362 .4288 .5176 .8646 .2916 .8519 .6282 .817 .7188 .827 .2010 .2980 .020 .4452 .3422 .061 .32
3 .03 6959 . 6243 . 6835 . 5461 .4393 . 5276 . 8659 . 2943 . 3535 . 6361 .822 . 7252 . 831 . 2099 .8079 . 022 . .4550 .8522 .066 . .33
2 .941 7068 . 6367 . 6947 .5558 .4496 . 5374 .3668 .2967 . 3547 .6489 .826 .7315 .885 .2189 .3178 .024 . 4648 .3623 .071 . . .84
2 . 857 7174 . 6489 . 7056 .5653 .4598 . 5471 .8674 2989 .8556 .6516 .830 . 7377 . 889 . 2281 .8278 .027 .4744 .3723 . 076 . . .35
2 .778 7278 . 661 18 .7163 .5747 .4700 .5567 .8678 .8008 .3563 .6591 .835 . 7438 .843 .2873 .3877 .029 .4840 .8823 .082 . . . .36
2.703 7379 . 6724 .7267 .5839 .4800 .5662 8679 .3024 .3567 .6665 .839 .7497 .847 .2466 .8477 .082 .4985 .3928 .087 . . .87
2 . 682 . 7477 .6838 .7368 .5930 .4900 . 5755 .3677 .8038 .3568 .6788 . 843 .7555 . 851 .2561 .8577 . 085 5080 .4028 . 093 .38
2 . 564 . 7572 . 6949 . 7466 . 6020 .4999 .5846 . 8672 .3049 .8566 . 6810 .846 . 7612 .855 . 2656 . 3677 . 089 5124 4122 . 099 . 89
2 .5 .7665 7058 7562 6109 .5097 . 5937 3665 3058 .8562 . 6881 .850 . 7668 .858 . 2752 .3777 .042 . . . .5216 .4222 .106 . . . .40
2.439 .7756 .7165 7656 . 6196 .5194 .6026 8656 3065 .3556 .6951 .854 .7723 .862 .2850 .3878 .046 . . . .5809 .4321 .112 . . . .41
2 .881 .7844 .7269 .7747 .6282 .5291 . 6115 3644 3069 .3547 .7019 .858 .7777 .805 .2948 .8978 .050 . . . .5400 .4420 .119 . .42
2 .326 .7929 .7370 .7 8‘35 .6367 .5386 . 6202 .8629 3070 .3535 . 7087 . 861 .7881 .869 .3047 4079 .054 . . . . .5491 .4519 .126 . . . .48
2.273 .8012 .7470 .7921 .6451 . 5481 .6288 .8612 .8070 .3521 .7154 .865 .7.‘ .872 .8148 .4180 .059 . . . . .5582 .4618 .134 . . . .44
2 . 222 . 8098 . 7567 . 8005 . 6533 . 5576 .6373 .8598 .8067 .3505 . 7220 . 868 . 7984 .875 .3249 .4281 . 064 .008 . 5672 . 471 6 .141 011 .45
2.174 .8172 .7662 8087 .6615 .5670 . 6457 .8572 .8062 .3487 .7285 .872 . 7985 .879 .8851 .4392 .069 .009 .5761 .4815 .149 012 .46
2 .128 . 8249 .7754 . 8166 .6696 . 5762 . 6510 .8549 .8054 .3466 . 7849 .875 8035 . 882 .3451 .4483 .074 .011 .5850 .4913 .157 014 .47
2 . 083 . 8323 . 7845 . 8244 6775 . 5855 . 6622 . 3593 .3045 .3444 . 7412 . 878 8084 . 885 . 8558 . 4585 . 079 . 012 . 5938 . 5012 . 105 016 .48
2.041 . 8395 . 7933 .8819 6854 . 5947 6703 . 8495 3033 . 3419 . 7475 .881 8138 . 888 .8668 .4686 . 085 . 014 6025 . 5110 . 174 018 .49

























7’89
'SHSVE) (INV WVEIJS .ElO NOISNVdXH
TABLE IV. (coniz'nuedl

Ratio of Mean to Initial Total Pressure, for given Ratio of
Volumes.



Ratio of Total Pressure at
Point of Cut-off to Portion of
Ratio of Initial and Final Tempera-
tures: Absolute Temperature for
Air; Temperature on Fahrenheit’a
Scale + 100° for Steam.
Ratio of Initial and Final Absolute
Pressures.
Ratio of Initial and Final
Volumes.
Rfssumi,

For given Ratio
For given Ratio 7'
.7




































{If
M
i
05
n.
i=7 Ratio of Mean Total Pressure of Tempem- of Tempera- ~,
g a. During whole Stroke during whole Stroke that turea: Absolute tures: Absolute g hi
8 . . . is due to Expansion, 4 v . For ven Ratio Temperature For given Ratio Temperature g g (supposmg Imtm} Pressure and During Expansion only. for given Ratio of Volumes. For}? en Ram) ofgjtbsolute For given Ratio or for Air; Tem- of Absolute for Air; Tem-
E
H ,4 Inverse Pressure at Point of Cut-off 01 “Volumes. Pleqsmes Volumes. mmre on Prcssures emture on w 1;:
2' 0 Ratio. to be identical). ~ - p _ . p “I O
E > Fahrenheit’s Fahrenheit’s E >
no a; Scale + 100° Scale + 100° a e:
a o for Steam. for Stem. I. o
2 1 A. m “ A. A. A. A. A. A! A. 9
[-7 1r ex- r ex- ir ex- 1r ex- . ir ex- ir ex- ir ex- r ex- 1r ex- [-1
g Pgga pnnding 1,32% pending P21?“ pending pending sank pending sank panding Pulldiua sank pending ku’udiug Sank 2
1 Tem e’m_ Without Saturated Tom ’m_ Without Saturated Tam e’m_ Without Saturated Without rated Without rated without Saturated without mud Without Saturated WIthout rated z
a ' mp Loss or Steam. ml: Loss or Steam. “56 Loss or Steam. Loss or 5mm Loss or St Loss or Steam. Loss or Steam Loss or Steam. Loss or Steam
2 g C I: t Gain of Com t Gain of C m t Gain of Gain of ' Gain of em“ Gain of Gain of ' Gain of Gain of ' E
o 1 °“5 “ ' Heat. “ ' Heat. “‘5 n ' Heat. Heat. Heat. Heat. Heat. Heat. Heat. 0
2 3 4 5 6 7 8 9 10 11 12 18 14 15 16 17 18 19 2O 21 22 23 24
. 50 2 . 8466 . 8019 . 8392 .6932 . 6038 . 6784 . 3466 . 3019 . 3392 .7537 . 884 .8180 . 891 .3768 .4788 . 091 . 016 . 6112 . 5208 .183 020 . 50
.51 1.961 .8534 .8103 .8463 .7008 .6128 .6868 .3434 .3003 .3363 .7598 .888 .8227 .894 .3875 .4890 .098 .018 .6199 .5306 .192 .022 .51
. 52 1 . 923 . 8600 . 8185 . 8532 . 7084 . 6218 . 6941 . 3400 . 2985 . 3332 7658 . 891 . 8274 . 897 . 3982 . 4992 . 105 . 020 . 6285 . 5404 . 201 . 025 . 52
.53 1 .887 .8665 .8264 .8599 . 7159 . 6307 .7019 .3365 .2964 . 3299 7718 . 894 . 8320 .900 .4091 .5094 .112 . 022 . 6371 .5502 .211 . 028 .53
.54 1 . 852 .8727 . 8342 .8664 .7234 . 6396 . 7096 .3327 .2942 .3264 .7777 .897 . 8365 . 902 .4200 .5196 .119 . 025 . 56 . 5599 . 221 .031 .54
.55 1 . 818 . 8788 . 8418 .8727 .7307 . 6484 .7172 .3288 .2918 .3227 . 7836 . 900 . 8409 . 905 .4310 .5298 . 127 .028 . 6540 5697 . 231 .034 .55
. 56 1 . 786 . 8847 . 8492 . 8789 . 7380 . 6572 . 7247 8247 2892 .3189 .7893 . 902 . 8453 . 908 . 4420 . 5401 . 135 . 031 . 6625 . 5794 . 241 . 038 . 56
.57 1 . 754 . 8904 .8563 . 8848 .7451 . 6659 . 7322 3204 . 2863 .8148 .7951 .905 .8497 . 911 . 4532 . 5503 . 144 . 034 . 6708 . 5892 . 252 . 042 . 57
.58 1 .724 .8959 .8633 .8906 .7522 . 6745 .7396 3159 .2883 .8106 .8007 .908 .8540 .918 .4644 .5606 .153 .038 .6792 5989 .263 ~ 046
.59 1.695 .9013 .8701 .8962 .7593 .6831 .7469 8113 .2801 .3062 .8063 .911 .8582 .916 .4757 .5709 .162 .042 .6875 6086 .274 .051 59
.60 1 .667 .9065 .8767 .9017 .7662 .6917 .7541 .3065 .2767 .3017 .8119 .914 .8624 .918 .4871 .5812 .172 .047 6957 .6183 .286 .056 60
. 61 1 . 639 .9115 . 8831 . 9069 . 7 731 .7002 .7618 .8015 .2731 .2969 . 8174 .916 . 8666 .921 .4986 . 5914 . 182 . 052 7039 . 6280 .298 .061 61
. 62 1 . 613 . 9164 . 8893 . 9120 .7800 . 7086 . 7684 . 2964 . 2693 . 2920 . 8228 . 919 . 8706 . 923 . 5101 . 6018 . 192 .057 . 7121 . 6377 .810 . 067 62
.63 1.587 .9211 .8958 .9169 .7867 .7170 7755 .2911 .2653 .2869 .8282 .921 .8747 .926 .5218 .6121 .203 .063 .7203 .6474 .322 .074 63
. 64 1 .568 9256 .9011 . 9217 . 7934 .7254 . 7824 . 2856 . 2611 . 2817 . 8335 . 924 . 8787 . 928 . 5385 . 6224 . 214 . 069 . 7284 . 65.70 . 335 . 080 64
. 65 1 . 538 . 9300 . 9068 . 9268 . 8000 . 7387 . 7894 . 2800 . 2568 . 2763 . 8388 . 927 - 8827 . 931 . 5452 . 6327 . 226 .075 . 7364 . 6667 . 348 . 088 65
. 66 1 .515 .9342 9123 .9307 . 8066 . 7419 .7962 . 2742 . 2523 . 2707 . 8441 . 929 . 8866 . 933 .5571 . 6431 . ‘238 .088 7445 . 6763 .361 .096 66
. 67 1 . 493 . 9383 9176 . 9350 .8131 .7501 . 8030 . 2683 . 2475 . 2650 . 8493 . 932 . 8904 . 935 . 5690 . 6534 . 251 . 090 7524 . 6860 . 375 .104 67
68 1 .471 .9428 9227 .9391 . 8196 .7583 . 8097 . 2623 .2427 . 2591 .8544 .934 . 8943 .938 . 5810 . 6638 . 264 .099 7604 . 6956 .389 .118
. 69 1 .449 . 9460 . 927 . 9431 . 8259 7664 8164 2560 . 2376 . 2531 8595 . 936 . 8981 . 940 . 5931 6742 . 278 . 108 7683 7052 . 403 123 . 69
.70 1 .429 .9497 .9324 .9469 .8822 7745 .8230 .2497 .2324 .2469 .8646 .939 .9018 .942 .6052 . 6846 .292 .1 18 .7762 .7148 .417 .183 70
.71 1 .408 .9532 .9369 -9506 .8385 .7826 .8296 .2432 .2269 .2406 .8696 .941 .9055 .945 .6174 .6950 .807 .128 .7841 .7245 .482 .14 5 .71
. 72 1 .389 . 9565 . 9414 . 9541 . 8447 . 7906 . 8861 . 2365 . 2214 .2341 8746 . 943 9092 . 947 . 6297 . 7054 .822 .139 . 7919 . 7341 .447 156 72
. 73 1 .370 .9597 . 9456 .9575 . 8509 .7985 . 8426 . 2297 . 2156 . 2275 8795 . 946 9128 .949 . 6420 .7158 .338 .151 . 7997 . 7436 .462 .1 69 .78 i
.74 1.351 .9628 .9497 .9607 .8570 .8064 .8490 .2228 .2097 2207 .948 9165 .951 .6545 .7262 .354 .164 .8075 .753 .478 .188 f .74?

'SEISV’E) (INV NV'HLS HO NOISNVcIXEI
989
TABLE IV.
(continued).
















































as. Ratio of Initial and Final Tempera- a; 1
n: Ratio of Mean to Initial Total Pressure, for given Ratio of tures: Absolute Temperature for Ratio of Initial and Final Absolute Ratio of Initial and final I:
D Volumes. _ Air ; Temperature on Fahrenheit’s Pressures. Volumes. 3
3 Scale + 100° for Steam. 5
5 Ratio of Total Pressure at
9‘ Point of Cut-ofl' to Portion of For given Ratio For given Ra '0; p"
g Ratio of Mean Total Pressure of Tempera- of Tempera- 11g
. _ during whole Stroke that tnres: Absolute tures: Absolute‘
D H During whole Stroke . . . D {a
[-1 _ _ , is due to Expansion, For given Ratio . _ . Temperature For given Ratio Tem ture B
E g (supposmg Imtml pressure and During Expansion only. for given Ratio of Volumes. For given Ratio of Absolute For 9“ en Rat'o 0f for Air; Tem- 01‘ Absolute for AirprTem- < E
a ,4 Inverse Pressure at Point of Cut-011‘ of Volumes. Pressures Volumes. ture on Pressures Ham on A
. A. 0 Ratio. to be identical). - pera _ pe - o
2 > Fahrenhelt’s Fahrenheit’s ‘ >
1:] a: Scale + 100° Scale + 100° i=1 n:
E: O for Steam. for Steam. o
2 A A1 A Air A A A1 A Al 9
[-1 1r ex- 1' ex- ir or ex- ir ex- ir ex- rex- 11' ex- r ex- 97
2 P825“ panding Page“ pending P823“ panding panding Sank panding Sank panding Pllld1u5 Snub pending Paladins Saw g
T ’ without Saturated Tm ’ _ without Saturated Tem e’m_ without Saturated without mud without rated without Saturated without mmd without Saturated without ‘ed
a empem' Loss or Steam. t pm Loss or Steam. t p Loss or Steam. Loss or Sm Loss or Steam Loss or Steam. Loss or St Loss or Steam. Loss or S? 1E
5: We Gain of C "t" t Gain of 0 “gm Gain of Gain of ' Gain of ‘ Gain of Gain of °““" Gain of Gain of “m- a
G consmnt' Heat. one an ' Heat. om ' Heat. Heat. Heat. Heat. Heat. Heat. Heat. 0
1 2 3 4 5 6 '7 8 9 10 11 12 13 14 15 16 17 18 19 2O 21 22 28 24
75 1 .333 .9658 . 9536 . 9638 . 8631 . 8143 . 8553 . 2158 2086 . 2138 . 8893 .950 . 9200 . 953 6669 . 7366 .871 .178 . 8152 . 7 628 . 494 197 75
76 1 .316 .9686 . 9573 . 9668 .8691 . 8221 . 8616 . 2086 .1973 . 2068 . 8941 .953 .9236 . 955 6795 . 7471 . 388 . 193 . 8229 . 7724 .510 212 76
77 1 . 299 .9713 9609 . 9696 . 8750 . 8300 .8679 . 2018 . 1909 .1996 . 8989 .955 .9271 .957 .6921 .7575 .406 .208 . 8306 . 7819 527 229 . 77
78 1 . 282 9738 9643 9723 .8809 . 8377 . 8741 . 1938 .1843 . 1923 .9036 957 .9305 .959 7048 .7680 .424 .225 . 8382 .7915 . 544 246 . 78
.79 1 . 266 9762 9675 9749 . 8868 . 8455 .8803 1862 1776 . 1849 . 9083 .959 . 9340 .961 7176 7785 .443 .243 .8459 . 8010 .561 264 79
. 80 1 .25 . 9785 .9706 .9773 . 8926 8532 . 8864 . 1785 .1706 . 1778 . 9130 . 961 .9874 . 963 7304 .7889 . 468 . 262 . 8534 . 8106 . 579 283 80
.81 1.235 .9807 .9736 .9796 .8983 8608 .8925 .1707 .1636 .1696 .9176 .968 .9408 .965 7483 .7994 .183 .282 .8610 .8201 .597 .304 | .81
.82 1.22 .9827 .9763 .9817 .9041 .8084 .8985 .1627 .1563 .1617 .9222 .965 .9441 .967 .7562 .8099 .504 .804 .8685 .8296 .615 .326 I .82
.83 1.205 .9847 .9789 .9838 .9097 .8760 .9045 .1547 1489 .1538 .9268 .908 .9474 .969 .7692 .8204 .526 .327 .8761 .8892 .633 .349 ' .88
.84 1.19 .9865 .9814 .9857 .9154 .8836 9104 .1465 .1414 .1457 .9818 .970 .9507 .971 .7823 .8309 .548 .351 .8835 .3487 .652 .374 .34
.85 1 .176 .9881 .9837 .9874 .9209 .8911. .9162 .1881 .1337 .1374 .9358 .972 .9540 .973 .7955 .9414 .571 .377 .8910 .8582 .671 .399 1 .85
.86 1.163 .9897 9858 .9891 .9265 .8986 .9221 .1297 .1258 .1291 .9403 .974 .9572 .975 .8087 .8519 .594 .405 .8984 .8678 .091 427 1 .86
.87 1.149 .9912 9878 .9906 .9320 .9000 .9279 1212 .1178 .1206 .9448 .976 9605 .977 .8220 .8625 .618 .484 9058 .8772 .711 .455 .67
.88 1 .136 .9925 9896 9920 .9375 '.9134 .9337 1125 .1096 .1120 .9492 .978 .9636 979 .8353 .8730 .648 .464 9182 .8666 .731 .486 1 .88
.89 1.124 9937 9913 9933 .9429 .9208 9394 1037 1013 .1033 .9536 .980 9668 .981 .8487 .8835 .669 .497 9206 .8961 .752 518 I .89
.90 1.111 .9948 9928 .9945 .9482 .9282 .9451 .0948 .0928 .0945 .9579 .982 .9699 .983 .8621 .8941 .695 .531 .9279 9056 .772 552 I .90
.91 1.099 .9958 9942 .9956 .9536 .9355 .9508 .0858 .0842 0856 .9623 .983 .9730 .984 8757 .9047 .722 .568 .9352 9151 .794 557 .91
.92 1.087 .9967 9954 .9965 .9589 .9428 9564 .0767 .0754 0765 .9666 .985 .9761 .986 .8892 .9152 .750 .000 .9425 .9245 .815 624 i .92
. 93 1 . 075 9975 9965 . 9973 .9642 .9500 9620 .0675 . 0665 . 0673 . 9708 .987 .9792 . 988 .9029 .9258 . 778 . 047 . 9498 .9340 . 837 . 664 .93
.94 1 .064 .9982 9974 .9981 .9694 .9572 .9675 .0582 .0574 0581 .9751 .989 .9822 .990 .9166 .9364 .808 .690 .9570 .9434 .859 705 .94
.95 1 . 053 .9987 9982 .9987 . 9746 . 9645 . 9730 .0487 . 0482 . 0487 .9798 .991 . 9853 .991 . 9303 .9470 .838 . 735 . 9642 . 9529 . 882 749 . 95
.96 1.042 .9992 .9989 .9991 .9797 .9716 .9785 .0392 .0389 0891 .9835 .993 9882 .993 .9441 .9576 .869 .783 9714 .9623 .905 794 .96
. 97 1.031 9996 .9994 .9995 .9849 .9788 .9840 .029 .0294 0295 9877 .995 .9912 .995 . 9580 .9682 .900 . 833 .9786 .9717 .928 S42 . 97
.98 1 .02 9998 .9997 9998 .9899 .9859 .9895 .0198 . 0197 0198 9918 .99 .9942 .997 .9720 .9788 .938 . 886 . 9808 .9812 .95 892 .98
. 99 1 . 01 9999 .9999 9999 . 9950 .9929 9947 .0099 . 0099 0099 9959 . 998 .9971 .998 .986 . 9894 .966 . 941 9929 . 9906 _ 976 945 .99
g____________ ________ -. .1..._..__.__._._ ..- .. _-.____ ..__._ .. _m . ._. ._ -- _. __ ...__._,_._ _ _._-

686 EXPANSION OF STEAM AND GASES.

The following formulas for the weight and volume of air at different temperatures will facilitate
the calculation of these data for any case that may arise in practice: A cubic foot of dry air, at atmos-
pheric pressure and any absolute temperature ( = temperature on Fahrenheit’s scale + 461.2°) T,

39.8 ,
weighs —,—- cubic feet. Some results of the above
7
19 . T
lbs., and the volume of a pound is
39 819
formulas are given in the next table.
TABLE 17., showing Weight and Volume of Dry Air at Atmospheric Pressure.












j
FTempex-a- Tempera- Tempera-
ture. Fah~ Weight of 11 Volume of a ture, Fah- Weight of :1. Volume of a ture, Fah- Weight of 0 Volume of a
renheit Cubic Foot, in Pound. in Cubic renheit Cubic Foot, in Pound, in Cubic renheit Cubic Foot, in Pound, in Cubic
Scale, Pounds. Feet. Scale, Pounds. Feet. Scale, Pounds. Feet.
Degrees. Degrees. Degrees. -
0 .0863 11.582 70 .0750 12.340 150 .0651 15.350
10 .0845 11.834 80 .0736 13.592 1\0 . .0641 15.601
20 .0827 12.085 90 .0722 13.843 170 .0631 15.852
30 .0311 12.336 100 .0710 14.094 180 .0621 16.108
32 .0807 12.386 110 .0697 14.345 190 .0611 16.354
40 .0794 12.587 120 .0685 14.596 200 . .0602 16.605
50 .0779 12.838 130 .0674 14.847 210 .0598 16.856
60 .0764 13.089 140 .0662 15.098 212 .0591 16.907



If the temperature and pressure of the air both vary, the weight of a cubic foot of dry air, at
absolute pressure P (in pounds per square inch) and absolute temperature T, is X P

lbs. ;
and the volume of a pound is cubic feet. If the temperature of air is changed from
T
2.7093 x P
one absolute temperature T to another absolute temperature 25, the volume remaining constant, the
P x T

pressure is changed from P to
When expansion takes place in the cylinder of an engine, the real ratio of expansion cannot be
ascertained by dividing the space passed over by the piston before expansion by the total space trav-
ersed, since expansion also takes place in the clearance space of the cylinder, which is made up of
the piston clearance and the port area; but table VI. gives the real cut-ofi corresponding to the
I C U I 1 .
apparent cutoff, for most fractions of clearance that obtain in practice. If - is the apparent cut-
r
1
;- + 0
off, and c the fraction of clearance, the real cut-off is 1 + ; which formula was employed in the
c

calculation of the table, and can be used for fractions of clearance beyond the range of the table.
Examples—1. It is required to find the mean pressure of air expanding without gain or loss of
heat, the initial pressure being 60 lbs. above zero. and the final pressure 15 lbs. per square inch;
also the ratio of expansion, the pressures at five points taken at intervals during the expansion, and
the final temperature, that at the beginning being 350° F. 15 + 60 = 0.25; and the number in col-
umn ’7 of table IV. corresponding to 0.25 in column 1 ,is 0.3529; hence the mean pressure during
expansion : 60 x 0.3529 : 21.174 lbs. per square inch. From column 20 of the same table it ap-
pears that the required ratio of expansion is 1 + 0.3736 : 2.6767. This ratio of expansion corre-
sponds to a cut-off of 0.37 of the stroke, so that the ratios of initial volume to volumes at the several
points of division are respectively 0.75, 0.60, 0.50, 0.43, and 0.37 ; and the pressures at these sev-
eral points are (according to column 16):
At commencement of expansion . . . . . . . . . . . . . . .. . . . . . . .. I. . . 60 x 1 = 60
At first point of division . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 X 0.67 : 40.2
At second point of division... .. . . .. . . .. . . . .. . . .. . . .. . . 60 x 0.49: 29.4
At third point of division . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 x 0.38 : 22.8
Atfourthpointof division............................... 60x0.30—_—18
Atendof expansion..................................... 60x0.25=15
The initial absolute temperature being 350 ° + 461.2° : 811.2°, the final absolute temperature by
column 12 : 811.2° x 0.667 : 541.1°, and the corresponding temperature on Fahrenheit’s scale :
541.1° --461.2° = 79.9°.
2. If air having a temperature of 70° F., and a pressure of 20 lbs. per square inch above zero, is
compressed without loss or gain of heat to 90 lbs., what is the final temperature? 90 —:- 20 = 0.45;

* These numbers are obtained as follows: (“ailing the final volume 1, the volume when expansion commences is
0 37, and the volume during expansion is 1 - 0.87 = 0.63. Dividing this volume into five equal parts, each part = 0.63
+ = 0.126, and the ratios of initial volume to volume at the several points of division are = 0.75,
0.27
0 31751.26 X 2
0.3
0.37 + 0.126
= 0.60, etc.
EXPANSION OF STEAM AND GASES.
687















































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688 , EXPLOSIVES.

hence, according to column 14 in table IV., the final temperature on Fahrenheit’s scale : (70° +
4612") + 0.793 —461.2° : 208/7".
3. Find, from column 15 in table IV., the approximate temperature of steam at a pressure of 80
lbs. per square inch above zero. The temperature of steam at atmospheric pressure (14.7 lbs. per
square inch) being 212°, the ratio of pressures = 14.7 + 80 = 0.18; so that the approximate tem-
perature :: (212° + 100°) -:- 0.751 -- 100° 2 315°.
4. If steam is cut off in a cylinder at quarter stroke, and expands without condensation, what is the
mean total pressure, the initial pressure being 80 lbs. per square inch above zero? According to
column 5 in table IV., the mean total pressure : 80 x 0.58 = 46.4 lbs. per square inch.
5. The theoretical curve of expansion in the ease of steam~engines is commonly assumed to be a
hyperbola with rectangular asymptotes; in making which assumption, it is supposed that the
steam in its expansion conforms to the law of a perfect gas, expanding at constant temperature.
Although this assumption is not strictly true, no serious error arises from its use in ordinary cases,
and it is very convenient when calculations are to be made without the aid of tables.
For other applications of the tables in this article, see ENGINES, DESIGNING OF. R. H. B.
EXPLOSIVES. It is convenient to divide explosive agents into explosive compounds and explosive
mixtures. In an explosive compound, the elements composing it are in chemical combination, and
cannot be separated except by chemical change. In an explosive mixture, the ingredients are
mechanically mixed, and can be separated by mechanical means. In an explosive mixture, properly
so called, the separate constituents do not have explosive properties, but these belong to the mixture
only. For instance, gunpowder is an explosive mixture, but dynamite is not, for it is merely the
explosive compound nitro-glycerine, contained in an inert absorbent which has no explosive prop-
erties. While this distinction is a good one in the main, it is not always strictly applicable. There
are some mixtures which contain substances having themselves explosive properties. In such a case,
however, the explosive properties of the compound are not sufficiently great to render it useful by
itself, and it enters into the mixture as a combustible ingredient. Thus, a picrate has a certain
quantity of oxygen available in the explosive reaction, but not enough, so it is mixed with a substance
supplying oxygen, such as potassium nitrate (saltpetre) or potassium chlorate.
There are a great number of compounds known to possess explosive properties, but only a very
few are used in practice. In his “Notes on Explosives,” Prof. W. N. Hill, of the United States
torpedo station, Newport, R. 1., describes nitro-glycerine and its preparations, gun-cotton and its
preparations, the picrates (including, for convenience, some mixtures containing pierates), and the
fulminates; afterward reference is made to gunpowder.
EXPLOSIVE COMPOUNDS.-—-Nii7'O-gly607‘i’n6 is formed by the action of nitric acid upon glycerine at a
low temperature. The process of manufacture consists essentially in the slow mixing of the glyfi
cerine with the acid, a low temperature being preserved during the whole operation, and in separat-
ing and washing the nitro-glycerine from the excess of acid with water. The glycerine is the com-
mercial article of good quality. It must be free from the adulterations often found in it. The
nitric acid must be strong, having a specific gravity of not less than 1.45. Nitric acid of this strength
cannot be obtained in the market, and must therefore be specially prepared for the purpose. This
is done by careful distillation from sodium nitrate (Chili saltpetre) and sulphuric acid (oil of vitriol).
Before it is used the nitric acid is mixed with twice its weight of strong sulphuric acid. The latter
does not take a direct part in the production of the nitro-glycerine, but takes up the water which is
formed during the reaction, thereby preventing the dilution of the nitric acid. The sulphuric and
nitric acids, mixed in the proper proportions (one of nitric to two of sulphuric), are placed in a large
stoneware receiver, from which the mixture can be drawn as it is required.
At ordinary temperatures nitro-glycerine is an oily liquid, having a specific gravity of 1.6.
Freshly made, it is creamy-white and opaque, but becomes transparent (“clears”) and colorless, or
nearly so, on standing for a sufficient time, depending on the temperature. It does not mix with
and is unafiected by water. It has a sweet, pungent, aromatic taste, and produces a violent head-
ache if placed upon the tongue, or even if allowed to touch the skin at any point. Those constantly
using it soon lose their susceptibility to this action. Nitro-glycerine freezes to a white crystalline
mass at 39° or 40°. When frozen it can be thawed by placing the vessel containing it in water at a
temperature not over 100°.
Pure nitro-glyeerine does not spontaneously decompose at any ordinary temperature, but if it con~
tains free acid decomposition is apt to occur. It is therefore very important that all acid should
be removed by thorough washing when it is made. '
If flame is applied to freely-exposed nitro-glycerine, it burns slowly without explosion. The firing-
point is about 180° 0. (356° F.). It begins to decompose at a somewhat lower temperature. Nitro-
glycerine is usually fired by means of a fuse containing fulminating mercury. By such a fuse it
is detonated, producing a very violent explosion. Fired with a fuse charged with gunpowder, its
action is very uncertain; sometimes it is exploded and sometimes it is not, but when so exploded its
explosive force is much less than when the fulminate is used.
N itro-glycerine may be conveniently kept in large earthen jars, with a layer of water over the explo-
sive. If it is to be transported, the liquid form is very inconvenient, especially from the danger of
leakage. It is therefore advisable to freeze it and carry it in the frozen state, when it is perfectly safe.
For transportation it should be put in strong tin cans holding about 45 or 50 lbs. Each can should be
paraffined on the inside, and have a tin tube passing vertically through its centre, so that freezing or
thawing may be more easily accomplished. All vessels in which nitro-glycerine has been kept should
be destroyed when not wanted for the same use, as the nitro-glycerine cannot be easily washed off.
N itro-glycerine is the most powerful explosive in use. In difficult blasting, where very violent effects
are required, it surpasses all others. It shatters rocks into fine fragments, leaving no residue and
giving no smoke. It has been very successfully used in submarine blasting. (See BLASTING.)
EXPLOSIVES. 689

NITRO-GLYCERINE Parrxaa'rross.-—The transportation and practical use of nitro-glycen'ne have been
found to be attended with such dangers, that it is now used almost entirely in the shape in which it
was first brought before the world—that is, absorbed in some substance which will hold it suspended
in its pores, as a sponge will water. Gunpowder and analogous substances were at first used for this
purpose; but as these cannot absorb any great quantities of nitro-glycerine, a silicious earth has been
largely substituted for them, forming what in this country is known as dynamite.
Dynamite—In 'dynamite, the absorbent is usually a natural silicious earth. Deposits of this
silicious earth are found in many places, notably in Hanover. From the Hanover earth the original
dynamite was made. This silicious earth, or “ kieselguhr,” 1s a fine white powder, composed of the
skeletons of microscopic animals (infusoria). It has a high absorptive power, being capable of tak-
ing up from two to three times its weight of nitro-glycerine without becoming pasty.
The ,process of making dynamite is very simple. The nitrc-glycerine is mixed with the dry, fine
powder in a leaden vessel with wooden spatulas. Dynamite has a brown color, and resembles in
appearance moist brown sugar. It usually contains from 60 to 75 per cent. of nitro-glycerine. In
this country dynamite is made and sold under the name of giant powder. The explosive propertics
of dynamite are those of the nitro-glycerine contained in it, as the absorbent is an inert body. It
freezes, at the same temperature as its nitro-glycerine, to a white mass. If solidly frozen, it cannot be
fired except by the use of an extra-strong cap; but if loose and pulverulent,‘ it can be exploded,
although with diminished violence. It can be thawed by placing the vessel containing it in hot
water. The keeping qualities of dynamite are those of the nitro-glycerine it is made lrom. It is
safer, because it avoids the liquid condition, and from its softness it will bear blows much better.
Exudation must be guarded against; therefore it must not contain too much nitro-glyceiine, espe-
cially if it is liable to be exposed to comparatively high temperatures, which tend to make the
nitro-glycerine more fluid, and consequently less easily retained. The firing-point of dynamite is
the same as its nitro-glycerine. If flame is applied to it, it takes fire and burns with a strong flame,
leaving a residue of silica. It is not sensitive to friction or moderate percussion. Dynamite is fircd
by a fulminatc fuse. Gunpowder will fire it, but not with certainty, and the effect obtained is much
less than when the stronger agent is employed.
The explosive force of dynamite is, of course, that of the nitro-glyceiine ccntained in it. If it
contains 75 per cent., its comparative force may then be approximately stated at six times that of
gunpowder. For practical details relative to the use of dynamite, see Engineering, xxv., 465.
Dynamite No. 2.—Dynamite proper contains only nitro-glycer-ine and the silicious absorbent.
Mixtures containing other substances are sometimes included under the same name. The true dyna-
mite is often called “Dynamite N o. 1,” and the others “ Dynamite No. 2,” or receive fanciful raires.
All these mixtures contain less nitro-glycerine than the No. 1, so that they cost less per pound, but
of course they are proportionately less powerful.
I/ithofi'actcw'.—--Lithofracteur is a mixture which has the composition (Tiauzl): Nitro-glyccrinc,
52.10 per cent. ; kieselguhr, 30; coal, 12; soda saltpetrc, 4; sulphur, 2. Sometimes, instead of the
sodium nitrate, the potassium or barium salt is used, and variations are made in the quantity of nitro-
glycerine contained in it. Like all the nitro-glycerine preparations, it has no necessarily definite
composition, being merely a mixture made according to the caprice of the manufacturers. Litho-
fracteur must be regarded as inferior to dynamite proper, especially for military purposes. It is
much more liable to exudation. The mixtures known in this country as giant-powder No. 2, rend-
rock, etc., and-those already spoken of under the head of dynamite No. 2, are somewhat similar to
lithofracteur.
.Dualin is a mixture made by Carl Dittmar, a Prussian, of nitro-glycerine, sawdust, and saltpetre,
in about the proportions: Nitro-glycerine, 50 per cent; fine sawdust, 30; saltpetre, 20 (Trauzl).
This preparation is also inferior to dynamite. The sawdust and saltpetre have much less absorptive
power than the silicious earth, and retain the nitro-glycerine comparatively feebly. Its firing-point
is said to be considerably lower than that of dynamite No. 1. Also, its lower specific gravity is a
drawback.
Dynamite, lithofracteur, and dualin have in great measure been supplanted by mixtures in which
the nitroglycerine is absorbed in an explosive substance, since in this way the whole of the material
put into the blast-hole is utilized. These mixtures are substantially the same as those in which nitro-
glycerine was first used. They all consist of a pulverized material analogous to gunpowder dust, to
which some wood-fibre or saw-dust is added to increase the capacity for absorption of the nitro-gly-
cerinc. By the force of the fulminating cap the absorbent body is detonated as well as the nitro-gly-
cerine. N ow, since detonated gunpowder has been proved to be much more powerful than fired gun-
powder, it will be seen that not only the nitro-glycerine is utilized, but also the gunpowder absorbent
to the fullest extent of which it is capable. These powders are known by various trade-names, such
as'rendrock, Hercules, giant-powder, etc. Since the first introduction of these explosives the care
exercised in their manufacture has been greatly increased. It has been found to be of great impor-
tance that the nitro-glyeerine should be pure and free from acid. To that end it is thoroughly washed
with water,\and also neutralized with an alkaline carbonate, so that now accidents resulting from
spontaneous decomposition are almost unknown.
GUN-coTTON.——Gun-cottoii is formed by the action of concentrated nitric acid on cotton. The pro-
cess of making gun-cotton consists essentially in exposing the dry cotton for a sufficiently long time
to the action of a mixture of the strongest nitric acid with sulphuric acid, and in thoroughly washing
the gun-cotton thus prepared to remove the excess of acid. In this reaction also the duty of the
sulphuric acid is to take up the water, which is a secondary product.
By the method of Abel, a very perfect washing is obtained, and, in addition, the material is pre-
pared in a form convenient to use and yet perfectly safe. The essential features of Abel’s process
are the reduction of the wet gun-cotton to a fine pulp, which can be easily washed, and the com-
44
690 EXPLOSIVES.

pression of this pulp into convenient shapes. This product evidently cannot be used for-certain
purposes for which the fibre is required, such as in gunnery. This is not of importance, as gun-cotton
is no longer so applied. For other military applications, such as demolitions, torpedoes, etc., the
pulped and compressed gun-cotton is an admirable agent.
After the cotton has been converted into gun-cotton, and the latter is reduced to a pulp and
thoroughly washed, the pulp is next to be separated from the large volume of water in which it is.
suspended, and compressed into cakes or disks. This is accomplished in two presses. The first
press has 36 hollow cylinders, in which perforated plungers work upward. The plungers having
been drawn down, the cylinders are filled with the mixture of pulp and water, and their tops covered
with a weight. The plungers are then forced up by hydraulic power. The pulp is compressed, the
water escaping through the perforations in the plungers. In the second press, the cylindrical masses
of gun-cotton from the first press are more highly compressed, a pressure of 6 tons to the inch being
applied. About 6 per cent. of water remains in the cakes, which can be removed by drying.
Properties and 1l[ocles of Firing.—The conversion of cotton int-o gun-cotton causes very little
change in its appearance. The latter is somewhat harsher to the touch than the former. Gunl
cotton is insoluble in and unaffected by water. If flame is applied to dry loose gun-cotton, it flashes
up without explosion. Dry compressed gun-cotton burns rapidly but quietly when ignited by a
flame. Moist compressed gun-cotton under the same circumstances burns away slowly. Even if a
considerable quantity of gun-cotton is inflamed, it will burn away without explosion; but if the quan-
tity is too great, the explosion of a part will be produced. In such cases the outer portion confines
the inner sufiiciently to cause its explosion. Dry, unconfined gun-cotton can be violently exploded
by a small amount of fulminating mercury. Even in the compressed wet state, gun-cotton can be
exploded; but to accomplish this it is necessary to apply the shock from the explosion of a small
amount of the dry. For firing wet compressed gun-cotton, a “ primer” is used, which is a cake of
the dry, to which is attached a fulminatc fuse. This primer must be inclosed in a water-proof bag
or box. It is asserted that complete explosion of large charges of wet gun-cotton can be brought
about in this way, but there is some doubt on this point. The firing-point of gun-cotton is about
360° F. (182° (3.). It is not sensitive to friction or percussion. Imperfectly converted or badly.
washed, it is liable to spontaneous decomposition, which may result in explosion if the conditions
are favorable. The pulped and compressed form is free from such danger, for since it can be fired
wet there is no need of ever drying it, so it may be kept and used saturated with water.
Compressed gun-cotton is stored in the wet state. Care must be taken that it is not exposed to a
temperature that will freeze the water in the cakes. If this occurs, they are liable to be disintegrated
by the expansion of the water in freezing. In cold climates it is therefore advisable to store gun~
cotton in pits below the reach of frost. For convenience in handling, gun-cotton is made into disks
of various dimensions, or it may be pressed into slabs or blocks, which may be sawn, drilled, or cut
as desired. The transportation of gun-cotton presents no special difficulties, since there is no danger
of leakage, neither is it sensitive to blows.
The relative force of gun-cotton as compared with gunpowder is variously given from 4—6 t0'1.
The lower figure is probably nearly right, at any rate for wet gun-cotton.
Nitrated gun-cotton is made by soaking the compressed gun-cotton in a saturated solution of salt-
petre (potassium nitrate) and drying. Chloratccl gun-cotton is similarly made, using potassium
chlorate instead of nitrate.
THE PICRATES.—-The picrates are salts of picric acid. Picrie acid is found in commerce, being
used to dye silk and wool yellow. If the acid is heated, it takes fire and burns sharply and rapidly,
without explosion. The picrates are all exploded with more or less violence by heat or blows.
When used as explosive agents, they are mixed with potassium nitrate (saltpetre) or potassium
chlorate. A large number of picrates are known, but the potassium and ammonium salts are the
only ones that have been much used in explosive preparations.
Potassium Picrate.—-Most violently explosive of the picrates. Potassium picrate and potassium
chlorate form a mixture nearly as powerful as nitro-glycerine, but it is so sensitive to friction or per-
eussion as to render it practically useless. With potassium nitrate instead of chlorate a less violent
mixture is obtained, but one still too liable to accidental explosion.
Ammonium Picrate.—-This salt has been proposed by Abel as an ingredient of a powder for
bursting-charges of shells. The properties of ammonium picrate are very different from those of
the potassium salt. If flame is applied to the former, it burns quietly, with a strong, smoky flame.
If heated, it melts, sublimes, and burns without explosion. It is almost entirely unaffected by blows
or friction. This salt, mixed with saltpctrc, forms Abel’s picric powder (Brugere’s powder). It is
more powerful than gunpowder and less violent than nitro-glycerine and gun-cotton. It is insensi-
tive to ordinary means of ignition. If flame is applied to it, the particles touched burn, but the
combustion does not readily extend to the others. Blows or friction do not explode it. It must be
confined in order to develop its explosive force. It does not absorb moisture from the air, so that it
may be stored and handled like gunpowder, and is at least equally safe and permanent.
THE FULMINA'rrzs.—-'l‘he fulminates are salts of fulminic acid. The mercury salt is the only one of
practical value. All of them are easily exploded, and some are excessively sensitive. Their explo-
sions are very sharp from the extreme rapidity of their decomposition; but from the small amount of
gas given off, the force exercised is not very great. The explosive effect obtained is of a local character.
Fulmz'nating Illercw-g/ is formed by the action of mercuric nitrate and nitric acid upon alcohol.
It explodes violently when forcibly struck, when heated to 186° 0. (367° F.), and when touched
with strong sulphuric acid or nitric acid, by sparks from flint and steel, or the electric spark. When
wet it is inexplosive. It is therefore always kept wet, and dried in small amounts when wanted for
use. Its explosive force is not much greater than that of gunpowder, but it is much more sudden in
its action.
EXPLOSIVES. - 691

', ,,.__
Detonators or detonating fuses are charged with pure fulminating mercury—15 to 25 grains in
each. Fifteen grains is sufficient for nitro-glycerine or its preparations; 25 grains is used with
compressed gun-cotton. In detonating fuses the fulminatc should be contained in a copper cap or
case, and must not be loose. Charging should be done with wet fulminatc, as it is very dangerous
to handle it when dry.
Exrwsrvn Marcus—These may be classed into two divisions: 1. Those containing nitrates; 2.
Those containing chlorates.
1. The Nitrate Class.-Any of the nitrates may be used in explosive mixtures, but, practically,
potassium nitrate (saltpctre) is the only one employed to any extent. With sulphur and charcoal, it
makes up the numerous compositions, of which gunpowder is the most important.
Sawdust powder, or Schultze’s white gunpowder, contains saltpctre. It is made by converting
purified sawdust into a nitre-cellulose (resembling gun-cotton), and mixing this with the nitrate.
2. The Chlorate Class—Chlorate mixtures are very sensitive to friction and percussion, and they
explode with great sharpness. The following are examples : Potassium chlorate with resin ;
potassium chlorate with galls (Horsley’s powder) ; potassium chlorate with gambier (Oriental
powder) ; potassium chlorate with sugar (used in “ chemical ” fuses) ; potassium chlorate with
potassium ferrocyanide (white or German gunpowder); potassium chlorate with tannin (Erhardt’s
powder); potassium chlorate with sulphur (Pertuiset powder, used in explosive bullets).
Sprengel has published some interesting and important statements in regard to certain new classes
of explosive mixtures. He finds that a variety of organic substances dissolved in nitric acid of 1.5
specific gravity explode by detonation. Nitro-benzol mixed with nitric acid in proper proportions
gives a mixture which explodes with intense violence, if fired by a detonating fuse. Absorbed in
silicious earth, it burns slowly when flame is applied, and is less sensitive to blows than dynamite or
gun-cotton. Pieric acid dissolves in nitric acid, forming a similar mixture. Many other combusti-
bles may be thus used, but these mixtures are inconvenient to handle, since they contain concentrated
nitric acid. Still their power and cheapness are so great that they may be of value.
Gunrownsn.*—'l‘he proportions of nitre, sulphur, and charcoal, most generally useful for ordinary
purposes in gunpowder manufacture, all approximate to the percentages required by the formula
2KN09 + S + 30, supposing the charcoal to be pure carbon. The percentage composition is gen-
erally nitre 74.8, sulphur 11.9, and charcoal 13.3. The percentage of nitre varies from 70 to 80;
that of sulphur and charcoal from 10 to 15 each. In the United States service, the regulation pro-
portions are, nitre 75, charcoal l5, and sulphur 10.
The gas produced by the explosion of good gunpowder occupies nearly 900 times the volume of
the powder itself ; but owing to the high temperature, the space occupied by the gas at the moment
of formation is probably 3,000 times greater than the volume of powder.
The woods used for charcoal are willow, alder, and black dogwood. The finest sulphur, containing
in roughly distilled state 3 or 4 per cent. of impurities, is employed. It is thoroughly purified before
use. The nitre is refined by boiling in water, filtering, crystallization, washing, and finally drying in
hot chambers.
The ingredients, being finely ground, are weighed out in quantities of 50 lbs. each, and placed in a
mixing machine, Fig. 1557, which consists of a hollow drum of gun-metal, rotated at 40 revolutions
1557.


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per minute. A shaft within this drum has arms or fliers, which revolve in opposite direction to
that of the drum. About 5 minutes suffices for the mixing, and the ingredients are then passed
through an S-mesh wire sieve and sent to the incorporating mill. This machine, which is shown in
Fig. 1558, is a pair of large edge-runners, of iron or stone, which revolve on a strong circular bed.

* Abridged from “Naval Ordnance and Gunnery," by Commander A. P. Cooke, U. S. N.
692 ' EXPLOSIVES-

The runners weigh from 3 to 4 tons each, and are from 4 to 7 feet in diameter. One runner is
placed on its spindle nearer the cross-head than the other, so that they describe different paths when
1558.


in motion. The cross-head is fixed on a vertical shaft actuated by machinery under the floor of the
mill. It also carries a plough of wood shod with felt and leather, which travels around the bed in
front of the runners and thus keeps the composition from working away from them. The speed is
[a 1559.
T T
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M
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about 8 revolutions per minute, and about 2 pints of water is sprinkled over the charge. Fifty lbs.
of cannon-powder requires 3% hours working under stone runners weighing ' a 71}
00
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' EXPLOSIVES. 693
revolutions per minute, but only 21} hours under iron runners of 4 tons making 8 revolutions per
minute. Small-arm (dogwood) powders require 5% hours in the former mills, and 4 in the latter.
Taking about 50 lbs. as the maximum amount which it is best to incorporate at one time under
one pair of runners, it is easy to calculate the capacity of a gunpowder factory. A certain amount
of work can be obtained from them, and no expedient can produce more. The manufacture cannot
be hastened without incurring danger of explosion. A drenching apparatus, Fig. 1559, is usually
erected over (rich pair of runners. It consists of a large shutter pivoted on a spindle which runs
15


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through the whole group of mills. Balanced on the pivot edge of the shutter is a large copper vessel
filled with water, so arranged that at the slightest lift of the shutter it capsizes and drenches the
charge beneath. An explosion of one mill, through all the shutters being on a single spindle, de~
termines the wetting of the charges in all the others.
Gunpowder leaves the incorporating mill in a state of soft cake (“ mill—cake "), partly dust. In
order to convert it into hard cakes of the particular density found to give best results, it is pressed
in layers between plates of copper in the hydraulic press. The construction of the press is exhibited
1561.
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in Fig. 1560. A is the cylinder, B the ram, 0' the press-box, D the overhead block, and E E the
standard. The granulation of the press-cake is efiected by revolving toothed rollers of gun-metal,
of which there are four, placed slanting, in each machine, Fig. 1561. They are placed in sliding
bearings, so as to open and admit the passage of an excess of material without injury, and the two
upper pairs have coarser teeth than the others. The press-cake is placed in a hopper at the back of
the machine, and carried up on an endless band to the first pair of rollers, which rotate at 30 revo'
lutions per minute. The grains thus produced fall through a short screen, and then through the
694 ' v EXPLOSIVES.


upper of a pair of long screens, and next through the lower one. The last permits the dust and
minuter particles to fall through upon a sloping board, down which they slide to a vessel placed to
receive them, but which retains the proper size of grain, which in turn rolls down into another
receptacle at the bottom. The larger pieces, which escaped proper crushing by the first rollers, are
shaken down by the first short screen into the second pair, to undergo the same process as at first,
and so on with the third and fourth pairs of rollers. The granulating process appears to be the
most dangerous of all. '
The powder is next freed from dust by placing it in revolving screens covered with cloth or wire
mesh of various degrees of fineness, through which the dust escapes. The horizontal reel shown

1562.
r U L M
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?MMIWM” [JWJZ M/IJI/L/l/A'l/llflwllllg
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in Fig. 1562 is usually employed for powder of large grain. It consists of a cylindrical skeleton of
wooden hoops supported on a shaft by radial arms, the skeleton being covered with canvas or wire
cloth A. The shaft B is of iron covered with wood. 0 C is the movable end, which can be drawn
back. In the middle of the reel is a square opening 1) closed with a wooden door, through which
the powder is run through a hopper E at the top of the parallel wood casing F, in which the reel is ,
placed to confine the dust which escapes from it. G is a block carrying the bearing of the lower
end, which can be raised or lowered by means of the rope K and lever L so as to put the reel on a
slope. Slope-reels are not intended to retain the powder, but only to extract a certain portion of
dust as it runs through them. They resemble the horizontal reels in general construction, except
xv U a #-












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that they have no ends and the shaft is set at a permanent slope. Each reel is provided with a feed-
ing-hopper at its upper end, attached to which is a loose spout for guiding the powder into the reel.
Powder is glazed by causing the grains to rub against each other in rotating barrels; a little black
lead is added in large-grained powders, to obtain a smoother surface. The barrels, Fig. 1563, are
generally placed in line on one shaft, and are made of oak. They are usually about 5 feet long and
21}- feet in diameter. The shaft is cased in wood where it passes through them.
Drying is done in large chambers heated by steam from 125° to 130° F., and usually occupies one
day. In fine-grained powders another dusting, called “finishing,” is sometimes requisite.
The foregoing is a description of the English method of manufacturing gunpowder, from which
EXPLOSIV'ES; 695


the American method diiferes in some particulars, arising principally from the fact that here the
manufacturer deals with much larger quantities. The charges worked in the mixing and incorporating
mills are from two to six times as large as above described, and the wheels in the incorporating
mill, having to work such an increased quantity of material, weigh from 5 to 71} tons each. It is
stated that the capacity of this country for the production of powder exceeds that of the whole
continent of Europe.
The disruptive force of gunpowder is measured by an instrument called a pressure-gauge. Three
forms have been used, two of which were invented by General Rodman of the United States Ordnance
Department. One is applied to the exterior of a gun, and communicates with the chamber by a nar-
row passage; the other is inserted in the cartridge-bag at the base of the charge, and remains in the
gun after the discharge. The internal gauge, Fig. 1564, consists of a cylindrical box of steel, a a,
with a cover 6 I) screwed on.. Through the axis of the cover is a cylindrical hole, in which a steel
piston-rod c is fitted. Within the box is a thick disk of steel (1, having a knife-edge e protruding
from its lower face. This knife has a double shear, the edges of the two shears meeting at the
centre in a very obtuse angle. At the bottom of the box the apex of the knife rests upon a disk of
soft annealed copper f. The inner end of the steel rod is stepped into the steel knife-disk, and-its
outer end is a little below the top of the cover. A copper cup g rests upon the top of the rod, to
serve as a gas-check. The pressure of the explosion is received by the rod, which communicates it
to the knife, the apex of which sinks into the copper, giving a cut, the length of which serves as the
measure of the pressure. h h is a copper washer. The smaller figures show the parts 0, d, e, and
f, enlarged and viewed from the side, and the indentation made on the copper disk. The work-
ing parts of the external gauge are quite similar to the foregoing, but the manner of housing them is
different. Another form of gauge, invented by Captain Noble of the English Artillery, substitutes for
the copper disk a short cylinder of copper, which is crushed by the pressure, the amount of crushing
being employed to measure the pressure. This gauge is screwed into the wall of the gun in such a
manner that the end of the rod receiving the pressure is very near the surface of the bore. Bath
1564.
' t
1
s1


forms of gauge are liable to grave objections, since the measure obtained is essentially dynamical,
while the quantity to be measured is statical. The English gauge is much inferior to the American,
and cannot be relied upon to give even approximate indications of pressure from violent powder.
Form of P020<Zcr.—-In the process of pressing the powder, by the methods used for many years,
great irregularities of density always occur; and as the explosive property is more influenced by the
density than by any other quality, the advantage of securing uniformity in this respect is manifest.
Geometrical .or “pellet” powder, Fig. 1565, requires a mould for each grain, whereby the density
can be regulated-with far more precision than by the old method. A leading variety of these geomet-
rical forms is the prismatic, in which the grains are hexagonal prisms, about an inch in length and
diameter. Each prism is perforated with 7 holes, one-tenth of an inch in diameter, parallel to the
axis. They are symmetrically packed in a cartridge, of very small bulk in proportion to its weight.
This form of powder is used for large rifled (Krupp) guns in the Russian, Prussian, and Austrian ser-
vice, and its performance is excellent. Short cylinders have been used by the English, but they have
been supplanted recently by pebble powder. Lenticular powder (grains in the form of lenses) has
been tried in this country, but with indifferent results. The central portions, as a necessary result of
the mode of pressing, were much less dense than the peripheral, and therefore burned too rapidly.
Grains which had been ignited in the gun and extinguished in the air, and collected afterward,
showed that the middleportions only had been consumed, leaving a ring of the denser portions.
litter prismatic powder is simply the prismatic form just described, but without the perforations; it
has been used in Belgium only. In recent experiments under the United States Government, pellets
in the form of two truncated pyramids, having a common hexagonal base, have been employed; and
the results appear to be better than those obtained by any other nation. The irregular, large- grained
powder, used in heavy guns, receives the name “mammoth powder ” in this country, and “pebble
powder ” in England; but these titles indicate no essential difference.
Gunpowder is classified, according to the size of the meshes through which the grain is sifted, into
696 EXPLOSIVES.

11 numbers, from 0 to 10, the latter being the finest rifle-powder, and the former the mammoth. In
classifying it according to quality, each maker has his own method and nomenclature. In the United
States Government service it is classified into: 1. lllusket; 2. Mortar; 3. Cannon; 4. Mammoth pow-
der. Two sieves are used for separating the grains of each class, all the grains being required to
pass through the larger, and none through the smaller. The sizes of the meshes in decimal parts of
an inch are:


CLASS. Large. Small.
Muskct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .06” .03"
Mortar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 .06
Cannon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 .25
‘ Mammoth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90 '- .60

The density of granular powder is either the absolute density, which is that of the grains them-
selves, or the gravimetric density, which is that of a quantity of grains with their interstices. The
absolute density ranges from 1.60 to 1.80, the most common figure being about 1.75. The gravi-
metric density is generally about equal to that of water.










1566
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Fig. 1566 represents various sizes of powder made by the Laflin & Rand Powder Company. A
shows the largest and B the smallest size of blasting powder; C and D show the largest and small-
est sizes of rifle powder. The greater proportion of powder used for sporting purposes belongs to
the rifle class. The most recent conclusions in relation to explosive compounds hitherto used for
firearms and ordnance show that they possess two defects—too rapid combustion, and the evolution
of dense volumes of smoke. The efforts of inventors in the last decade have largely been expended
in the direction of overcoming these drawbacks.
Gun-cotton, alone and in its fibrous state, has been found to be too quick, or violent, for propulsive
purposes, such as use in firearms, as, under such conditions of confinement, it is very likely to deto-
nate and burst the gun. However, if gun-cotton be dissolved in a suitable solvent which is capable
of being evaporated out, such as acetone, or acetate of ethyl, which are very volatile. it becomes,
when thus dissolved and dried, a very hard, horn-like, amorphous substance, which may be used for
a smokeless gunpowder.
Balistite consists of about equal parts of nitro-glycerine and soluble nitre-cotton, with the addition
of a small proportion of camphor for the purpose of bringing about the combination of the materials;
the effect of the camphor is also to greatly moderate the violence of the explosion.
Uorclite, invented by Abel and Dewar, is a similar mixture of nitro-glycerine and ordinary gun-
cotton, the combination of the two being brought about by the aid of acetone or other solvents;
camphor or tannin is added to reduce the rapidity of the explosive action. These powders are similar
to blasting gelatine in appearance, and are used in the form of small cubical grains.
EXPLOSIVES. 697

Apyrz'te is a smokeless powder, based upon highly nitrated cellulose. It gives a low pressure of
2,200 to 2,500 atmospheres, and an initial velocity of 630 to 650 metres, with no flame. It is to a
high degree unaffected by rubbing and blows, and burns, when ignited, even in large quantities,
without an explosion. With the present Swedish rifle, a charge of 311; gr. of apyrite is used with a
bullet weighing 14% gr., resulting in a velocity when leaving the rifle of 640 metres, and a pressure
of about 2,260 atmospheres.
Robum'te consists of a mixture of nitrate of ammonium with chlorinated di-nitro-benzole, the result-
ant being a yellowish powder. It volatilizes without explosion or ignition when slowly heated, and
burns slowly in the open in small quantities. It requires an extra strong detonator to develop its
power, and in this respect is a very safe explosive. It is practically flameless when exploded in con-
finement, the gases evolved by its combustion being of such a nature as to quench any initial flame
there may be.
Gelatine Dynamite is an outcome of blasting gelatine, and it occupies a place midway between the
latter compound and dynamite. It consists of a thin blasting gelatine mixed with other substances,
such as nitre-cotton and charcoal.
Gela'gm'tc consists of gelatine dynamite mixed with nitrate of potash or other nitrates. The varieties
of these two explosives in practical use contain nitro-glycerine, nitre-cotton, nitrate of potash, and
wood-meal. They are similar in appearance to blasting gelatine, and, while gelatine dynamite con-
tains about 80 per cent. of explosive, gelignite contains 60 per cent. only. All three varieties are
stated to be in regular practical use. _
Securiie consists of a mixture of di-nitro-benzole and nitrate of ammonium. By the addition of an
organic salt, securite is rendered flameless, and therefore forms a fitting explosive for collieries.
Bellite is composed of di-nitro-benzole and nitrate of ammonia in certain proportions, the ingredients
being mixed together and then subjected to heat. While still warm the plastic mixture is moulded
into cartridges, which, on cooling, are found to be more or less solidified. It is free from explosion
by shocks, pressure, friction, or exposure to flame.
Pauclasta'ts is based on hyponitric anhydride, or nitrogen-tetroxide, prepared by strongly heating
lead nitrate. It is a very powerful explosive, but is not of use for blasting in mines, as the presence
of sulphurous acid in the gases would render the air unbreathable. The use of these nitrogen tetrox-
ide explosive mixtures appears, however, to be at present at a standstill.
Hellofite consists of an admixture of nitrate of petroleum, or tar-oil, and nitric acid. When mixed,
it has a specific gravity of 1.4. It is rendered inexplosive when mixed with water.
Roma'tc consists of ammonium nitrate, naphthalene, or nitrdnaphthalene and paraffine-oil, to be
mixed with potassium chlorate or with nitrodactin at the place where it is to be used.
Kinetite is made by dissolving gun-cotton in nitre-benzene, or other liquid benzene or benzenoid
nitre-compound ; the jelly thus formed is mixed, by kneading, with finely powdered potassium
chlorate or nitrate (or other metallic chlorate and nitrate), sulphur in the free state, or as sulphide, is
added, and the whole well kneaded.
Altogether there are more than 350 explosives, some of which have never been practically used ;
others are suitable for mining purposes only. Although few have as yet proved a decided adaptability
to military purposes, there are one or two at present in use that bid fair to answer the conditions
required.
JlIelinite was the first of these, and its manufacture was kept for a long time, a well-guarded
secret by the French Government. The immense quantities of picric acid that were being consumed
in France aroused suspicion, and led to the belief that that was a chief ingredient. We now know
that the word derives its name from meli, honey, the color of picric acid. Lately, changes have been
made which have had the efiect of rendering melinite insensible to shock and friction. Its composi-
tion is now believed to be fused picric acid mixed with gun-cotton dissolved in ether and compacted
into granules. It is exploded by a detonator, and upon explosion produces large quantities of carbonic-
oxide gas. Its specific gravity is 1.7.
Lyddite is supposed to be the original melinite. It requires confinement to develop its force, and is
authorized as safe to handle.
Tom'te is a compound of gun-cotton and nitrate of baryta. It burns slowly, has withstood severe
tests of heat and the shock of rifle-bullets fired into it, and when wetted can be dried in the sun
without deteriorating; moisture does not affect its strength. It requires a strong detonator.
Ewasitc has been successfully fired in shell as an explosive charge. In 1889 an 8.24—in. shell weigh-
ing 206.6 lbs., containing 15.88 lbs., perforated two plates each 4 in. thick, and exploded in a third
plate. When tested against masonry, ten shots completely destroyed an old fort at Olmiitz, not a
single casemate remaining intact ; and against earthworks, mortar-shells charged with eerasite are
said to be very destructive. It is reported that palisades representing 500 men, when fired at by
ccrasite shells at a distance of 1,300 yds., were all injured.
Emmensite, when fired into by a pistol-ball, only the particle actually struck explodes, the detona-
tion not being communicated to the mass. Cartridges 1:} in. in diameter, put up in a tin case and
fired as a projectile from a small gun, perforated a 2hr. board without exploding. Seven-ounce can
tridges, detonated on the sides, top, and bottom of §~-in. iron plates, broke them in every case. It has
not yet been experimented with in guns of large calibre. The grade of emmensite experimented with
was composed of nitratcd carbolie acid, nitrate of soda, and nitrate of ammonia.
librcz'te.--Oharges of 11 and 12 lbs. have been fired successfully from a 6-in. gun in Snyder shells,
and all exploded on impact against rock. But it possesses the disadvantage of exploding when struck
by musket-balls, and by some authorities its stability is still questioned.
Of the various high explosives the following have been adopted in different countries: Austria,
ccrasitc has been adopted for the army; England, gun-cotton (wet) is adopted for use in submarine
mines, and lyddite is being experimented with for use in shells ; France, gun-cotton (wet) is used for
698 FANNING-MILL.

submarine mines, and melinite for shells; Germany uses wet gun~cotton; Italy has adopted wet'gun-
cotton for use in submarine mines, and is experimenting with it and lyddite as bursting charges for
shells; Russia, shells and submarine mines are loaded with wet gun-cotton; Sweden has adopted
bellite as an explosive for military and submarine purposes ; United States, wet gun-cotton has been
adopted for the navy for submarine use; the army have used dynamite, but are inclined to adopt
blasting-gelatine or forcite.
Bucknill has arrived at the following relative horizontal distances and charges necessary to inflict
a fatal blow 011 a modern ironclad :








DISTANCE IN mama. 2.5 5 10 20 80 88 40 45 47 50 52 54 60 67 78 90
Lbs Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs.
Blasting gelatine. .. 4.7 23.5 75 177 274 369 465 484 500 600 900
Forcitegelatine.... 5.1 >25 80 188 293 395 496 . . . . .. Gelatinc dynamite. 5.4 27 S7 196 816 427 500 537 558 900 ..
Dynamite No. 1.... 6.6 88 107 251 389 500 525 600 . . . . 660 687 900 . . . . . ..
Gun-cotton . . . . . . . . 6. 6 38 107 251 389 500 525 600 . . .. 660 687 . . . . . . .. .. ..
Gunpowder . . . . . . . . 26.4 132 428 1,064 1,556 . . 2.100 .. .. . .. 2,640 . . . . .


















W'orks for Reference.-—“ The Modern High Explosives,” Eissler, New York, 1884; “An Index to
the Literature of Explosives,” C. E. Munroe, Torpedo Station, Newport, R. I., Part I, 1886, Part II,
1892.
FANNING—MILL. See AGRICULTURAL MACHINERY.
FANS. See BLOWERS. .
FEED—CUTTER. See AGRICULTURAL MACHINERY.
FILES. Files and rasps have three distinguishing features: 1. Their length, which is always meas-
ured exclusively of their tangs ; 2. Their out, which relates not only to the character, but also to the
relative degrees of coarseness of the teeth; 3. Their kind or name, which has reference to the shape
or style. In general the length of files bears no fixed proportion to either their width or thickness,
even though they be of the same kind. The tang is the spike-shaped portion of the file prepared
for the reception of a handle, and in size and shape should always be proportioned to the size of the
file and to the work to be performed. The heel is that part of the file to which the tang is affixed.
Cur—Of the cut of files we may say that it consists of three distinct forms, viz.: single-cut, double-
uut, and rasp ,- each of which has different degrees of coarseness, designated by terms, as follows, viz.:
SINGLE-GUT. DOUBLE-CUT. R-Asr.
Rough, Coarse, Coarse,
Coarse, Bastard, Bastard,
Bastard, Second-cut, Second-cut,
Second-cut, Smooth, Smooth.
Smooth. Dead-smooth.
The terms rough, coarse, bastard, second-cut, smooth, and dead smooth have reference only to the
coarseness of the teeth; while the terms single-cut, double-cut, and rasp have special reference to the
character of the teeth. _
Single-Cut—The single-cut files (the coarser grades of which are sometimes called floats) are those
in which the teeth are unbroken, the blanks having had a single course of chisel-cuts across their
surface, arranged parallel to each other, but with a horizontal obliquity to the central line, varying
from 5° to 20° in different files, according to requirements. Its several gradations of coarseness are
designated by the terms rough, coarse, bastard, second-out, and smooth. (See Fig. 1567.) The rough
and coarse are adapted to files used upon soft metals, as lead, pewter, etc., and to some extent upon
wood. The bastard and second-cut are applied principally upon files used to sharpen the thin edges
of saw-teeth, which from their nature are very destructive to the delicate points of the double-cut.
The smooth is seldom applied upon other than the round files, and the backs of the half-rounds.
Doable-Cut.—Files having two courses of chisel-cuts crossing each other are called double-cut. The
first course is called the over-cut, and has a horizontal obliquity with the central line of the file, rang-
ing from 35° to 55°. The second course, which crosses the first, and in most double-cuts is finer, is
called the zap-cut, and has a horizontal obliquity varying from 5° to 15°. These two courses fill the
surface of the file with teeth, inclining toward its point, the points of which resemble somewhat,
when magnified, those of the diamond-shaped cutting tools in general use. This form of cut is made
in several gradations of coarseness, which are designated by the terms coarse, bastard, second-cut,
smooth, and dead-smooth, the first four of which are very cleariy illustrated in Fig. 1567. The dead-
smooth is exactly like the smooth, but considerably finer, and little called for. The double-cut is ap-
plied to most of the files used by the machinist, and in fact to much the larger number in gen-
eral use.
Resp-cut—Rasps differ from the singlc- or double-cut files in the respect that the teeth are discon-
nected from each other, each tooth being made by a single pointed tool, denominated by filemakers
a punch; the essential requirement being that the teeth thus formed shall be so irregularly inter-
mingled as to produce, when put to use, the smoothest possible work consistent with the number of
teeth contained in the surface of the rasp. Rasps, like files, have different degrees of coarseness,
designated as coarse, bastard, second-cut, and smooth. The character and general coarseness of these
cuts, as found in the different sizes, are also shown in Fig. 1567. Generally speaking, the coarse
teeth are applied to rasps used by horse-Sheers; the bastard, to those used by carriage-makers and
wheclwrights; the second-cut, to shoe rasps; and the smooth, to the rasps used by cabinet-makers.
Floats—Fig. 1572 represents a float used for filing lead. It will be seen that the teeth are
FILES. 699

nearly straight across the file, and are very open, both of these features being essential requirements.
While employed to some extent upon bone, horn, and ivory, these files are principally used by plumb-
ers and workers in lead, pewter, and similar soft metals.
Several kinds of floats are made with coarse, shallow, and sharp teeth; these teeth could not be
cut with the chisel and hammer in the ordinary manner, but are made with a triangular file. In Fig.
1568, a to l represent the sections of several of these floats, which have teeth at the parts indicated
by the double lines; for instance, a is the float, b the graille, c the found, d the cartct, e the topper,
used by the horn and tertoise-sheel comb-makers. The floats f to 2' are used by ivory-carvers for the
handles of knives, and in the preparation of works the carving of which is to be completed by
scoopers and gravers. la and l are used in inlaying tools in their handles; It is made of various
widths, and is generally thin, long, and taper; l is more like a keyhole saw. The larger of the
SECOND-CUT.
S A! com.


SEPOND-CITT.
BABTARD.
SscoND-CUT.








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floats, such as those a to 0, used by the comb-makers, are kept in order principally by the aid of a
burnisher, represented in two views in Fig. 1569 ; the blade is about 2 inches long, 1 inch wide, and
116th thick; the end is mostly used, and is forcibly rubbed, first on the front edge of every teeth,
as at a, Fig. 1570, and then on the back, as at b, by which means a slight burr is thrown up on
every tooth, somewhat like that on the joiner’s scraper; but in this art the burnisher is commonlv
named a tu-r-njile. '
The guannet is a float resembling Fig. 1597, but having coarse-filed teeth, of the kind just de-
scribed; it may be considered as the ordinary flat file of the horn and tortoise-shell comb-makers;
and in using the quannet, the work is mostly laid upon the knee as a support. An ingenious artisan
in this branch, Mr. Michael Kelly, invented the quannet represented in Figs. 1570 and 1571. The
stock consists of a piece of beech-wood, in which, at intervals of about one-quarter of an inch, cuts
700 FILES. \

inclined nearly 30° with the face are made with a thin saw; every cut is filed with a piece of
saw-plate. The edges of the plates and wood are originally filed into the regular float-like form,
and the burnisher is subsequently resorted to as usual. The main advantage results from the small
quantity of steel it is necessary to operate upon when the instrument requires to be restored with
the file. From this circumstance, and also from its less weight, the wooden quannet, Fig. 1570, is




1568. 1569. 1570. 1571.
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made of nearly twice the width of the steel instrument, Fig. 1597, and the face is slightly rounded,
the teeth being sometimes inserted square across, as in a float, at other times inclined some 30°,
as in a single-cut file. _
Brass hues—Figs. 1573, 1574, and 1575 are respectively coarse, bastard, and finishing second-cut
files for brass. Fig. 1573, being open in both its over- and up-cut, is not expected to file fine, but
fast, and is adapted for very rough work on the softer metals, as in filing 01f sprues from brass and
bronze castings, filing the ends of rods, and work of a similar nature. It is also to some extent used
upon wood. The essential difference between the bastard file shown in Fig. 1574- and that just de-
scribed is the degree of fineness of the up-cut, which is nearly straight across the tool. This form
of teeth, which may be applied to any of the finer cuts, and upon any of the shapes usually made
doable-cut, is especially adapted to finishing brass, bronze, copper, and similar soft metals, and is not
so well adapted to the rougher work upon these metals as the coarse brass file previously described.
Fig. 1575 is a finishing file. The first or over—cat, in this case, is very fine, and, contrary to the
general rule, has the least obliquity; while the rap-cut has an unusual obliquity, and is the coarser of
the two cuts. The advantages in this arrangement of the teeth are that the file will finish finer, and,
by freeing itself from the filings, is less liable to clog or pin, than files out for general use. This
1573.
_\.__\-\_ _.__ _ \ _ s
.




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form of out is especially useful when a considerable quantity of finishing of a light nature is re»
quired upon steel or iron. It is not recommended for brass or the softer metals, nor should it be
made of a coarser grade than second-cut.
Kmns or FII.ES.——T110 names of files are often derived from their purposes, as in saw_files, slitting,
warding, and cotter files ; the names of others from their sections, as square, round, and half-round
FILES. 701.

files. Files of all the sections represented in the groups, Figs. 1576 to 1578, are more or less em-
ployed, although many of them are almost restricted to particular purposes.
Taper files, or taper fiat files, are made of various lengths from about 4 to 24 inches, and are rec
tangular in section, as in B, Fig. 1576; they are considerably rounded on their edges, and a little also
in their thickness, their greatest section being toward the middle of their length or a little nearer to
the handle, whence these files are technically called “bellied; ” they are out both on their faces
and edges with teeth of four varieties, namely, rough, bastard, second-cut, and smooth-cut teeth.
Taper flat files are in extremely general use among smiths and mechanics, for a great variety of ordi~
nary works.
Hand files or flat files resemble the above in length, section, and teeth, but the hand files are
nearly parallel in width, and somewhat less taper in thickness than the foregoing. Engineers, ma-
chinists, mathematical-instrument makers, and others give the preference to the hand file for flat
surfaces and most other works.
Cotter files are always narrower than hand files of the same length and thickness; they are nearly
flat on the sides and edges, so as to present almost the same section at every part of their length, in
which respect they vary from 6 to 22 inches. Cotter files are mostly used in filing grooves for the
cotters, keys, or wedges used in fixing wheels on their shafts, whence their name.
Pillar files also someWhat resemble the hand files, but they are much narrower, somewhat thinner,
as in O, and are used for more slender purposes, or for completing works that have been commenced
with the hand files. Pillar files have commonly one safe edge, and vary from 3 to 10 inches in length.
Half-round files are nearly of the section L, notwithstanding that the name implies the semicircu-
lar section; in general the curvature only equals the fourth to the twelfth part of the circle.
Triangular files are of the section R, and from 2 to 16 inches long; they are used for internal
angles more acute than the rectangle, and also for clearing out square corners.
Cross files, or crossing files, are of the section M, or circular on both faces, but of two different
curvatures.
Round files, of the section I, range from the length of 2 to 18 inches ; they are in general taper,
and much used for enlarging round holes.
éguare files measure in general from 2 to 18 inches in length, and are mostly taper.
tgualing files are files of the section D. In width they are more frequently parallel than taper ;
in thickness they are always parallel. They are in general cut on all faces, and range from 2 to 10
inches long.
Knife files are of the section T, and in general very acute on the edge ; they are made from 2 to 7
inches long, and are as frequently parallel as taper.
Slitting files, called also feather-edged files, resemble the last in construction and purpose, except
in having, as in section V, two thin edges instead of one; they are almost always parallel.
Rubbers are strong heavy files, generally made of an inferior kind of steel ; they measure from 12
to 18 inches long, from g to 2 inches on every side, and are made very convex ; they are frequently
designated by their weight alone, which varies from about 4 to 15 lbs. Rubbers are nearly restricted
to the square and triangular sections A and R. Some few rubbers are made nearly square in section,
but with one side rounded, as if the sections K and B were united ; these are called half-thick.
Many artisans, and more particularly the watchmakers, require other files than those described,
and it is therefore proposed to add the names of some of the files to which the sections refer, pre-
mising that such names as are printed in Italics designate small files especially used in watchmaking.


1576.
Sections derived from the Square.
A B 0' D E F G H
[___I :3 ==== / 7 Z \ 2::
1577.



Sections derived from the Circle.
I K L M N O P Q
1578.
Sections derived from the Triangle.
S T V W .Y Y Z
5 > <> [l V {U M
Names of some of the Files corresponding with the Sections A to Z, in. Figs. 157 6 to 157 8.
A. Square files, both parallel and taper, some with bne safe side; also square rubbers.
B. When large, cotter files; when small, verge and pivot files.
0. Hand files, parallel and flat files; when small, pottance files; when narrow, pillar files; to these
nearly parallel files are to be added the taper flat files.
702 * FILES.

. When parallel, equaling, clock-pinion, and endless-screw files; when taper, slitting, entering, ward-
ing, and baw'el-lzole files.
E. French pivot and shouldering files, which are small, stout, and have safe edges; when made of
large size, and right and left, they are sometimes called parallel V files, from their suitability
to the hollow V’s of machinery.
F. Name and purpose similar to the last.
G. Flat file with hollow edges, principally used as a nail file for the dressing-case.
H. Pointing mill-saw file, round-edge equaling file, and round-edge joint file; all are made both
parallel and taper.
I. Round file, gulleting saw-file, made both parallel and taper.
K. Frame saw-file, for gullet teeth.
L. Half-round file. .ZWck'lng and piercing files, also cabinet floats and rasps; all these are usually
taper. Files of this section which are small, parallel, and have the convex side uncut, and
have also a pivot at the end opposite the tang, are called round-of files.
M Cross or crossing files, also called double half-rounds.
Oval files; oval gulleting files for large saws, called by the French limes d double dos; oval dial
file when small.
. Balance-wheel or swing-wheel files, the convex side cut, the angular sides safe.
Swa-ged files, for finishing brass mouldings; sometimes the hollow and fillets are all cut.
The curvilinear file.
Triangular, three-square, and saw-files, also triangular rubbers, which are cut on all sides.
Cant file, probably named from its suitability to filing the insides of spanners, for hexagonal and
octagonal nuts, or, as these are generally called, six- or eight-canted bolts and nuts; the cant
files are cut on all sides.
When parallel, flat-dovetail, banking, and watch-pinion files; when taper, knife-edge files. With
the wide edge round and safe, files of the section T are known as moulding files and clock-
pz'nion files. ’
Screw-head files, feather-edged files, clock- and u'az‘ch-sl'itling files.
Is sometimes used by engineers in finishing small grooves and keyways, and is called a valve
file, from one of its applications. '
A file compounded of the triangular and half-round file, and stronger than the latter; similar
files with three rounded faces have also been made for engineers.
Double or checkering files, used by cutlers, gunmakers, and others. The files are made separately
and riveted together, with the edge of the one before that of the other, in order to give the
equality of distance and parallelism of checkered works, just as in the double saws for cut-
ting the teeth of racks and combs. ,
Double file, made of two flat files fixed together in a wood or metal stock; this was invented for
filing lead pencils to a fine conical point.
b
2
V
saws
F0
H gs H
N
§q
In Figs. 15'? 9 to 1583 are represented full views of difierent shapes of files manufactured by the
1579.
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1580.
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Nicholson File Company of Providence, R. I. Fig. 1579 shows the general form of a quadrangular
file; Fig. 1580 is a flat file; Fig. 1581, a round file; Flf“. 1582, a triangular file; and Fig. 1583, a
roller file. The roller file is designed for use in a machine for filing the flutes of feed-rollers in cot~
ton-spinning machinery. It is usually 4 inches in length and second-cut, single.
Fig. 1584 represents a bent riffler. This tool is made in a variety of forms and of different cuts.
FILES. 703

It is used principally by carvers in wood, metals, marble, and stone; also in shaping and finishing in
and about the many irregular pieces of pattern work.
THE MANUFACTURE or FILES.—-The pieces of steel, or the blanks, intended for files are forged out
of bars of steel that have been either tilted or rolled as nearly as possible to the sections required, so
as to leave but little to be done at the forge; the blanks are afterward annealed with great caution,
so that in neither of the processes the temperature known as the blood-red heat may be exceeded.
The surfaces of the blanks are now rendered accurate in form and quite clean in surface either by
filing or grinding. For the smaller files, the blanks are mostly filed into shape as the more exact
method; for the larger, the blanks are more commonly ground on large grindstones as the more expe-
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ditious method; in some few cases the blanks are planed in the planing machine, for those called
dead-parallel files. The blank before being cut is slightly greased, that the chisel may slip freely
over it.
The file-cutter is seated before a square stake or anvil, and places the blank straight before him,
with the tang'toward his person; the ends of the blank are fixed down by two leather straps or
loops, one of which is held fast‘by each foot.
The largest and smallest chisels commonly used in cutting files are represented in two views, and
half size, in Figs. 1585 and 1586. The first is a chisel for large rough files; the length is about 3
inches, the width 2} inches, and the angle of the edge about 50“ ; the edge is perfectly straight, but
the one bevel is a little more inclined than the other, and the keenness of the edge is rounded off,
the object being to indent rather than out the steel; this chisel requires a hammer of about 7 or 8
lbs. weight. Fig. 1586 is the chisel used for small superfine files; its length is 2 inches, the width
half an inch ; it is very thin, and sharpened at about the angle of 35° ; the edge is also rounded, but
in a smaller degree: it is used with a hammer weighing only one or two ounces, as it will be seen the
weight of the blow mainly determines the distance between the teeth. Other chisels are made of
intermediate proportions, but the width of the edge always exceeds that of the file to be cut.
The first cut is made at the point of the file; the chisel is held in the left hand, at a horizontal
angle of about 55° with the central line of the file, as at a a, Fig. 158?, and with a vertical inclina-
1585. 1586. 1587. 1588.






tion of about 12° to 4° from the perpendicular, as represented in Figs. 1585 and 1586, supposing
the tang of the file to be on the left-hand side. The following are nearly the usual angles for the
vertical inclination of the chisels, namely: for rough rasps, 15° beyond the perpendicular; rough
files, 12°; bastard files, 10°; secoud~cut files, 7°; smooth-cut files, 5°; and dead-smooth-eut files, 4°.
The blow of the hammer upon the chisel causes the latter to indent and slightly to drive forward the
steel, thereby throwing up a trifling ridge or burr ; the chisel is immediately replaced on the blank,
and slid from the operator until it encounters the ridge previously thrown up, which arrests the chisel
or prevents it from slipping further back, and thereby determines the succeeding position of the
chisel. The chisel, having been placed in its second position, is again struck with the hammer, which
is made to give the blows as nearly as possible of uniform strength; and the process is repeated
with considerable rapidity and regularity, 60 to 80 cuts being made in one minute, until the entire
length of the file has been cut with inclined, parallel, and equidistant ridges, which are collectively
denominated the first course. So far as this one face is concerned, the file, if intended to be single-
cut, would be then ready for hardening; and when greatly enlarged, its section would be somewhat
as in Fig. 1588. The teeth of some single-cut files are much less inclined than 55° ; those of floats
are in general square across the instrument.
Most files, however, are double-cut, or have two series or courses of chisel cuts; and for these the
surface of the file is now smoothed by passing a smooth file once or twice along the face of the teeth,
to remove only so much of the roughness as would obstruct the chisel from sliding along the face in
receiving its successive positions, and the file is again greased. The second course of teeth is now
704 . FILES.

cut, the chisel being inclined vertically as before, or at about 12°, but horizontally about 5° to 10°
from the rectangle, as at b b, Fig. 1587 ; the blows are now given a little less strongly, so as barely
to penetrate to the bottom of the first cuts, and consequently the second course of cuts is somewhat
finer than the first. The two series of courses fill the surface of the file with teeth which are in-
clined toward the point of the file, and that when highly magnified much resemble in character the
- points of cutting tools generally, as seen in Fig. 1588. If the file is flat and to be cut on two faces,
it is now turned over; but to protect the teeth from the hard face of the anvil, a thin plate of pew-
ter is interposed. Triangular and other files require blocks of lead having grooves of the appropriate
sections to support the blanks, so that the surface to be out may be placed horizontally. Taper files
require the teeth to be somewhat finer toward the point, to avoid the risk of the blank being weak-
ened or broken in the act of its being cut, which might occur if as much force were used in cutting
the teeth at the point of the file as in those at its central and stronger part.
Eight courses of cuts are required to complete a double-cut rectangular file that is cut on all faces,
but eight, ten, or even more courses are required in cutting only the one rounded face of a half-round
file. There are various objections to employing chisels with concaveedges, and therefore in cutting
round and half-round files the ordinary straight chisel is used and applied as a tangent to the curve.
It will be found that in a smooth half-round file one inch in width, about 20 courses are required for
the convex side, and two courses alone serve for the flat side. In some of the double-cut gullet-
tooth saw-files, of the section K, as many as 23 courses are sometimes used for the convex face, and
but two for the flat. The same difficulty occurs in a round file, and the surfaces of curvilinear files
do not therefore present, under ordinary circumstances, the same uniformity as those of flat files.
Hollowed files are rarely used in the arts, and when required it usually becomes imperative to em-
ploy a round-edged chisel, and to cut the file with a single course of teeth.
The teeth of rasps are cut with a punch, which is represented in two views, Fig. 1589. The punch
for a fine cabinet rasp is about 3%! inches long, and five-eighths of an
inch square at its widest part. Viewed in front, the two sides of the
point meet at an angle of about 60°; viewed edgewise, or in profile, the
edge forms an angle of about 50°, the one face being only a little in-
clined to the body of the tool. In cutting rasps, the punch is sloped
rather more from the operator than the chisel in cutting files, but the dis-
tance between the teeth of the rasp cannot be determined, as in the file,
by placing the punch in contact with the burr of the tooth previously
made. By dint of habit, the workman moves or, technically, hops the
punch the required distance; to facilitate this movement, he places a
piece of woolen cloth under his left hand, which prevents his hand from
coming immediately in contact with and adhering to the anvil. The teeth
of rasps are cut in rather an arbitrary manner, and‘ to suit the whims
rather than the necessities of the workmen who use them. Thus the
lines of teeth in cabinet rasps, wood rasps, and fairiers’ rasps, are cut
in lines sloping from the left down to the right-hand side; the teeth of
rasps for boot- and shoe-last makers and some others are sloped the re-
verse way; and rasps for gun-stockers and saddle-tree makers are cut in
circular lines or crescent form. These directions are quite immaterial;
but it is important that every succeeding tooth should cross its prede-
cessor, or be intermediate to the two before it; as, if the teeth followed one another in right lines,
they would produce furrows in the work, and not comparatively smooth surfaces.
In cutting files and rasps they almost always become more or less bent, and there would be danger of
breaking them if they were set straight while cold; they are consequently straightened while they are
at the red heat, immediately prior to their being hardened and tempered. Previously to their being
hardened, the files are drawn through beer grounds, yeast, or other sticky matter, and then through
common salt, mixed with cow’s hoof previously roasted and pounded, which serve as a defence to
protect the delicate teeth of the file from the direct action of the fire. The compound likewise serves
as an index of the temperature, as on the fusion of the salt the hardening heat is attained; the
defense also lessens the disposition of the files to crack or clinlr on being immersed in the water.
The file, after having been smeared over as above, is gradually heated to a dull red, and is then
mostly straightened with a leaden hammer on two small blocks, also of lead; the temperature of the
file is afterward increased until the salt on its surface just fuses, when the file is immediately dipped
in water. The file is immersed quickly or slowly, vertically or obliquely, according to its form ; that
mode being adopted for each variety of file which is considered best calculated to keep it straight.
It is well known that from the unsymmetrical section of the half-round file, it is disposed, on being
immersed, to become hollow or bowed on the convex side, and this tendency is compensated for by
curving the file while soft in a nearly equal degree in the reverse direction. It nevertheless common“
ly happens that with every precaution the file becomes more or less bent in hardening; and if so, it
is straightened by pressure, either before it is quite cold, or else after it has been partially reheated.
The pressure is variously applied: sometimes by passing one end of the file under a hook, supporting
the centre on a prop of lead, and bearing down the opposite end of the file ; at other times by using
a support at each end, and applying pressure in the middle, by means of a lever, the end of which
is hooked to the bench. Large files are always straightened before they are quite cooled after the
hardening, and while the central part retains a considerable degree of heat. When straightened, the
file is cooled in oil, which saves the teeth from becoming rusty.
The tangs are now softened to prevent their fracture; this is done either by grasping the tang in
a pair of heated tongs, or by means of a bath of lead contained in an iron vessel with a perforated
cover, through the holes in which the tangs are immersed in the melted lead that is heated to the
1589.



FILES. 705

proper degree. The tang is afterward cooled in oil; and when the file has been wiped and the teeth
brushed clean, it is considered fit for use. . .
The superiority of the file will be found to depend on four points: the primary excellence of the
steel, the proper forging and annealing without excess of heat, the correct formation of the teeth,
and the success of the hardening. _ .
Increment-Cut File—This name is given to a machine-cut file manufactured by the Nicholson File
Company, the rows of teeth of which are spaced progressively wider, from the point toward the mid-
dle of the file, by regular increments of spacing; and progressively narrower, from the middle toward
the heel, by regular decrements of spacing. This general law of the spacing of the teeth is modi-
fied by introducing, as they are cut, an element of controllable irregularity as to their spacing; which
irregularity is confined within maximum and minimum limits, but is not a regular progresswe incre-
ment or decrement. The teeth are arranged so that the successive rows shall not_be exactly parallel,
but cut slightly angularly with respect to each other, the angle of inclination.bemg reversed diiring
the operation of cutting, as necessity requires. Files possessmg the characteristics above mentioned
do not produce channels or furrows in the work, but effect a sheamng cut, for the reason that up two
successive teeth in any longitudinal row of a cross-cut file are in alignment ; the file is, it is claimed,
' thereby able to cut more smoothly and more rapidly, and possesses greater endurance as a tool for
dressing metal than files not so cut. _ _ .
Means of Grasping ‘the File—In general, the end of the fileis forged simply into a taper tang or
spike, for the purpose of fixing it in its wooden handle ; but Wide files reqmrejchat the tang should
be reduced in width, either as in Fig. 1590 or 1591. The former mode, especially in large files, is











\=\
1592. ‘- _ 1596.





apt to cripple the steel and dispose the tang to break off, after which the file is nearly useless. The
curvilinear tang, 1591, is far less open to this objection. Some workmen make the tangs of
large files red-hot, that they may burn their own recesses in the handles; but this is objectionable,
as the charred wood is apt to crumble away and release the file. It is more proper to form the
cavity in the handle with coarse floats made for the purpose. _
In driving large files into their handles, it is usual to place the point of the file in the hollow behind
the chaps of the tail-vise, and to drive on the handle with a mallet or hammer. Smaller files are
fixed obliquely in the jaws of the vise, between clamps of sheet brass, to prevent the teeth either of
the vise or file from being injured, and the handle is then driven on.
In the double-edged rifl'lers, or bent files, Fig. 1592, and in some other files, there is a plain part in
the middle, fulfilling the office of a. handle; and in several of the files and rasps made for dentists,
farriers, and shoemakers, the tool is also double, but without any intermediate plain part, so that the
one end serves as the handle for the other. _
In general, the length of the file exceeds that of the object filed, but in filing large surfaces it
becomes occasionally necessary to attach cranked handles to the large files or rubbers, as in Fig. 1593,
in order to raise the hand above the plane of the work. Sometimes the end of the file is simply
inclined, as in Fig. 1594, or bent at right angles, as in Fig. 1595, for the attachment of the wooden
handles represented; but the last two modes prevent the second side of the file from being used,
until the tang is bent the reverse way. The necessity for bending the file is avoided by employing as
a handle a piece of round iron, five-eighths or three-fourths of an inch in diameter, bent into the
semicircular form asian arch, the one extremity (or abutment) of which is filed with a taper groove
to fit the tang of the file, while the opposite end is flat, and rests upon the teeth; in this manner
both sides of the file may be used without any preparation.
Fig. 1596 represents, in profile, a broad and short rasp with fine teeth, used by iron-founders in
smoothing ofit‘ loam moulds for iron castings; this is mostly used on large surfaces, to which the ordi-
nary handle would be inapplicable, and the same kind of tool when made with coarser teeth will be
recognized as the baker’s rasp.
Cabinet-makers sometimes fix the file to a block of wood to serve for the grasp, and use it as a
plane. Thus mounted, the file may also be very conveniently used on a shooting-board, in filing the
edges of plates to be inlaid. Fig. 1597 represents a very good arrangement of this hind. a a is the
plan, b the section of the file stock; cc is the plan of the shooting-board, and (1 its section. Two
files (that are represented black) are screwed against the sides of a straight bar of wood, which has
45
7 06 ' FILES.

also a wooden sole or bottom plate, that projects beyond the files, so that the smooth edge of the
sole may touch the shooting-board instead of the file-teeth. The shooting-board is made in three
pieces, so as to form a groove to receive the file-dust, which would otherwise get under the stock of
the file. The shooting-board has also a wooden stop s, faced with steel, that is wedged and screwed











1597.
a, I
Lb: a a 6
______ _‘
a? J'
2/2
2%?
a C' c



into a groove made across the top piece; and the stop, being exactly at right angles, serves also to
assist in squaring the edges of plates or the ends of long bars, with accuracy and expedition.
Short pieces of files (or tools as nearly allied to saws) are occasionally fixed in the ends of wooden
stocks, in all other respects like the routing gauges of carpenters, as seen in two views in Fig. 1598.
The coopers’ croze is a tool of this description. .
Files intended for finishing the grooves in the edges of slides are sometimes made of short pieces
of steel of the proper section (see Fig. 1599), cut on the surfaces with file-teeth, and attached in
various ways to slender rods or wires, serving as the handles, and extending beyond the ends of the
slides; or the handle is at right angles to the file, and formed at the end, as a staple, to clip the
ends of the short file, as in reaching the bottom of a cavity. Files intended to reach to the bottom


@ MW/ ‘53 1599.
Ft: 1600.


1598.



of shallow cavities are also constructed as in Figs. 1600 and 1601 ; or sometimes an inch or more of
the end of an ordinary file is bent some 20° or 30°, that the remainder may clear the margin of the
recess. '
To stiffen slender files, they are occasionally made with tin or brass backs, as in Figs. 1602 and
1603; such are called dovetail files. Thin equaling files are sometimes grasped in a brass frame,
Fig. 1604, exactly like that used for a metal frame-saw.
See “A Treatise on Files and Rasps,” Nicholson File Company, Providence, 1878, from which
many extracts and illustrations are embodied in the foregoing article.
SHARPENING FILES. By the Sand-Blast.—Figs. 1604 A, B, and 0, represent the latest forms of ap-
paratus for sharpening files by the sand- blast. In this process a stream of very fine sand and water,
in the state of fluid mud, is directed at a certain angle against the face of the file, and is driven with
great velocity by jets of steam against the back of the teeth, the effect being to grind away the burr
or curl produced by the chisel, and to give the teeth keen and well-supported edges. New files so
treated out much faster, work more freely, “pin ” less, and wear longer than the ordinary kind.
Their superiority is shown in a marked degree when used upon gun-metal, and broad surfaces of cast
and wrought iron and steel, where great pressure is necessary to make the ordinary file bite or take
hold of the work.
A file which has been fairly worn out in the fitting-shop, but which is not rusty and has not many
broken teeth, can be sharpened by the sand-blast so as to cut equal to a new file, and when again
dulled by wear it can be again sharpened, and this can be repeated many times. To obtain satis-
factory results from the use of the process for resharpening worn files, the fitters should be instructed
to lay aside their files as soon as they commence to drag or lose their smoothness of cutting. The
partly dulled files are collected from time to time, taken to the file-sharpening apparatus, touched up and
redistributed. The fine sand and water is contained in the conical reservoir on the left, and is raised
by a pump to the small hopper above, from which it is conveyed by aflexible pipe to the blast-jet. On
FILING. 707

the right is shown Mathewson’s file-sharpening jet. The sand and steam ’enter the jet at separate
points, the former by the flexible tube 0 and passage D, and the latter where marked, and do not
1604 B.


come in actual contact within the jet. On issuing from the jet the mixture of sand and water is suddenly
encompassed by the two converging sheets (or wide and thin jets) of steam at b b, and thus projected
with great velocity against the teeth of the file C, which is passed obliquely over the sloping rest B,
held between the guide F and the wedge A. The steam
acts exactly as when employed as an injector of water into
boilers, lifting the sand and water and forcing it at a press- . _ Z _ _ a .
ure of from 60 to 80 lbs. per sq. in. against the file-teeth. ‘f- 'T,".,.; ‘- 5 i, This process is feuiid much more efficacious than the acid ' ° method of file-sharpening. - '
By Electricity—M. A. Personne, of Senneroy, France,
has devised the apparatus for electrically sharpening files,
shown in Fig. 1604 D. He arranges a carbon and acidu-
lated water battery in which the tool to be sharpened
forms the anode, the circuit being closed directly between
the carbon and the tool. Under the influence of the elec- {a tric current the water is rapidly decomposed into its ele-




4: is? -
i .
:“CZ'IZ ' -,
a ""‘t?




. s'»
3.5-L ..-.
E—bg Q1.
“.153 E






ii. "


...<""-_._ .A '1‘ “H
n _-\"l ' ‘ ~.
Afllll
l
ments, each of which then“ performs an entirely different ,Zgsa-tiaesaané
role. While the oxygen proceeds to the bottom of the fin _‘
I. {in}
i I
l 1.-
rows, which it gradually deepens, the hydrogen forms, in




a nascent state, a covering of small bubbles over all the 2° " '
projecting parts, which are thus protected against the an "a
tack of the liquid. It is claimed that there results from
the separation of the two gases a sharpening of each tooth
superior to that given by hand.
FILING. The excellence of a piece of work operated
upon by a file is only limited by the skill of the operator;
for, since a file can be made of any shape and size, and
since the quantity of material it will cut away and the loca-
tion of the same may be varied at will, it is evident that
it is possible to perform with the file every operation that
can be performed with steel tools. The legitimate use of
the file may be classed under four headings: 1, For the re-
moval of a surplusage of metal; 2, to correct errors in the truth of work which has been operated
upon by such machinetools as the planer and shaper; 3, for the production of small intricate or
irregular forms ; and, 4, to fit work together more accurately than can be done by other means.
Work to be filed should be held with the surface to be operated upon lying face upward and
horizontally ,' and the general rule for the height of the work above the ground is, that the surface
to be filed should be nearly level with the elbow-joint of the workman. Some latitude is, however,
required in respect to the magnitude of the works, as, when they are massive, and much is to be filed
ofi from them, it is desirable that the work should be a trifle. lower than the elbow; when the work
is minute and delicate, it should be somewhat higher, so that the eye may be the better able to add
its scrutiny to that of the sense of feeling of the hand, upon which principally the successful practice
depends.
Since the teeth of a file are unequal in height, and the form of the file warps in the hardening
708 FILING.

process, it is evident that, even supposing the operator to be able to move the file in a straight linO;
the surface filed would not be straight. Hence a file to act upon flat surfaces should be thickest ii.
the middle, and thinner at each end of its length. . This gives to the surface of the teeth a curve or
sweep in the length of the file; and if the file should warp, the effect is ‘ merely to lessen the sweep
on one side and increase it on the other. This is of but little consequence, since, by altering the
height of the respective ends of the file, any part of the same may be brought into contact with the
work. Furthermore, the file can be so applied as to act upon any high spot or part of the surface
without cutting the surrounding surface. It is of no consequence if one side of the file possesses
more sweep than the other, because, so long as it is moved in a straight line, the teeth performing
duty will cut a straight surface if passed clear .across the work. The curve of the file, however, is
usually about sufficient to compensate for any variation of the stroke from a horizontal plane. The
level of the teeth crosswise of the file may be either flat or a little rounding, the latter being prefer-
able; but in no case should it be (for flat surfaces) hollow, because in that case the edges would cut
grooves in the work. For convex surfaces a flat file is usually employed; but for concave surfaces
the file must be given a convexity greater than the concavity of the work, so that any desired part
of the file may be brought into contact with the work, notwithstanding a slight irregularity in the
curve of the file. »
In Fig. 1605 is shown the shape of file desirable for a concave surface. The difficulty experienced
in filing a narrow surface flat is explained by reference to Figs. 1606, 1607, and 1608. The file, held
1605. 1606.





in the two hands upon the narrow work, may be viewed as a double-ended lever, or as a scale-beam
supported on a prop; and the variation in distance of the hands from the work or prop gives a di-.-
position to rotate the file upon the work, which is only counteracted by habit or experience.
Assuming, for the moment, that in the three diagrams the vertical pressure of the right hand at
r and of the left at Z is in all cases alike, in Fig. 1606, or the beginning of the stroke, the right
hand would, from acting at the longer end of the lever, become depressed; in Fig. 1607, or the cen-
tral position, the hands would be in equilibrium and the file horizontal; and in Fig. 1608, or the end
of the stroke, the left hand would preponderate; the three positions would inevitably make the work
round, in place of leaving it plane or flat. It is true the diagrams are extravagant, but this rolling
action of the file upon the work is in most cases to be observed in the beginner; and it is only by
much practice that it can be counteracted, which is done by maintaining a pressure at and upon each
end of the file so proportioned that, the teeth performing duty forming a fulcrum, the pressure on
each end of the file decreases in proportion to its distance from that fulcrum.
In using the file for large work, such as is common in a general machine shop, it should be fixed
firmly in its handle, which should be placed truly upon the file. The butt end of the handle should
press firmly against the palm of the hand, the forefinger being placed beneath the file-handle. To
take off a quantity of metal, the operator should stand sufficiently far from the work to be able to
bend the body and place its weight upon the file during the forward stroke. During the back stroke
the pressure upon the file-teeth should be removed, otherwise the teeth of the file become rapidly
worn. A new file should never be used upon a very narrow surface, because the teeth, from their
keenness, sink so deeply in the metal and take so firm a grip that they receive a strain from the cut
sufficient to break them off. The most economical way to employ a file is to use it upon brass first,
because brass requires a keen file. After the tool has become impaired for brass work, it is still
good for use on cast-iron, wrought-iron, or steel. If the cuttings jam in the file (this is called piw
ning), they should be removed with a file-card; or if too fast to be taken off by that tool, a piece of
sheet copper or brass about three-eighths of an inch wide, 2% inches long, and one-thirty-second of an
inch thick, should have one end hammered thin, and this thinned edge should be passed across the
file. It should be pressed firmly to and moved along the rows of teeth, in order that it may become
serrated and force out the pins. To prevent pinning, the file-teeth may have soft chalk rubbed over
them, which will prevent the filings from getting locked in the teeth. After every few strokes of
the file the hand should be brushed over it, and the file should be lightly tapped against the bench
or vise-box, when the loose filings will fall out. When, however, the file requires reehalking, which
will easily become apparent, the use of the file-card may precede the application of the chalk. This
chalking process is especially necessary during the finishing, as the pins are sure to scratch the work.
In using rough or bastard files to remove a quantity of metal, it is well so to regulate the motion of
the file that the file-marks cross and reeross each other, which not only tends to keep the filing true,
but increases the efficiency of the operation. It is to be especially noted, however, that in giving the
file lateral side motion during each stroke, it will pin less if that motion takes place from right to
left, and this in consequence of the cut of the file. The serrations forming the teeth cross each
other diagonally. The first series are nearest to the front end of the file on the left-hand side, while
the last and therefore the deepest serrations, forming on the finished file the rows of the teeth, stand ~
FILING. 70!)

diagonally, being nearest to the file-handle on the left-hand side. Therefore, by giving to the
file stroke a certain amount of lateral side motion, the cutting duty is performed by the teeth more
in a direction parallel to the rows of the file-teeth, and the cross-filing, as the forward motion of the
file is termed, partakes slightly of the nature of draw-filing.
Work requiring to be finely finished should be operated upon by the second-cut, smooth, and super-
fine smooth files, the cross-filing being succeeded by draw-filing.
The object of draw-filing is two-fold: first, the file can be held more steadily, and can therefore
be applied to any circumscribed part of the work exclusively, as is necessary in truing work; and
secondly, the teeth cut finer and smoother. Hence it is that draw-filing is necessary to the produc-
tion of fine and accurate work. In draw-filing to obtain accuracy, the high spots or parts of the
file should be selected to remove the places which the test-marks upon the work indicate as requir-
ing to be filed, and the file-marks should be kept as straight as possible. But in draw-filing to fin-
ish finely, the file-marks may be made to cross each other at frequent intervals. In either case the
stroke of the file should be a short one, in no case exceeding about 4 inches, as longer ones produce
pinning and the attendant evil, scratches. A worn file, either smooth, superfine smooth, or dead
smooth, will finish finer than a new one; and better results will be obtained by finishing the work
crosswise of the grain than on a line with it, because any inequality in the metal will usually run
with the grain, and the file-teeth will cut the softer parts of the metal better when following their
length than when merely crossing them. For the very finest of work, the Groubet files should be
used, as they are the finest-cut files made, besides being unusually true to shape.
Filed work is usually polished by the application of emery paper. With emery paper, as with
files, the more used it is, the better it will polish, because it becomes coated with a glazed surface
composed of particles of the metal it has been rubbing, and all metals polish better by the applica-
tion of such a surface than by that of any other.
Half-round files should be used, during both the roughing-out and finishing processes, with a side
or lateral sweep; otherwise they are apt to- produce waves in the work.
In filing out keyways, it often becomes necessary to use the most rounded or curved face at the
end of the file only, so that, the operation being out of sight, the workman may insure that the file
has contact with the work in such places only as is necessary. A similar method is also pursued in
facing outside surfaces very true; and if great care is taken and very fine files are used, surfaces
equal to the finest scraped ones may be produced by the file.
Files are often employed for the finishing of work turned in the lathe. F or this purpose fine files
1609. 1011.


only should be used, and the amount of the duty should be kept as small as possible, because the
file is apt to cut more readily into the softer parts of the metal, and hence to make the work out ( f
round.
The work, when small, is almost invariably held on the filing-block with the left hand, occasionally
through the intervention of a hand-vise, Fig. 1612. In this case the two hands act in concert, the
right in moving the file, the left in adjusting the position of the work, until the workman is con-
scious of the agreement in position of the two parts. Sometimes indeed the partial rotation of the
work, in order to adapt it to the file, is especially provided for, so as to compensate for the acciden-
tal swaying of the file; such is the case in the various kinds of swing tools, used by watchmakers
in filing and polishing small flat works. A similar end is more rarely obtained, on a larger scale,
when the file is required to be held in both hands. For example, filing-boards, resembling Fig.
1609, and upon which the work is placed, have been made to move on two pivots, somewhat as a
gun moves on its trunnions; consequently the work, when laid upon the swinging board, assumes
the same angle as that at which the file may at the moment he held.
A more common case is to be seen in filing a rectangular mortise through a cylindrical spindle, as
in Fig. 1610. The hole is commenced by drilling three or four holes, which are thrown into one by
a cross-cut chisel or small round file; and the work, when nearly completed, is suspended between
the centres of the lathe, so that it may freely assume the inclination of the file. At other times, the
cylinder is laid in the interval between the edges of the jaws of the vise, that are opened as much
as two-thirds the diameter of the object, which then similarly rotates on the supporting edges; this
mode is shown in Fig. 1611. These three applications are objectionablein some instances, as the
file is left too much at liberty, and the work is liable to be filed hollow instead of flat, especially if
the file be rounding, because the unstable position of the work prevents the file from being cen-
strained to act on any particular spot that may require to be reduced.
A great number of small works are more conveniently filed while they are held with the left hand,
the file being then managed exclusively with the right ; this enables the artisan more easily to judge
of the position of the file. In such cases, a piece of wood, f, Fig. 1612, called a filing-block, is
fixed in the table or tail-vise. (See VISE.)
Numerous fiat works are too large, thin, and irregular in their superficies to admit of being fixed
in the various kinds of bench-rises, as there would be risk of bending such thin pieces by the pres-
sure of the vise applied against the edges of the work. The largest flat works are simply laid
on the naked surface of the work-bench, and temporarily held by half a dozen or more pins or
710 FILING.

nails driven into the bench. The pins should be as close to the margin as possible, and yet below
the surface of the work. For thin fiat works of smaller size, the filing-board, Fig. 1613, is a conve-
nient appendage ; it measures 6 or 8 inches square, and has a stout rib 0n the under side, by which
it is fixed in the vise. In filing thin fiat works, such as the thin handles or scales of penknives and
razors, and the thin steel plates used in pocket-knives, cutlers generally resort to the contrivance
represented in Fig. 1614, known as a fiattt'ng-vz'se. One face of the small filing-block f, Fig. 1612,
is also used for very small thin works, which are prevented from slipping from the file by the
wooden ledge, or by pins driven in. In many instances, also, thin works are held upon a piece of,
cork, beneath which is glued a square piece of wood, that the cork may be held in the vise without
being compressed. The elasticity of the cork allows the work to become somewhat imbedded by the
pressure of the file, between which and the surface-friction it is sufficiently secured for the purpose
without pins.
Before any effective progress can be made in filing flat works, the operator must be provided with


the means of testing the progressive advance of the work; he should therefore possess a true
straight-edge and a true surface-plate. The straight-edges used by smiths are generally of steel; and
although they have sometimes a nearly acute edge, it is much more usual to give them moderate
width; thus, in steel straight-edges from 1 to 4 feet in length, the width of the edge is from one-
sixteenth to one-fourth of an inch; and in cast-iron straight-edges from 6 to 9 feet in length, the ‘
width is usually 2 to 3 inches. The straight-edge is used for trying the surface that is under correc-
tion, along its four margins, across its two diagonals, and at various intermediate parts, which
respective lines, if all exact, denote the surface to be correct. But the straight-edge alone is a
tedious and scarcely sufficient test; and when great accuracy is desired, it is almost imperative to
have at least one very exact plane metallic surface or surface-plate, by which the general condition
of the surface under formation may be more quickly and accurately tested at one operation; and
to avoid confusion of terms, it is proposed in all cases, when speaking of the instrument, to employ
the appellation planomcter, which is exact and distinctive. (See PLANOMETERS.)
The flat piece of cast-iron intended to be operated upon having been chipped all over, a coarse
hand-file, of as large dimensions as the operator can safely manage, is selected. In the commence-
ment the rough edges or ridges left by the chipping chisel are leveled, those parts however being
principally filed that appear from the straight-edge to be too high. The strokes of the file are
directed sometimes square across as on a fixed line, or obliquely in both directions alternately; at
other times the file is traversed a little to the right or left during the stroke, so as to make it apply


to a portion of the work exceeding the width of the file. These changes in the applications of the
file are almost constantly given, in order that the various positions may cross each other in all possi-
ble directions, and prevent the formation of partial hollows. The work is tried at short intervals
with the straight-edge ; and the eye, directed on a level with the work to be tested, readily perceives
the points that are most prominent. After the rough errors have been partially removed, the work
is taken from the vise and struck edgewise upon the bench to shake off any loose filings, and it is
then inverted on the planometer, which should be fully as large as or larger than the work. As, how-
ever, it cannot be told by the eye which points of the work touch the planomcter, this instrument
is coated allover with some coloring matter, such as pulverized red chalk mixed with a little oil,
and then the touching places become colored. The work is slightly rubbed on the surface-plate,
and then picks up at its highest points some of the red matter; it is refixed in the vise, and the file
is principally used in the vicinity of the colored parts, with the occasional test of the straight-edge,
and after a short period the work is again tried on the planomcter. This process is continually
repeated, and if watchfully performed it will be found that the points of contact will become grad»
ually increased.
FILING. - 711

The grooved or roughing-out cutter is employed in the commencement, because it more rapidly
penetrates the work, and a few strokes are given to crop off the highest points of the surface ; the
furrows made by the serrated cutter are then nearly removed with the file, which acts more expe-
ditiously although less exactly than the plane, and in this manner the grooved plane-iron and the
coarse file are alternately used. In the absence of the planometer, the metal plane assumes a
greatly increased degree of importance. As the work becomes gradually nearer to truth, the grooved
cutter is exchanged for that with a continuous or smooth edge. A second-cut or bastard file is also
selected, and the same alternation of planing and filing is persevered in, the plane serving as it
were to direct the file, until it is found that the plane-iron acts too vigorously, as it is scarcely satis-
fied with merely scraping over the surface of the cast-iron, but when it acts removes a shaving hav-
ing a nearly measurable thickness, and therefore, although the hand-plane may not injure the gen-
eral truth of the surface, it will prevent the work from being so delicately acted upon as the contin-
uance of the process now demands ; a smoother hand-file is consequently alone employed in further-
ing the work.
It is now often usual to discontinue the use of the file, and to prosecute the work with a scraper,
which, having a sharp edge, instead of a broad and abrading surface, may be made to act with far
more decision on any, even the most minute, spot or point. (See SCRAPER.) The scraper, however, is
not intended to remove a quantity of metal; hence even work requiring to be finished by the scra-
per should be first made true by smooth filing, especially if the planing or milling-tool marks are
left upon the work, for in that case the scraper edge is apt to follow those marks instead of cutting
smoothly as it should do.
The former instructions have been restricted to the supposition that only one of the superficies of
the work was required to be made plane or flat; but it frequently happens in rectangular works,
such as the piece A B C, Fig. 1615, that all six surfaces, namely, the top and bottom A a, the two
sides B b, and the two ends 0 c, all require to be corrected and made in rectangular arrangement
(the surfaces a b 0 being necessarily concealed from view); and therefore some particulars of the
ordinary method of producing these six surfaces will be added. ,
The general rule is first to file up the two largest and principal faces A and a, and afterward the
smaller faces or edges B b and O c. The principal faces A a, especially when the pieces are thin,
must he proceeded with for a period simultaneously, because of the liability of all materials to
spring and alter in their form with the progressive removal of their substance; and on this account
1616. 1617.
U



the work, whether thick or thin, is frequently prepared to a certain stage at every part, before the
final correction is attempted of any one part. The straight-edge and surface-plate are required to
prove that each of the faces A and a is a plane surface, and the calipers or a similar gauge is also
needful to prove them to be in parallelism. Calipers, unless provided with set-screws, are very lia-
ble to be accidentally shifted, and it is needful to use them with caution ; otherwise their elasticity,
arising from the length of their legs, is apt to deceive. There are gauges, such as Fig. 1616, with
short parallel jaws that open as on a slide, and are fixed by a side screw; and a still more simple
and very safe plan is to file two rectangular notches in a piece of sheet-iron or steel, as in Fig. 1617,
the one notch exactly of the finished thickness the work is required to possess, the other a little
larger to serve as the coarse or preliminary gauge. (See CALIPERS, and Games.)
Sometimes, the one face of the work, or A, having been filed moderately fiat, a line is scored
around the four sides of the work with a metal marking-gauge, the same in principle as the mark-
ing-gauge of the joiner. At other times the corrected face A is laid on a planomcter larger than
the work, and the marginal line is scribed on the four edges by a scribing-point p, Fig. 1619, pro-
jecting from the sides of a little metal pedestal that bears truly on the surface-plate. Chamfers or
beveled edges are then filed around the four edges of the face a, exactly to terminate on the scribed
lines : the central part of a. can be reduced with but little watchfulness, until the marginal chamfers
are nearly obliterated. This saves much of the time that would be otherwise required for investi-
gating the progress made; but toward the last the calipers and planomcter must be carefully and
continually used, to assist in rendering A and a at the same time parallel and plane surfaces. The
two principal edges B b are then filed under the guidance of a square. The one arm of the square
is applied on A or a at pleasure, as in joinery work; or if the square have a thick back, it may be
placed on the planomcter, as at s, Fig. 1615; if preferred, the work may be supported on its edge
B upon the planometer, and the back square also applied, as at s, in which case the entire length of
the blade of the square comes into operation, and the irregularities of the plane B are at the same
time rendered obvious by the planomcter. Another very convenienttest has been recommended for
this part of the work, namely, a stout bar, such as 'r, Fig. 1615, the two neighboring sides of which
have been made quite flat and also square with each other. When the work and trial-bar are both
laid down, the one side of the bar presents a truly perpendicular face, which may, by the interven-
712 FILING.

tion of coloring matter, be made to record on the work itself the points in which B differs from a
rectangular and vertical plane. When the edge B has been rendered plane and square, the oppo-
site edge I) may in its turn be marked either with the gauge or scribing-point at pleasure; the four
edges of b may be then chamfered, and the entire surface of b is afterward corrected (as in produe
ing the second face a), under the guidance of the square, calipers, rectangular bar, and surface-plate,
or some of these tests. The ends 0 0 new claim attention, and the marginal line is scribed around
these by the aid of the back square alone; but the general method so closely resembles that just
described as not to call for additional particulars.
Should one edge of the work be inclined or beveled, as in the three following figures, in which the
works are shaded to distinguish them from the tools, the rectangular parts are always first wrought,
1618. 1619. 1620. 1621.
WNN
and then the beveled edges, the angles being denoted by a bevel instead of a square; either with a
bevel having a movable blade, Fig. 1618, or by a beveled templet made of sheet metal, as in Figs.
1619 or 1620, which latter cannot get misadjusted. The beveled edge of the work. is also applied if
possible on the planomcter; in fact, the planomcter and bevel are conjointly used as the tests.
Beveled works are either held in the vise by aid of the chamfcr-clamps, or they are laid in wooden
troughs, with grooves so inclined that the edge to be filed is placed horizontally. Triangular bars
of equilateral section are thus filed in troughs, the sides of which meet at an angle of 60°, as in
Fig. 1621. ~
The succeeding examples of works with many plane surfaces are objects with rebates and grooves,
as represented in Figs. 1622 to 1625. Pieces of the sections, Figs. 1622 and 1623, supposing them
to be short, would in general be formed in the solid, either from forgings or castings, as the case
might be ; the four exterior and more accessible faces would be filed up square and true, and after»
ward the interior faces, with a due regard to their parallelism with the neighboring parts, after the
mode already set forth. The safe edge of the file is now indispensable; as in filing the face I), the
safe edge of the file is allowed to rub against the face a of the work, which therefore serves for its
guidance, and in filing the face a the side 6 becomes the guide for the file. The groove in Fig. 1623
requires a safe-edge square file. When, however, pieces of these sections, but of greater lengths,
have to be produced by means of the file alone, it is more usual to make them in two or three pieces


1627.
B
a 1628.
s 1626.




' ‘\\\
\i.‘““‘~
. s“
w“
oflfmjq


respectively, as shown detached in Figs. 1624 and 1625 ; which pieces are first rendered parallel on
their several edges, and are then united by screws and steady-pins.
In works of these kinds, which have rebates, grooves, internal angles, or cavities, the square with
a sliding blade, shown in Fig. 1623, is very useful, as the blade serves as a gauge for depth, besides
acting as a square, the one arm of which may be made of the precise measure of the edge to be
tried. This instrument is often called a turning-square, as it is particularly useful for measuring
the depth of boxes and other hollowed works turned in the lathe.
In making straight mortises, as at ss, Fig. 1626, unless the groove is roughly formed at the forge
or in the foundry, it is usual to drill holes nearly as large as the width of the mortise, and in a
straight line; the holes are then throwninto one another by a round file or a cross-cutting chisel.
FILING. 713


and the sides of the mortise are afterward filed square and true. For a curved mortise“, c c, the
mode is just the same, with the exception that the holes are made on a curved line; and that,
instead of a flat file being used throughout, a half—round or a crossing file is used for the concave
side of the mortise. Short rectangular mortises, or those which may be rather considered to be
square holes, as in Fig. 1627, would, if large, be prepared by forging or casting the material into
the form; and then, the six exterior faces having been corrected, the aperture would be filed on all
sides under guidance of some of the various tests before referred to. In such a case it is conve-
nient to employ a small square 8, in the form of a right-angled triangle, to which is attached a wire
that may serve as a handle, whereby the square may be applied at any part within the mortise with-
out the sight of the workman being intercepted by his own fingers. Sometimes also a cubical block,
filed truly on four of its faces to the exact dimensions of the aperture, is used as a measure of the
parallelism and flatness of the four interior faces.
In making by hand the keyways in the round holes of wheels, it is to be observed that it is com-
mon to turn a cylindrical plug exactly to fill the hole, and to make a notch in the plug as wide as
the intended keyway and parallel with the axis; the plug is shown at g, Fig. 1628. A piece of steel
f is then filed parallel, and exactly to fit the notch, and its edge is cut as a file, and used as such
within the guide-block, the latter being at the time inserted in the hole of the wheel. In this case
the block becomes the director of the file, and the notches in any number of wheels are made both
parallel and axial. The only precaution that remains to be observed is in regard to the depth of the
notches, and this is not always important; the depth may, however, be readily determined by mak-
ing the grooves at first a little shallower than their intended depth, and then, the plug having been
removed from the hole, a stop is attached to the side of the file, parallel with its edge, as at s, to
prevent its penetrating beyond the assigned depth. (See KEYS AND KEYWAYS.)
The manipulation of the file upon curvilinear works is entirely different from that required to pro-
1629. 1630.
NW1 \'\\~\<\.\\\
\, .w-‘x- \,\ \W
duce a plane surface, in which latter case the work is held at rest and the hands are moved as stead-
ily as possible in right lines ; but in filing curved works an incessant change of direction is impor-
tant, and, so far as practicable, either the file or the work is made to rotate about the axis of the
curve to be produced. A semicircular groove of half an inch radius, as in Fig. 1629, would be most
easily filed with a round file of nearly the same curvature, and the correspondence between the file
and work, and consequently of their axes likewise, would render the matter very easy ; but the file,
from the irregularity of its teeth, would leave ridges in the work, unless in every stroke it were
also twisted to and fro axially by the motion of the wrist, and occasionally in the reverse direction,




1682. 1633.


so that the furrows made by the teeth might cross each other. If the groove to be filed had a diam-
eter of three or four inches, although the file might be selected to correspond in curvature with the
groove, as it would not embrace the entire hollow, the twisting and traversing of the file would be
imperative in order to arrive at all parts of the work. Under ordinary circumstances it is certainly
best that the curvature of the file and work should agree as nearly as possible; but it is obvious
that the file, if more convex than the work, can only touch the latter at one part, as at a, Fig. 1630;
whereas, if the file is less convex or flatter than the work, it will act at two places, as at b b, Fig.
1631. Cutlers, in filing out the bows‘ of scissors, always avail themselves of this circumstance, and
until nearly the conclusion use files flatter or less convex than the work.
In filing concave works, there is but little choice of position, as the file is always parallel with the
axis of the curve, as in the dotted line in Fig. 1632; but in convex works, such as Fig. 1633, the file
may be applied either parallel with the axis, as at p p, or transversely thereto, as at t t. In general,
however, the work would be fixed obliquely, as in Fig. 1634, and the file would be first used trans-
versely for some one or two strokes, at an inclination of about 30° with the horizontal line, as at a,
so as nearly to agree with the straight side of the object; the file would be succesrively raised to
the horizontal, and depressed in the same degree on the other side; in fact, proceeding through
the positions a b c, Fig. 1634, at some eight or ten intervals, which would tend to make as many
insignificant ridges upon the work. The ridges would be then melted together by swinging the
hands from the position a to c in every stroke, to be repeated a few times ; but as the entire semi-
circle could not be embraced at one stroke, the work would be refixed in two or more positions, so as
to divide the operation into about three stages. A more exact although less energetic method would
be to place the file parallel with the axis, as on p 1), Fig. 1633, and to sweep round the curve prin-
cipally by the twisting motion of the wrist. A third mode, frequently adopted in such small pieces
714 FILING.

as can be held upon the filing-block with the hand-vise, is to swing the work upon its axis, and to
use the file with the right hand, as if on a flat surface.
Some works are curvilinear in both directions, such as curved arms and levers with rounded edges;
many of these kinds are completed by draw-filing them, or rubbing the file sideways or laterally
around the curve, instead of longitudinally as usual. The great majority of curved works are mould--
ed and formed prior to the application of the file, which is then principally used to smooth and
brighten the-.n. Other works are shaped almost entirely with the file, assisted by outlines drawn on
the pieces themselves; and again other works are shaped with the file, under the guidance of term»
plets or pattern-plates of hardened steel. Some observations will be offered on all three of these
modes.
First, in respect to filing up metal works that have been accurately shaped by founding or forg-
ing, little or nothing remains to be added, as the only object is to act on every part of curvilinear
surfaces in the most expeditious and commodious manner, with the general aim of reducing any tri~
fling errors of form that may already exist in them, and avoiding the introduction of new ones;
which circumstances call for the frequent scrutiny of the eye, and an incessant yet judicious variation
in the position of the hands. _
Secondly, curved works, that are moulded or formed almost entirely with the file, are blocked out
square, and the outlines of the curves are drawn on the ends and sides of the pieces, to guide the file
in a manner analogous to the routine pursued by carpenters, masons, and other artisans. For in-
stance, to form a bead, as in Fig. 1635, the work is prepared of a nearly rectangular form, and the
half circle having been drawn at each end, the angles of the work are coarsely removed at about
45”, making the end a semi-octagon; sometimes the four angles are further reduced, giving to the
work eight facets, prior to their being thrown together in making the general curve. If these sides
are made with only a very moderate degree of exactness, they will greatly tend to preserve the uni-
formity of section throughout. Many workmen, when they have removed the two principal angles
at 45°, make a chamfer entirely around the semicircle at each end, to guide the file in hastily redde-
ing the principal bulk of the material. It is also desirable that the straight-edge should be frequent-
1y applied along the axis of the curve, at various parts, during the progress of the work. Should
the entire piece, Fig. 1636, have to be made from a solid block, two cuts, a and I), made with the
saw, would remove the corner. The round part of the head would be made as before, and previous
to filing the hollow it would be chamfered on the line 0; a half-round file, of less curvature than
the hollow itself, would be first sunk in the middle of the chamfer, and the hollow would be deepened
and extended sideways, always maintaining an easy curve, until it reached the marginal lines where
1635. 1636. 1637.
1e 111.
I
l
I
I
I
I
_ I
I
v
\
i
\
x '
\ I
v I
\ I
\ I
\ l
\ I
\I
\
\
s
\ .
‘ .
\
\
\
(6 ‘
the hollow meets the plane surfaces. Where hollows run on to right lines, as at a, Fig. 1637, there
is some risk of making a break in the junction, either from the curve sinking below the right line, as
at b, or from the straight line, as at c, advancing too far and breaking in upon the curve. On this
account a break or fillet is usually made at the part, as at d, or else it is usual primarily to give that
form by filing the flat first, and then sinking down the hollow just to meet it, and at the conclusion
letting the half-round file run a little way on to the right line. Some, however, prefer the opposite
course, or that of sinking the hollow to its full depth, and then filing down the remainder with the
flat file; but this mode is certainly attended with more risk.
Thirdly, curved works that are shaped with the file under the guidance of templets or pattern-
plates of hardened steel. This mode is much followed in works of two principal kinds, namely, thin
works required in great numbers and precisely of one form, and in a variety of works that require
to be exactly circular, althongh they may not admit of being so fashioned in the lathe. Many thin
works of the first kind are stamped or punched out of the sheet metals, as for instance the washers
for machinery, the links of jointed chains, steel pens, parts of locks for joinery, and numerous other
thin works; but many objects of larger kinds, and that are not wanted in such large numbers, are not
stamped, but are either cast or cut out with the shears, and afterward filed between templets. The
snail-wheel of a striking clock,.Fig. 1638, is frequently thus formed by means of a templet; it has
an edge formed in twelve steps, arranged spirally, the positions of which determine the number of
strokes of the hammer on the bell. In this case, which will serve as a general example, a piece of
sheet-steel is cut out, flattened, and smoothed on one side, to receive the drawing of the snail-wheel,
and a second piece is also prepared. The two are first drilled together with a central hole, and an-
other hole as distant from the centre as admissible. The two plates are then united by two pins, and
the outline of the work having been drawn on one of them, they are next filed in steps carefully to
the lines, and square across the edges, and they are afterward hardened and slightly tempered to
lessen their liability to fracture on being pinched in the vise. The dozen or more snail-wheels hav-
ing been cast or cut out of sheet-brass, and flattened with the hammer, two or three at a time are
pinched alongside one of the templets, while the two pin-holes are made with the breast-drill or in
the lathe, with a drill that exactly fits the holes in the templets. It only remains to place the dozen



FILTERS. '715

plates between the templets, keeping them in position by two pins extending through the whole num-
ber, and then all the notches are filed in the brass plates, until the file very nearly touches the steel
patterns, as absolute abrasion on the steel itself would greatly injure the files. In this mode the
several brass plates become very exact copies of the pattern.
“ Templets are as much used for setting out and producing series of holes in any special arrange-
ment, as in filing works to any particular form. A complex example of templets being used in this
1640.

\
Lice


.manner is in drilling the side plates of harps intended for the arbors and link-works used in tem-
porarily shortening the strings. The respective positions of the holes in these side plates require a
most exact arrangement, any departure from which would prevent that precise shortening of the
string required to produce the semitones with critical accuracy, and would also cause an unbearable
jar, unless the cranks of the harp were severally in true position, or on the lines of centres, so as
firmly to support the tension of the strings under all circumstances.
A difierent application of templets is sometimes met with in filing up numerous similar parts in
' the same object, as the arms or crosses for the wheels of clocks and other machines. The exact
pattern of one spoke is filed up as a templet, which is shaded in Fig. 1639, and serves for the similar
configuration of every spoke ; the position of the templet being given by a central pin, aided by any
little contrivance which catches into the 3, 4, 5, or 6 equidistant teeth corresponding with the num-
ber of arms.
It frequently happens that certain forged, cast, and other works have parts, known as bosses,
swells, collars, and knuckles, that are pierced with holes, which require their flat surfaces and also
their margins to be made partially or entirely concentric with the holes. \Vhen such parts occur as
bosses, they often project from a flat surface; and after the central hole is drilled, some of the pin-
(lrills, or analogous tools used in drilling-machines, are employed in finishing the margins.
When the circular margins are discontinuous, files and templets are more or less required. Thus
the extremity of a forged arm, such as Fig. 1640, is drilled, and in the configuration of the remain-
ing parts, if but one or two such pieces are to be made, a boss or plug of wood is turned like a, that
shall fit the hole ; the shoulder of the wood is then rubbed with red chalk to mark that part of the
surface which is not at right angles to the hole, and the circular edge of the boss serves for the guid-
ance of the file in finishing the exterior margin, visually rather than obstructively, as the wooden
boss would be reduced instead of the file being checked. If therefore there were many such objects
to be filed, two bosses or templets would be made of hardened steel, and used one at each ex-
tremity of the hole, and they would be held in position by grasping the three pieces collectively in
the tail-vise. The same general method is very largely and more rigorously followed in making
joints or hinges. , J. R.
FILTERS. When water containing substances in suspension is passed through a medium pro-
vided with fine pores, it is, of course, at least the purer by virtue of the removal of all such matters as
are unable to pass through the pores. If this were all filtration accomplished, it would be merely a
fine straining process. But all porous substances contain an immense amount of air between their
pores, and the water, by being passed through them, is divided into an infinite number of exceedingly
small streams, and thus the substances in solution in the water are brought into the closest possible
contact with the oxygen of the air, giving rise to a chemical action. rIhis oxidation occurs in
ammonia, and the putrescible organic matters which are so dangerous when left in drinking-water.
According to experiments by Dr. Frankland, water containing in solution about 18 grains to the
gallon, after filtration through animal charcoal contained 11.6 grains. The organic and other volatile
matter contained in the water before filtration amounted to .37 of a grain in a gallon, and after the
filtration the amount was .15; that is to say, more than one-half of these matters were removed.
After a. month this charcoal removed still more organic matter, and also some mineral matters; and
even a few months afterward one-half of the organic and volatile matters only remained after filtra-
tion. These experiments show that it is not by storing up matters that a filter works—for, in such
case, it would soon be choked—but by oxidizing the putrescible substances, the results of which oxi-
dation are afterward found in the shape of nitrites, nitrates, and carbonates. Dr. Frankland states
that he passed the water supplied to London by the Grand Junction Company through a thickness of
3 feet of animal charcoal at the rate of 41,000 gallons per square foot per day of 24 hours, under
a head of water of 30 feet, the. charcoal being in granules like coarse sand. Even at the above high
rate more than half the organic matter was removed. Vegetable charcoal is almost entirely useless
for purposes of filtration. It contains an enormous amount of salts soluble in water, renders the
latter harder than before passage, and does not purify it as does animal charcoal.
At the Gorbals Filtering Works, near Glasgow, the filtering materials are placed in vertical com.
partments with passages between them, in each of which the water rises to nearly its original level,
and then flows over into the next compartment and down through the filtering material in it. In St.
710 FILTERS.

.... ...—__-.‘
Petersburg, Russia, the water is made to fall down a series of steps, and then through wire gauze,
and lastly through sand filters; and by these means the water, which is generally very impure, is ren-
dered tolerably pure, and a considerable amount of putrescible organic matters is collected from this
wire gauze.fie
._ The water both of rivers and of gathering grounds in most cases requires to be filtered. A filter-
bed for that purpose, suggested by Prof. Rankinefir consists of a tank about 5 feet deep, having a
paved bottom, covered with open-jointed tubular drains lcadingto a central culvert; the drains are
covered with a layer of gravel about 3 feet deep, and that with a layer of sand 2 or 3 feet deep. The
water is delivered upon the upper surface of the sand very slowly and uniformly; it gradually de-
scends, and is collected by the drains into the central current. The area of the filter should be such
that the water to be filtered may not descend vertically with more than a certain speed; for the whole
ellieiency of the filtering process depends on its slowness. The speed of vertical descent recommended
by some authorities is 6 inches per hour; but according to Rankine, in some cases a speed as high
as 1 foot an hour has been used.
From experiments by M. Havrez (Revue Universalle (les .M'incs, May, June, 1874, and “Proceedings
of the Institution of Civil Engineers,” vol. xxxix.), it appears that filtration is influenced by the pres-
sure and temperature of the water, the thickness of the filtering medium, the size of the grains form-
ing the filter, and their mixture. The delivery of a filter per square foot per 24 hours is equal to
"
Ir/ ’¢
.1
/-‘("a.‘ ,
fy~4.
'7 vs
I /' .,. , ' / fif-
1, 22.335" ' if (":31


2.4 cubic yards, multiplied by the pressure of the water in yards and divided by the thickness of the
filtering medium in yards nearly. When large and small grains of sand are mixed, the delivery is
found to diminish, as also by silting and fouling. Formula: for the velocity, influenced as stated
above, are given in the original paper, to which reference may be made. The filter-beds at Stoke
Newington, London, Liverpool, and Dublin are respectively 45,000, 30,000, and 22,500 square feet
each in area. Their forms are rectangular, 300 x 150 feet, 300 x 100 feet, and 205 x 110 feet.
At London there are 7 beds, with a delivery of 12,000,000 imperial gallons daily; at Liverpool there
are 6 beds, with a daily delivery of from 9,000,000 to 12,000,000 gallons; and at Dublin there are
7 beds, with a delivery of 12,000,000 gallons.
Figs. 1641 and 1642 are a plan and section of the classification reservoir and filter basin at Batter-
sca, near London. The reservoir A communicates with the river Thames by a canal R, and at the
bottom is a semicircular trench C' D, in which sediment from the water is collected. From this basin
the water passes through a stone conduit abcut 1 foot 8 inches in diameter to the filtering basin E.
At the bottom of this are 6 tubes B, separated by intervals of about 5 feet, and pierced with holes
to allow of the escape of the water. Above these is placed the filtering bed, composed of 11.7
inches of gravel, 8.7 inches of coarse sand, and 5.8 inches of fine sand. After traversing this filter-
ing layer the water enters the tubes a b and escapes at 1-1.
The filtering of the water of Glasgow, Scotland, is conducted on the gravitation system. The
water begins by traversing the coarsest material, and proceeds gradually to the finest. The layers,
instead of being parallel, are disposed in form of steps of unequal l'ieights. This arrangement will
be understood from Fig. 1643. E consists of coarse sand; B is a mass of fine pebbles; C is a
’1‘ Abstract of lectures on water supplies, delivered before the School of Military Engineering, 1875, by W. A. Corfield.
. A., M. I).
'l' “ A Manual of Civil Engineering,” 11th ed., London, 1876.
FILTERS. 717


thicker bed of fine sand; and DD is the reservoir. From this the water passes to a conduit, the
gates of which are at S. In proceediner from one bed to another, the water traverses automatic
locks, a section of one of which is given in Fig. 1644, their positions being indicated at a b, c d, e f
in Fig. 1643. M and N are the walls
forming the reservoir R. I’ is the
upper filter of coarse sand. The wa-
ter from this passes to a false bot-
tom h 1, formed of bricks J separated
and placed on their edges. In the
intervening space the water is collect-
ed and goes to the channel K in the
reservoir R, where it rises until it
reaches the opening L, whence it
passes to the filter next in succession.
3y changing the position of the valves
so as to close K’ and L, and to open
K and L', the water from the filter 1’
and reservoir R may be led to a discharge-pipe whenever it is necessary to clean the filters.
In the filters illustrated in Figs. 1645, 1646, and 1647, the stone pipe A brings the water from the
regulating basin to the filters, and iron pipes communicate between the stone pipe or aqueduct and
the top and bottom of the filters. A
valve near the top of the iron pipe
8 P, at S, Fig. 164-5, forces the water
to enter on the top or at the bottom
of the filter at pleasure. The filter
is 100 feet in length and 60 feet in
breadth, divided into three compart-
ments, which may either act together
or separately, so that when one com-
partment is being cleansed, the other
two continue in operation. The site
of the filters is a piece of level ground,
excavated to the depth of 6 or 8 feet,
with retaining walls all round, joined
‘ A _ with cement, and puddled behind, so
- f,,',;;,,;,,\- ' _ i ' _ --
,_ as to become water-tight. The bot-
“ e ,f , all?“ ' , ~ I-
tem is laid about a foot deep with a
= ' H strong stiff puddle, over which is a
' pavement so cemented as to be im-
pervious to water. The whole of this
bottom is then divided into drains or
.I .. _ . . _ , , spaces, 1 foot wide and 5 inches deep,
, __ _. _, 5r e by means of fire-brick laid on edge,
and covered with flat tiles of the same
material, perforated with small holes, like those used in a kiln for drying oats. These holes are
placed very near each other, and are rather more than one-tenth of an inch in diameter; there is
also a space of a Quarter of an inch left open between the ends of the bricks which support the per-
3.1—L
ear-.111:- -


1644.


_A__





l 1‘
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.|. a .
.IT‘P. IIFLZLiLwgJJ-wu-w
,
















foratcd tiles, and their upper edges are little more than an inch broad, in order that there may be
no space without holes, and nothing to prevent the water from spreading equally over every part of
the bottom of these drains. This is particularly necessary when the filters are being cleaned by the
718 ' FILTERS.

upward motion of the water. The perforated tiles or plates are covered to the depth of 1 inch with
clean gravel, about three-tenths of an inch in diameter; this is followed by 5 other layers of gravel,
each of the same depth, and each succeeding layer a little finer than the previous one, the last being
coarse sand; over this is placed 2 feet depth of clean, sharp, fine sand, similar to that used in hour-
glasses, but a very little coarser; about 6 or 8 inches deep of the fine sand nearest the top is mixed
with animal charcoal, ground to the size of coarse meal, each particle about one-sixteenth of an inch
in diameter. A longitudinal drain or pipe N runs between the filter and the pure-water basin, com-
municating with both ; on each of the openings between the pipe and the filter is a stop—cock to close
the communication when necessary; there are also two drains, one to carry oil“ the foul water when the
filters are being cleaned, and another to prevent the water from rising too high. When the filter is
1646. “
L_El__1 l____l l 4 L4
L l‘F‘I \l 1| 1| II n 'l 1 u \|__ J II ll n 1| n H II \1 'l 'i 1| I Fr I jljm‘lfli‘rmll um 11









.___._..._.--.-___....,___. ,_.__._r__________-_______.,___.-. __ ...__



complete, its action is as follows : The sluice R and the valve 8' are opened, and the water permitted
to flow through the filter into the drain N below, until it becomes quite clear. This will take two or
three days when first set to work, unless very great pains are taken to wash the gravel and sand
before they are put into the filter, which will now flow copiously for some weeks; and when the
quantity passing begins to decrease, the stop-cocks are shut and the valves 8 S raised. The water
then enters below, filling all the drains, and, having a head pressure of several feet, it will force its
way up through the sand to the top, and in its passage raise the scales or particles of mud which
have been deposited in the downward passage, and carry them into the foul-water drain below. If
the sand of the surface be stirred by a fine-toothed rake after the water has been raised above it,
and a little additional water admitted on the top through the conduit, it will facilitate the operation
of cleaning, as the mud is always deposited on the very surface’of the sand. By this means the sed-
iment will be carried off, and the water pass through quite clear again in a few hours; the valve S
should then be lowered, the stop-cocks opened, and the operation of filtering will again proceed as
above described. The cost of this filter would be about $3,000, and the quantity of pure water pro-
duced regularly every 24 hours on an average about 106,632 cubic feet.
M. Fonvielle of Paris has invented a filter in which two currents of water instead of one are
1647.












employed to cleanse the materials used for filtering. This arrangement can be readily understood
from the section, Fig. 1648, in which S is the pipe supplying water to the filter; D, the discharge
pipe; a a, stop-cocks by which the current may be made to pass in any direction through the filtering
material F, which is supported between two perforated diaphragm plates. When in operation one
cock only in each pipe is opened, diagonally opposite, as shown in the section. But to cleanse the
filtering materials, both supply-cocks are opened and one discharge-cock, alternately the lower and
upper; by this means the filtering materials are effectually cleansed. Filters on this principle, with
numerous compartments and of various capacities, are used for the filtration of the waters of the
Seine, and give complete satisfaction.
FIRE-ARMS, CONSTRUCTION AND TRIALS OF. 719

Fig. 1649 represents an improved intermittent filter, the principal feature of which is that it
intermittently runs dry, so that the filtering material becomes aerated, and the impurities detached
by it from the water are to a certain extent oxidized. During the day, when the water is being
drawn ofl.’ for use, the extent to which aeration and oxidation will take place will, of course, depend
upon the rate at which the water is used; but at night several hours may generally be counted upon
during which a'ération and preparation for further effective filtration may take place. Referring to
the section, A is the cistern containing the filtering material. The bottom of this is perforated, and
is placed over a second cistern B, which contains the filtered supply. 0 is the supply-pipe from the
main or from a service cistern; and D is a ball-cock which regulates the admission of water to the
filter as the filtered water is drawn from cistern B. The ball D, however, cannot fall to admit fresh
water except in unison with the ball E, which acts by a lever upon the same valve. An interval is
thus gained between the admission of water to the filter A and the partial emptying of the cistern
B, and during this interval aeration of the filtering material may take place. I is an overflow pipe
connected with both cisterns. With reference to this it may be remarked that, although the current
induced by the water falling from the cistern A will most probably tend to draw air with it as it
passes the connection with the cistern B, still it is possible, as the short piece of pipe is new placed,
for some water from A to run unfiltered into B. If this piece of pipe were placed at an angle, so as
to dip from the cistern, or if the connection were made by a double angle-piece, this risk would
be avoided. The pipes F G— H for supply to different parts of a building may, of course, be placed
either at the side or at the bottom of the cistern, and may be more or less in number.
An ingenious centrifugal filter has been devised by MM. Autier and Allaire, the efficiency of which
does not depend on the use of any filtering matter, but on the application of a simple mechanical
action. Its construction is based on the principle that if a cylinder be set revolving rapidly in a
fluid in which solid particles are suspended, the fluid participates in the velocity given to the cylin-
der, that next it revolving at the highest speed, and the remainder of the fluid at ratios the in-
verse of their distances from the cylinder. The solid particles suspended in the fluid are thus driven
away from the neighborhood of the cylinder, where the fluid is left clear, in which condition it can
be led away by properly placed draw-off pipes.
Works l,‘for Reference—“Lectures on “later Supplies,” Corfield, delivered before the School of
Military mgineering, 1875; “A Manual of Civil Engineering,” Rankine, 11th ed., London, 1875;
“Merveilles dc l’Industrie,” F iguier, Paris, no date; also works on water-works quoted under CANALS.
See also SUGAR MACHINERY. '
FIRE-ARMS, CONSTRUCTION AND TRIALS OF. The essential parts of all portable fire-arms
are the barrel, the lock, the stock, the sights, and the mountings. The principal parts of the barrel,
Fig. 1650, are the breech, the breech-screw, near to the flats (3), bevels (2), and oval ; the cone and
cone-seat (4); the bayonet stud and front sights (5); the bore, the grooves, and the lands (6). The
breech-screw is composed of the body (a), tenon (b), and tang (c). The object of the breech-screw is
to close the bottom of the bore; the tenon fits into a mortise cut in the stock, and prevents the
barrel from turning on its bed ; the tang is the part by which the breech of the barrel is secured to
the stock, and for this purpose it is pierced with a hole for the tangerrezr, which passes through the
stock and enters the guard-plate. The flats are two vertical plane surfaces, situated at equal dis-
tances from the axis of the bore. They serve to prevent the barrel from turning in the jaws of the
vise when the barrel-screw is taken out; the flat on the right side of the barrel also presents a sur-
face of contact for the lock-plate, which prevents the hammer and cone from changing their relative
positions. The functions of the cone, Fig. 1651, are to support the cap when exploded, and to con-
duct the flame to the vent of the piece. The parts are the nipple (1), upon which the cap is placed ;
the square (2), to which the wrench is applied; the shoulder (3), the sm-ew-thread (4), and the vent





1651.




(5). The cone-seat is a projecting piece of iron welded to the barrel near the breech for the purpose
of sustaining the cone. The principal parts are the female screw, the vent, and the rim; the last
prevents the flame from penetrating between the lock and the barrel.
The ordinary percussion-lock, Fig. 1652, is composed of the lock-plate (1), to which the several
parts are attached, and by which the lock is fastened to the stock; the hammer (2), which strikes
upon the cap; the mainsprz'ng ( 3), which sets the hammer in motion; the tumbler (4), or axle, by
which the movement of the spring is communicated to the hammer; the sear (5), or lever, the point
of which fits into the notches of the tumbler and holds the hammer in the required position: the
notches are designated as the full-cock notch and safety notch ,' the sear-spring (6), which presses the
point of the scar into the tumbler notch ; the bridle (omitted in the figure), which is pierced with two
720 vFIRE—ARMS, CONSTRUCTION AND TRIALS OF.

holes for the inner pivots of the sear and tumbler; the swivel (7), which joins the mainspring and
tumbler. The more important parts of the stock are the butt, the handle, the beds for the barrel-
loek, band-spring, guard-plate, and butt-plate; the shoulders for the tip and bands, and the ramrod
groove. The mountings comprise the butt-plate, guard-plate, bands, springs, and tip.
Great improvements have been made everywhere in recent years in military small arms, whereby
great efficiency has been gained by diminished weight of piece and cost of manufacture. The fol~
lowing may be enumerated as the principal changes on which these improvements are based, viz. : i“
1. The adoption of the rifle-grooves and the elongation of the bullet. 2. The loading at the breech,
and the metallic~case cartridge, by which the joint is closed against the escape of the flame of the
charge. 3. The reduction in the diameter of the bore and the length of the barrel. 4. The sub-
stitution of low steel in place of wrought-iron in the manufacture of the principal parts, and
especially the barrel, and the American plan of manufacture by machinery, making all parts inter-
changeable for repairs. The reduction in length of the barrel has been from 8 to 10 inches; the
reduction in the diameter of bore and the weight of ammunition is shown in the following table :









CALIBRE. PO\VDEB. PROJECTILE.
COUNTRIES. ‘ New Breech-
Old Muzzle-loading. load,“ Old. New. Old. New.
g.
Inch. Inch. Grains. Grains. Grains. Grains.
England . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . .577 .45 (52 85 504 480
France . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69 and .72 -43 ’17 85 494 280
Prussia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6'3 .45 86 SO 36.) . 380
Austria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 . 425 62 68 450 3 r 8
Russia. . .'. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 .42 80 $0 560 375
Bavaria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ _ . _ _ . .45 66 ' I 66 675 340




Breech-loading Fz're-Awns.——From a valuable digest of “Patents relating to Breech-loading and
Magazine Small Arms,” by V. D. Stockbridge, Examiner U. S. Patent Office (Washington, 1874), we
take the following classification:

as, [ 1. Sliding longitudinally forward.
<3 “N. . . (a) Up at breech.
m g i, 2. Tilting . . . . . . . . . . . . . . . . . . . . . . . . .. s: (b, With muzzle upward
m g .3 -( . . .
3 a s 3. Hinged or JOIIltCd to stock.
0 g m 4. Swinging laterally on vertical pin.
'3 L 5. Rotating on parallel longitudinal pin.
’ . . a . . _ (a) Operated by lever.
1. Sl1d1n=3 longitudinally backward. . . . g (b) Operated by handle.
’ (a) Upward and forward.
8 (b) Laterally forward.
:1, (c) Backward and downward.
_ 3 . N. a . . 0 (d) On centres and trunnions.
m 2. Swmglng or tlltlno . . . . . . . . .. . . . . .. 4 (c) Upward and backward.
2 \{ (f) Laterally backward.
i): 2 (g) Downward and backward.
g k (h) On a longitudinal pin or hinge.
. . a ' _ (r ._ ( .(a) Movin<r vertically.
g 3. Sliding transversely through mortise. -, (b) Movinglatemny.
gt ( (a) Chamber in faucet.
4. Faucet or spigot . . . . . . . . . . . . . . . . . . I (6) Chamber in from of faucet
5. Rotating sleeve, etc.
(a) Behind a barrel; cylinder charged in front.
(b) Behind a barrel; cylinder charged in rear.
(0) Cylinder without other barrel: pepper-box.
. Chambered cylinder revolving on vertical axis behind a barrel.
. Chambered cylinder revolving on horizontal transverse axis behind a barrel.
. Revolving hammer acting on several stationary barrels.
1. Chambered cylinder revolving on par- )
allel axis . . . . . . . . . . . . . . . . . . . .
CLASS C
Revolvers.
A

rP-OON)
1
These weapons may also be divided into the two principal classes of single-loaders and magazine
or repeating guns.










H 1653
. sfirsa D
~ \\ W/fX/elOr-nman \
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Single-loaders.-—Fig. 1653 represents the breech mechanism of the Springfield rifle, the manufac-
ture of Which is described in detail in the succeeding article. A is the receiver; B, the barrel with

* From Report of Chief of Ordnance, U. S. A., 1877.
FIRE-ARMS, CONSTRUCTION AND TRIALS OF. 721

its screw-thread; O, the breech-screw with circular recess to receive the cam-latch F; D, the breech-
block, turning around the hinge-pin shown on the right; H, the firing-pin, which transmits the blow
of the hammer to the priming of the cartridge. Beneath this pin is shown the cam-latch spring
which presses the latch F into the recess in C. J is the extractor to withdraw the empty cartridge-
shell after firing, and K is the ejector-spring and spindle. When the breech-block is closed, the
point of the ejector-spring spindle presses against the extractor above the position of the axis of the
hinge-block, and no motion takes place. When the breech-block is raised so as to press against the
lug shown on the upper portion of the extractor J, the point on the lower part of the latter moves
slowly to the rear, withdrawing the shell—the upper part of the extractor meanwhile compressing
the ejector-spring. When the direction of the pressure of the spring passes below the centre of
the hinge, the extractor moves rapidly and throws the shell clear of the receiver. L is the ejector-
stud, which serves to deflect the shell upward and thereby clear the well of the receiver. The firing-
pin spring, shown at the lower end of the pin and used to press the latter back when the hammer is




*2
1. Gun complete. 2. Section showing lock and riding of gun ready to fire. 3. Cartridge.
raised, has been abolished. The arrangement of the cam and eccentric handle for lifting the block
is such that, unless the block is closed, the hammer cannot strike the firing-pin, but will merely strike
the handle. 'The calibre is .45 “inch; the barrel has three grooves equal in width to the lands, and
the rifiing has a twist of 22 inches. The length of the barrel is 36 inches (with receiver), and of
the stock 48.7 inches. The piece weighs 8.68 lbs. without the bayonet. The weight of the powder
charge is 70 grains and of the ball 405 grains.
The Bench Chassepot Rziflc, Fig. 1654.——In this weapon there is a bolthandle by which the bolt
is held in place, the latter containing lock and needle. The fulminatc is in a paper wad, which
forms the rear of the cartridge envelope. The gas-check is a cylindrical ring of vulcanized India-
rubber, which is pressed against the surface of the chamber when the explosion takes place. The
number of grooves is four. An opening on the right hand of the chamber allows of the insertion of
the cartridge, which by the forward thrust of the knob is driven into the breech, when a partial
rotation of the knob locks the breech-piece.
The Remington Rifle, Fig. 1655, is a single breech-loader, using metallic cartridges. An iron
receiver, made to correspond externally to the
shape of a gun-stock, is screwed to the breech
of the barrel; in this are contained the breech-
block and lock. Supposing the piece to have been
discharged, it is loaded as follows: 1, it is cocked;
2, the breech-block is pulled back by the handle
at its right side, ejecting the shell of the exploded
cartridge ; 3, the cartridge is inserted ; 4, the
breech-block is pushed back to its place, closing
the breech. The gun is then ready for firing.
The hammer has a projection which passes under
the breech-block when it is down or closing the
breech, and prevents the block from flying back
when the explosion takes place. The firing-pin passes the breech-block from the nose of the ham-
mer to the percussion-cap in the base of the cartridge-shell.
' The Pieri Rifle, Fig. 1656.—The principle of this arm is the same as that of the Dreyse, Chasse-
pot, Berdan, and Vetterlin guns. The breech mechanism consists in all of only seven pieces: the
cylinder, with handle, A and S; the trigger-spring, H; the head-piece, G; the extractor, C’,‘ the
spiral spring, E ,- the thumb-screw, F ,- and the striker. D. The cylinder is bored throughout its
whole length, to receive within it the spiral spring, the striker, and the head—piece. The striker is
larger in diameter at one end than at the other. Between the two portions is a raised part, against
~y which the end of the spiral spring bears, and this raised part carries a tooth or projection, the ex-
tremity of which has a spiral surface. The other end of the striker has a. notch in it for the tooth
of the trigger-spring to work in. The head-piece is bored throughout, in order to give a passage for
the point of the striker, and has the form of two connected cylinders of different diameters. The
surface of the cylinder of greater diameter has a groove parallel to the axis in which the extractor
G is placed, and in the cylinder of lesser diameter is a groove in which the point of the thumb-screw
works. ()n the rear face of this last piece is a small notch, in which the point of the projection on


46
722 FIRE—ARMS, CONSTRUCTION AND TRIALS OF.
I


the striker lodges when the arm is at full coek. The trigger-spring, which is placed in a groove in
the cylinder, is provided with two teeth, one to prevent the spring from withdrawing from the cylin-
der, the other to take the notch in the striker. The spring projects to the rear of the cylinder and
terminates in a thumb-piece, which is pressed when wishing to fire. The thumb-piece is protected
by the two wings of the breech-shoe from injury or accidental blows. To load the rifle, the handle
of the cylinder is turned up and drawn back until the head of the thumb-screw lodges against the
y/ ‘ 1..~ I.
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head formed on the breech-shoe. The rotation of the OYllldGl‘ is not given to the head-piece, which
is prevented from rotating by the projection on the extractor, which works in a groove cut along the
bottom of the breech-shoe. By virtue of this the projection on the striker is compelled to rotate
with the cylinder over the spiral surface of the cavity in the head-piece, and consequently to go back
in the cylinder until the projection in the trigger-spring enters the notch in the striker, when the
spring is compressed. The cartridge having been placed in the chamber, the cylinder is forced for-
1657. -. 1653.


ward and turned to the right, by which movement the projection on the striker is brought opposite
the cavity in the head-piece, and the arm is ready to be discharged.
The Afterward-Henry Rifle, Fig. 1657.——The breech-block is pivoted at its upper rear portion, being
moved up and down by a lever at the rear of the trigger-guard. The firing is by a spiral spring
which actuatcs a firing-pin. The cartridge-shell extractor works on a pivot below and behind, the
barrel being operated by the descent of the front
end of the breech-block upon one arm of the
bell-crank lever.
The Peabody Rifle, Fig. 1658.-—There is a.
falling breechsblock hinged at the rear and dc-
pressed by the guard-lever, whose short arm on-
gages in a recess of the block and controls its
movements. When the block is down, the car-
tridge is slipped into the bore, and the piece is
fired by the fall of the hammer upon a firing—
pin sliding in a groove in the side of the block.
In opening to reload, the block drops upon an
elbow lever, and withdraws the spent cartridge
shell.
The Snider Rifle, Fig. 1659.-—The breech-block is hinged to the rear and above the barrel, the
block throwing upward and forward, and exposing a chamber in rear of the bore. Into this the car-
tridge is dropped, pushed into the bore, the block brought down and locked by a latch in the rear.
The firing-pin passes obliquely through the block, and is struck by the ordinary hammer.
CARBINES in the U. {4. army differ from the Springfield rifles only in the length of barrel and
stock, and in various minor fittings which need no special reference. The total length of the barrel
1659.


FIRE-ARMS, CONSTRUCTION AND TRIALS OF.
723
_ .-_._.___ ..."...- w

is 25.4 inches, and that of the stock 29.85 inches. The total weight of the arm is 7.17 lbs., of the
charge 55 grains, and of the ball 405 grains.
The most complete series of tests yet made on breech-loading arms was conducted in 187 2—’7 3 by
a U. S. Army Board, the report of which will be found in “ Ordnance Memoranda,” N o. 15, Wash-


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D ,' firing-pin spring, E; andextractor, F.
are propelled forward by a spiral spring.
ington, 1873. Ninety-nine models of American
arms were tested, together with the Chassepot
needle-gun, needle-carbine, Mauser, Werndl, \Vcr-
der, Vetterlin, and Martini-Henry systems, as rep-
resentative of the best foreign practice. The na-
ture of the-trials was substantially similar to that
of the trials of magazine guns in 1878. On the
conclusion of the first series of tests the follow-
ing guns were ordered to supplementary trial : Pea-
body, No. 63; Whitney carbine, No. 77; Springfield-
Stillman, No. 66; Elliot carbine, No. 80; Ward-
Burton magazine carbine, No. 58; Updcgraif, No.
42; Sharps, No. 5; Springfield, No. 69; Reming-
ton-Ryder, No. 67; Berdan Russian, No. 57 ; Free-
man, No. 76; Dexter, No. 38; Lee, No. 61; Rob-
erts, No. 2; Remington locking rifle, No. 82; Win-
chester, No. 78; Broughton, No. 79; Sharps, No.
81 ; Remington navy rifle, No. 85; and of the for-
eign arms, the Martini-llenry and Werndl. Out of
the 21 arms thus selected, after undergoing stip-
plementary testing six were chosen to be altered
to calibre, .45 inch, that calibre having been deter-
mined upon by a board of U. S. army officers (see
also “Ordnance Memoranda,” No. 15) as the most
advantageous one for small arms. The six were
the Springfield, Elliot, Ward-Burton, Remington,
Freeman, and Peabody. These were thoroughly
tested, and the result was the victory of the Spring-
field systcm and its subsequent adoption into the
military use of the United States. The Board
strongly advocated magazine gains, and pointed out
that “whenever an arm shall be devised which
shall be as eifcctive as a single breech-loader, as
the best of the existing single breech-loading arms,
and at the same time shall possess a safe and easily
manipulated magazine, every consideration of pub-
lic policy will require its adoption.” In this con-
nection, scc final tests of the Hotchkiss gun, trial
of 1878-
Maexznvn on Rrr'sx'rrxc Runes—An exceed-
ingly valuable and complete series of tests of the
principal types of weapons of this class was con-
ducted at the National Armory, Springfield, Mass,
in April, 1878. The details of the experiments and
other data are given in the report of the Chief of
Ordnance, U. S. A., 1878. An abstract of the re-
sults of this trial will be found further on.
The Hotchleiss llfrrgcm'aze Gun—This weapon be—
longs to that class which has a fixed chamber closed
by a movable breech-block which slides in the line
of the barrel by direct action; i. e., bolt-guns which
have concealed locks. It is the device of Mr. B. B.
Hotchkiss, the inventor of the revolving cannon
described under Onnsxxcs. In exterior appear-
ance this arm resembles an ordinary single-shot
bolt-gun. The magazine is in the butt end of the
stock; the supply of cartridges from the magazine
can be cut ofl’ by moving a thumb-piece placed on
the left side of the receiver or “ shoe,” and the gun
is then loaded and fired as a single-loader. The
peculiarity of the arm consists in the construction
of the magazine movement and in the breech
mechanism, or system. This consists of but 6
parts, Fig. 1660, viz.: Breech-bolt, A ,- recoil-
block, or nose-piece, B ; hammer, C; firing-pin,
The magazine is located in the stock, and the cartridges
Their motion is, however, governed as follows: The trig.
gcr C' is traversed by a tubular passage, of sufficient size to allow the cartridge toxpe fed through it
into the magazine and to pass in the opposite direction to the chamber. The a
s of this tubular
724 FIRE—ARMS, CONSTRUCTION AND TRIALS OF.

passage is not quite in the same line with the passage in the receiver. This displacement is so
arranged that the body of the cartridge can pass, but not the head. vWhen the trigger is pulled to
fire the gun, the trigger-passage and that in the receiver are brought to coincide. A cartridge is
thus liberated and allowed to pass through by the pressure of the magazine-spring into the receiver.
The action of closing the bolt then pushes the cartridge into the chamber ready to be fired. Hence,
each time the trigger is pulled to fire the gun, one cartridge is liberated, and the extraction of the
empty shell and closing of the gun is necessary to bring the new cartridge into firing position.
The gun, when used as a repeater, is operated by 3 motions, viz.: Opened, closed, fired. When
used as a single-loader, it is operated by 4 motions, viz.: opened, loaded, closed, fired. To open the



piece, the handle of the breech-bolt is raised, and then withdrawn as far back as possible. This
brings back at the same time the nose-piece, and also the firing-pin is retracted. The gun is by
this action cocked. The nose-piece, meanwhile, is kept from turning by the resistance afiorded
by the projection on it against the receiver, which allows the nose-piece to follow only the longi-
tudinal motion of the bolt. By reversing the movement of the bolt, the nose-piece catches against
the head of the cartridge and shoves it up the incline of the receiver into the chamber. In push-
ing forward the bolt, the lower edge of the hammer catches against the sear H, and is retained by it
during the remaining slight forward motion of the bolt. This motion is imparted to the bolt by its
bearing against the beveled surface of the rear shoulder of the mortise in the receiver, while the
handle is turning down into place. To fire the gun, the trigger is pulled and the sear is disengaged
from its hold against the face of the hammer. This allows the firing-pin spring to impel it for-
ward, and to drive the firing-pin against the percussion-cap in the cartridge. Extraction is provided
for by a strong spring-hook extractor, carried by the nose-piece. The natural spring of the extractor
presses the rim of the cartridge against the side of the receiver, and by the friction thus created the
cartridge is thrown sideways round the hook of the extractor and clear of the gun. The cartridges













1662.
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are loaded into the magazine from its forward end, the bolt being previously drawn backward, so as
to expose that part of the magazine-passage which connects between the stock and the chamber
in the barrel.
Fig. 1661 shows the same gun with various minor improvements, and represents one of the varia-
tions of the form which proved victorious in the tests above referred to. For performances of this
and other weapons, see table on page 789. In the improved model, five cartridges are carried in
the magazine and one in the chamber.
The Remington Magazine Gun, Fig. 1662.--This gun belongs to the system in which a fixed cham-'
ber is closed by a bolt by direct action, and in which the lock is concealed. The breech-bolt is com-
posed of three parts, viz. : the body or locking-tube A, the cocking-piece B, and the portion by which
these are connected. The extractor lies in front of the rib of the locking-tube, and its tenon enters
FIRE-ARMS, CONSTRUCTION AND TRIALS OF. 725
w

a recess in the side of the latter. When the bolt is unlocked, the extractor rides around the head of
the cartridge. The ejector is struck by the carrier-lever G when the bolt is withdrawn. The extractor
then pulls on the upper side of the cartridge, while the under side is struck by the ejector. The effect
is to throw the shell clear of the gun. The cocking-piece B receives the firing-pin and spring, and a
projection H upon it enters a recess in rear of the locking-tube. The form of this projection and that
of its corresponding recess is such as to cam back the half-cock notch to pass beyond the sear, at the
same time withdrawing the point of the firing-pin within the face of the bolt. The piece may be full-
cocked by pulling the cocking-piece to the rear by the button with which it is terminated, or by draw-
ing back the bolt and then returning it to its locking position. The magazine is in the tip-stock.
The carrier is pivoted on a strong screw through the side of the receiver. Its lever works in a groove
in the bottom of the locking-tube. When the bolt is withdrawn, the front end of the groove strikes
on the lever and tips the carrier up in a position oblique to the axis of the bore, bringing the point
of the cartridge opposite the centre of the chamber. The carrier is held in this position by the catch
L, which springs over a pin on the inner surface of the receiver. When the bolt is closed, its front
presses against the catch and releases it, while the rear end of the groove in the bottom of the lock-
ing-tube strikes the carrier-lever and causes the carrier to descend opposite the mouth of the maga-
zine. When the bolt is unlocked, the side of the groove presses down on this end, and the stop
moves downward, permitting a cartridge to come out of the magazine on the carrier. The stop is so
constructed that a projection on its upper side descends just in front of the rim of the cartridge as
the lower part falls in rear of it, so that the escape of a second cartridge is prevented. When the
bolt has been withdrawn, the spring returns the stop to its first position. A magazine cut-off is pro-
vided, which works in connection with the cartridge-stop.
The magazine is loaded from below, and in any position of the bolt. As a magazine gun, 3
motions are necessary to operate it, viz.: opened, closed, fired. As a single-loader, 4 motions are
necessary, viz.: opened, loaded, closed, fired. This gun carries 8 cartridges in the magazine and 1
in the chamber. ,
Sharps Rifle Company’s Magazine Gun, Fig. 1663.—This gun belongs to that system in which a
fixed chamber is closed by a bolt, by direct action, and in which the lock is concealed. The receiver



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has a slot in its upper surface for the purpose of loading the chamber or filling the magazine. It is
bored through at rear for the reception of the breech-bolt, which is composed of two principal parts,
the body and the locking-tube. The bolt is locked by lugs A on the locking-tube, turning in
corresponding cuts in the receiver. The bolt carries on its upper surface the extractor, which is of
the ordinary spring-hook pattern, and in its axis the firing-pin, which extends the whole length of
the bolt. The spiral form of the face of the locking-tube and of the shoulder of the bolt is such as
to cam the bolt up against the head of the cartridge when the bolt is locked. On the rear face of
the locking-tube are two spiral surfaces, which bear against corresponding surfaces G of the firing-
pin. The unlocking of the bolt cams back the firing-pin until the point H passes beyond the nose
1 of the sear. When the handle is turned down to lock the bolt, the firing-pin spring is compressed
between the shoulders J on the pin and the nut 11" on the extreme rear of the bolt. On withdrawing
the nose of the sear, the firing-pin, under the influence of its spring, moves forward and explodes the
cartridge. The shell is ejected by the ejector-pin L, which strikes against the lever ll! of the carrier
when the bolt is withdrawn, and is driven forward against the lower side of the head of the shell,
while the extractor is pulling on the upper. The magazine is in the tip-stock. The carrier is shown
at 0. When the breech-bolt is withdrawn, the projection P, in which the ejector-pin is situated,
strikes the lever ll! of the carrier, tipping the latter up in a position oblique to the axis of the bore,
bringing the point of the cartridge nearly opposite the centre of the chamber. The carrier is held
in this position by the pin and spring shown at Q. When the bolt is closed, the cartridge is driven
into the chamber, while the projection R on the bolt strikes the lever, causing the front of the carrier
to descend opposite the mouth of the magazine to receive another cartridge. As a magazine gun, 3
motions are necessary to operate it, viz.: opened, closed, fired. As a single-loader, 4 motions are
'726 FIRE—ARMS, CONSTRUCTION AND TRIALS OF.
a. .W
necessary, viz.: opened, loaded, closed, fired. This gun carries 9 cartridges in the magazine, 1 in
the carrier, and 1 in the chamber.
The l/Wnchcster Magazine Gum—This gun, manufactured by the Winchester Repeating Arms
Company of New Haven, Conn., belongs to that system in which a fixed chamber is closed by a bolt,
sliding in line with the axis of the barrel, and operated by a lever from below. The receiver, Figs.
1664 and 1665, is divided by a vertical partition A into two parts. The carrier occupies the front
1664.
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‘ -—- ' -- "Ti-.0 'WW\& I
r.;t~~~~.-g_ B ' ‘ ‘ E ..‘2'
m p __









portion, while the rear contains, with the exception of the breech-bolt lever, the mechanism necessary
to operate both breech-bolt and carrier. The breech-bolt is a single piece, at the upper front end of
which is the extractor (of the spring_hook pattern) pinned to it, and at its rear a mass of metal
which supports at either side the front end of one of two side links, B and O, which form a knuckle-
joint. The rear ends of the other links bear against the rear of the receiver, giving the necessary
support for the bolt in firing. The outer ends of the links are pivoted to the bolt and receiver. A
groove D, on the inside of each rear link, receives the end of a strong pin on the breech-bolt lever.
Motion of the lever consequently produces a corresponding motion of the links, and through them of
the bolt. The firing-pin extends the whole length of the receiver. Its point is retracted within the
face of the bolt, when the bolt is drawn back, by a small lever E, one end of which enters a recess
in the pin, while the other strikes against the pin F, Fig. 1665, causing the lever to rotate about the
pivot through the front end of the links attached to the breech-bolt. A flat spring (not shown in
the figures) bearing against the surface of the breech-bolt lever holds it in place. The hammer is
cocked by the end of the firing-pin when the breech-bolt lever is thrown forward. The piece is fired
by a centre lock of the usual pattern. A safety device or sear prevents the pulling of the trigger
when the piece is unlocked. When the breech-bolt lever is closed, it strikes the pin K projecting
from the under side of the soar, and removes it from the safety position. Shells are ejected by the
carrier, which, rising as they are being withdrawn, strikes them at a distance of about one-third their
length from the rear, and rotates them about the extractor, throwing them clear of the gun. The
magazine is in the tip-stock. It is loaded through a gate in the side cover of the receiver, as is also
the piece when used as a single-loader. rlshe carrier is moved at right angles to the axis of the
barrel by its lever G. This lever is thrown up by the shoulder H of the breech-bolt lever striking
its under surface when the latter is thrown open. The carrier-lever is depressed in a similar manner
when the breech-bolt lever is closed, by the latter bearing on a shoulder on its upper surface. The
spring J holds the lever and carrier in either position, Figs. 1664. and 1665. In rising, the carrier
does not completely uncover the mouth of the magazine ; cartridges cannot therefore escape below
1665.


111111101111”
mm _



it. As a magazine gun, 3 motions are necessary to operate it, viz.: opened, closed, fired. As a
single-loader, 4 motions are necessary, viz. :_ opened, loaded, closed, fired. The motions of opening
and closing might perhaps be classed as a single motion, being continuous, the hand not being re-
moved from the lever. This gun carries 9 cartridges in the magazine, 1 in the carrier, and 1 in the
chamber.
Among other well-known forms of magazine guns are the Hunt, which belongs to the class in
FIRE—ARMS, CONSTRUCTION AND TRIALS OF. 727

which a fixed chamber is closed by a bolt by direct action, but has a centre lock; the Ward-Burton,
belonging to the same general class as the IIotchkiss and Sharps; the Burgess and the Tiesing, in
which a fixed chamber is closed by a bolt sliding in line with the axis of the barrel and operated by
a lever from below, both guns belonging to the same class as the Winchester. The Chaifee and
Buifington guns have fixed chambers closed by movable breech-blocks, sliding and rotating, and
operated by a lever from below. The Springfield-Clemmons and Springfield-Miller arms have fixed
chambers closed by movable breech-blocks, which rotate about horizontal axes at 90° to the axis of
the barrel, lying above the axis of the barrel and in front. Both are adaptations of the Springfield
breech-loading rifle previously described. The Lewis-Rice gun belongs to the system in which a
fixed chamber is closed by a movable breech-block rotating about a horizontal axis at right
angles to and below the axis of the barrel, and in front, and in which the lock is concealed.
The Franklin, Burton, and Lee guns belong to the same class as the Hotchkiss and Remington.
For detailed descriptions of all these, the reader is referred to the report of the Chief of Ordnance,
U. S. A., 1878.
The Springfie'd Arsenal Tests of lilagazz'ne Guns, 187 8.-The following were the principal condi-
tions of trial (for results, see following table): 1. Safety-test. The piece to be fired 10 rounds by
the exhibitor or with a lanyard. 2. Rapidity with accuracy. The number of shots which, fired in
two minutes from the gun—both as a magazine gun and as a single-shooter—strike a target 6 feet
by 2 feet at a distance of 100 feet. The test to be begun with the chamber or magazine filled;
other cartridges to be disposed at will on a table. 3. Iiapidit-y at will. The number of shots which
can be fired in one minute, irrespective of aim, under the same circumstances as in test 2. 4.
Endurance. Each gun to be fired 500 continuous rounds without cleaning, using the magazine. The
state of the breech mechanism to be examined at the end of every 50 rounds. 5. Defective car-
tridges. Each gun to be fired once with each of the following defective cartridges : 1, cross-filed on
head to nearly the thickness of the metal; 2, cut at intervals around the rim ; 3, with a longitudi-
nal cut the whole length of the cartridge, from the rim up; a fresh piece of white paper, marked
with the number of the gun, being laid over the breech to observe the escape of gas, if any occur.
6. Dust. The piece to be exposed in the box prepared for that purpose to a blast of fine sand-dust
for 2 minutes ; to be removed, fired 20 rounds, replaced for 2 minutes, removed, and fired 20 rounds
more. '7. Rust. The breech mechanism and receiver to be cleansed of ga-case, and the chamber of
the barrel greased and plugged, the butt of the gun to be inserted to the height of the chamber in
a solution of sal-airmoniac for 10 minutes, exposed for 2 days to the open air standing in a rack,
and then fired 20 rounds. 8. Excessive charges. To be fired once with 85 grains of powder and
one ball of 405 grains of lead, once with 90 grains and one ball, and once with 90 grains and two
balls. The piece to be closely examined after each discharge.
The following supplementary tests were made upon guns which successfully withstood the fore-
going: 1. To be fired with two defective cartridges, Nos. 1 and 2, and then to be dusted 5 min_
utes, the mechanism being in the mouth of the blow-pipe, and closed, the hammer bcing at half
cock; then to be fired 6 shots, the last two defective Nos. 1 and 2; then without cleaning to
be dusted with the breech open, and fired 4 shots. The piece to be freed from dust only by
pounding or wiping with the bare hand. 2. To be rusted for 4 days after immersion as before,
and then fired 5 rounds with the service cartridge; then without cleaning to be fired 5 rounds with
120 grains powder and a ball weighing 1,200 grains; the gun to stand 24 hours after firing without.
cleaning, and then to be thoroughly examined. 3. Facility of manipulation by members of the
Board. 4. Liability to accidental explosions of cartridges in the magazine. Additional tests may
be made by the Board to clear up doubts raised by previous trials.
SPORTING Amus—Smoath-Borea—The bores of shot-guns are made in four ways : 1st, cylindrical ;
2d, drawn; 3d, choked; and 4th, bell-muzzled. The cylindrical bore is of uniform size throughout.
The drawn bore is less in diameter at the muzzle than at the breech, the decrease however being
very small. Choked-bore guns have near the muzzle a slight swelling or ridge, the bore being cylin_
drical; and in bell-muzzlcd guns the bore is enlarged or slightly flared at the muzzle. The object
of drawing and choking is to bring the shot together, and give a more advantageous “pattern.”
This term is used to designate the number of pellets projected into a circular target 40 inches in
diameter at about 30 yards range. Bell-muzzling increases the dispersion of the shot. In choke-
bore guns, it is supposed that the shot in passing out impinge upon the choke or ridge, and are de-
flccted inward toward the axis of the bore. Most sportsmen favor a moderate choke, as it is claimed
to afford even pattern or distribution and good penetration at a moderate range, with light charges
of powder—these being the essential requirements of any well-constructed shot-gun.
The Parker Breech-loading Shot-Gun, Fig. 1666, is an example of the most approved American
construction, and is the manufacture of Parker Brothers of Mcriden, Conn. The engraving repre-
sents the gun as opened. This is effected by pressing upon the finger-piece 1 in front of the guard
2. The lifter 3 is thus raised, and its beveled side, coming in contact with the screw 4, acts as a
wedge to draw the bolt 5 from the mortise which is cut in the ing 6, and releases the barrels as
shown, ready for the insertion of the cartridges. It will be observed that when the bolt 5 is back to
the position represented, a small hole in the under side of this bolt comes directly over the trip ’7,
which by the assistance of the small spiral spring 8 is made to enter the hole and so hold the bolt in
position. At 11 is shown an improved cartridge-extractor, which draws the shells or cartridges from
the barrels during the operation of opening the gun. It is inserted in a hole in the lug 6, with its
rear end enlarged and extending into and around a portion of the chambers of the barrels. When
the gun is closed, the extractor 11 extends from the rear end of the barrels to the projection on the
point 13; and as the barrels swing on this point, which remains stationary, this projection forces the
extractor from the rear end of the barrels, so that, when they arrive at the position shown in Fig. 1666,
the cartridges are withdrawn from them far enough to be entirely removed by hand. After removing
728
FIRE-ARMS, CONSTRUCTION AND TRIALS OF.
3‘.

Table showing Data of Trials of the Four Magazine Guns which gave best Results at Experiments
made at Springfield Arsenal, 187 8.































































Lg WEIGHT. SAFETY TEST: RArmITY WITH ACCURACY.
o
in As Magazlne Gun. As Single-loader.
NAME or GUN. g '
2 "g; E '5 s "a -
2 s 5 s: s s g s s s
g .3 >. a; “a 3' E E; go 43' .3 q': a E ‘2 O Q ' O a: fl
2 2 E :4 z a = s s z s m z»: 8% °
N 0. Lbs. 02. Lbs. 02. Sec.
Hotchkiss . . .19 6 9 0 9 8 19 29 20 5 44 26
Winchester..13 11~ 10 6.5 11 s e 85 22 s so 24
Remington. .17 9 9 9 10 6 13 3! 20 2 2 44 17 1
Sharps . . . . .. 8 11 10 0 10 15.7 15 1 27 24 6 41 83 1
RAPIDITY AT WILL. ENDURANCE.
As h-lagnzine Gun. As Single-loader.
NAME OF GUN. M ._-_ _~___ __
.5 . .5
. g . 1: . REMARKS.
s s -— s s 2 s
_ s .s 3,, , s .s g _ s
% bl E ‘1 3 '3 E .4: 3 {2
A E 2 "" o .g ""
'12 a :3": w '2 E u; S.
No.
Hotchkiss.. .19 22 1 28 500 Gun worked well.
Winchester..13 23 2 23 1 500 One shell failed to extract.
Remington. .17 10 8 24 1 500 2
Sharps . . . . . . S 21 4 I 26 5500 Worked well.
i DEFECTIVE CARTRIDGES. DUST. RUST.
l
NAME OF aux! g; g-
l 3- “? REMARKS. 2; “F REMARKS. 3' “F REMARKS.
] o .2 O 32 o .‘2
; fl 2 i E G S.
_ [.___._ -—~*
No.5 ‘ . 5 Magazine cut-off rust-
}lotchkiss.. .19 5 .. Gun worked well... Gun worked well. . . .. . ed in seat; otherwise
( worked well.
Winchester..13 I “ .. .. ' "‘ Gun worked well.
. 5 Shell burst un- Cartridges would
Remington..17 i derneath gas-es- .. 2 not feed from . . . . . . . . . . . . . . . . . . . ..
{ cape. . . . . . . . .. magazine . . . . . ..
Sharps. . . .. 8 Gun worked well.. . Gun worked well.. . .. Gun worked well.
EXCESSIVE onARcRs. SUPPLEMENTARY TESTS.
'8 >,'§
NAME or GUN. a; 3;; .e '2 _ .
, E REMARKS. '5 E: § or 60 OARTRmens rmnn—
s .2 5:2 3 s“
5 >: E m s
No. ‘ Min. Sec 48 hit target 6 x 24 inches. 100 yards - 17
Hotchkiss...19 } niggftzhflwggfitlu‘ggfir 1 l } hit figure of man at centre of target;
’ L 1 c r’ ' 2 others grouped well around it.
W. h t 13 lTwo shells failed to em} 1 58 {48 hit target as above; 28 hit figure of
me 98 er" l tract until 2d trial. . . .. man; others well grouped.
. 47 hit target as above; 15 hit figure 01‘
Remington -17 ' ' ' ' ' ' ' ' ' ' ' ' ' ‘ ' ' 2 29 % man; others well grouped. i fl, f
38 hit target as above' 11 h t gure 0 ~
Sharps . . . . .. 8 Gun worked well . . . . . . . . . .. 2 84 man; others we“ grohpe¢ J

FIRE—ARMS, CONSTRUCTION AND TRIALS OF. ~
729

Table showing Final Test of the successful @1012 at Springfield Arsenal Trials, 18'? 8.

MEAN TIME OF FIRING SIX SHOTS, THREE TRIALS.

NAME OF GUN .
Piece brought to the Shoulder.

As a Magazine Gun.
As a Single-loader. As a Magazme Gun.

fi-otchklss. No. 19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
U. 5. Springfield rifle . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Fired at Will. i
l
l
13 secpnds. 6 seconds.



the cartridges and inserting others, the barrels are brought to place, and the cartridges, coming in
contact with the face of the frame, are forced into the chambers, when the gun is ready for firing.
1666.


An ingenious form of lock, represented in Fig. 1667,
When the gun is fired, the mainspring carries the
to prevent premature or accidental discharges.


is used on these guns, the object of which is
hammer in the usual manner until the spring
comes in contact with the stud in the plate
and stops. The hammer by its own mo-
mentum now explodes the cap, and the nose
of the sear then rests on the incline of the
tumbler, so that the hammer is thrown back
to half cock as soon as the pressure is re-
lieved from the trigger.
These guns weigh from 595 to 13 lbs. The
dimensions are as follows: length of bar-
rels, 28 to 32 inches, “drop” from 2% to 3
inches at butt; stocks (from centre of front trigger to centre of butt plate) vary from 14 to 149;
inches.
1668.


The quantity of powder used varies from 2 to 6 drams, and of shot from three-fourths of
v‘.
7mm.m“m\mw-wsl,
/
an ounce to 2 ounces. A coarse-grained powder, about the size of extra-large mustard seed, is to
be preferred. (See EXPLOSIVES.)
The Climax Self-cocking Gun, Fig.
1668, is of English construction,vmade by Messrs. Holland of
730 FIRE-ARMS, CONSTRUCTION AND TRIALS OF.

London. It is so constructed that its cocking occurs simultaneously with the opening of the breech,
so that only one motion of the lever is necessary to accomplish both these objects. This self-cocking
action is produced by means of a lifter O, jointed on to the short arm of the lever A. The operation
is performed by pushing the lever downward ; and this opens the bolts of the grip, and at the same
time drives up the lifter (which works in a slot in the body), which presses against the extreme end
of the hammers D, and drives them back either to the half or full cock as may be desired ; this is
regulated simply by the extent to which the lever under the guard is depressed. When the gun is
closed, the head of the lifter, which lies under the hammers and between the nipples, is sunk in the
body, and presents an appearance there similar to other guns.
Rifles—Sporting rifles made by manufacturers of military arms differ from the latter chiefly in
point of weight and finish, the system of construction being the same. Nearly all American makers
publish very full catalogues, which often embody treatises on the manufacture of sporting rifles, and
are especially complete in details referring to the weapons used at long-range target competitions.
In some of these matches Remington’s and Sharps’s rifles, of American make, and lligby’s and Met-
ford’s, of English make, the former breech-loading and the latter muzzle-loading, have come into
direct competition, and the relative efficiency of the two radically different systems has been severally
tested, with a preponderance of advantage in favor of the American arms. As the trade publications
above referred to contain full reports of competitions in which the various rifles were used, it seems
unnecessary to do more than refer the reader to the manufacturers, who supply such information
gratis.
One of the most noted sporting rifles of foreign make is the “Express,” constructed by the Messrs.
Holland of London. This rifle is breech-loading, and is made double-barreled. It is chiefly noted
for long range and accuracy. The 5'7 7 here Express takes a charge of 6 drama of powder. Larger
sizes take as high as 8 drams, and are commonly used by African explorers against large game.
They project hollow-fronted, solid hardened, or explosive bullets.
R.uvoI.V1cRs.——Colt’s.-—Fig. 1669 represents a sectional view of Colt’s army revolver. This has
6 chambers; total length of barrel, 12.5 inches; weight, 2.31 lbs.; weight of powder charge, 28
grains, and of bullet, 230 grains. The various parts are as follows : A is the barrel; B, the frame;
0, the cylinder; 1), the centre-pin; E, the guard; F, the back strap; G, the hammer; H, the
mainspring: I, the hammer-roll and rivet; J, the hammer-screw ; K, the hammer-cam ; L, the
hand and hand-spring; 11!, the stop-bolt and screw; N, the trigger and screw; P, the firing-pin and
rivet; Q, the ejectonrod and spring; R, the ejector-head ; S, the ejector-tube screw ; T, the guard-
screw; U, scar and stop-bolt spring; V, the back-strap screw; W, the mainspring screw; X, the
front sight; Y, centre-pin catch-screw; B', the recoil-plate; D', the centre-pin bushing; and Q’,
the ejector-tube. On the base of the cylinder is a ratchet having as many teeth (5 or 6) as the
chamber has barrels. The teeth are so arranged that, when the hammer is at full cock, a chamber
is directly in line with the barrel. ()n the surface of the cylinder are cut as many small slots as
there are chambers. That which happens to be lowest at -the time is entered by a belt which is
moved by the action of the lock, and is pressed into the slot by a spring, so that while in this posi-
tion the cylinder is immovable. The scar and trigger are in one piece, as are also the hammer
and tumbler G upon which the main spring acts directly. On the face of the tumbler is a pawl or
hand, L, which successively engages each of the teeth on the rear of the cylinder; and the tumbler
1669.




_- ,‘x: ‘ \ _ .
.‘A‘q. , - ,
G ~ r;-!"~‘ I
-' § ‘ \ - M
f w n _ v a - - x 34,-.“ - 'mua-unwz'zin-a'rn-rzv'w 4‘, A]
\axxxsntxuaawnwmmnutmarshya 581:1. ~ ‘ -
may ‘ -—~_7-—- - . ir- '. ‘
q ' fix,
I

$
IL
has also a projecting pin, which at the proper
time engages the bolt that locks the cylinder,
lifting it out of the slot and allowing the cylin-
der to rotate under the action of the hand.
When the pin no longer acts upon the bolt, it
is forced by the spring into the next notch that
presents itself. The operation is as follows:
The chambers having been loaded by inserting a
cartridge, the hammer, supposed to be resting
on one of the capped nipples, is drawn back;
this causes the pin to disengage the bolt, and the
, hand rotates the cylinder about one-fifth of a
revolution. On arriving at full cock the pin is disengaged from the bolt, which then falls into the
next slot and locks the cylinder. The weapon is then discharged by pulling the trigger.
The Seltqfield-Sm'ilh db Wesson Revolver, Fig. 1670.-—This arm has 6 chambers, and for army
use the total length of the barrel is 12.5 inches. Its weight is 2.5 lbs. ; weight of powder charge, 28
grains, and of bullet, 230 grains. A is the barrel, connected with the frame B by the joint-screw
C’. From the rear of the barrel projects the base-pin, on which the cylinder F revolves. This is
kept in place on its pivot by the inner book of the cylinder-catch D. The latter is pivoted at its
front end on the cylinder-catch screw D”, and is held down by the cylinder-catch cam-screw D', the
cutting away of the upper part of the middle portion of which allows the catch to rise when the
cam is turned to a certain position. The base-pin is hollow, and contains the extractor-stem H, made
in two parts, which screw together. Between the head of the stem and the bottom of the hole in


FIRE-ARMS, MANUFACTURE OF. 731

the cylinder is confined the extractor-spring H' (more properly the retractor-spring), which is com-
pressed when the extractor moves out. The extractor G is recessed into the face of the cylinder.
The ratchet by which the cylinder is revolved is cut in the face of the extractor, and the extractor-
stud G" forms a rear
bearing for the cylinder
on the frame when the
revolver is closed. The
steady-pin I keeps the
extractor exactly in place
when it is down. The
lifter J moves upon the
friction-collar K, under the influence of the pawl L, in the mam
ner hereafter described. The pawl is pressed against the lifter
by the pawl-spring 11!. The lifter is moved by the pawl in one
direction only, and is therefore free to follow the motion of the
extractor-spring. In closing the revolver, the outer hook of the
cylinder-catch presses back the barrel-catch E, and engages
with it under the influence of the barrel-catch spring E'. The
position of the hammer prevents the openingr of the barrel-
catch, and consequently of the piece, until it has been brought
to the position of half cock. The parts of the lock resemble
in their general features those of Colt’s revolver, already de-
scribed. They are: N, the hammer; R, the hammer-stud; O, the main-
spring; Q, the strain-screw; P, the swivel and swivel-pin; 1, the trigger
and trigger-pin; and S, the trigger-spring. The hand IV is kept in place
by the hand-spring in the front surface of the hammer, which bears against
a flat place on the pivot-arm of the hand. The stop V is thrown up into
the stop-motion of the cylinder by the stop-spring; it is drawn down out of
them by the action of the trigger-spring on the trigger when the piece is at
half cock. When the hammer is at full cock, and also during its fall, the
upper arm of the trigger bears down on the rear end of the stop, and keeps
its head securely in the stop-notch. The guard X is secured to the frame
by the guard-screw Y, and by a lip on the rear end of the guard-strap which fits under a projection
on the frame. Z is the sight, and O the recoil-plate.
For full details as to dimensions of revolvers, modes of inspection, etc., see “ Ordnance Memo-
randa, U. S. A,” No. 22 (“The Fabrication of Small Arms ”).
FIRE—ARMS, MANUFACTURE OF. THE MANUFACTURE OF RIFLES.——Th6 manufacture of rifle-
barrels is one involving a great deal of skill and delicate manipulation, [or the reason that the length
of the bore is so great in proportion to its diameter that the boring appliance, whether drill-reamer
1670.
































1671.
~__-/ $§§ . w-
A F5€=
' / .4
_ ' / '
_ B
/ _.
_ l_.l__L_ » ~—
n . l_
_I/ / /, D \ 6, B) 0
p
_ /
_ J/f ‘3 ea

7" \ /
0r bit, is exceedingly liable to spring, and will consequently, to some extent, follow the inaccuracies
of the hole, even under the most careful manipulation and with the very best tools and machines.
To obviate this difficulty has been the object of many inventions, the most prominent among which
abroad is probably the hydraulic cold-steel drawing process, in which ingots of cold steel are forced
by hydraulic pressure through dies.
732 FIRE-ARMS, MANUFACTURE OF.

The following is the method of manufacture of Springfield rifles in the National Armory at
Springfield, Mass. A most minute description of every stage of the various operations will be found
in “ The Fabrication of Small Arms,” in “Ordnance Memoranda, No. 2'3," by Lieut. 001. J. G. Ben-
ton and others, Washington, Government Printing-Office, 1878.
Barrel-Rolling.—A Springfield gun-barrel is made from a 2-inch round bar of decarbonized steel.
This bar is cut into lengths of 9} inches each, and through these holes are drilled, forming what is '
known as the “barrel mould,” represented at G in 1672. This is heated and drawn out be-
tween grooved rolls. Each set of rolls, as shown in the engraving, has 8 grooves, 2 cylindrical
and 6 taper, and in connection with the grooves 8 mandrels of various sizes are employed. The
action of the rolls is to draw the heated mould over the mandrel, when the cylinder is straightened
and reheated. Each mould is therefore rolled 8 times. H and], in Fig. 1672, show its form at
difierent stages during the process. A is the housing, BB the rolls, 0 the connecting gears, D
the clutch, E the gun-barrel, and F the barrel-rod. While still hot the barrel is cut to the proper
1672. ,_,./--""’




length by circular saws, and is afterward straightened between two dies, each of the length and shape
of the half barrel, which are arranged in a special machine. Annealing in charcoal follows, after
which the barrel is straightened on the outside. This done, the boring processes commence, the first
one being termed the nut-boring, which is performed as follows: -
Boring—The boring-rod or tool consists of a long rod of steel, sufficiently small and long to pass
through the hole in the rifle-barrel; on the end of this red is an enlarged piece about an inch in
length, the cutting edges being at the shoulder; the operation is to pass the rod through the rifle-
barrel and bore, by the revolving tool being pulled, and not pushed, by the feeding motion. It is
obvious that if the resistance to the cut, or the strain caused by the cut, is in a direction tending to
compress the metal of the boring-rod, that rod will spring and bend from the resistance; whereas, if
the strain is a tensile one, the whole strain due to the cut will tend to keep the boring-rod straight
and true, and prevent it from springing, no matter how heavy the cut may be. After the first
boring, the rifle-barrel is again bored with another tool similar in every respect, save that it is of
larger diameter. The next operation is to straighten the bore, which is performed, as shown in Fig.
1672, as follows: '
Straightening the Bore—A is a frame containing a plate of ground glass, across which is placed
horizontally the small, dark-colored bar B, the frame being placed in such a position that daylight
shines directly through it; at about 40 feet distance stands the rest 0, which is to support one end
of the rifle-barrel D, while the operator ranges the other end direct to the horizontal bar B.
When the operator adjusts the barrel so that the light from the ground glass shines in a straight
line through the rifle-barrel, the bar B will throw a dark line along each side of the rifle-bore for a
distance, commencing at the end farthest from the operator’s eye, about three-fourths the length of
the bore. (The rest of the bore appears from end to end like broad rings of light.) It is the
straightness of these lines which is a guide to test the straightness of the bore. 'If there is the least
waver, the barrel is not straight; but here arises the difficulty—in that to see the waver inside is a
very easy matter, but to locate it on the outside requires such correctness and judgment of vision
that not more than one man in ten who essay to learn the business ever attains proficiency. It is
necessary to revolve the barrel, so that the dark line shall strike all parts of the barrel, which must
also be turned end for end in the rest 0, because, as stated, the dark lines do not extendfrom end
to end of the barrel. When the location of the bend is determined, the barrel is laid across an
iron anvil or block, on which there are two projecting blocks, about 8 to 10 inches apart, and the
straightening is performed with an ordinary blacksmith’s hammer. After the first straightening, a
collar of Babbitt metal is run on the outside and in the centre of the length of the barrel, which
collar is faced up true, and used in a steady rest to prevent the barrel from springing while the
roughing cuts are being taken off the outside in the lathe; it would be quite useless to finish the
bore before the outside was turned, because, the latter operation releasing the tension on the outside
of the metal, the inside would get out of true again. After the first outside turning has been per~
FIRE—ARMS, MANUFACTURE OF. 733

formed, the barrel is again bored, this time with' a square reamer, revolved at a somewhat quick
speed, and led first forward and then backward and forward somewhat rapidly. .
The next operation is to repeat the straightening process, and then the outside is again turned,
and the boring process repeated, the same square reamer being used with a piece of wood placed on
one square, which piece of wood steadies the reamer, as well as causing it to cut a slightly larger
bore, by reason of fitting a little tight in the rifle-bore. After this boring, the outside of the barrel
is ground on a quick-running stone, and the straightening and boring processes are repeated, slips of
paper being placed under the piece of wood, so as to increase the size of the bore until it becomes of
the correct, plug-gauge size. Here we may note that the dark lines thrown on the inside of the bore
by the horizontal bar B in the frame A magnify any defect in the bore, and that, as the operatives
express it, the wave in the barrel never appears to be where it actually is; and hence the difficulty
of locating the defect on the outside of the barrel. Proving takes place at this stage, heavy charges
of powder and lead slugs being used ; 4O barrels at a time are thus tested.
Polishing—After various milling and filing operations, to square off ends and prepare parts for
the sights, comes the polishing of the outside, which is performed as follows: The barrel is held
vertically, and revolved while being passed down between the end faces of two pieces of wood,
upon which emery has been glued in the same manner as on an ordinary wooden polishing emery-
wheel. After the first polishing process, however, the barrel is not made to revolve, but is moved
vertically back and forth between the pieces of wood, so as to leave the polishing marks straight
lengthwise of the barrel. The first polishing is performed with a grade of emery about No. 60; the
last is done with flour emery. The machine in which the polishing is performed holds five barrels at
once, the polishing woods opening and closing as the barrel passes through them, so as to accom-
modate the taper.
Riflz'ng is done in the machine illustrated in Fig. 1673. The bed A is similar to that of a lathe,
the rifle-barrel B being held in a head 0' at one end of the bed; to this head is attached suitable
1673.





gearing, by which the barrel is made to suddenly make one-third
of a revolution. The cutter~mandrel D, or rifiing-rod, is held by
a carriage traveling along the machine-bed, and operated back and
forth by the gear E. F is the shipper motion, G the oil-pump,
and H H the oiler-heads. The cutters for rifiing are arranged on
the end of the rod in three groups, there being two cutters in each
group. The width of the cutters is such that the rifle-grooves are
of the same width as the spaces between them. At the end of
the stroke the rifling-rod also makes a one-third revolution, but in a direction opposite to that in
which the barrel moves when partly revolved ; so that each set of cutters cut first in one groove and
then in another, by which means the rifling is performed more true than would be the case if the
same cutters always ran in the same groove. The cutting is performed on the stroke in which the
rifiing-rod is being pulled through the rifle-bore, and does not operate when being pushed, because a
tensile strain tends to keep the rod straight, while a compressing one would inevitably spring and
bend the rod.
The cutters are ranged so that their cutting edges stand at a right angle to the rifle-groove, and
not to the bore of the barrel. They are not in reality cutters, but scrapers. The cutters are ex-
panded as the rifling proceeds by a cone attachment applied to the bar, the feed-motion being on the
sliding carriage. When, however, the rifle-grooves have been cut sufficiently deep, which is deter-
mined by the amount of the expansion of the cutters, an automatic arrangement, which is~very simple
in its construction, throws the cutters back to their smallest diameter, and the process ceases. Du-
ring the whole of the boring and rifling processes, the bore of the barrel is liberally supplied with
oil, the tools being tempered to a light straw color.
Stock-makingv—The rifle-stocks are made as follows: The wood, black walnut, is kiln_dried, and
the stock sawn out to the necessary shape, allowing sufficient surplus in the size for the finishing
process. In this condition the wood is left to season. The first operation is facing off the stock on
the part where the barrel fits. The second is termed the tip-turning; that is, turning the under or
outside face of the part where the barrel fits. The stock is then ready for the butt-turning machine
or lathe. To drive it, a dog composed of a piece of iron somewhat less in size than the finished end
of the butt, and having several protruding spikes on one of its faces, is driven on to the end of the
734 FIRE—ARMS, MANUFACTURE OF.

butt, and this driver fits into a socket which takes the place of the face-plate of an ordinary lathe.
In place of a tail-stock, or dead-centre, there is provided a standard fastened to a carriage sliding
upon the lathe-bed, the standard containing a washer revolving in a hearing. The washer is made in
two halves, one half containing an oval slot to fit the outside or oval face of the tip, the other being
flat to fit the face of the part where the barrel fits or rests. The halves of this washer are thrown
open; the tip of the stock is passed through them; the butt end with the dog in position is then put
into the socket-driving chuck, and held firmly back against it ; then the washers are by means of a set-
screw clamped to the tip, and the cap securing the washers in the bearing is closed, and the stock or butt
is chucked, ready to be turned. The bed A of the lathe, Fig. 1674, is similar to an ordinary flat-
surface lathe-bed, and upon it there slides a carriage B, which carries the standard and the socket-
driving chuck with the butt or rifle-stock C placed in them, as above described. Immediately below
the butt, and held by the same carriage, is a pattern stock or former, D, made of cast-iron, and
held in the same manner as is the wooden butt, the driving chucks of both being made so that they
revolve in the same plane and at the same speed.
Independent of the bed and carriage, and in a permanent position, there is an upright frame G,
pivoted at the bottom or foot so that the top can swing. In this frame there is a wheel F, which
revolves against the cast-iron former-butt referred to above, so that when the upright frame is
I



\\f\

moved out of the perpendicular its weight presses the wheel against the cast-iron former, and thus
causes the frame to partake of the irregular motion caused by the revolving of the iron former-butt.
In the same upright pivoted frame is a revolving cutter-head E, the distance between the centres of
the cutter-head and the wheel referred to (whose bearings are both horizontal and parallel one to
the other) being the same as the distance between the centres of the cast-iron former-butt and the
wooden butt to be operated upon. H is the feed-motion and I the shaft for revolving the stock and
former. The cutter-head is provided with 12 cutters, arranged in sets of 3, and each taking a dif-
ferent depth of cut. The cutter-head revolves at a speed of 3,600 feet per minute, the cutters all
being formed more or less on the turning'gouge principle. The machine being started, the iron
former-butt and the wooden one revolve slowly—say at about 80 revolutions per minute; the cutter-
head, as above stated, at 3,600 feet per minute. The frame is moved out of the perpendicular,
and rests by its own gravity against the iron former-butt, which by friction revolves the guide-wheel.
The carriage, which stands all on one side of the revolving cutters, then traverses past them until it
stands all on the other side, the whole of the turning being performed during one traverse. The
roughing cutters stand in advance on the cutter-head, and the finishing ones, protruding beyond the
roughing ones, are placed behind them. The butt-turning process occupies in all about 3 minutes
15 seconds ; the whole stock-turning and tip-facing and turning takes 5 minutes ; the length of cut
taken during the operation being about 13 miles, if placed in a straight line.
FIRE—ARM S, MANUFACTURE OF. 7 35

Bedding Machines—The rifle-stock now passes to the lock-bedder, which cuts out the recess into
which the lock fits. The general appearance of this machine, which is shown in Fig. 1675, is similar
to a revolving-head gang-drilling machine, containing 5 spindles C, with their cutters .D. The rifle—
stock G is chucked in its proper position in a fixed chuck or appliance F, which insures that the
stock is correctly held; to the


1675. ' right of the stock and in a fixed
' position is an iron section H of
’ . that part of the stock into which
the lock is bedded, which iron sec-
/ , \ tion is used as a guide or former.
The machine being started, the
first operation is to drill two holes,
A the drills entering until a stop
, , prevents them from going any
further, and hence insuring uni-
B formity and correctness in their
depth. The position of these holes
0 J is regulated by a pin, which stands
D the same distance from the drill
as is the centre of the recess in
the iron former from the required
centre of the recess for the lock
0 A ¢ 1 a 0 ° in the stock being operated upon.
a J The pin reaches the iron former
, a little in advance of the drill
/ reaching the rifle-stock, so that
the position can be accurately set
by swinging the machine-head
until the guide-pin enters the hole
in the iron former; then the drill
is fed to its duty by hand. One
hole being drilled, the spindles
carrying the drill and the guide-








\ pin, which spindles are in the same
~\\:~ frame and operate together, are
raised, the machine-head is swung
l, ~ one-fifth of a revolution, and the
EQ first cutter 1) comes in position
to operate. On lowering the cut-
ter-spindle there descends with
it, and slightly in advance of it, a guide-pin E in the iron former; and when the guide-pin is well
within the iron former, the cutter reaches the surface of the wood, and is guided by the oper-
ator moving the head so that the guide-pin travels all around the edge of the recess in the
former. The motion of the guide-pin and of the cutter being laterally identical, the operator has
but to enter the cutter as far into the rifle-stock as a stop provided for the purpose will admit,
and then to move the frame carrying the guide-pin and cutter so that the guide-pin moves and
touches all around the sides of the recess in the iron former. The recess in the rifle-stock will be
then the exact counterpart, in size, form, and depth, of that in the pattern. The whole operation
is but a repetition of the above, with the remaining cutters swung one after the other into position,
the one iron former answering to regulate the lateral movement of them all. A is the frame of the
machine; B, revolving cutter-head; I, a fan-blower; and J, the air-pipes leading therefrom. The
speed at which the cutters revolve is about 8,000 revolutions per minute. As soon as each drill or
cutter is swung out of position, it stops running, which prevents wear and tear. It is apparent that
grinding the revolving cutters (which cut on their sides as well as on the end faces) to rcsharpen them
reduces their diameter, and would, unless some provision were made for it, destroy the correctness
of the work. This provision exists in the machine by the following means: In the spindles for
driving the cutters there is a socket which will partly revolve, but which can be locked or retained in
any position. When a cutter is new, and is consequently of full size, it revolves centrally in the
socket: but after it has been reduced in size by resharpening, the socket is moved in its position in
the spindle by being partly revolved. This causes the cutter to be sufficiently eccentric to the spin-
dle to make up for its lack of correctness in diameter. As a guide in setting the amount of this
eccentricity, the spindle is marked into 10 divisions, each being denoted by a line which extends
down to the junction of the socket and the spindle end. Upon the socket there is also marked a line,
so that this one line acts as a pointer and the other 10 as a rule. To cut out a recess, complete and
ready to receive a lock, occupies about a minute. This machine affords a superior specimen of de-
signing, performing many and very accurate operations with great exactitude, and being very sin. ple
to operate.
The guard-bedding machine and the machine for bedding the stocks to receive the barrels operate
in substantially similar manner to the lock-bedder, and therefore need no separate description.
Numerous other machines are employed, notably milling-machines for various purposes, boring appa-
ratus, screw-threaders, hammers, etc., all of which are adaptations of standard forms of these de-
vices. For descriptions the reader is referred to the work previously quoted. The various portions
of the weapon are finally assembled, when it is subjected to proofs and inspection.
736 FIRE—ARMS, MANUFACTURE OF.

THE MANUFACTURE or SMOOTH-BORES.—Every best finished gun usually passes through 15 or 16
hands, each of which constitutes almost a distinct trade ; although two or three branches are often
combined, or subdivided according to the extent of business. They may be arranged in the following
order: 1, barrel forger; 2, look and furniture forger ; 3, barrel borer and filer; 4, look filer; 5, furni-
ture filer; 6, ribber and breecher; 7, stocker; S, screwer-together; 9, detonator; 10, stripper and
finisher; 11, lock finisher; 12, polisher and hardener; 13, engraver; 14, browner; 15, stock polish-
er. The barrel-making is also divided into several branches.
The first process in the manufacture of musket or common barrels is the making what are techni-
cally called skcllos. The skelp is a piece of iron about a foot long, but thicker and broader at one
end than at the other; and the barrel of a musket is formed by forging out such pieces to the proper
dimensions, and then folding or bending them round into a cylindrical form until the edges overlap,
so that they can be welded together. It is then placed in a furnace, raised to a welding heat, and
taken out, when, a triblet or cylinder of iron being placed in it, it is passed quickly through a pair of
rollers. The effect of this is that the welding is-performed at a single heating, and the remainder
of the elongation necessary for bringing it to the length of a musket-barrel is performed in a similar
manner, but at a lower temperature. This method of welding is far less injurious to the texture of
the iron, which is now exposed only once, instead of three or four times, to the welding heat.
The barrels for fowling-pieces are of various kinds, as stub, stub-twist, wire-twist, and Damascus-
twz'st, and sometimes a combination of the two latter ones, as well as another description called
stub Damascus. These are the best varieties, but a number of inferior kinds are made, which are
only employed for very common guns.
In order to make stub-iron, old horse-shoe nails, called stubs, are collected, then packed closely
together, and bound with an iron hoop, so as to form a ball about 10 or 12 inches in circumference;
which, being put into a furnace or forge-fire, and raised to a welding heat, is united by hammering,
and drawn out into bars of convenient lengths, for the purposes intended. This method is adopted
for the locks, furniture, and breechings of all best guns, and is to a certain extent practised for
barrels, though not so much as formerly, more expeditious methods being employed on a large scale.
The most approved modern method of converting them into gun-barrels (after carefully sorting
and picking them, to see that no cast-iron or impurities are mixed with them) is first to put about
half a hundred weight into a large cast~iron drum or cylinder, crossed internally with iron bars,
through the centre of which a shaft passes, which is connected by a strap with the steam-engine, and
the revolution of the drum actually polishes the nails by their friction against each other; they are
then sifted, by which every particle of dust is removed. The steel intended to be mixed with them
is clipped by means of large shears, worked by the engine, into small pieces, corresponding in
size to the stubs, and afterward cleansed by a similar process. About 40 lbs. are thrown on the
inclined hearth of an air-furnace, where they are paddled or mixed together with a long iron rod, and
withdrawn in a mass called a bloom, almost in a state of fusion, to be welded under a hammer of
3 tons weight, by which it is formed into a long square block; this, being put in at another door
of the same air-furnace, is raised to a bright-red heat, and drawn out under a tilt-hammer of 11}
ton weight into bars of a proper size to pass the rollers, by means of which it is reduced to
rods of the required size. The air-furnace having two doors prevents any loss of time, as the mo-
ment one ball of stubs is withdrawn, another charge is put in, and the two operations go on together,
keeping both hammers employed. The iron thus produced is very tough, and free from specks or
grays; but stubs are hardly ever used alone, as they were formerly, being too soft; therefore a por-
tion of steel is mixed with them, which varies from one-eighth to one-half of the whole mass. It
need hardly be remarked that the advantage to be derived from the use of horse-shoe nails does not
arise from any virtue in the horse’s hoof, as some have imagined, but simply because good iron is,
or ought to be, originally employed for the purpose, otherwise the nails will not drive into the hoof;
and the iron, being worked much more, is freed from its impurities, which can only be effected by
repeated workings.
When gun-barrels are manufactured from stub-iron by a process similar to that of musket-barrels,
they merely exhibit a mottled appearance on the application of acids. It is also usual to make what
are called stub barrels from scrap iron out into small pieces by means of shears worked by the en-
gine. It would be difficult to define what scrap iron is, or what it is not, being composed of every-
thing in iron that has previously been manufactured, as well as of the cuttings from the various
manufactories; these are sorted and employed in preparing iron of various qualities, known by the
names of wire twist, Damascus twist, stub twist, charcoal iron, thrccpcamg/ skelp iron, twopcnng/ skelp, etc.
The object of preparing iron from small pieces is to cross and interweave the fibres in every pos-
sible direction, and thus greatly to increase its tenacity. Very few plain stub barrels are now made,
as iron of inferior quality, when twisted, finds a more ready sale. For the finest description of bar-
rels, a certain proportion of scrap steel, such as broken coach-springs, is cut into pieces and mixed
with the iron by the operation called puddling, by which the steel loses a considerable portion of its
carbon, and becomes converted into mild steel, uniting readily with the iron, and greatly increasing
the variegation and beauty of the twist. In whatever manner the iron may be prepared, the opera-
tion of drawing it out into ribbons for twisting is the same. This is effected by passing the bars
while red-hot between rollers, until extended several yards in length, about half an inch wide, and
varying in thickness according to whichever part of the barrel it may be intended to form; these
ribbons are cut into convenient lengths, each being sufficient to form one-third of a barrel ; one of
these pieces is made red-hot and twisted into aspiral form, by placing one end in the prong of an iron
rod which passes through a frame, and is turned by a handle, the ribbon being prevented from going
round without twisting by means of an iron bar placed parallel to the revolving rod. The spiral thus
formed is raised to a welding heat, and dropped on to a cylindrical iron rod, which being struck forcibly
on the ground jumped), the edges of the spiral unite, and the welding is then completed by hammering
FIRE-ARMS, MANUFACTURE OF. 737

on the anvil: the other spirals are added according to the length of the barrel, and the forging is
finished by hammering regularly all over. The ends of each spiral should be turned up and united at
each junction of the spirals, to avoid the confusion in the twist occasioned by merely dropping one
spiral on another; but this is rarely done. Wiretwist, of any degree of fineness, may be obtained by
welding alternate laminae of iron and steel, or iron of two qualities, together; the compound bar thus
formed is drawn into ribbons, and twisted in the same manner as the preceding. The operation of
twisting the iron not only increases the beauty of the barrel, but adds considerably to its strength by
opposing the longitudinal direction of the fibres to the expansion that takes place in the act of firing.
The iron called Damascus, from its resemblance to the celebrated Oriental barrels and sword-blades, is
now manufactured by welding 25 bars of iron and mild steel alternately, each about 2 feet long, 2 inches
wide, and a quarter of an inch thick; and having drawn the whole mass into a long bar, or red, three-
eighths of an inch square, it is then cut into proper lengths of from 5 to 6 feet; one of these,
being made red-hot, is held firmly in a vise, or in a square hole, to prevent it from turning, while the
other end is twisted by a brace, or by machinery, taking care that the turns are regular, and holding
those parts which turn'closer than others with a pair of tongs; the rod is by this means shortened
to half its original length, and made quite round. If only two pieces are employed to form the ribbon,
one is turned to the right and the other to the left; these, being laid parallel to each other, are united
by welding, and then flattened ; but if three square rods are used, the centre one is turned in a con-
trary direction to the outside ones, and this produces the handsomest figure. By these operations the
alternations of iron and steel change places at every half revolution of the square rod composed
of 25 laminae; the external layers winding round the interior ones, thus forming, when flattened
into a ribbon, irregular concentric ovals or circles. The fineness of the Damascus depends on the
number and thickness of the alternations; and the figure of the ribbon when brought out by acids
resembles that of a curled ostrich feather; but when wound into a spiral form, and united on its
edges by jumping, the edges bend round and the figure is completed. This is sometimes veneered on
common iron; and they often wind a thin ribbon of Damascus, or superior iron, round iron of the
worst quality; even gas-tubing is considered good enough, when coated in this manner, to form gun-
barrels of a very low price with a high-priced appearance. Stub Damascus is merely one square rod
of Damascus iron twisted and flattened into the ribbon for forming the barrel. Damascus and wire-
twist is a ribbon of each, twisted together to make a greater variety; but there is no quality so good
as the best regular stub-twist. The Swedish iron, known by the mark C C N D, and coach-springs,
form an excellent combination for Damascus barrels.
The next operation is rough boring, usually by machinery. A long square bit, attached to a rod,
revolves with great rapidity, while the barrel is pressed forward by a crooked lever, one end of
which the workman holds, and passes the other end along a series of nails or pegs, driven into the
top edge of the trough or bench on which the barrel is placed, thus forcing the barrel forward along
the boring-bit. Water is kept constantly flowing over the barrel during the process, otherwise the
heat generated by the friction would soon soften the bit and render it useless. The outsides are
then ground on very broad stones turned by the engine. The workman sits on a kind of wooden
horse, firmly chained to the floor; a sloping board, nearly in contact with the grindstone, is placed
before him, against which he leans, and rests the barrel; a long iron rod passes through the barrel,
and projects at each end, sufficiently to form handles, and at the same time an axis, on which the
barrel rotates more or less freely, according to the degree of pressure against the board. By moving
it regularly sideways, the whole surface is ground ever. It is evidently impossible to finish barrels
with any great accuracy on a grindstone, though most of the barrels that are made into guns in Bir-
mingham are merely smoothed up after this process, an appearance of regularity being given to
them at the muzzle by filing; but if transverse sections were made at different distances, they would
be found very unequal in substance, as is always the case with musket and other common barrels,
although some of the grinders are able to finish with considerable accuracy. It is in the groimd and
rough-bored state that most of the best barrels are sent to the finishing gunsmith, where, after being
set perfectly straight, they are fixed on a movable carriage, which is drawn gradually forward along
a level surface or railway, by means of a weight and pulleys; the boring-bit being fixed in a square
hole in the axis of a fly-wheel which is turned by hand or by steam machinery, while the barrel slowly
advances until the bit passes out at the opposite end to that at which it entered. The same square
bit is made to enlarge the bore to the required size by the addition of a spill, which is simply a long
thin piece of wood slightly taper, flat on one side and round on the other; this, being placed along
one side of the bit, causes it to cut on two angles only, and the size of the calibre may be very grad-
ually increased by the interposition of strips of writing-paper between the spill and the bit. After
the barrel is correctly bored, the external part is turned in a lathe, a steel mandrel being intro-
duced at each end. The barrel is thus rendered perfectly correct and equal in every part. The
barrel, being tapped, that is, screwed at the breech end, and the plug fitted, is‘ now proved with a
charge of powder proportioned t0 the weight of a leaden ball that fits the bore; this is always five
or six times the ordinary load; beside which, it is forced with water, as minute defects, invisible
to the eye and not affected by the proving, are thus easily detected. When false-breeclzed, ribbed,
stocked, and sm-eu'cd together, the barrel is bored for shooting, and smoothed outside. Double barrels
have a flat struck along the inner side of each, previous to laying them together; about 4 inches of
the breech end is brazed or hard-soldered, and the remainder of the length soft-soldered ; the upper
and under ribs being soldered on at the same time.
The progressive stages of best gun-making may be briefly enumerated in the following order, sup-
posing the lock and barrel to be already made: The lock and barrel, being jointed to each other (if
the plan require it), are given to the stocker, who lets them into the wood, which ought to have been
previously cut out of the plank at least two or three years, in order to 'be perfectly seasoned. The
next workman is the screwer-together, who lets in all the furniture and puts in all the screws ; when
47
7 38 FIRE—E XTIN GUISHERS.

this is done, the gun is detonated by another workman, who fits the cock, and finishes the external
part of the breeching. The barrel then goes to the barrel-maker to smooth and bore for shooting,
and the gun is returned to the screwer-together. From him it passes to the stripper and finisher, who
takes the whole to pieces and corrects any trifling errors of preceding workmen. The barrel is en-
graved and browned—an operation performed by producing successive coatings of rust on the surface,
and brushing them off as they arise with a fine steel-wire scratch-brush, until the required color is
obtained, which usually takes a week, and is cifected by a solution of metallic salts, combined with
nitric ether; during this process the lock and furniture are polished, engraved, blued, and hardened,
and the stock is oiled and polished. The hardening is performed by stratifying the various parts in
an iron pan with animal charcoal, prepared from b0ne~ and ivory-dust, or old shoes; the whole is
then exposed to a full red heat for about an hour, or according to the size of the work; the pan is
withdrawn from the fire, and the contents are thrown into water. The surface of the iron becomes
converted into steel by the absorption of the carbon, and beautiful colors are produced, the variega-
tion of the color being affected by the quantity of the iron. The finisher then completes the gun.
FIRE-ENGINES. See ENGINES, FIRE.
FIRE-EXTINGUISHERS. Nearly all modern special apparatus for the extinguishment of fire is
based on the use of carbonic-acid gas. This gas is heavier than air, and when projected upon the
flames it cuts off the supply of oxygen
which supports combustion. Five per cent. 1676, 1677,
of the gas in the ordinary atmosphere is
sufficient to check fire.
Portable fire-extinguishers differ only in
the mechanical construction whereby the
chemicals which generate the carbonic-acid
gas are brought together.
The Champion Fire-Extinguisher is rep-
resented in Fig. 1676. The mouth of the
acid-jar is above the water-line. The lead
stopper is held by its own weight in the
mouth of the glass acid-jar. It is plain
that, by simply inverting the machine, the
stopper will fall out of the mouth of the
acid-jar and allow the acid and alkaline
water to come together at the base below
the faucet, instantly producing a force of
100 lbs. to the square inch. The power
thus obtained, it is claimed, will throw a
stream fully 50 feet.
The Babcock apparatus, illustrated in
Fig. 1677, contains sulphuric acid in a glass bottle placed in a support, as shown. The alkali is dis-
solved in water, which fills the extinguisher to within 3 inches of the top. The bottle, after being









1678.






filled with acid, is held by the screw-cap which comes down over its neck. ‘ In case of fire, the handle
is screwed up. The bottle, no longer held in upright position by the cap, at once turns over, so that
FIRE-EXTINGUISHERS. 739

the acid is discharged into the carbonated water.- Instantaneous chemical action takes place, sup-
plying about 90 lbs. pressure to the square inch to throw the mingled stream of water and gas.
The arrangement of two large extinguishers of this type, so as to form a chemical fire-engine, is
illustrated in Fig. 1678. One cylinder is recharged while the other is working. At a test of one of
these engines before the Fire Commissioners of New York, 300 feet of hose was led from it over
1679.




the roof of an engine-house, and thence to the top of a bell-tower 100 feet high; the pressure was
turned on at the engine, and a stream was thrown through the 300 feet of hose, from the top of the
bell-tower, over the adjoining buildings into the street. It is well known that the most powerful
steamer throws a comparatively feeble stream when the hose is led to the top of a lofty building.
\ This is owing partly to the friction in the hose, the weight of water, and, most of all, the fact that
all the propelling force is behind the water at the steamer. In the chemical engine it is claimed that
any pressure can be obtained, and the propelling force goes out with the stream, thus always giving
nearly the same pressure at the nozzle, which pressure can be regulated by merely turning a valve.
One of the most successful applications of carbonic-acid gas to the extiriguishment of fires on
shipboard, or among shipping in a barber, has been devised by Mr. A. M. Granger of New Orleans.
The general principle on which the apparatus, Fig. 1679, is based, is the direct use of the dry gaseous
carbonic acid in smothering volume, in eontradistinction to the ordinary employment of limited
quantities of the gas dissolved in water under pressure. The generators A are copper cylinders,
capable of withstanding some 300 lbs. pressure, lined with tin to resist the acid, and suspended by
straps under the deck-beams. These vary in number, according to the requirements of the size of
the ship, and preferably are about 26 inches in diameter by 9 feet in length, so that each holds about
448 lbs. bicarbonate of soda mixed with water to a paste. Domes B extend upward from the gen-
erators to a height of 36 inches, and through these the chemicals are admitted. In each generator
(as shown by the broken-away portion of one) is a horizontal shaft on which agitating vanes are
spirally disposed. When these shafts are rotated, by means of the bevel-gearing O and cranks
740 F1 RE—E XTI N GUISHERS.

D, a slowly moving current of acid is carried through the soda, and thorough mixing insured.
Opening outboard is a water-supply pipe E, which communicates with two branch pipes, F and G,
respectively above and below the generators. The pipe F serves to conduct water to the latter.
The pipe G may be used as a waste-pipe, as it leads outboard on the other side of the vessel; or
when the valve H is opened, and the valve I closed, it conducts water from E into the cylinders
from below, to break up the caked residuum before discharging the same overboard. The acid
reservoir J is firmly secured on the bottom of the vessel. It is thus situated apart from the other
machinery, so that the corrosive action thereon of its contents is avoided; while, if it should leak,
no harm would be done, as the acid would simply run into the bilge. The cylinder, which has a capa-
city of 213 gallons, is made of quarter-inch lead reinforced by an iron shell, which, while strongly
backing and holding the weaker metal, may be easily removed when the inner case needs repairs.
The reservoir is charged from the deck above through the pipe K. The vessels L are intermediate
and distributing receptacles, to hold the acid in small amounts until needed, and also to apportion
the charges to the respective generators. They are of copper, load-lined; they possess gauges for
showing the level of their contents, and are directly connected with the domes B by pipes III. To
fill these vessels, a pipe is provided which extends into and near the bottom of the acid reservoir.
From this, branch pipes lead to the separate chargers. An air-pump, N, the lever of which is shown
in the hands of the figure, forces air by a small pipe into the acid cylinder ; and the pressure gen-
erated drives the acid up through the conduits and into the chargers L, in quantities as desired.
Valves are provided, so that one or all of the chargers may be filled. The alkali generators have
like valves in the water-pipes, so that water may be admitted to as many as needed.
The carbonic-acid gas may itself be used for forcing up the acid by causing the pressure generated
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in a portion of the apparatus to act so as to drive thcliquid up into the other parts This is done
by a simple adjustment of valves and connections which need not here be explained. Steam may
also be conducted to the acid reservoir to serve the same purpose. A water-trap, O, is provided in
the air-pump pipe, which prevents the acid fumes from injuriously affecting the Working parts of the
pump. The pipes P, connecting the domes with the charges, serve to equalize the pressure between
FIRE—EXTINGUISHERQ. 741

the two, and to permit the free passage of the acid down 'to the generator, when the chemicals are to
be mixed, by preventing a vacuum above the acid. Each dome, by means of a horizontal distribut'
ing pipe Q, with suitable vertical branches, communicates with the gas holder or purifier R, into
which the generated gas is thus conducted. The purifier is a cylindrical vessel, which is imperforate
at the points where the entering gas strikes it in issuing from the branch pipes ; and between these
pipes it is perforated to admit the passage of the gas. The object of this partition is to eliminate
the solid and liquid particles which are mechanically carried up in the form of spray, by causing
them to impinge against the imperforate portion of the diaphragms. The gas then passes to the
hose 8.
In order to remove the collected impurities from the purifier, a pipe, with suitable valve, leads
from the bottom thereof to the discharge-pipe G. In this way, water may be led in from the main
supply E, and also discharged through the same pipe. The latter also serves as a drain for any of
the liquid contents of the generator which might surge up into the holder; and thus it operates as
an equalizer to restore the said liquid to the generators. In order to introduce the gas into the
burning vessel, without causing it to entrain air with it, the nozzle T has a tapered screw-threaded
swiveling sleeve, which is‘ provided
with handles, and which may be
screwed into a hole of any size bored
in the deck. An attendant at the
nozzle is thus dispensed with, and the
latter is firmly held air-tight. An ex-
tra pipe is connected to the distribut-
ing pipe, and leads into the open air
so as to prevent the escape of the
gas into the room through the safeu. -
valves. There is a separate safety-
valve on each dome, and also one on
the purifier, which is arranged to blow
off into the atmosphere at a lower
pressure than those on the domes, in
order to insure that no gas shall es-
cape between decks. Pressure-gauges
are also arranged on each generator,
and one is provided to indicate the
pressure applied upon the acid in the
reservoir.
An English inventor, Captain W.
H. Thoinpson, has succeeded in per-
fccting a device, illustrated in Fig.
1680, that has secured the indorse-
ment of the directors of the “White
Star Line ” of steamers, upon two of
which the apparatus has been fitted.
At a point, A, on the upper-deck mid-
ships, a series of four iron pipes pro-
jeet, and are, when not in use, closed
by screw-caps. The pipes terminate
‘ below respectively in the main-deck,
\ q f f\f f ’tween-deck, hold, and coal-bunkers.
To the right of this line of projecting
% % ® ® ® ® ® ® pipes is a second single one leading
I I from the boilers below, and half-way
between this steam-pipe and the other
four is a large box, in which carbonic-
' u 1 'q__ acid gas can be generated by some one
'i' WM" of the usual methods. The reagents
' “‘l Pi needed to generate the gas are then
brought together in the box, and con-
, nection between it and the nozzle of
i y the pipe leading to the bunkers is es-
‘ , ‘ tablished, as here shown. \Vhen all
‘ 1 is in readiness, the steam-valve is
l










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i opened, and at once a blast of steam
/ Ff”: enters the box, where it combines with
" r H " the carbonic acid, and these two pow-
_F/'T i g crful agents rush on_ and downward
_, egg?» L] ~‘>~:- together. The carbonic acid, aided by
'/ \JW the energy imparted to it by the steam,
soon finds its way to the seat of the
‘ conflagration, and, replacing the air
that favored the combustion, acts as a wet blanket, smothering and finally extinguishing the flames.
In order that the distribution of the steam'and gas may be as general and positive as possible, the
conducting-pipes, on entering their special precinct, are perforated along their sides, the steam emerg-

742 I FIRE-EXTINGUISHERS.

ing from these holes in the manner indicated in the illustration. It will be seen from the
method of its construction that this apparatus is so contrived that either gas or steam may be used
alone.
Hall’s Sysfem of Fire-Extinguishing Apparatus is adapted to carrying a supply of water to all
portions of a factory by means of pipes, through perforations in which it is discharged at any desired
point. The receiver (Fig. 1681) is placed in the counting-room, or any other suitable place where
the valves can be got at readily. The large pipe entering the bottom of the receiver is used where
there is a natural head of water. The hose at the left is connected with a hose from a force-pump
or steam fire-engine. The pipes at the top are mains leading to each room in the building—each
numbered to correspond to the number of the room to which it leads—and cut off from the receiver
by valves. The mains are water-tight until they enter the rooms, where the perforated pipes or
“sprinklers ” begin. The latter cross the rooms at intervals of 8 or 10 ft. If, for example, a fire
occurs in any room—say, room N o. 3—the valve of No. 3 leading-pipe is turned, and in an instant a
fine rain-shower of spray fills that room. As soon as the fire is extinguished, the valve, upon being
turned back, will immediately stop the supply of water; and as soon as the pressure is turned from
the receiver, the valve is again opened, and the water remaining in the pipes escapes from a waste-
cock at the bottom. '
Fire-Resisting Construction—The idea of making a building fire-proof has been practically aban-
doned in the United States, and the rule is now to build slow-burning structures instead. For this
purpose wood is found more suitable than iron. The most important application of slow-burning
construction is to the building of mills and other industrial establishments. This subject has been
elaborately discussed in special circular N o. 33 of the Boston Manufacturers’ Mutual Fire-Insurance,
Company, from which the following valuable tables and information are taken: -
Floors should be carried on square wooden columns connected by wooden beams about 8ft. apart,
and of a strength sufficient to support the load. The floor should be of 3-in. planks, above which
should be laid two thicknesses of asbestos-paper, covered by li-in. planking, which takes all the wear
and protects the paper from abrasion. Such a floor will weigh from 16 lbs. to 17% lbs. per sq. ft.
To facilitate the calculation of such floors, Table I. gives safe loads for beams of Southern pine 1 in.
wide. This wood has a modulus of rupture of 2,160 lbs., and weighs about 48 lbs. per cub. ft. The
table is calculated with a factor of safety of six. In many cases the above table, though giving a
floor of sufficient strength, would not insure the stiffness necessary where the floor carries delicate or
high-speed machinery. For use in such cases Table II. is given, which has been calculated so that the
average curvature of the beam under the load is that of a circle of 1,250 radius, the modulus of elas-
ticity of the beam being taken as 2,000,000 lb. per sq. in. It is usually found desirable to employ com-
pound beams for supporting the floor, as in this way the soundness of the timber is assured, and by
keeping the components apart by distance pieces, good ventilation of the beam is assured; and the
risk of dry-rot avoided. The columns should be square, and not round, as experiments at the Water- I
town Arsenal show that beams of the dimensions usually employed in mill practice fail by crushing
and not by crippling. They will therefore carry safely a load of 600 lbs. per sq. in. ; and as a square
column has a greater area than a round one of the same diameter, and takes up no more floor-space,
it is advisable to use this shape, the more especially as it can be obtained with greater facility. It has
been found advantageous to pierce the column with a %-in. hole down its centre, as a precaution against
dry-rot.
TABLE I.-—-Safe Distributed Loads upon Southern Pine Beams 1 in. in l/Vz'dth.
(If the load is.concentrated at the centre of the span, the beams will sustain half the amount as given in the table.)





DEPTH OF BEAM 1N INCHES.
SPAN, ,.
FtET. 2 I 3 I 4 I 5 I 9 I 7 I 3 I 9 I 19 I 11 I 12 I 13 I 14 I 15 I 19
LOAD IN POUNDS PER FOOT OF SPAN.
5 ...... .. 33 39 154 249 349 479 914 773 999
11 ...... .. 27 99 197 197 249 327 427 549 997 397
7 ...... .. 29 44 73 122 179 249 314 397 499 593 795 323
3 ...... .. 15 31 99 94 135 134 249 394 375 454 549 934 735
9 ..... .. .. 27 47 74 197 115 199 249 299 359 427 591 531 997 759
19 ...... .. .. 22 33 99 39 113 154 194 249 299 349 499 479 549 914
11 . . . . . .. .. .. 32 59 71 97 127 191 193 249 239 335 339 449 593
12 ...... .. .. .. 2 42 99 32 197 135 197 292 249 232 327 375 474
13 ...... .. .. .. .. 39 51 79 99 115 142 172 295 249 273 329 394
14 ...... .. 31 44 99 73 99 124 143 179 297 249 279 314
15 ...... .. 27 33 52 93 39 197 129 154 139 299 249 273
19 ..... .. 34 49 99 79 94 113 135 153 134 211 249
17 ...... .. 39 41 5. 97 33 191 129 149 193 137 217
13 ...... .. .9 47 99 74 99 197 125 145 197 199
19 ...... .. 43 7 99 39 99 112 139 159 1.9
29 ...... .. 33 49 99 71 39 191 113 131 154
21 ...... .. 44 54 99 7s 92 197 122 139
2. ...... .. 59 99 71 34 97 112 127
21 ...... .. 45 55 95 77 39 192 119
24 ...... .. 59 99 79 32 94 197
25 ...... .. 49 55 95 75 39 93

















Whenever and wherever solid beams or heavy timbers are made use of in the construction of a
factory or warehouse, they should not be painted, varnished, oiled, filed, or encased in an impervwus
concrete or air-proof plastering or metal for at least three years, as a security against dry-rot.
FIRE-EXTINGUISHERS. 743





1
TABLE 11.—Distributed Loads upon Southern Pine Beams szgfiezent to produce Standard Limzt of
‘ Deflectwn.
DEPTH OF BEAM LN INCHEB.
Deflec-
2.2g,2I3I4I5I9I7I3I9I19I11I12I13I14I15I19“on,
Q inches
LOAD IN POUNDS PER FOOT OF SPAN.
8 10 23 44 77 122 182 259 .0300
2 7 16 81 53 85 126 180 247 .0432
.. 5 12 23 39 62 93 132 181 241 .0588
8. . . . . . . 4 9 17 30 48 71 101 139 185 240 305 . . . . . . . . . .0768
.. .. 7 14 24 38 56 80 110 146 190 241 301 .. .0972
10. .. .. 6 11 19 30 46 65 89 118 154 195 244 300 .. . .1200 ,
11. . .. .. .. 9 16 25 38 54 73 98 127 161 202 248 301 .1452 i
12. . . . . 18 21 32 45 62 82 107 136 169 208 253 1728
18. . . . . 11 18 27 38 53 70 91 116 144 178 215 2028
14. . . . . 16 33 45 60 7 100 124 153 186 2352
15. . . . . 14 20 29 40 53 68 87 108 133 162 2700
16. . . . . . 18 25 35 46 60 76 95 117 147 3072
17. . . . . . 16 22 31 41 53 68 84 104 126 3468
18. . . . . 20 27 37 47 60 75 93 112 3888
19. . . . . . 18 25 33 43 54 68 83 101 4332
20. . . . . . 22 30 88 49 61 75 91 4800
21. . . . . 20 27 35 44 55 5292
22. . . . . 24 32 40 50 62 75 5808
23..... .. .. .. .. .. .. .. .. .. 22 .29 37 46 57 69 .6348
24..... .. .. .. .. .. .. .. .. .. .. 27 34 42 52 68 .6912
25..... .. .. .. .. .. .. .. .. .. .. 25 31 39 48 5S 7500



















I -
In designing a floor, it is important to know the probable load to which it will be subjected. This
information is difficult to get at, but is given in the valuable Tables III., IV ., and V., which are an~
nexed, of the weights of merchandise and cotton machinery:
TABLE III.— Weights of Merchandise.










.unasunnnssrs. wnrcnrs.
MATERIAL. Per Per
Floor-Spaw' cab": Feet" Gm' Square Feet. Cubic Feet.
Wool.
Bale, East India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 12 .0 840 113 28
“ Australia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5.8 26 0 885 66 15
“ South America . . . . . . . . . . . . . . . . . . . . . . . . . . 7 .0 34.0 1.000 143 29
“ Oregon . . . . . . . . . . . . . . . . .~ . . . . . . . . . . . . . .. 6.9 33.0 2. 70 15
“ California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 .5 38.0 550 73 17
Bag wool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5.0 30 .0 200 40 7
Stack ofscoured wool . . . . . . . . . . . . . . . . . . . . . . .. . 5
Woollen Goods.
Case fiannels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 12 7 220 40 17
“ “ heavy . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1 15 2 830 46 .3
“' dress goods . . . . . . . . . . . . . . . . . . . . . . . . . .. 5.5 22 O 460 84 21
“ cassimeres . . . . . . . . . . . . . . . .' . . . . . . . . . . . . .. 10.5 28 0 550 '2 20
“ underwear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 .3 21 0 350 48 16
“ blankets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10.3 85 0 450 44 _ 13
“ horse-blankets . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1) 14.0 250 5‘3 18
Cotton, etc.
Bale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8.1 44.2 515 64 12
" compressed . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4.1 21.6 550 134 25
“ Dederick compressed . . . . . . . . . . . . . . . . . . . .. 1.25 8.13 125 100 40
“ jute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2.4 9.9 300 123 80
“ “ lashings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 10.5 450 172 4‘3
“ manila . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 10.0 280 88 26
“ hemp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8. 7 84.7 700 I 81 20
“ sisal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5.8 17 .0 400 75 24
Cotton Goods.
Bale unbleached jeans . . . . . . . . . . . . . . . . . . . . . . . .. 4.0 12.5 80) 7°. 24
Piece duck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .1 2 .8 75 68 b3
Bale brown sheetings . . . . . . . . . . . . . . . . . . . . . . .. 3.6 10. 1 235 65 2‘)
Case bleached sheetings . . . . . . . . . . . . . . . . . . . . . . . 4.8 11.4 831) 60 8.1
" quilts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2 19.0 295 \ 41 16
Bale print-cloth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 9 .3 175 44 10
Case prints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4.5 13.4 420 93 31
Bale tickings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8 8 8.8 825 99 87
Skeinscottonyarn . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
Burlaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .... . .. 180 . . .. 80
Jute bagging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 .l 5 8 100 70 i
Rugs in Bales.
White linen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8.5 89 5 910 107 ‘73
“ cotton . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 40.0 v 715 78 18
Brown cotton... . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7.6 30.0 442 59 15
Paper shavings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 .5 84.0 507 68 15
Seeking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16.0 65.0 450 ‘28 7
Woollen .......... ... ...................... .. 7 5 39.9 999 39 29 I
Jute butts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8 11.0 400 143 36 1
744. FIRE-EXTINGUISHERS.

TABLE III. (continued).




















mnesunnmnn'rs. ' WEIGHTS.
MATERIAL. Per Per
Moor-Space. Cubic Feet. Gross. Square Feet cubic Feet.
Paper.
Calenderedbook . . . . . . . . . . . . . . . . . . . . . . . . . . .. 50
Super-calendered book . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . .. .. 69
Newspaper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38
Strawboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33
Leatherboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 59
Writing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. M 64
Wrapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10
Manila . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 37
Grain.
Wheat in bags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4.2 4 2 165 39 39
“ bull; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 44
“ " . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39
“ “ mean . . . . . . . . . . . . . . . . . . . . . . .. . 41
Barrels flour on side . . . . . . . . . . . . . . . . . . . . . . . .‘ .. 4 .1 5.4 218 53 40
“ " on end . . . . . . ... . . . . . . . . . . . . . . . . .. 3 1 7.1 218 70 31
Corn in bags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3.6 3.6 112 31 31
Corn-meal in barrels . . . . . . . . . . . . . . . . . . . . . . . . .. 3.7 5.9 218 59 37
Oats in bags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3.3 8 6 96 29 27
Bale of hay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0 20 .0 284 57 14
Hay, Dederick compressed . . . . . . . . . . . . . . . . . . . 1.75 5.25 125 72 24
3 Straw “ “ . . . . . . . . . . . . . . . . . . . . 1 .75 5 25 100 57 19
3 Tow “ “ . . . . . . . . . . . . . . . . . . . 1 .75 5.25 150 86 29
g Excelsior, Dederick compressed . . . . . . . . . . . . . . 1 .75 5.25 100 57 19
I Dye-Stuflls, etc.
1 IIogshead bleaching powder . . . . . . . . . . . . . . . . . .. 11.8 39.2 1 200 102 31
' “ soda ash . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10 8 29 .2 1,800 167 62
Box indigc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 0 9 .0 385 128 43
“ cutch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 3.3 150 38 45
“ sumac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .6 4.1 160 100 39
(‘austic soda in iron drum . . . . . . . . . . . . . . . . . . . .. 4.3 6.8 600 140 88
Barrel starch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 . 0 10 .5 250 23 23
“ pearl alum...... . . . . . . . . . . . . . . . . . . . . . .. 3.0 10.5 350 117‘ 33
Box extract logwood . . . . . . . . . . . . . . . . . . . . . . . .. 1.06 0.8 55 52 70
Barrel lime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 .6 4.5 225 63 50
“ cement, American. . . . . . . . . . . . . . . . . . . 3.8 5 .5 325 86 59
“ "' English . . . . . . . . . . . . . . . . . . . . . . .. 3 .8 5.5 400 105 73
“ plaster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 7 6.1 325 88 53
“ resin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3.0 9 .0 430 143 48
“ lard-oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 12 .3 422 98 34
1 Rope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . .. . 42
1 Miscellaneous.
Box tin . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . .. 2 7 0.5 139 99 278
“ glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 60
Grate crockery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 .9 39 .6 1,600 162 40
(Yask “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.4 42 5 60 . 52 14
Bale leather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 12.2 190 26 16
“ goat-skins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 16.7 300 27 1S
“ raw-hides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 30.0 400 67 13
“ “ compressed . . . . . . . . . . . . . . . . . . . . 6 .0 30.0 700 117 23
“ sole leather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.6 8.9 200 22 16
File “ . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4 17
Barrel granulated sugar . . . . . . . . . . . . . . . . . . . . .. 3.0 7.5 317 106 42
“ brown sugar . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 7 .5 340 113 45
Cheese.’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 30
TABLE IV.— Cotton Mill of 32,000 Spindles—N0. 24 Y aa'n.
, Each Total Stock in Shafting, Opera- Total Load Area of Load upon
MACHILERY' Machine. Machines. Process. etc. tives. upon Floor. Floor Floor.
Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Sq. ft. Per sq. ft.
6 lappers . . . . . . . . . . . . . . . . . . . . . . . . 12,000 72.000 280 3.000 800 76,080 in separate building.
240 36-in. cards . . . . . . . . . . . . . . . . . . 1,600 384.000 4,800 11,920 275 400,995
2 double-rs . . . . . . . . . . . . . . . . . . . . . . . 980 1,960 40 1,100 . . . . .. 3,100 17,856 23.24
12 railway heads . . . . . . . . . . . . . . . . .. 800 9,600 . . . . . . 1,100 130 10,880 -
21 drawing “ . . . . . . . . . . . . . . . . . . 2,000 42,000 300 1,250 180 44,280 2.160 20.50
36 roving-frames . . . . . . . . . . . . . . . .. 9,000 324,000 2,000 14,500 4.300 344,800 10.944 31.50
90 spinning-frames, 176 spindles. . 4,000 360,000 15,340 125,000 1,820 ‘ 502,160 16,128 31‘. 14
24 mules, 672 spindles . . . . . . . . . . .. 10.000 240,000 16,000 24,000 2,800 282.800 22,500 12.56
8 spoolers * . . . . . . . . . . . . . . . . . . . . 2,600 20,800 890 I 5,000 825 27.515 1,728 15.92
6 warpers * . . . . . . . . . . . . . . . . . . . . . 450 2,700 2,760 410 500 6,370 1,152 5 .53
2 slashers* . . . . . . . . . . . . . . . . . . . . .. 10,000 20,000 5,400 2,200 480 28.080 1,080 26.00 .
8 drawing-in frames . . . . . . . . . . . .. 60 480 1,600 . . . . .. 1,000 3,080 192 16 04
800 looms . . . . . . . . . . . . . . . . . . . . . . . .. 800 640,000 128,000 140,000 16,000 924,000 39,672 23.29
. . . . . . 2.045,540 17 7,680 326,480 28,360 ‘ 2,578,060 113,412 20.57
Add for contingencies 20 per cent . . . . . . . . . . .. 515,615
3093,675 0.69







* In the part of the mill used for spooling, warping, and sizing, provision must be made for the greatest loads, due
to accumulation of warp yarn on beams.
FLY-WHEELS. 745

TABLE V.-— Warp-Yarn S 'nning-Mill, 50,000 Spindles (Ring? for No. 28 Yam. Card/Room fitted
with removing Top Flat Cards and English Card-Room Machinery.













Space, includ- . Weight .
MACHINES ing Alley and wag” Then of Stock Tim] Mm" weight
' S are Floor- 0 eflicb Wei bi. in each we'ght or 0f
p Machine. g of Stock. Hands. Hands.
Space. Machine.
Sq. a. Lbs.
80 cards, 41 in. wide . . . . . . . . . . . . . . . . . . . . . . . 8.393 6.000 480.000 20 1.600 12 1,920
180 deliveries drawing 6 into 1 . . . . . . . . . .. 3,270 . . . . . 90,720 . . . 6.300 14 2,240
10 slubbers, 52 spindles, 12 x 6 bobbin . . . . . . . . . . .. 7.056 70.560 340 3.40) 6 960
18 intermediate, 80 spindles. 10 x 5 bobbin.. 16,350 8,400 151,200 320 5.7 60 10 1,600
36 roving, 152 spindles, 7% x 3} bobbin . . . . . . . . . . .. 9,056 354,816 340 13,240 20 3,200
28,013 . . . . . 1,147,296 . . . 30,300 . . 9,920
Weight of machines . . . . . . . . . . . . . . . . . . . . . . . 1,147,296 lbs. Total area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28,013 sq. ft.
“ of stock in proce=s . . . . . . . . . . . . . . . . . 30.300 “ “ load . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 1,217,466 lbs.
“ of hands . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.920 “ Load per square foot . . . . . . . . . . . . . . . . . . . . . .. 43.46 “
Thirty trucks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.700 “
Stock in same . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,250 “
'I‘wo thousand cans . . . . . . . . . . . . . . . . . . . . . . . . 20,000 “
Grinders and furniture . . . . . . . . . . . . . . . . . . . 5,000 “
1,217,466 lbs. _
An important point in constructing floors is to reduce all openings through them as much as pos-
sible. In cotton-mills few openings are required; but in flour-mills it is necessary to have openings
through the floors for the grain and flour elevators, and hence with them there is much greater risk
of a serious fire, as it is not so easy to confine it to a single floor of the building. The openings for
men and goods between the various rooms of the mill should be closed with fire-proof doors, so as to
confine any fire to as small an area as possible.
These doors are best made of two thicknesses of matched boards not more than 4 in. wide, thor-
oughly seasoned, laid at right angles to each other, and nailed together with clinched nails. The
wood should be covered with tin, the plates being lock-jointed and nailed under the joints, bending
the sheets round the door, so that there are no seams at the edge. It is essential that all fixt-
ures should be secured to the door by carriage-bolts, and not by screws, as the latter may fail in case
of fire. The door should be 4 in. wider all round than the opening it closes. It is best hung on a
sloping rail, and is normally held open. Should, however, the neighboring temperature get too high,
a fusible fastening‘ gives way, releasing the door, which then slides down and closes the opening.
In a pamphlet on “Economical Fire-resisting Construction,” Mr. F. C. Moore, President of the
Continental Fire Insurance Co., of New York, states as follows: “It is a fallacy, to a large extent
believed in, that iron is the only material for so-called fire-proof construction, and that the only build-
ing capable of effectually resisting fire is one into the construction of which iron enters as the substi-
tute of wood, especially in floor-beams, girders, columns, etc. Admirable as such construction may be
when properly built, it should be remembered that iron, by reason of its tendency to expand in severe
heat, and by reason of its liability to bend and break in high temperatures, is a most dangerous mate-
rial unless protected from the effects of fire. Probably the best protection is that of covering the
metal with terra-cotta or hard-burned fire-clay. Columns may be protected by being enclosed with a
jacket of tile, or plaster on metallic lathing, leaving an air-space between, the outer surface being
finished for ornamental purposes by a coating of hard plaster. It is claimed that a double column
of iron, with an air-space between the two, the inner column being of sufficient carrying capacity to
safely bear the superimposed weight without reference to the outer shell, is a safe one. Unless iron
beams and columns are so protected they are not so safe as those of wood, provided the latter are
of sufficient thickness to safely bear the superimposed weight after say two inches of their diameter
has been reduced to charcoal by a fire. No ordinary fire is likely to consume an upright 12-in. wooden
post, since the charring of the surface actually tends to preserve the inner and untouched core. A
post of this kind removed from a building which had been on fire for hours, in London, some time
since, was actually subsequently subjected for hours to an intense fire by Chief Shaw, of the London
fire-brigade, and when taken from the test was found to still retain sufficient carrying capacity for
its original duty.” The post was of pitch-pine, about the most inflammable wood known, and yet,
after exposure for seven hours to the flame, it contained within not only an ample amount of unin-
jured wood, but the heat of the latter was so low as to be only just perceptibly warm to the touch.
For full description of new fire appliances see “ Modern Mechanism,” vol. iii. of this work.
Works for-Reference.—“ Fires: their Causes, Prevention, and Extinction,” by F. C. Moore. Mr.
C. J. H. Woodbury has written extensively and with great ability on this subject. See his “Fire
Protection of Mills and the Construction of Mill Floors ” ; also, “ Methods of reducing the Fire Loss,”
in Th'a'ns. Am. Soc. Mechanical Engineers, 1889; “Fire Hazards of Electricity,” Scientific American,
supplement, December, 1891; “Rules and Regulations for the Installation of Electric Lighting and
Motive Apparatus,” published by the Boston Manufacturers’ Mutual Insurance Co., 1890; “ (‘onflagra-
tions in Cities,” a lecture before the Franklin Institute of Philadelphia, 1891.
FLY—WHEELS. It has been shown, in discussing the action of the crank (see Cnnxx), that the
pressure on the crank-pin throughout the revolution is unevenly distributed. It results from this
that the speed of an engine will vary unless some means are provided to counteract the ill efiects
arising from the changing pressure. In the case of land engines,‘a fly-wheel is commonly attached,
which is simply a wheel with a heavy rim that absorbs energy at points where it is in excess of the
mean, and gives it out where the rotative efieet is below the mean. Referring to Fig. 1708, it will
be seen that there are portions of the curve without the mean line; and the fly-wheel should be
746 _ FORGE.

sufficiently heavy to absorb the greatest excess of power within the limits of a given variation of
speed. The object of other contrivances for the regulation of speed, such as governors and adjusta-
ble cut-offs, is to control the engine under sudden variations of load, so as to make it produce at all
times a crank diagram showing the same relative variation of power; but the principal office of the
fly-wheel is to supply the correction for this regular variation, although it is of course useful in the
case of irregular variation in the load. In order to
F\ design a flywheel for a given engine, the first step
\ is to lay off a crank diagram, similar to Fig. 1708,
W for the case when the engine is developing its max-
\l iinum power. The greatest excess of power is then
.__ to be determined by measuring the greatest excess
1708.
m\ _ , -T
l '
7
‘43" 13° 36° 51;- 7z° 96° 10 ° 6% 162, I80 /'8 36" 6‘4- 7£° S
L w 'W . ll \,
Forward. Return.
of area included by the curve 'without the mean line. If E : greatest area without mean
area + mean area, a : velocity in feet per second of a point in the centre of the rim of the fly-












0° /08 /
. . 1 . .
wheel, 12 = revolutions per minute, P: horse-power of the engine, and— = proposed variation
m x E x P x 1,062,600 '
21’ x n
suppose a fly-wheel is to be designed for an engine of 50 horse-power, making 100 revolutions per
minute; that the fly-wheel is to be 12 feet in diameter, and is to regulate the speed of the en-
gine within one-fiftieth. The diame-
ter measured from the centre of the 09
rim can be assumed at 11.7 feet, so 17 ' _,_.
,\
11.7 X 3.1416 X 100 /
that v I 60 : 613; '/—-F 4%
and if it is found, on laying off the ‘
crank diagram, that the greatest excess
of area is 0.25 of the mean area, the
proper weight for the fly-wheel will be
50 x 0.25 x 50 x 1,062,600
3757.69 X 100
lbs. The above formula can be readily
adapted to the determination of the
proper diameter for a fly-wheel of
given weight.
FOLDING MACHINE. See CLOTH-
FINISHING MACHINERY, BOOK-FOLDING
MACHINE, and PRINTING.
FORCE. See DYNAMICS.
FORGE. The term forge is com-
monly applied to a manufactory in
which iron or- steel is softened by heat
and worked under the hammer, or
works in which the native oxides of
iron are reduced without fusion to a
metallic state, and then forged into
blooms or bars. Forges differ from
foundries and blast furnaces in their
. _. §
products being aiticles of wrought-
iron, while those of the latter are cast-
ings. (See FORGING, FORGING MA-
cnmns, HAMMERS, and IRON-WORKING

in speed, the weight of the fly-wheel in pounds is To illustrate this rule,



= 1770








‘ws$\\ . x
g .









MACHINERY.) The term “forging” is ' '1
equally applicable to the working of §
other metals, as gold, silver, and cop-
per, when these are heated and hammered into the desired shape.
A common forge consists of the hearth or fireplace, which is merely a cavity in masonry or brick-
work well lined with fire-clay or brick, upon which the ignited fuel is placed, and upon the back or
FORGING. 747

side of which' a powerful blast of air is driven in through the nozzle of a double-blasted bellows,
which in a common forge is generally worked by a hand-lever. Forges are sometimes constructed
so as to be portable, when the bellows is most
conveniently placed under the hearth; these
are used in ships, and for various jobs on rail-
ways, etc.
Fig. 1709 represents a portable forge made
entirely of iron, and provided with a bellows
placed beneath the hearth and operated by a
treadle. In Patterson’s forge, the blast from a
bellows or blower is conducted into a lower
chamber, from which it is allowed to pass to
the fire by a tuyere, a valve being operated by
the handle in front of the support. Fig. 1710
represents the Keystone portable forge, in which
the blast is produced by a small fan-blower
driven by the hand-wheel shown. The Root
blower (see BLOWERS) has also been adapted to
blowing forge fires. Its arrangement in connec-
tion with a blacksmith’s forge is shown in Fig.
1711. It is claimed to equal a 36-inch to 50-ineh
bellows, according to size. The revolutions made
are from 10 to 30 per minute. Among the ad-
vantages of using blowers for forges are, that
the blast can be varied by the operator to suit
the case in hand, and can be instantly stopped
when no longer needed. This results in a saving of fuel and in economy of room; and it is also
claimed that the tuyeres require less cleaning, and that the fire can be more rapidly rekindled, than
with the ordinary bellows.


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ul lllllllllllll \h


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"Iilllllllllllllllllllllllllllltilliilhllllll l:
uuuuumummmlmmlmmura
innmmnmlllnmmmmmmmnmlllmil
1 Hillllllllll nmnmmmnmmma
l""“lllllltlllllfll
"H" unmmnnumu
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duties
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1 .
__—‘_‘. __
______-_
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‘L
FORGIN G. (See Axes, FORGE, Foucme MACHINES, HAMMERS, and Iaox-wonmxe MACHINERY.)
In forging iron or steel the metal is in almost every case heated to a greater or less degree, to make
it softer and more malleable by lessening its cohesion. Pure iron will hear an almost unlimited de-
gree of heat; hot-short iron bears much less, and is in fact very brittle when heated; other kinds
are intermediate. Of steel, shear-steel will generally bear the highest temperature, blistered steel
the next, and east-steel the least of all; but all these kinds, especially cast-steel, differ very much
according to the processes of manufacture, as some cast-steel may be readily welded, but it is
then somewhat less certain to harden perfectly. The smith commonly speaks of five degrees of tem-
perature, namely: The black-red heat, just visible by daylight; the low_red heat; the bright-red
7 48 FORGING.

heat, when the black scales may be seen; the white heat, when the scales are scarcely visible; and
the welding heat, when the iron begins to burn with vivid sparks.
Steel requires, on the whole, very much more precaution as to the degree of heat than iron ; the
temperature of cast-steel should not generally exceed a bright-red heat, and that of blistered and
shear-steel a moderate white heat. Although steel cannot in consequence be so far softened in the
fire as iron, and is therefore always more dense and harder to forge, still from its superior cohesion
it bears a much greater amount of hard work under the hammer, when it is not overheated or
burned ; but the smallest available temperature should be always employed with this material, as in
fact with all others.
The cracks and defects in iron are generally very plainly shown by a difference in color at the parts
where they are heated to a dull red; this method of trial is often had recourse to in examining the
soundness both of new and old forgings.
When a piece of forged work is required to be particularly sound, it is a common practice to sub-
ject every part of the material in succession to a welding heat, and to work it well under the ham-
mer, as a repetition of the process of manufacture to insure the perfection of the iron: this is tech-
nically called taking a heat over it ,' in fact, a heat is generally understood to imply the welding heat.
For a 2-inch shaft of the soundest quality, 21}-inch iron would be selected, to allow for the reduction
in the fire and the lathe ; some also twist the iron before the hammering to prevent it from becom-
ing spilly. I
The use of sand sprinkled upon the iron is to preserve it from absolute contact with the air, which
would cause it to waste away from the oxidation of its surface, and fall off in scales around the an-
vil. If the sand is thrown on when the metal is only at the full red heat, it falls off without adher-
ing; but when the white heat is approached, the sand begins to adhere to the iron; it next melts on
its surface, over which it then runs like fluid glass, and defends it from the air. When this point
has been rather exceeded, so that the metal nevertheless begins to burn with vivid sparks and a hiss-
ing noise like fireworks, the welding temperature is arrived at, which should not be exceeded. The
sparks are, however, considered a sign of a dirty fire or bad iron, as the purer the iron the less it is
subject to waste or oxidation in the course of work. In welding two pieces of iron together, care
must be taken that both arrive at the welding heat at the same moment; it may be necessary to keep
one of the pieces a little on one side of the most intense part of the fire (which is just opposite the
blast), should the one be in advance of the other. In all cases a certain amount of time is essen-
tial ; otherwise, if the fire be unnecessarily urged, the outer case of the iron may be at the point of
ignition before the centre has exceeded the red heat. In welding iron to steel, the latter must be
heated to a conSiderably less degree than the iron, the welding heat of steel being lower from its
greater fusibility; but the process of welding will be separately considered under a few of its most
general applications, when the ordinary practice of forging has been discussed, to which we will now
roceed.
p The general practice in forging works from the bar of iron or steel is for the most part included
in the three following modes, the first two occurring in almost every case, and frequently all three
together, namely: by drawing down, or reduction; by jumping or upsetting, otherwise thickening and
shortening; and by building up, or welding.
To meet the variety of cases which occur, the smith has hammers in which the pencs are made in
different ways, either at right angles to the handle, parallel with the same, or oblique. In order to
obtain the same results with more precision and effect, tools of the same characters, but which are
struck with the sledge-hammer, are also commonly used: those with flat faces are made like ham-
mers, and usually with similar handles, except that for the convenience of reversing them they are
not wedged in; these are called set-hammers ,' others, which havevcry broad faces, are called fiat-
iei-s ; and the top tools, with narrow round edges like the pone of the hammer, are called top fullers;
they all have the ordinary hazel-rods. (See HAMMERS.)
When the sides of the object are required to be parallel, and it is to be reduced both in width and
thickness, the flat face of the hammer is made to fall parallel with the anvil, as represented in Fig.
1712 ; or oblique for producing taper pieces, as in Fig. 1713. Action and reaction being equal, the
lower face of the work receives the same absolute blow from the anvil as that applied above by the
hammer itself; it is not requisite, therefore, for works of moderate dimensions, to present every one
1712. 1718.







of the four sides to the hammer, but any two at right angles to each other. The smith must acquire
the habit of feeling when the bar lies perfectly flat upon the anvil, by holding it loosely, leaving it
almost to rotate in his grasp, er in fact to place itself. Next he must cause the hammer to fall flat
upon the work. It would be desirable practice to hammer a bar of cold iron, or still better one of
steel, as there would be more leisure for observations; the indentations of the hammer could be
easily noticed; and if the work, especially steel, were held too tightly, or without resting fairly on
the anvil, it would indicate the error by additional noise and by jarring the wrist; whereas, when
FORGIN G. 749

hot, the false blows or positions would cause the work to get out of shape without such monitorial
indications.
As to the best form of the hammer, there is much of habit and something of fancy. The ordinary
hand-hammer is represented in Figs. 1712 and 1713; but cutlers and most tool-makers prefer the
hammer without a pene, or narrow edge, and with the handle quite at the top, the two forming almost
a right angle, or from that to about 80° ; and sometimes the head is bent like a portion of a circle.
Similar but much heavier hand-hammers, occasionally of the weight of 12 or 14 lbs., are used by
spade-makers for planishing; but, the work being thin and cold, the hammer rises almost exclusive-
ly by the reaction, and requires little more than guidance. Again, farriers prefer for some parts of
their work a hammer the head of which is almost a sphere; it has two flat faces, one rounded face
for the inside of the shoe, and one very stunted pene at right angles to the handle, used for drawing
down the clip in front of the horse-shoe. In fact, nearly a small volume might be written upon all
the varieties of hammers. '
Suppose it required to draw clown 6 inches of the end of a square or rectangular bar of iron or
steel. The smith will place the bar across the anvil with perhaps 4 inches overhanging, and not rest-
ing quite flat, but tilted up about a quarter or half an inch at the near side of the anvil, as in Fig.
1713, but less in degree, and the hammer will be made to fall as there shown, except that it will be
1715. 1716. 1717.






at a very small angle with the anvil. In smoothing off the work, the position of Fig. 1712 is
assumed ; the work is laid flat upon the anvil, and the hammer is made to fall as nearly as possible
horizontally; a series of blows are given all along the work between every quarter turn, the hammer
being directed upon one spot, and the work drawn gradually beneath it. In drawing down the tang
or taper-point of a tool, the extreme end of the iron or steel is placed a little beyond the edge of the
anvil, as in Fig. 1713, by which means the risk of indenting the anvil is entirely removed, and the
small irregular piece in excess beyond the taper is not cut off until the tang is completed. Fig. 1714
shows the position of the chisel in cutting off the finished object from the bar of which it formed a
part; that is, the work is placed between the edge of the anvil and that of the chisel immediately
above the same; the two resemble in effect a pair of shears.
When it is required to make a set-op“, it is done by placing the intended shoulder at the edge of
the anvil: the blows of the hammer will be effective only where opposed to the anvil, but the re-
mainder of the bar will retain its full size and sink down, as represented in Fig. 1715. Should it be
necessary to make a shoulder on both sides, a flat-ended set-hammer, struck by the sledge, is used
for setting down the upper shoulder, as in Fig. 1716, as the direct blows of the hammer could not
be given with so much precision. In each of these cases some precaution must be observed, as
otherwise the tools, although so much more blunt than the chisel, Fig. 1714, will resemble it in
effect, and cripple or weaken the work in the corner; on this account the smith’s tools are rarely
quite sharp at the angles. This mischief is almost removed when the round fullers, Fig. 1717, are
- used for reducing the principal bulk, and the
a 1718- sharper tools are only employed for trimming
~ the angles with moderate blows.
When the iron is to be set down, and also
Ff spread laterally, as in Fig. 1718, it is first
' nicked with a round fuller, as upon the dotted
line at a, and the piece at the end is spread by
_ the same tool upon the short lines of the ob-
ject, or parallel with the length of the bar. The first notch greatly assists in keeping a good shoulder
at the bottom of the part set down, and the lines are supposed to represent the rough. indentations
of the round fuller before the work is trimmed up.
Tonga—Figs. 1719 and 1720 are called flat-bit tongs; these are either made to fit very close, as
in Fig. 1720, for thin works, or to stand more open, as in Fig. 1719, for thicker bars, but always
parallel; and a ring or coupler is put upon the handles or reins, to maintain the grip upon the
work. Others of the same general form are made with hollow half-round bits; but it is much
better that they should be angular, like the ends of Fig. 1721, as then they serve equally well for
round bars or for square bars held upon their opposite angles. Tongs that are made long, and
swelled open behind, as in Fig. 17 21, are very excellent for general purposes, and also serve for bolts
and similar objects, with the heads plated inward. The pincer tongs, Fig. 1722, are also applied to
similar uses, and serve for shorter bolts.
Fig. 1723 represents tongs much used among cutlers; they are called crook-bit tongs; their jaws
overhang the side, so as to allow the bar of iron or steel to pass down beside the rivet, and the
nib at the end prevents the rod from being displaced by the jar of hammering. Fig. 1724-, the
hammer tongs, are used for managing works punched with holes, such as hammers and hatchets, as
the pins enter the holes and maintain the grasp.




750 FOBGING.

Fig. 1725, hoop tongs, are very much used by ship-smiths, for grasping hoops and rings, which
may be then worked either on the edge, when laid flat on the anvil, or on the side, when upon the
beak-iron; and lastly, Fig. 1726 represents the smith’s pliers, or light tongs, used for picking up
little pieces of iron, or small tools and punches.
There is often considerable choice~of method in forging, and the skillful workman selects that
method of proceeding which will produce the result with the least amount of manual labor.
1719.








Forging a. Screw-Bolt.-—Figs. 1727 to 1730 explain the processes of making an ordinary screw~
bolt. The latter is a single tool, but the heading tool, Fig. 1731, with several holes, is also used.
In upsetting the end of the work, if more convenient, it may be held horizontally across the anvil,
and struck on the heated extremity with the hand-hammer; or it can be jumped forcibly upon the
anvil, when its own weight will supply the required momentum. If too considerable a portion of the
work is heated, it will either bend, or it will swell generally ; and therefore to limit the enlargement
to the required spot, should the heat be too long, the neighboring part is partially cooled by immers-
ing it in the water-trough, as near to the heat as admissible.
A bolt may be made by building up or welding. An eye is first made at the end of a small rod of
square or flat iron; by bending it round the beak-iron, as in Fig. 1732, it is placed around the rod of
round iron, and the curled end is cut ofi with the chisel, as in Fig. 1733, enough iron being left in
the ring, which is afterward welded to the rod, to form the head of the bolt, by a few quick light
blows given at the proper heat; the bolt is then completed by any of the tools already described
that may be preferred. A swage at the angle of 60°, Fig. 1734, will be found very convenient in
forming hexagonal heads, as the horizontal blow of the hammer completes the equilateral triangle,
and two positions operate on every side of the hexagon. Fig. 1734 is essential likewise in forging
triangular files and rods.
For the parts of mechanism in which a considerable length of two different sections or magnitudes of
iron are required, the method by drawing down from the large size would be too expensive ; the method
by upsetting would be impracticable; and there- '
fore a more judicious use is made of the iron
store, and the object is made in two parts, of bars
of the exact sections respectively. The larger bar
is reduced to the size of the smaller, generally
upon the beak-iron with top fullers, and with a
gradual transition or taper extending some few
inches, as represented in Fig. 1735 ; the two pieces
are scarfed or prepared for welding.
Bending Bare—Fig. 1735 is also intended to
explain two other proceedings very commonly re-
quired in forging. Bars are bent down at right
angles as for the short end or corking of the piece,
Fig. 1735, by laying the work on the anvil, and
holding it down with the sledge-hammer, as in Fig.
1736; the end is then bent with the hand-hammer,
and trimmed square over the edge of the anvil;
or when more precision is wanted, the work is
screwed fast in the tail-vise, which is one of the
tools of every smith’s shop, and it is bent over the
jaws of the vise. When the external angle, as well as the internal, is required to be sharp and
square, the work is reduced with the fuller from a larger bar to the form of Fig. 1737, to compensate
for the great extension in length that occurs at the outer part, or heel of the bend, of which the
inner angle forms as it were the centre.
Punching Holes.—The holes in Fig. 1735 for the cross-bolts are made with a rod-punch, which is
driven a little more than half-way through from the one side while the work lies upon the anvil, so
that, when turned over, the cooling efiect of the punch may serve to show the place where the tool


1728. 1734.
FORGING. 751

must be again applied for the completion of the hole; the little bit or burr is then driven out,
either through the square hole in the anvil that is intended for the bottom tools, or else upon the
bolster, Fig. 1738, a tool faced with steel, and having an aperture of the same form and dimensions
as the face of the punch. In making a socket, or a very deep hole in the one end of a bar, some
difficulty is experienced in getting the hole in the axis of the bar, and in avoiding the bursting open
of the iron; such holes are produced differently, by sinking the hole as a groove in the centre of a
flat bar by means of a fuller; the piece is out nearly through from the opposite side, folded together
lengthwise, and welded. The hole thus formed will only require to be perfected by the introduction
of an appropriate punch, and to be worked on the outside, with those tools required for dressing off
its exterior surface, while the-punch remains in the hole to prevent its sides from being squeezed
1736.









Z O 1/7 s" f j ..
[ e—fi ~ J 1 ‘41.
h—lg
fl.
1:: QU/CT _ E i) 1742.

in; this method is very good. For punching square holes, square punches and bolsters are used, and
the split bolster, Fig. 1739, is employed for cutting out long rectangular holes or mortises, which is
often done at two or more cuts with an oblong punch.
Forging Nuts—Fig. 1741 shows the ordinary mode of making the square nuts for bolts. A flat
bar is first nicked on the sides with the chisel, then punched, and the rough nuts, if small, are sep-
arated and strung upon the end of the poker (a slight round rod bent up at the end), for the con-
venience of managing them in the fire, from which they are removed one at a time when hot, and
finished on the triblet, Fig. 1742, which serves both as a handle and as the means of perfecting the
holes.
For making hexagon nuts, the flat bar is nicked on both edges with a narrow round fuller; this
gives a nearer approach to the hexagon: the nuts are then flattened on the face, punched, and dressed
on the triblet within the angular swage, Fig. 1734, before adverted to. Thick circular collars are
made precisely in the same way, with the exception that they are finished externally with the ham-
mer, or between top and bottom rounding tools of corresponding diameter
It is usual, in punching holes through thick pieces, to throw a little coal-dust into the hole when it
is partly made, to prevent the punch sticking in so fast as it otherwise would: the punch generally
gets red—hot in the process, and requires to be immediately cooled on removal from the hole.
Various Forgings—When a thick lump is wanted at the end of a bar, it is often made by cutting
the iron nearly through and doubling it backward and forward, as in Fig. 1740; the whole is then
welded into a solid mass as the preparatory step.
A piece with three tails, such as Fig. 1743, is made from a large square bar; an elliptical hole is
first punched through the bar, and the remainder is split with a chisel, as in Fig. 1744, the work at
the time being laid upon a soft iron cutting plate in order to shield the chisel from being driven
1713. 1744.


against the hardened steel face of the anvil; the end is afterward opened into a fork, and moulded
into shape over the beak-iron, as indicated by the dotted lines.
Such a piece as Fig. 1743, if of large dimensions, would be made in two separate parts, and
welded through the central line or axis.
Should it happen that the two arms are not quite parallel, an error that could scarcely be corrected
by the hammer alone, the work would be fixed in the vise with the two tails upward, and the one
or other of these would be twisted to its true position by a hook-wrench or set, made like the three
sides of a square, but the one very long to serve as a lever; it is applied exactly in the manner of a
key, spanner, or screw-wrench, in turning round a bolt or screw.
Some bent objects, such as cranks and straps, are made from bar-iron bent over specific moulds,
which. are sometimes made in pairs like dies, and pressed together by screw contrivances. When
the moulds are single, the work is often retained in contact with the same, at some appropriate
752 . FORGIN G.

part, by means of 'straps and wedges, while the work is bent to the form of the mould by top tools
of suitable kinds.
Objects of more nearly rectilinear form are cut out of large plates and bars of iron with chisels.
For example, the cranks of locomotive engines are fagoted up of several bars or uses laid t0gether,
and pared to the shape ; they are sometimes forged in two separate parts, and welded between the
cranks ; at other times they are forged out of one parallel mass, and afterward twisted with a hook-
wrench, in the neck between the cranks, to place the latter at right angles. The notches are
sopaetimes cut out on the anvil while the work is red-hot; or otherwise by machinery when in the
co state.
' A very different method of making rectangular cranks and similar works is also recommended, by
bending one or more straight bars of iron to the form; the angles, which are at first rounded, are
perfected by welding on outer caps. In this case the fibre runs round the figure, whereas, when the
gap is cut out, a large proportion of the fibres are cut into short lengths, and therefore a greater
bulk must be allowed for equal strength: this method is however seldom used.
All kinds of levers, arms, brackets, and frames are made after these several methods, partly by
bending and welding, and partly by cutting and punching out; and few branches of industry present
a greater variety in the choice of methods, which call the judgment of the smith continually into,v
requisition.
Welding—There are several ways of accomplishing the operation of welding, which bear some
little analogy to the joints employed in carpentry, more particularly that called Scarfing, used in the
construction of long beams and girders by joining two shorter pieces together endwise, with sloping
joints, which in carpentry are interlaced or mortised together in various ways, and then secured by
iron straps or bolts. In smiths’ work likewise, the joinings are called scarfs; but from the adhesive
nature of the iron when at a suitable temperature, the accessories called for in carpentry, such as
glue, bolts, straps, and pins, are no longer wanted.
The scarfs required for the shut are made by first upsetting or thickening the iron by blows upon
its extremity, to prepare it for the loss it will sustain from scaling off, both in the fire and upon the
anvil, and also in the subsequent working upon the joint. It is next rudely tapered off to the form
of a flight of steps, as shown in Figs. 1745 and 1746, and the sides are slightly beveled or pointed,
as in Fig. 1746, the proportion being somewhat exceeded to render the forms more apparent. The



1749.




(Li*—-j&——~—
114s. % - @
(Z c-


0
two extremities are next heated to the point of ignition; and when this is approached, a little
sand is strewed upon each part, which fuses and spreads something like a varnish, and partially
defends them from the air ; the heat is proper when, notwithstanding the sand, the iron begins to
burn away with vivid sparks. The two men then take each one piece, strike them forcibly across
the anvil to remove any loose cinders, place them in their true positions, exactly as in Fig. 1745, and
two or three blows of the small hammer stick them together; the assistant then quickly joins in
with the sledge-hammer, and the smoothing off and completion of the work are soon accomplished.
It is of course necessary to perform the work with rapidity, and literally “to strike while the iron
is hot.” The smith afterward jumps the end of the rod upon the anvil, or strikes it cndways with the
hammer; this proves the soundness of the joint, but it is mostly done to enlarge the part, should it
during the process have become accidentally reduced below the general size. The sand appears to be
quite essential to the process of welding, as, although the heat might he arrived at without its
agency, the surfaces of the metal would become foul and covered with oxide when unprotected
from the air; at all events, common experience shows that it is always required. The scarf joint,
shown in Figs. 1745 and 1746, is commonly used for all straight bars, whether fiat, square, or
round, when of medium size.
In very heavy works the welding is principally accomplished within the fire; the two parts are
previously prepared either to the form of the tongue or split joint, Fig. 1747, or that of the butt
joint, Fig. 1748, and placed in their relative positions in a large hollow fire. When the two parts
are at the proper heat, they are jumped together cndways, which is greatly facilitated by their sus-
pension 'l‘rom the crane, and they are afterward struck on the ends with sledge-hammers, a heavy
mass being in some cases held against the opposite extremity to sustain the blows; the heat is kept
up, and the work is ultimately withdrawn from the fire, and finished upon the anvil.
The butt joint, Fig. 1748, is materially strengthened, when, as is usually the case for the pad"
dle-shafts of steam-vessels and similar Works, the joint while still large is notched in on three or four
sides, and pieces called stick-in pieces, dowels, or chm-Zine, one of which is represented by the dotted
lines, are prepared at another fire, and laid in the notches; the whole, when raised to the welding
FORGING. 753

heat, is well worked together and reduced to the intended size; this mingles all the parts in a very
substantial manner. For the majority of works, however, the scarf joint, Fig. 1745, is used, but the
stick-in pieces are also occasionally employed, especially when any accidental deficiency of iron is to
be feared.
When two bars are required to form a T-joint, the transverse piece is thinned down as at a, in Fig.
1749; fer an angle or corner the form of b may be adopted; but e, in which each part is cut off ob-
liquely, is to be preferred. The pieces a, b, e are represented upside down, in order that the ridges
set down on their lower surfaces may be seen. In most cases, when two separate bars are to be
joined, whatever the nature of the joint, the metal should be first upset, and then set down in ridges
on the edge of the anvil, or with a set-hammer, as the plain chamfcred or sloping surfaces are apt to
slide asunder when struck with the hammer, and prevent the union. When a T-joint is made of
square or thick iron, the one piece is upset, and moulded with the fuller much in the form of the let-
ter; it is then welded against the flat side of the bar: such works are sometimes welded with dowel
or tenon joints, but all the varieties of method cannot be noticed.
Fig. 1740 may be taken as an example in which the parts have no disposition to separate ; in this
and similar cases the smith often leaves the parts slightly open, in order that the very last process
before welding may be the striking the whole edgeways upon the anvil, to drive out any loose scales,
cinders, or sand, situated between the joints. In works that have accidentally broken in the welded
part, the fracture will be frequently seen to have arisen from some dirty matter having been allowed
to remain between them, on which account shuts or welded joints extending over a large surface are
often less secure than those of smaller area, from the greater risk of their becoming foul. In fact,
throwing a little small coal between the contiguous surfaces of work not intended to be united, is a
common and sometimes a highly essential precaution to prevent them from becoming welded.
The conical sockets of socket chisels, garden spuds, and a variety of agricultural implements, are
formed out of a bar of flat iron, which is spread out sideways or to an angle with the pene of the
hammer, and then bent within a semicircular bottom tool, also by the pene of the hammer, to the
form of Fig. 17 50; after which the sockets are still more curled up by blows on the edges and are
perfected upon a taper-pointed mandrel, so that the two edges slightly overlap at the mouth of the
socket, and meet pretty uniformly elsewhere, as in Fig. 1751 ; and 'lastly, about an inch or more at
the end is welded. Sometimes the welding is continued throughout the length, but more commonly
only a small portion of the extremity is thus joined, and the remainder of the edges are drawn to-
gether with the pene of the hammer.
In making wrought-iron hinges, two short slits are cut lengthways and nearly through the bar, to-
ward its extremity; the iron is then folded round a mandrel, set down close in the corner, and the
1750. 1751. ' 1759..





two ends are welded together. To complete the hinge, it only remains to cut away, transversely, either
the central piece or the two external pieces to form the knuckles, and the addition of the pin or
pivot] finishes the work.
In spades, and many similar implements, the steel is introduced between the two pieces of iron of
which the tools are made; in others, as plane irons and socket chisels, it is laid on the outside, and
the two are afterward extended in length or width to the required size. The ordinary chisel for the
smith’s shop is made by inserting the steel in a cleft, as in Fig. 1747, and so is also the pene of a
hammer; but the flat face of the hammer is sometimes stuck on while it continues at the extremity
of a flat bar of steel; it is then cut off, and the welding is afterward completed. At other times the
face of the hammer is prepared like a nail, with a small spike and a very large head, so as to be driven
into the iron to retain its position, until finally secured by the operation of welding.
In putting a piece of steel into the end of an iron rod to serve for a centre, the bar is heated, fixed
horizontally in the vise, and punched lengthways with a sharp square punch, for the reception of the
steel, which is drawn down like a taper tang or thick nail, and driven in; the whole is then returned
to the fire, and when at the proper heat united by welding, the blows being first directed as for form--
ing a very obtuse cone, to prevent the piece of steel from dropping out.
For some few purposes blistered steel is used for welding, either to itself or to iron. It is true
the first working under the hammer in a measure changes it to the condition of shear-steel, but
less efficiently so than when the ordinary course of manufacture is pursued, as the hammering is
found to improve steel in a remarkable and increasing degree.
For the majority of works in which it is necessary to weld steel to iron, or steel to steel, the shear,
or double shear, is exceedingly suitable; it is used for welding upon various cutting tools, as most
cast-steel will not endure the heat without crumbling under the hammer. Shear-steel is also used
for various kinds of springs, and for some cutting tools requiring much elasticity.
It is more usual to reserve cast-steel for those works in which the process of welding is not re-
quired, although of late years mild cast-steel, or welding cast-steel, containing a smaller proportion
of carbon, has been rather extensively used ; but in general the harder the steel the less easily will it
admit of welding, and not unfrequently it is altogether inadmissible.
The hard or harsh varieties of cast-steel are somewhat more manageable when fused borax is used
as a defense instead of sand, either sprinkled on in powder or rubbed on in a lump; and cast-steel,
otherwise intractable, may be sometimes welded to iron by first heating the iron pretty smartly, then
placing the co‘léi3 steel beside it in the fire, and welding them the moment the steel has acquired its
754 . FORGIN G.
I
maximum temperature, by which time the iron will be fully up to the welding heat. When both are
put into the fire cold alike, the steel is often spoiled before the iron is nearly hot enough, and there-
fore it is generally usual to heat the iron and steel separately, and only to place them in contact to-
ward the conclusion of the period of getting up the heat. In forging works either of iron or steel,
the uniformity of the hammering tends greatly to increase and equalize the strength of each mate-
rial; and in steel, judicious and equal forging greatly lessens also the after-risk in hardening.
ZhoLForging.—-With the utmost care and unlimited space, it would have been quite impossible to
convey the instructions called for in forging the thousand varieties of tools and parts of mechanism
the smith is continually called upon to produce; and all that could be reasonably attempted in this
place was to convey a few of the general features and practices of this most useful and interesting
branch of industry. It is hoped that such combinations of these methods may be readily arrived
at as will serve for the majority of ordinary wants.
The smith in all cases selects or prepares that particular form and magnitude of iron, and also
adopts that order of proceeding, which experience points out as being the most exact, sound, and
economical. In this he is assisted by a large assortment of various tools and moulds for such parts
of the work as are often repeated, or that are of a character sufficiently general to warrant the out-
lay; and to some of these we will advert. '
The heading tools, Figs. 1730 and 1731, are made of all sizes and varieties of forms ; some with a‘
square recess to produce a square beneath the head, to prevent the bolt from being turned round in
the act of tightening its nut; others for countersunk and round-headed bolts, with and without square
shoulders; many similar heading tools are used for all those parts of work which at all resemble
bolts, in having any sudden enlargement from the stem or shaft. The holes in the swage-block,
Fig. 1753, are used after the manner of heading tools for large objects; the grooves and recesses
around its margin also serve in a variety of works as bottom swages beyond the size of those fitted
to the anvil. At the opposite extreme of the heading tools, as to size, may be noticed those con~
stantly employed in producing the smallest kinds of nails, brads, and rivets, of various denomina-
tions ; some of which heading tools divide in two parts like a pair of spring forceps, to release the
nails after they have been forged. These kinds are called wrought nails and brads, in eontradistinc-
tion to similar nails cut out of sheet-iron by various processes of shearing and punching, which latter
kinds are known as cut brads and nails.
The top and bottom rounding tools, Fig. 1727, are made of all diameters for plain cylindrical
works; and when they are used for objects the different -
parts of which are of various diameters, it requires much
care to apply them equally on all parts of the work, that
the several circles may be concentric and true one with the
other, or possess one axis in common. To insure this con-
dition, some of these rounding tools are made of various
and specific forms, for the heads of screws, for collars,
flanges, or enlargements, which are of continual occurrence
in machinery, for the ornamental swells or flanges about
the iron work of carriages, and other works. Such tools,
like the pair represented in Figs. 17 54 and 1755, are called
swage or collar tools; they save labor in a most important
degree, and are thus made. A solid mould, core, or striker,
exactly a copy of the work to be produced, is made of steel
by hand-forging, and then turned in the lathe to the re-
quired form, as shown in Fig. 1756.
The top tool is first moulded to the general form in an ap-
propriate aperture in the swage-block, Fig. 1753; it is faced
with steel like a hammer, and the core, Fig. 1755, is indented .
into it, the blows of the sledge-hammer not being given directly upon the core, but upon some hollow
tool previously made; otherwise the core must be filed partly flat, to present a plane surface to the
1761.




hammer. The bottom tool, which is fitted to the anvil, is made in a similar manner, and sometimes
the two are finished at the same time while hot, with the cold striker between them ; their edges carefully rounded with a file, and lastly they are hardened under a stream of water.
FORGING. 755

In preparing the work for the cellar-tools, when the projection is inconsiderable, the work is always
drawn down rudely to the form between the top and bottom fullers, as in Fig. 1717 ; but for greater
economy, large works in iron are sometimes made by folding a ring around them, as in Fig. 1733.
The metal for a large ring is occasionally moulded in a bottom tool like Fig. 1757, and coiled up to
the shape of Fig. 17 58, after which it is closed upon the central rod between the swages, and then
welded within them. The tools are slightly greased, to prevent the work from hanging to them, and
from the same motive their surfaces are not made quite flat or perpendicular, but slightly conical,
and all the angles are obliterated and rounded.
The spring swage-tool, represented in Fig. 1759, is used for some small manufacturing purposes;
it differs in no respect from the former, except in the steel spring which connects the two parts; it
is employed for light single-hand forgings. Other workmen use swage-tools, such as Fig. 1760, in
which there is a square recess in the bottom tool to fit the margin of the top tool so as to guide it
exactly to its true position; 5* this kind also may be used for single-hand works, and is particularly
suited to those which are of rectangular section, as the shoulders of table-knives; these do not admit
of being twisted round, which movement furnishes the guide for the position of the top tool in
forging circular works.
The smith has likewise a variety of punches of all shapes and sizes, for making holes of corre-
sponding forms; and also drifts or mandrels, used alone for finishing them, many of which, like the
turned cones, are made from a small to a large size to serve for objects of various sizes. Two
examples of the very dcxterous use of punches are in the hands of almost every person, namely, ordi-
nary scissors and pliers. The first are made from a small bar of flat steel; the end is flattened and
punched with a small round hole, which is gradually opened upon a beak-iron, Fig. 1761, attached to
the square hole of the anvil; the beak-iron has a shallow groove (not shown) for rounding the inside
of the bows. The remaining parts of the scissors are moulded jointly by the hammer and bottom
swage-tools; but the bows are mostly finished by the eye alone. In the Lancashire pliers, the cen-
tral half of the joint is first made ; the aperture in the other part is then punched through sideways,
and sufficiently bulged out to allow the middle joint to be passed through, after which the outsides
are closed upon the centre. This proceeding exhibits, in the smallest kinds especially, a surprising
degree of dexterity and dispatch, only to he arrived at by very great practice; and which in this and
numerous other instances of manufacture could be scarcely attained but for the enormous demand,
which enables a great subdivision of labor to be successfully applied to their production.1- f
General Hints on Forging.—The following hints on forging have been officially published by the
British Government from data given by several eminent iron-working firms :
With reference to the means of producing sound smiths’ work, the most fertile sources of defects
which from time to time have been experienced are: 1. The original inferior quality of the iron; 2.
Improper treatment in the forging; 3. Improper treatment of articles of smiths’ work in actual service.
It being most important that every condition necessary for the operation of welding should be in
the highest state of perfection, this requires that the iron should be at the right welding heat, rather
than over or under it; so that, if any slight delay or impediment arise in bringing the parts together,
there may be, as it were, a surplus of heat to work upon; and next in importance to this is that as
little scoria, or oxide, or other foreign material as possible should cling to or interpose between the
surfaces about to be welded. As the welding of iron is accompanied by its combustion, and by the
production of an oxide in a melting state, we must altogether get quit of this interposing material,
as, ere the two pieces are laid together, it has a tendency to form as rapidly as it is swept or wiped
ofl. But, very fortunately, in almost every case, if due care be paid to the form and manner in
which the surfaces are presented together, the instant the blows are given to the parts in question,
the interposing scoria is forced out, and the then perfectly pure surfaces of the welding-hot iron are
so brought into intimate contact as to unite together and form one mass. There is no department of
the art of forging more important than this, inasmuch as, in the majority of cases of defective weld-
ing, it is observed that the defect in question has arisen either from the scoria being shut up by
means of improper forms of the surfaces, or that it has been insufficiently expressed from between
the surfaces, for want of due energy in the blows of the hammer. That great attention should be
paid to this is the more important and requisite, inasmuch as, in a great many cases, the system of
“dab-on” welding is unavoidable in the production of certain pieces of work; and as such “ dab-
on ” parts are generally subject to great and unfavorable strain, it is more than usually requisite to
adopt the proper precautions, so as to secure the proper expression of the scoriae, and the intimate
union of the surfaces.
Much evil arises from the risk of viseid and sulphurous scoria: clinging to the surfaces of the iron,
owing to the use of raw or impure coal as the material for the smith’s fire. If the coal were of a
pure quality, namely, such as contains nothing but carbon and its ordinary bituminous accompani-
ments, the evil alluded to would be less felt; but as all coal contains, besides earthy matter. more or
less of sulphur, a class of evils arises which is of a very serious nature. When we attempt to weld
together two pieces of iron which have been heated in a fire formed of very sulphurous coal, not
only is the- quality of the iron damaged by being rendered brittle, but also its surface becomes cov-
ered with a certain substance which, in a very remarkable degree, destroys that adhesive quality
which accompanies iron when at a welding heat.
When this evil exists to excess, the parts will not unite, however much they may be hammered.
But although such an extreme case as this is not frequent, yet it is a question of degree, and not of

* In 'ractice the recess in the bottom tool would be deeper. and taper or larger above to guide the tool more easily
to its 1) ace; but if so drawn the figure would have been less distinct.
'l' The remarks on steel also refer to the necessity of good primary forging and hammering to produce homogeneity,
and also to many of the other points general] admitted by practical men as being conducive to the success of hardening.
1: I'Ioltzapfi‘el‘s “Turning and Mechanical Manipulation)
756 \ FORGING MACHINES.

existence, so long as raw coal is used. It is therefore advisable, for those fires which admit of it,
slightly to carbonize the coal in a separate oven previous to use. This is the practice in most pri-
vate establishments, where the quality of the smith’s work is a prime object. The practice should
be discontinued of making notches in the scraps of two pieces of iron about to be welded together,
as such notches afford a lodgment for scoriae, etc. ‘
Another extremely bad practice should be discontinued, namely, that of throwing a few fresh coals
into a 11110110W fire on the hot iron, just before the heat is coming out. The use of air-furnaces pre-
vents t is.
It is recommended also to abolish cold hammering, unless the articles can afterward be annealed.
Detailed descriptions of all forging operations will be found in “The Mcchanician and Construc-
tor,” Knight, London'and New York, 1869. '
FORGIN G MACHINES. This class of machinery is especially adapted to the forging of articles
of definite forms, such as spikes, rivets, nuts, horse-shoes, etc., and as such as may be distinguished


I,
from the various forms of power hammers which perform general work. One of the oldest and
most successful forging machines is represented in Figs. 1762, 1763, and 1764. Fig. 1762 is a front
view, and Fig. 1763 an end view of the machine; Fig. 1764 is a section across the swages, and the
apparatus connected with their motion. The machine consists of a strong cast-iron frame, carrying
the driving-shaft a. On this shaft are forged eccentrics, which give motion to the upper swage-hold-
ers b 6. These swage-holders are guided vertically by the frame, while the motion required by the
eccentric. is allowed for by the pieces cc, the toes of which work in the hollow on the top of the
FORGING MACHINES. 757

swage-holder. Each upper swageholder is provided with a spiral spring, shown in Fig. 17 64, which
bears on a key fixed in the frame, and raises the swage after the eccentric has depressed it. A slot
is cut in the swage-holder to allow it to slide on the key.
Machines of this class are always liable to breakage from a bar of too large a size being put be-
tween the swages. This can only be remedied by allowing some elasticity, which in this case is in-
geniously effected in the following manner: A space e, in the lower swageholder, is filled with cork,
which can be compressed by the screw f to any degree of hardness. The screw 9, which passes
through the nut h, let into the framing, serves to raise the lower swage bodily, when it is required to
vary the size of the work to be executed. The tool 2' forms a pair of shears to finish the work to a
1763. 1764.
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proper length, by moving the handle is, which, acting on an eccentric, raises the lower tool to meet
the upper one. This arrangement is necessary, as, from the rapid motion of the tools, which make
600 to 700 blows per minute, it would be impossible to introduce the work without bruising it. o o o o
are a series of rests, one being opposite to each pair of tools, which can be adjusted both in height
and horizontal distance by means of the screws nr; the table as, carrying the rests, can also be
moved along the frame to facilitate the adjustment. In using the machine, the swages are adjusted
so that by placing the rod of iron successively between them, it is drawn down to the size required,
while the length of each part is accurately determined by placing the end of the rod in the rest. The
machine cannot thus turn out the work too small, while at the same time it is so near the finished
size that very little has to be taken off in the lathe.
758 FORGING MACHINES.

Swain-Forging Machine.—-Fig. 1765 represents a screw-thread forging machine, devised by MM.
Bouchacourt and Delille of Fourchambault, France. The rod or bolt to be threaded is placed upon
the lower die B, and fed forward while screwing it. The upper die is mounted on a slide 0 G, which
is actuated in the downward direction by an eccentric E on the main shaft and the toggle~bar D, the
upward motion being obtained by an internal spiral spring F. The lower die B is carried in a slide
G, and is adjusted at the proper distance from the upper die by means of wedge H and the inclined
plate I beneath slide G. The wedge H is operated by a pedal L, and secured in its highest position
by a bolt J received in a mortise made in the plate 1, the bolt being operated by a pedal 11!. In
order to release the wedge and return it to its lowest position, the bolt is raised by pressing down the
pedal M, whereupon the wedge is free to be returned by the counterweights K in connection with
pedal L. Slide G, carrying the lower die, then descends by its own gravity, and so separates the two
dies sufficiently to allow of the removal of the screw belt or rod therefrom. To compensate for the
wear of the dies, and admit of their
adjustment, another wedge 0, with
screw adjustment, is disposed below
W
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the inclined plate I ”. Fig. 1766 rep-




resents the screw forgcd by this ma-
chine. _
Nut-Forging lh'achines.—An ex—
ceedingly ingenious machine for forg.
ing nuts without waste of iron, the
invention of M. Le Blane of Paris,
is represented in Fig. 1767. The
principles of its operation are shown
in Fig. 1768. The friction-disk A
is rotated in either direction by the
wheels B, and in this way the screw
0 is turned. This screw is stepped
in the cross-bar D, and it causes the
ascent or descent of the head E, to
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which is secured, by the rods F, the
follower G. The punches, three in
L number, are secured to the cross-
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punches are adjusted rigidly on the
, cross-bar D and over the centres
Q L of the dies. They are of varying
_ lengths, so that a bar placed suc-
cessively under them becomes indent-
ed more and more deeply as each
punch operates on the same point.
The operation of the machine is as follows : The bar of metal, being heated, is inserted between
the first pair of dies, No. 1, Fig. 1768. The rotation of the screw 0 then causes the ascent of the
follower, and the jointed levers H are thus caused to force the dies together, so compressing the
end of the bar into the shape of a nut. While thus compressed, the ascent of the follower brings
the blank so formed in contact with a punch, which produces a shallow indentation. The follower
then descends, the dies open, and the operator pushes the partly-formed nut between dies No. 2, a
new section of metal thus becoming exposed to the action of dies No. 1. 0n the rise of the fol-
lower the hole in the first nut is punched more deeply by the second punch. The bar is pushed
forward once more as the follower falls for the second time, and on the last pressure the nut first
formed is punched through and cut off. It will be seen that the operator has only to feed in bars to
cause the continuous forging of the nuts, at the rate of from 6,000 to 10,000 per day. Bolts and
spikes are similarly forged by suitable modifications of the machine. _
Messrs. Taylor & 00., of Birmingham, England, have also invented a machine in which the bars
are indented before being cut or punched, though in a different manner from that adopted in the


FORGING MACHINES. ' 759











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French apparatus. The principle of the indenting device, which consists of a pair of rolls geared
together, will be clear from Fig. 1769. The rolls are blank for a portion of their periphery, while






the remainder has projections or teeth formed on it as shown. In us'ng this apparatus, the bar is
heated in the ordinary way, and then thrust rapidly through the gap in the indenting rolls until
7’ 60 FORGING MACHINES.

arrested by an adjustable stop. The serrated portions of the rolls then seize upon the bar and
return it toward the attendant serrated as shown in the figure, the bar being thus brought to a form
suitable for conversion into hexagon nuts without waste of material, while the quality of the nuts
is improved.
Bolt-Forging Jtfachine.-Fig. 1770 represents Abbe’s bolt-forging machine. The holding-vise is
operated by a handle A attached to the cross-shaft. On each end of the latter are the arms, having
1771.






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links attached to work the sliding frame, which open the radial arms that carry the holding-dies.
These holders are backed up by a filling-in piece adjusted forward by screws. The driving-wheel is
constantly in operation—the machine only when it is forging on the bolt. The long slide carries the
bottom die on its lower end. The top slide-die (J works on the face of the long slide, which is
actuated by two levers D E, having curved slots, the top die-slide having one lever with reverse
curve, all working on the same pin. The pin in the upset carrier F passes through the curved slots,
and as it acts back and forth moves them in opposite directions. The side-dies have their motion
by means of links G, attached to the upset carrier. _When the bolt-blank is placed in the holders
and clamped tightly by means of the handle A, the handle H clutches the driving-wheel with the
shaft, and the upset carrier advances by means of the connections to upset the iron, the forging dies





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being all open. As the upset carrier recedes to half stroke, the side-dies compress the sides of the
head ; and at the extreme end of stroke the top and bottom dies act upon the other two sides of the
head, and so continue to do until the bolt is finished, which is done in four revolutions of the driv-
ing-wheel. The capacity of this machine varies with the size of bolt to be forged, from 8 to 16 per-
fect bolts per minute. .



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FORGIN G MACHINES. '7 61

Twisted Forgings.-—In order to secure homogeneity, Mr. Melling, of the Rainhill Iron Works, Liv-
erpool, proposed to twist together the bundles of constituent bars which go to form a shaft, or other
forging of large size, and devised a machine for the purpose, which is herewith represented.
Fig. 1771 is a complete longitudinal elevation of the machine in working order, having the front
heavy driving gearing removed
1773_ to avoid obscuring the twisting
- =9. details. In the same view are
* also shown the carriages on which
the bars under treatment are con-
. veyed to and from the machine.
_, i y . Fig. 1772 is a corresponding
51; plan, partly in section, showing
“W the drivmg gearing. In this View




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4‘ -'- 5 a bar is represented as in the act
' L 1 of passing through the twisting
.- “Iii
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ing upon the delivering rollers.
Fig. 1774 is a side elevation of
a modification of the delivering
rollers, differing slightly from
the same portion in Fig. 1773 in














‘ 9 ..,------;Mm,“,,\,, jmwmf ,.,. 5 point of regulation of the upper
' all), ,,,....“". My); Mt , )3!" W W, roller-bearing.
1,! ,tflljpl :Ililll|./l,;jf§lllt "‘lfj', “Hr-‘1 ,\ r-l'gi " "f T Fig. 1775 is a front elevation
“ ||.iv,,",u Lhlm _| ,d!|,ltm,t,g,fi'**‘m ,5? My of the first. or. revolving set_of
- -' I I.“ “ll Will I, , arr H.“ m, .“'-‘l- _,-' ., rollers, exhibltmg the actuating
.' EImam!.f‘q,:_‘l-l1“¥“ii-Ah “will '-"_ at mechanism whence the revolving
movement round the axis of the
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twisting bar is obtained.
Figs. 177 6 to 1780 represent
various kinds of work, as finished
from the original pile of bars.
The machine stands upon a massive foundation of masonry, to the surface of which the cast-
iron bed-plate is bolted. The driving power is communicated to the shaft A, from which motion is
communicated through the pair of wheels B B to the transverse shaft 0 C, passing right across the
machine, and having a heavy fiy-wheel D at its opposite end. From this shaft the first pair of roll-
ers E E, from their peculiar movement distinguished as the revolving rollers, are worked by the
worm E, which gears with the large worm-wheel G, cast in one piece with the back of the plate H,
and bored out at the back to work upon a fixed carrier bolted to an upright bracket fixed to the back
part of the bed-plate. The shafts T T carrying these rollers are supported in four bearings K K,
fitted into a pair of transverse cheeks L L, bolted and keyed between the two plates H 11!. The
latter is supported by a corresponding plate N, into which is fitted a turned ring cast on the front
of the plate 1H, and this plate N is again bolted to flanges O 0 on the upright checks of the deliv-














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ering rollers. It is easy to see how by this arrangement the revolution of the main shaft C com-
municates a revolving movement to the framework carrying the rollers E E ; but in addition to this
movement they revolve also round their own axes, and this is effected by means of the two plates
H and ill, which carry round with them two small spur-pinions P P, gearing with the fixed toothed
762 FORGING MACHINES.

rim Q. This motion is then transmitted from these pinions to the rollers, through the two worms
R R upon their shafts, to the two worm-wheels out upon the roller-shafts.
In the plan, Fig. 1772, the machine is shown as thrown out of gear with the driving-shaft, while
a bar S S is passing through. This disengagement is effected by the two lever-handles T T acting
each one upon a clutch-box, corresponding with similar clutches on worms, the latter being that
through which motion is communicated to the front delivering rollers, which latter may be thrown
into or out of gear by the attendant, when on the opposite side of the machine, by means of a
short handle. The lower of the two delivering rollers W W, which simply revolve round their
own axes, receives its motion from the main shaft, through the worm gearing with the worm-
wheel X on the second transverse shaft Y, carrying a pinion Z gearing with a similar one on the
lower roller-shaft. The object in giving motion to the lower roller first is, to admit of the raising
and lowering of the upper one as may be required to suit the work, the upper being driven from the
lower one by the pair of pinions c c on the opposite side of the roller-standards b b. In the com-
bined views of the machine, the pressure upon the upper delivering roller is represented as obtained
from the weight 0, adjustable on the long lever d having its fulcrum at e, and pressing upon the
journals of the upper roller by the two spindles f f. Crane-power may be applied to raise or lower
this weighted lever, by attaching a chain to either of the two loops formed for the purpose, both on
the weight and on the lever. In Fig. 1771 the oflice of this weighted lever is represented as suP-
plied by a pair of adjusting screws pressing upon the upper roller-bearings.
The bars to be operated upon are brought from the furnace in the carriage g 9, running upon four
wheels on a tramway. The body of this carriage carries two brackets supporting a cross-shaft, on
which are two pulleys h h, employed for the withdrawal of the bars from the furnace. The pulley!
shaft is worked by a short winch-handle, as in Fig. 1772, and the ends of the two chains, coiled on
the pulleys, are attached to a box which is slipped over the bar while in the furnace. Guides are
1776.












1779.
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attached to the carriage at la k for the support of the bar or pile of bars to be twisted; and to
admit of their free revolution they are turned on the outside and fitted into the cast-iron rings, bored
to correspond. These bearing-rings are put together in halves, and are carried upon a pair of
parallel longitudinal rods connected with the body of the carriage, or they may be simply suspended
from a crane. The carriage for receiving the twisted bar, as delivered from the machine, is at l on
the opposite or delivering end. It is nothing more than a semicircular iron trough, mounted upon a
pair of wheels, with a drawing handle. The bar or pile of bars being entered between the revolv-
ing rollers, and passed through until the end reaches the delivering pair, the upper one of this
latter pair is pressed hard down upon it, so as to prevent it from turning. Being thus firmly held
at this end while the after portion is carried round by the revolvers, it is clear that a twist must
take place, and so the simultaneous revolutions of each pair upon their own axes carry forward the
bar; it is preserved perfectly straight, and an even and regular twist is given to it. Fig. 1776 is
the original pile of rectangular bars; Fig. 1777 represents these bars as twisted together previous
to the subsequent finish under the hammer. In Fig. 17 7 8 the twisted metal is shown under the form
of a double T rail. Fig. 1779 is an axle formed out of round bars twisted together, and welded
only at each end for the wheels and journals. Fig. 1780 is a tire-bar exhibiting the striated tex-
ture, as in Fig. 1778. -
Horseshoe-Fmying JIIachz'ncs.—- Walker’s flfachine consists of one or more detachable independent
and automatically traveling horseshoe-dies, in combination with a pair of smooth-surfaced pressure-
rollers, between which the die or dies pass. Fig. 1781 is a perspective view of this machine; Fig.
1782 is a plan; Fig. 1783 is an enlarged perspective view of one of the dies; Fig. 1784 is a view
of the creased and perforated blank; and Fig. 1785 is a view of the same after being bent ready
to be operated upon by the machine. A and B are two housings to receive the journals of two
horizontal rollers, the upper roller, 0, being made adjustable up and down by any suitable means to
FORGING MACHINES. 763


regulate the pressure thereof. D represents the table or platform, over which the dies E travel.
These dies are connected to an endless chain or carrier H, passed around ordinary sprocket-wheels
I I, which are secured upon upright shafts J ; and one of these shafts is provided with a pulley or
band-wheel K, to be run by a belt, and by which the endless chain H is caused to rotate and name
each die successively in between the pair of horizontal rollers, the lower roller acting as a rolling


















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support or bed for the die, while the upper roller, C, is the pressure-roller for pressing the blank
into the die. The die E is constructed as shown in Fig. 17 83, the upper surface of the die forming
the frog h, around the toe and sides of which is a slightly-convex incline i, to form the required
concavity on the top of the shoe. The tread e of the die is made inclined, so as to be the deepest
1782. 1783.








at the heel on both sides, and the highest at the toe. This tread is also gradually made wider from
the quarters to the toe. The die is also provided with a joint a, to connect it to the endless chain.
The operation of the machine is as follows: The horizontal rollers being continuously rotated,
and the endless chain set in motion so as to successively move the dies in between the rollers, the
bent blanks, properly heated, are placed on the dies, and, being carried between the rollers, are by
the pressure thus given caused to receive the impress of the die, and thus complete the shoe.
764. ‘ FORGING MACHINES.

The process of making shoes by this machine is this : The blanks are first creased, as the iron is
rolled, in the last pass of an ordinary rolling-mill ; then they are cut to length; then the holes for
the nails are punched ; then the bent blank is operated upon as heretofore described. It is obvious
that by a change in the dies various sizes and shapes of shoes can be easily made. The advantages
of this process are, a better finished and shaped shoe than those heretofore produced, less waste in
the manufacture, and less wear and tear of the machinery. The machine is in operation at the
works of the Albany and Rensselaer Iron and Steel Company, Troy, N. Y., with an average produc-
tion of 60 kegs of 100 lbs. each, every turn of 10 hours. Two boys are required to run it, one to
place the shoes on the dies and one to take off.
This machine can also be used for impressing or embossing other materials as well as metals, by
simply providing requisite dies. For cases where the embossing, etc., is to be done on both sides of
the material, the dies are made double so as to close over the material before passing between the
rollers.
In Burden’s Izorseshocforgi-ng machine the motions are rotary and continuous. The red-hot bar is
introduced at the side of the machine, and a sufficient piece is cut off by a descending cutter. The
material then passes between guides to a stop, and is held in place till a bending-piece on a roller
comes against it and carries it along. This piece corresponds to the inner shape of the shoe, and
with this as a former the blank is carried past a series of dies which press it into shape, thinning
the inner edge, thickening the heels, pinching in the heels, making the creases by dies and the nail-
holes by punches in succession. After flattening, the shoe is dropped from the machine.
Other forms of machines have circular beds carrying formers, which pass the blank between dies,
which act successively upon the edges and face to give the required proportions and contour as well
as the creases and nail-holes. Another form pinches the heated blank between a central former and
two posts, while top rollers shape it vertically, and side rollers lap the heels around the receding
portion of the former, which acts as a die. In another the bar is fed in between the shears until it
butts against the adjustable gauge-plate. Being severed by the shears, the bender advances and
drives it between a pair of rollers, giving it a proximate horseshoe shape. The heels of the shoe
fall into a depression, and as the bender retires the shoe is drawn from it. The creasing and nail
punches are on an oscillating lever, and the latter acts upon and in conjunction with a lower lever
which perfects the perforation.
Apparatus for Hydraulic Forging—This method of forging, known as “ Haswell’s system,” is
claimed to give results superior to those obtained by the ordinary methods. It consists essentially
in forcing or pressing iron or steel, while at a welding heat, into suitable moulds by means of the
hydraulic press, carrying a follower or “stamp ” upon the end of the piston. Both the mould and
the stamp are used cold. Ingots or bars may be similarly forged or drawn down without a mould
upon an anvil, without giving any blow or shock, as is done of necessity when heavy steam-ham-
mers are used.
Mr. 11V. P. Blake, in his “Report on Iron and Steel” at the Vienna Exposition of 1873, states that
a small press examined by him with an 18-inch piston gave 600 tons pressure, and the large press with
a piston of 24 inches gave 1,200 tons pressure. The pressure in the pumps was 600 atmospheres.
A soft Bessemer-steel ingot, weighing 2,030 lbs., was forged under the large press, and yielded
noiselessly to the pressure as if it had been putty or soft cheese. As the piston-head descends, the
metal is forced each way, and the pressure visibly extends to the very centre of the mass, as shown
by the movements of the lines of scale at the sides. The ends of the ingot are bulged out at the
centre, and not drawn over at the surface, as is often the case with hammer-forging, which, com-
pared with hydraulic-press forging, seems very superficial. Under the press, the whole mass of the
ingot is affected. One great advantage of this method is the avoidance of great shocks, attendant
upon the use of ponderous steam-hammers. In forging intricate pieces, the moulds are so made
that they can be taken apart, and are held during the forging by strong bands. The follower, or
stamp, is made of cast-iron. The inside of the mould is oiled with old grease from railway-boxes.
A lump of white-hot steel of the proper weight is thrown in; the stamp descends upon it and
forces the metal into every recess and angle of the mould. Any excess of metal rises at the sides
of the stamp, and is cut ofi when cold. Such forgings are alike in size and weight, and, of course,
require much less trimming and fitting to bring them into shape for finishing. Care is required, of
course, to get the right quantity of metal, to avoid a deficiency or an excess. The method is suc-
cessfully applied to the manufacture of car-wheels, the spokes and parts of the hub being forged
in one piece, together with the crank-pin. Boiler-heads are made under the press in two heats.
They are forced through a ring, and come out very true and perfect in form.
The manufacture of the parts of locomotive wheels by the process of pressure will serve as an
example of the mode of operation. A wheel with 10 spokes, when made by the common methods,
consists of 12 pieces, but when made by this process it is composed of but 4 pieces. We give
here only a description of the manufacture of the most complicated part of the wheel, that is, the
part with the crank-pin, as the other parts are made by a simpler repetition of the same process.
The bloom is made in the ordinary way, from scrap-iron, and has a weight of 250 lbs. The bloom
is forced under a steam-hammer (6O ewt.) into a parallelopipedon 16 inches long, 11 inches high,
and 7 inches wide. While still warm it is put into the heating furnace, and when very hot is forged
with the steam-hammer into the form shown in Fig. 1786. The piece is then replaced in the heat-
ing furnace preparatory to pressing. The piece is pressed in the cast-iron mould, Fig. 1787, which
consists of the upper mould A A, the lower mould BB, and the die 0. . The punch d, which is seen in
the lower mould, is kept in position by a brace. The outline of the die 0 is like that of the bot-
tom of the mould, but with the addition of the shoulder f, which makes an impression to guide the
subsequent perforation. The mould stands on a bed-plate O O, on which it can slide either to the
right or left as desired. When the mould is fixed in the proper position, and the braces Z Z are fixed
FOUNDATIONS. 7 65

so as to hold it there, and the mould thoroughly greased to facilitate the removal of the form, the
piece (Fig. 1786) is placed in the mould, being taken from the heating furnace at a strong. welding
heat. Now follows quickly the action of the press, by which the piece is shaped. The the c is raised,
and a punch corresponding in shape to the piece cl in the lower mould is placed upon the impression
made at f. The piece cl is then removed by knocking away the brace, and the piece is perforated,
thus forming the spokes. By a similar process the hub is formed. The piece is removed from the




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mould by the same general process before described, by raising the upper part of the mould and
gently forcing the piece out. With two furnaces 24 pieces are produced in 10 hours. The expense
is from 30 to 35 per cent. of the cost of forging the same under a steam-hammer.
The making of smaller wheels in one solid piece is, of course, only a repetition of the process of
making segments. The whole wheel is first pressed and the spokes indented, and the interspaees
afterward punched out.
FOUNDATIONSE‘e Foundations may be classed under two heads: 1. Ordinary foundations, on
land, or protected from any considerable rush of water; 2. Hydraulic foundations, in rivers or in
the sea.
To ascertain the nature of the soil on which foundations are to be laid, borings are generally taken;
but they sometimes prove deceptive, owing to their coming upon some chance bowlders, or upon some
adhesive clays, which, without being firm, stick to the auger, and twist it or arrest its progress, and
the specimens brought up, being crushed and pressed together, look firmer than they really are. To
remedy these defects, some engineers have adopted ahollow boring tool, down which water is pumped,
and reascends by an annular cavity between the exterior surface of the tool and the soil, with such
velocity that not only the detritus scraped off by the anger, but pebbles also, are lifted by it to the
surface. This process is rapid, and the specimens, which are obtained without torsion, preserve their
natural consistence. On stifi clay, marl, sand, or gravel, the safe load is generally from 55 to 110
cwt. on the square foot; but a load of 165 to 183 cwt. has been put upon close sand in the founda-
tions of the Gorai bridge, and on gravel in the Loch Ken viaduct and at Bordeaux. On a rocky
ground, the Roquefavour aqueduct exerts a pressure of 268 cwt. to the square foot.
Ordinary Foundations—~When the ground consists of rock, hard marl, stiff clay, or fine sand,
the foundations can be laid at once on the natural surface, or with slight excavation, and with hori-
zontal steps where the ground slopes. At the edge of steep descents, with dipping strata, it is
necessary to find layers which will not slip, or, if there is such a tendency, to strengthen the layers
of rock by a wall, especially when it is liable to undergo decomposition by exposure to the air, or
to use iron bolts uniting the layers of rock. On ground having only a superficial hard stratum rest-
ing upon a soft subsoil, buildings have sometimes been erected by merely increasing the bearing
surface, and lightening the superstructure as much as possible; but generally it is advisable to
place the foundations below all the soft soil. On an uneven surface of rock a layer of concrete
spread all over afiords a level foundation. Sometimes large buildings have been securely built on
quicksands, of too great thickness to be excavated, by the aid of excellent hydraulic mortar, and by
excavating separately the bed of each bottom stone. Such a building will be stable if its pressure
on the foundation is uniform throughout, and if it is placed sufficiently deep to counterbalance the
tendency of the sand to flew back into the foundations. Instances of this class of foundations are
to be found in sewers built on water-bearing sands, which sometimes give rise to as much difficulty
as foundations built in rivers; as, for example, in the network of London sewers, and in the Met-
ropolitan Railway. The flowing in of sand with the water in pumping, and consequent undermining
of the houses above, was prevented in these cases by constructing brick or iron sumps for the

* The following article is partly abridged from a paper on “ Foundations ” by Jules Gaudard, C. E., in “ Proceedings
of the Institution of Civil Engineers,” 187 6.
'7 66 ' - FOUNDATIONS.

pumps in suitable places, surrounding them by a filtering bed of gravel, and using earthenware col-
lecting pipes, thus localizing the disturbance.
One means of reaching a solid foundation without removing the upper layer of soft soil is by pil-
ing, but piles are liable to decay in many soils. In Holland, buildings on piles of larch, alder, and
fir have lasted for centuries ; while in Belgium, large buildings have been endangered by the decay
of the piles on which they rest. Sometimes columns of masonry support the superstructure, but,
being placed farther apart than piles, it is necessary to connect them with arches at the surface for
carrying the walls. -
Too great care cannot be exercised in driving piles near buildings, lest they undermine the founda-
tions of the latter. In erecting the extension of a large apartment house in New York, it was
deemed advisable to drive piles for the foundations of the extension, although the existing building
had stood safely without a similar foundation. The driving of 5 piles over an area 7 feet in width
by 7 feet in length next to the corner pier of the old structure caused the pier to sink some 6 inches,
and so endanger the front (27 feet wide and 80 feet high) that the owner was compelled to rebuild
a large portion of the latter. Other and similar cases are known to have occurred in New York.
See Building News, Sept. 24, 1875, p. 39, on this subject, in relation to the widening of London
Bridge; also “Foundations and Concrete W orks,” Dobson, London, 1872, showing other objections
to pile-driving.
To avoid the difficulty and expense of timbering deep foundations, a lining of masonry is some-
times sunk, by gradually excavating the ground underneath, and weighting the masonry cylinder,
which is eventually filled in with rubble stone, concrete, or masonry, and serves as a pier. In
India. a similar system has been followed for centuries for sinking wells. When the stratum of
soft soil is too thick for the foundations to be placed below it, the soil must be consolidated, or
the area of the foundation must be sufficiently extended to enable the ground to support the load.
The ground may be consolidated by wooden piles ; but in soils where they .are liable to decay, pillars
of sand, or mortar, or concrete, rammed into holes previously bored, may be used. Artificial foun-
dations are also formed by placing on the soft ground either a timber framework, surrounded occa-
sionally by sheeting, or a mass of rubble-stone, or a layer of concrete, or a thick deposit of fine sand
spread in layers 8 to 10 inches thick, which, owing to its semifluidity, equalizes the pressure.
A heavy superstructure is partially supported on a soft foundation by the upward pressure due to
the depth below the surface to which it is carried, in the same manner that a solid floats in a liquid
when it displaces a volume of water equivalent to its own weight. According to Rankine, a build-
' 2
ing will be supported when the pressure at its base is 20h per unit of area, where h is
the depth of the foundation, w the weight of the soft ground per unit of volume, and it the angle of
friction. Mr. W. J. McAlpine, O. E., in building a high wall at Albany, N. Y., succeeded in safely
loading a wet clay soil with two tons on the square foot, but with a settlement depending on the
depth of the excavation. In order to prevent a great influx of water, and consequent softening of
the soil, he surrounded the excavation with a puddle trench 10 feet high and 4 feet wide, and he
also spread a layer of coarse gravel on the bottom. When the foundatiOn is not homogeneous, it is
necessary to provide against unequal settlement, either by increasing the bearing surface where the
ground is soft, or by carrying an arch over the worst portions.
Hydraulic Foundationa—Under this head are comprised all foundations in rivers, and where run-
ning water has to be contended with.
Foundations are laid upon the natural surface where it is rocky, also upon beds of gravel, sand,
or stiff clay, secured against scour by aprons, sheeting, rubble-stones, or other means of protection.
When the foundations are to be pumped dry, dams are resorted to if the depth of water is less than
10 feet, and are specially applicable to the abutments of bridges, where the water is less deep and
rapid and the bank forms one side of the dam. The dam can be made of clay, or even earth free
from stones and roots, with slopes of l to 1 ; the width at the top being about equal to the depth of
water when the depth does not exceed 3 feet in a current, or 10 feet in still water.
Concrete makes a solid dam, but it is expensive to construct and difficult to remove. A coffer-
dam with a double row of piles takes up less space, and is less liable to be worn away or breached,
than an earth-work dam. The width of a coffer-dam is often as great as the head of water; but if
the coffer-dam is strutted inside, so that the clay merely acts as a water-tight lining, the width need
not exceed from 4 to 6 feet. In a coffer-dam of concrete at Marseilles constructed for .the basin of
the graving docks, the widths were calculated at 0.45 of the total height; the maximum width thus
attained was 20 feet. -
In building the viaduct of Lorient, on a foundation dry at low water, a single row of strutted
piles, 3;} feet apart, plankedfrom top to bottom on both sides, was used (Fig. 1788), and the space
between the planking, 10 inches wide, was filled with silt pressed down. When the filling is so
much reduced in thickness the planks are carefully joined, and the clay is mixed with moss or tow,
or sometimes with fine gravel or pounded chalk. As water leaks through joints and connections,
the ties are placed as high up as possible, and the bottom is scooped out or cleaned before the clay
is put in. If large springs burst out in an excavation, they must be either stepped up with clay or
cement, or be confined within a wooden, brick, or iron pipe, in which the water rises till the pressure
is equalized, and then it is stepped up as; soon as the masonry is sufficiently advanced and ther-
oughly set. If, however, there is a general leakage over the whole bottom of the excavation, it
must be stopped by a layer of concrete, incorporated with the foundation courses (Fig. 1789). Where
there is not space for a clay dam, timber sheeting well strutted and calked is used. Hollow timber
frames without a bottom, and made water-tight at the bottom after being lowered by concrete or clay,
are suitable in water from 6 to 20 feet deep on rocky beds, or where there is only a slight layer of silt.
FOUNDATIONS. , I 707

When a limit to the space occupied is immaterial, as on large rivers, a sort of double-cased crib-
work dam is frequently adopted. M. Malézieux has given various details of this class of work,
such as the coffer-dam in Lake Michigan to obtain the water-supply for Chicago. A caisson 200
feet long and 98 feet wide, inclosed by double water-tight sides from 13 to 19 feet high, was used
at Montreal on the St. Lawrence. The interval between the two sides was about 11 feet wide, and
1788. 1789.
16' '



planked at the bottom so that the caisson could be floated into place. When the caisson was sunk,
piles were driven in holes made in the bed of the river to keep it in place, and the bottom was made
water-tight by a lining at the sides of beams and clay. These kinds of caissons are only suitable
where the bottom is carefully leveled. Although iron caissons are generally used for penetrating
some distance into the soil, there are instances of iron caissons being merely deposited upon the
natural bed.
The methods employed for laying foundations in the avatar, either on the natural surface or after
a slight amount of dredging, have next to be considered.
A rubble-mound foundation is sometimes employed for dams where any settlement can be re-
paired by adding fresh material on the top ; also for landing-piers in lakes by solidifying the upper
portion with concrete, and in breakwaters where a masonry superstructure is erected on the top.
Such a method, however, is not suitable where a slight settlement would be injurious; and in the
sea the base of the mound is generally less exposed to scour than in a river.
Another method consists in sinking a framing, not made water-tight, inside which concrete is run,
and the framing remains as a protection for the concrete, and is surrounded by a toe of rubble. If
the framing is of some depth, iron tie-rods are put in by divers after the bottom has been dredged,
to enable the framing to support the pressure of the concrete. When piles can be driven, the fram-
ing is fixed to them. The piles, 5 to 8 feet apart, have a double row of walings fixed to them,
between which close planking is driven, from 10 to 14 inches wide and from 3 to 5 inches thick;
and sometimes, when the scour of a sandy subsoil has to be prevented, the planks are grooved and
tongued, or have covering pieces put on by divers, or are driven in close panels. The insufficiency
of a simple framing of planks for foundations on running sand was demonstrated by the destruc-
tion of the Arroux bridge at Digoin, and the Gué-Moucault bridge over the Somme by the flood of
September, 1866, in spite of the fascines and rubble-stone protecting their piers, owing to the wash-
ing out of the underlying sand through small interstices by the rapid whirling current. Open fram-
ing is sometimes used for inclosing a mound of rubble-stone. These monnds require examination
after floods, and renewing till the mound has become perfectly stable. In permeable soils founda-
tions of concrete inclosed in frames are frequently employed. Lastly, concrete can be deposited in
situ for bridge foundations. Used in sea-works, bags of concrete, like those at Aberdeen, by Mr.
Dyee Cay, M. Inst. C. E., might be sometimes employed, instead of rubble-stones, for forming the
base of piers or for preventing scour.
Piles are used where a considerable thickness of soft ground overlies a firm stratum, when the
upper layer has sufficient consistence to afford a lateral support to the 'piles; otherwise masonry
piers must be adopted. The piles are usually placed from 2:1- to 5 feet apart, centre to centre,
and the distance is occasionally increased to 63; feet for quays or other works only slightly loaded.
Sometimes, under abutments or retaining walls, the piles are driven obliquely to follow the line of
thrust. The Libourne bridge rests on piles 2} feet apart, and driven about 40 feet in sand and silt.
At the Voulzie viaduct, on the Paris and Mulhouse Railway, some piles were driven 80 feet without
reaching solid ground, and theground between the piles had to be dredged, and replaced by a thick
layer of concrete. Piles which have not reached firm ground sustain loads nevertheless, owing to
the lateral friction; as, for instance, in the soft clay at La Rochelle and Rochefort, piles can support
164 lbs. per square foot of lateral contact, and 123 lbs. in the silt at Lorient. On the Cornwall
Railway, viaducts were built upon piles 65 to 80 feet long, driven, in groups of four fastened close
together, by a four-ton monkey with a small fall. A timber grating is fastened to the top of the
piles, or a layer of concrete is deposited, as at Dirschau, Hollandsch Diep, and Dordrecht; or both
grating and concrete, as the grating distributes the load and strengthens the piles. Planking is
sometimes put on the framing which distributes the pressure, as at London Bridge; but it is consid-
ered objectionable, as it prevents any connection between the superstructure and the concrete, and
increases the chance of sliding. The space between the piles from the river-bed to low water is
sometimes filled with rubble-stones, and sometimes with concrete, which is less liable to disturbance.
When the ground is very soft, a filling of clay has been preferred, on account of its being lighter
than concrete.
7 68 . FOUNDATIONS.

A mixed system of piling and water-tight caissons, of rubble-filling and concrete, was adopted at
the Vernon bridge. After the piles had been driven, the spaces between them were filled up to half
the depth of water with rubble-stones; a caisson 10 feet high was then placed on the top, and a
bottom layer of concrete deposited in it. In a month’s time the interior of the caisson was pumped
dry, the heads of the piles cut off, and the filling with cement concrete completed to low-water levels
The caisson was cut off to the level of the grating as soon as the pier was well above water.
The heavy ram of Nasmyth, moved by steam, with a small fall, but giving 60 to 80 blows per
minute, enables piles to be driven 33 feet in a few minutes, and with much less chance of diver-
gence or jumping than in driving .with less powerful engines. In certain soils, in which there is a
momentary resistance during pile-driving, it has been proposed to bore holes in which the pile
should be afterward driven. At St. Louis, the annular piles, 3;}; feet in diameter, made of 8 pieces
of wood, used for guiding the pneumatic caisson, were driven by the aid of the hydraulic sand-pump
working inside, the invention of Captain James B. Eads. The load that a pile driven home and
secure from lateral fiexion can bear may be estimated at from one-tenth to one-eighth of the crush-
ing load, which varies between 5,700 and 8,500 lbs. per square inch. Thus, taking a fair load of
710 lbs. per square inch, a small pile of 7 inches diameter will bear about 12 tons, and a pile of 18
inches diameter will bear about 80 tons ; and a pile to bear the load of ‘25 tons used as a unit by
M. Perronet should be about 10 inches in diameter. According to‘ M. Perronct, a pile can support
a load of 25 tons as soon as it refuses to move more than three-eighths of an inch under 30 blows
of a monkey weighing 11 cwt. 90 lbs., falling 4 feet, or under 10 blows of the same monkey fall-
ing 12 feet. At N euilly, however, M. Perronet placed a load of 51 tons on piles 13 inches square,
but driving the pile till it refused to move more than three-sixteenths of an inch under 25 blows of
a monkey of the same weight falling 41}- feet; but such a load is unusual. At Bordeaux the driving
was stopped when the pile did not go down more than three-sixteenths of an inch under 10 blows of
a monkey weighing 1,100 lbs., falling about 15 feet; but one of the piers settled considerably, the
load on a pile being 22 tons; whereas at Rouen, by insisting on M. Perronet’s rule, no settlement
occurred. From experiments made at the Orleans viaduct, M. Sazilly concluded that piles might
support with security a load of 40 tons when they refuse to move more than 1% inch under 10 blcws
of a monkey weighing 15 cwt. and falling about 13 feet. Various formulae have been framed for
calculating the safe load on piles, which are quoted in a paper by Mr. W. J. McAlpine, O. E., on
“The Supporting Power of Piles,” and in a paper on “The Dordrecht Railway Bridge,” by Sir
John Alleyne, Bart, M. Inst. C. E. If Weisbach’s formula is applied to M. Perronet’s rule, it
appears that, assuming a safe load, the limiting set of the pile might be 3} inches instead of three-
eighths of an inch for 10 blows; and the formula shows that large monkeys should be adopted in
preference to a large fall, and in this it agrees with practice for preventing injury to the piles. In
order to provide against the danger of overturning in silty ground, the ground is sometimes first
compressed by loading it with an embankment, which is cut away after a few months at those places
where foundations are to be built. At the Oust bridge it was even necessary to connect the piers
and abutments by a wooden apron, which, for additional security, was surrounded by concrete.
Screw-piles, Fig. 17 90, were introduced by Mr. Mitchell, M. Inst. 0. E., for securing buoys. They
can be applied with advantage to the construction of bollards and beacons, on account of the re-
sistance they offer to drawing out; but as in the process of screwing down the ground is more or
less loosened, judgment must be used in employing them for mooring or warping buoys. In founda-
tions for beacons they should be screwed down from 15 to 20 feet below the level to which the shift-
ing sand is liable to be lowered. Even when all cohesion of the ground is destroyed in screwing
down a pile, a conical mass, with its apex at the bottom of the pile and its base at the surface, would
have to be lifted to draw the pile out. The resistance to settlement is also increased by the bear-









151'-—-- -
- ---___
. _ _ _ - - _ ...,




ing surface of the screw; and the screw-pile is accordingly to be preferred to an ordinary pile in
soft strata of indefinite depth, or when the shocks produced by ordinary pile-driving are liable to
produce a disturbance. The screw-pile has likewise the advantage of being easily taken up. Screw-
piles have been principally used in England and in the United States. They have usually one or two
FOUNDATIONS. 769.

spirals projecting considerably from the shaft, these spirals being cylindrical for soft ground and
conical for hard ground, and either of wrought-iron or of east-iron. The shaft may be of wood,
or, by preference, of iron, which must be pointed at the end for hard ground, but cylindrical and
hollow when the ground is soft. The screw will penetrate most soils except hard rock; it can get
a short way into compact marl, through loose pebbles and stones, and even enter coral reefs. A
screw-pile turned by 8 capstan bars 20 feet long, each moved by 4 or 5 men, with a( screw 4 feet in
diameter, passed in less than 2 hours through a stratum of sand and clay more than 20 feet thick,
the surface of which was about 20 feet below water, and dug itself to a depth of about one foot
into an underlying schisteus rock. At the Clevedon pier screw-piles penetrated hard red clay to
depths varying between 7 and 17 feet; and although the screw had a pitch of 5 inches, they rarely
went down more than 3 inches in one turn. Mr. W. Lloyd, M. Inst. C. E., has recorded an unsuccess-
ful use of screw-piles, which in the shifting sandy bed of a South American river became twisted
like a corkscrew, and were overturned in the first breaking up of the ice.
The proper area of the screw should, in every case, be determined by the nature of the ground in
which it is to be placed, and which must be ascertained by previous experiment. The largest size
hitherto used has been 4 feet in diameter ; but within certain sizes, premribed by the facility of man-
ufacturing them, the dimensions may be extended to meet any case, and may be said to be limited
only by the power available for forcing them into the ground. Either the screw-pile or the screw-
mooring can be employed in every description of ground, hard rock alone excepted; for its helical
form enables it to force its way among stones, and even to thrust aside medium-sized bowlders. In
ports, harbors, estuaries, and roadsteads, rock is seldom met with, except in detached masses, the
ground being usually an accumulation of alluvial deposit, which is well adapted for the reception of
such foundations, and is also that in which they are generally most required.
The ground-screw has been extensively used for several purposes, and its applicability to many
others will be evident from a succinct account of its present employment. The fixed or permanent
moorings at present most commonly used are of two kinds—the span-chain mooring, and the sinker
or mooring-block. The former of these consists of a strong chain of considerable length, stretched
along the ground (across the river), and retained by heavy anchors or mooring-blocks at either end,
and to the middle of the ground-chain the buoy-chain is shackled. The other kind, which is more
generally employed, consists of a heavy sinker, to which a strong chain is attached, extending to a
buoy shackled at the other end, Fig. 1791. This sinker, which is a block of stone or iron, is either





laid upon the surface of the ground, or placed in an excavation ,prcpared for its reception. As r.
simple, effective, and at the same time an inexpensive mode of holding the buoy-chain down, Mr. Mit-
chell adopted a modification of the screw-pile, Fig. 1792, which offers great facilities for entering the
ground, and when arrived at the required depth evidently affords greater holding power than any
other form. Every description of earth is more or less adhesive, and the greater its tenacity, the
larger must be the portion disturbed before the mooring can be displaced by any direct force. The
mass of ground thus affected, in the case of the screw-mooring, is in the form of a frustum of
a cone inverted, that is, with its base at the surface, the breadth of the base being in proportion to
the tenacity of the ground; this is pressed on by a cylinder of water equal to its diameter, the axis
of which is its depth, and the water again bears the weight of a column of air of the diameter of
the cylinder. It is evident, therefore, that if a cast-iron screw of a given area be forced into the
49
770 FOUNDATIONS.

earth to a certain depth, it must afford a firm point of attachment for a buoy-chain in every direction
(Fig. 1793), and will oppose a powerful resistance even to a vertical strain, which generally proves
fatal to sinker moorings, depending as they do chiefly on their specific gravity. The first trials were
upon a comparatively small scale ; but their success was so decisive that the merits of the moorings
were acknowledged, and their use soon became extended. The depth to which these moorings have
been screwed varies from 8 to 18 feet; the former is deep enough where the soil is of a firm and un-
yielding description, and the latter depth is found to give sufficient firmness in a very weak bottom.
The apparatus used for fixing screw-piles, ‘
Fig. 1794, consists of a strong wrought-iron 1794-
shaft, in lengths of 10 or 12 feet each, cen- '
nected with each other by key-joints or coup-
lings, the lower extremity having a square
socket to fit the head of the centre-pin or
axis of the mooring. When the centre-pin
rests on the bottom, a capstan is firmly keyed, i ,,
upon the shaft at a convenient height; the men \\\ J _
then shift the capstan bars and apply their \:\ ~~ '1 l "
\ . ._:':
# ~ “
—l=; m.“-
I
.
.




power while traveling round upon the stage, _
the capstan being lifted and again fixed as the _ mooring is screwed down into the ground. The operation is continued until the men can no _
longer move the shaft round, or until it is - l',
considered to have been forced to a sufficient depth. ‘ l
The most important purpose to which the
screw-pile has hitherto been applied to any con-
siderable extent is for forming the foundations
of lighthouses, beacons, and jetties, in Sit! a-
tiens where the soil, or sand, is so loose and
unstable as to be incapable of supporting any
massive structure, or where thc'waves have so
much power of undermining by their continu-
ous action, or beat so heavily, that the stability
of any mass of masonry would be seriously en-
dangered.
Figs. 1795 to 1798 represent various forms
of screw-pile. Fig. 1795 shows-the largest size,
weighing 2 cwt. 3 qrs. 14 lbs., adapted for ,
whole timber piles, which are often so splir- l
tered and shattered, and even set on fire, by
the rapid blows of the steam pile-driver, when ‘l
traversing compact ground, and where wrought- i"
iron shoes are generally crushed into the tim-
ber even in ordinary ground with the force of
the common pile-engine. The small screw-point ;
opens the way for the conical part, and the larger screw not only draws the pile down, but,
when it has penetrated to a sufficient depth,
affords an extended base for preventing further _
depression. Thus several feet of timber must I , '5‘
be saved, and the general length of the pile can be reduced, as it will bear a greater weight and offer a more solid base when introduced to ,
a less distance, than when it rests upon the or- |
_ dinary sharp,'wrought-iron-pointed-shoe. Fig. {1’
, 1796 shows the shape'adapted for railw'ay'sjg- ' '
nal-pests, and Fig. 1797 that for the supports
for telegraph wires. The cast-iron screw socket-
points, Fig. 1795, have been successfully ap-
plied for the supporting posts or columns of ..f
timber-sheds and buildings for railway stations lit.“ _
and other purposes. Fig. 1798 shows the ap- ,llyn'il'r'j l,"-
plicability to smaller objects, and a tent-pin has been selected as the most familiar exam-
Q-
ple, as it requires to be removed so frequently.
It also shows the use that may be made of the -
screw for the standards of fencing, and for an infinite number of agricultural and other purposes.
Sheetpiles are flat piles which, being driven successively edge to edge, form a vertical or nearly
vertical sheet, for the purpose of preventing the materials of a foundation from spreading, or of
guarding them from the undermining action of the weather.
_ Piles with disks diifer little from screw-piles, except in the method of sinking them. This opera-
tion was performed at the Leven and Kent viaducts, by sending a jet of water down a wrought-iron
tube inside the cast-iron pile, which washed away the silty sand from underneath the disk and caused
‘l‘illlfillll 'Il‘nllll
| : l
l





.I2. .4
’ l1







_ /
|(-.--__-__-_______- ..-
FOUNDATIONS. 771

the pile to descend. Hollow wrought-iron piles have also been forced down by. blows of a monkey
in silty ground interspersed with bowlders to a depth of about 60 feet, the diameter of the piles
being about 19% inches. The method of cased wells is suitable where the Silt lS sufficiently compact
and water-tight to admit of pumping the well dry, and where the depth of water is small and can
easily be kept out by a cofl’er-dam or caisson
without a bottom. (See FILE-DRIVING MA-
curses.)
Cylindrical Foundations are sunk with or
without the aid of compressed air, according
to circumstances. These foundations possess.
the two great advantages of being capable of
being sunk to a considerable depth, and of
presenting the least obstruction to the current.
In a clay soil the cylinder acts as a movable
coifer-dam, which is sunk by being weighted,
and enables the foundations inside to be built
up easily and cheaply. Iron cylinders are pre-
ferred in certain cases to cylinders of brick,
masonry, or concrete, on account of the ease
with which they are lowered in deep water on
to the river-bed, in spite of the disadvantages
attachingr to them of high price, of the consid-
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erable weights required for sinking them, and, lastly, of being only cases for the actual piers. The
Dutch engineers have often used oval-shaped iron tubes sunk by dredging inside. Thus, in the
bridge on the North Sea Canal the piers are elliptical ; the one on which the opening portion turns
having axes of 23 and 18 feet, and the others axes of 39% and 14 feet. The horizontal flanges and
ribs are larger where the radius of curvature is increased, and the vertical ribs are not continuous,
but arranged so as to overlap. The bridge over the Yssel, on the Utrecht and Cologne Railway, rests
upon cylinders which were sunk by internal dredging 17%} feet below the river-bed. '
The system of sinking by dredging is generally to be preferred to the compressed air system, ex-
cept where numerous obstacles, such as bowlders or imbedded trees, are met with.
The friction between cylinders and the soil depends on the nature of the soil and the depth of
sinking. For cast-iron sliding through gravel the coefficient of friction is between 2 and 3 tons on
the square yard for small depths, and reaches 4 or 5 tons where the depth is between 20 and 30 feet.
In certain adhesive soils it would be more. In sinking the brick and concrete cylinders in the silt of
the Clyde it was found to amount to about 3% tons per square yard.
The various details of the compressed air system are given in the descriptions of the works in
which it has been employed. Theoretically, when the lower edge of the cylinder has reached a depth
of h feet below the surface of the water, the pressure required for driving the water out of the ex-
cavations is atmospheres; but frequently the intervention of the ground between the bottom
of the river and the excavation enables the work to be carried on at a less pressure, as Mr. Brunel
did at Saltash. A considerably greater pressure would be required if the water had to be forced
from the excavation through the soil below the river-bed; but this is avoided by placing a pipe inside
to convey away the water, and M. Triger has found that the lifting of the water was facilitated by
the introduction of bubbles of air into the pipe at a certain height. Pressures of 2 or even up to
3 atmospheres do not injure healthy and sober men, and suit best men of a lymphatic temperament,
but prove injurious to men who are plethorie or have heart-disease. It is advisable to avoid working
in hot weather, and each workman should not work more than 4 hours per day, or more than 6
772 _> FOUNDATIONS. '

weeks consecutively. At Harlem, New York, however, workmen have remained 10 hours under a
pressure of 50 feet, and even 80 feet of water. 0n the other hand, at St. Louis, under a pressure
of little more than 3 atmospheres, several men were paralyzed or died, and the period of work was
gradually reduced from 4 hours to 1 hour. From experiments on animals M. Bart has found that
the accidents caused by a sudden removal of pressure are due to the escape of the excess of gas
absorbed by the blood. Beyond 6 atmoSpheres any sudden return to the normal pressure is attended
with danger; the usual rule now is to allow one minute per atmosphere. The cylinders subjected to
pressure should be furnished with safety-valves, pressure-gauges, and alarm-whistles, as explosions
occasionally occur. Iron rings from 6 to 13 feet in diameter are cast in one piece, and a caoutchouc
washer is introduced at the joints between the rings; cylinders of larger diameter are cast in seg-
ments, and cylinders of smaller diameter than 6 feet are rarely used. The thickness is usually 1%
inch, increased to 1% inch or 1% inch where exposed to blows, in conical joining lengths, and in the
bottom length. When two cylinders have to be sunk close together, it is best to sink them alter-
nately, as they tend to come together when sunk at the same time. At Macon, where there was only
an interval of 33; feet between two cylinders, one of the cylinders was seen to rise suddenly as much
as 6 feet when the other was forced down. Sometimes, where cylinders of small diameter have to
be used, the excavations are extended beyond the cylinder at the bottom, and filled with concrete to _
give a greater bearing surface; this plan was adopted at Harlem bridge, New York, and by the late
Mr. Cubitt, Vice-President Inst. C. E., at the Blackfriars railway bridge. Another way of accom;
plishing the same object is by enlarging the lower rings of the cylinder, and putting in a connecting
conical length, Concrete deposited under compressed air appears to set quicker, and to increase
somewhat in strength, provided it is deposited in thin layers allowing the excess of water to escape.
At Szegedin this was effected by mixing very dry bricks with the concrete.
The foundations of the piers of the Kohl bridge were accomplished by the engineers, MM. Fleur
Saint-Denis and Vuigner, by a combination of the principles of the compressed air process, the sink-
ing of a pier by its own weight, the sinking by dredging, and the cofl’er-dam system. As the bed of
the Rhine at Kehl consists of large masses of gravel liable to be disturbed to a depth of 55 feet
below low-water level, it was deemed advisable to carry the foundations down about 70 feet below
low water. For the two central piers the chamber of excavation was divided into three caissons, the
length of each being 18 feet 4 inches, the width of the foundation. For the piers forming the abut-
ments for the swing bridges there were four caissons, each 23 feet long, the breadth of all the cais-
sons being 19 feet. The plate-iron forming the caissons was three-eighths of an inch thick at the
top, and five-sixteenths of an inch thick at the sides, and strengthened by flanges and gussets. The
top was strengthened by double T beams for supporting the weight of the masonry above. There
were three shafts to each caisson, two being air-shafts, 31- feet in diameter, one being in use while
the other was being lengthened or repaired; the other shaft in the centre was oval, open at the top,
and dipping into the water in the foundations at the bottom, so that the water could rise in it to the
level of the river. In this shaft a vertical dredger with buckets was always working, and the labor-
ers had only to dig, to regulate the work, and remove any obstacles. The screw-jacks controlling
1800.




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the rate of descent had a power of 15 tons, and were in four pairs. The wooden framing serving
‘13 a cofl'er-dam was erected above the chamber of excavation; it was useful at the commencement
for getting below the water, but might subsequently have been dispensed with. _It_ was also found
by experience that the caissons were sunk better in one division than in several dwisions, and dome
of communication were accordingly made through the double partitions. The iron linings to the
air-shafts were removed before the shaft was filled up. The shaft containing the dredger was at
first made of iron, but afterward of brick for the sake of economy. The sinking occupied 68 days
for one abutment and 32 days for the other, giving a daily rate of 1 foot 1 inch and 1 foot 81} inches
respectively. The sinking of the caissons for the intermediate piers took 20 to 30 days, which gives
a daily rate of 2 feet 711; inches (Fig. 1799). y '
For large works, where the load on the foundations is considerable, carrying down the foundations
FOUNDATIONS. 77 3

to a hard bottom is much better than piling. The dredger used at Kchl cannot be regarded as' uni-
versally applicable. Some soils are not Suitable for dredging, and in other cases the small amount
of excavation renders the addition of an extra shaft inexpcdient, as, for instance, at Lorient. The
chamber of excavation is almost invariably made of plate-iron, but, unlike those at Kehl, with the
iron beams above the ceiling, instead of below, so that the filling in may be accomplished more easi-
ly. , The cutting edge is always strengthened by additional plates. At Lorient the thickness was
2,1,,- inches, with several plates stepped back so as to form a sort of edge; the sides were about one-
half of an inch thick at the bottom, and five-sixteenths of an inch at the top, and the roof was
curved a little to increase its strength. There were two air-locks, each connected with two shafts, in
which balanced skips went up and down, Fig. 1802. On the top of the bottom caisson a casing of
sheet-iron, from three-sixteenths to one-eighth of an inch thick, and weighing about 15 tons, was
erected in successive rings. -
At the St. Louis bridge the foundations were carried to a greater depth than had ever been pre-
viously attained; and at the East River bridge compressed air was used in wooden caissons of
large dimensions. The particulars of the St. Louis bridge have been given by Mr. Francis Fox,
M. Inst. C. E. The hydraulic sand-pumping tube of Mr. Eads must only be recorded. The follow-
ing details relate to the East River bridge: The Brooklyn pier was to be carried 50 feet and the
New York pier '75 feet below high water. To provide against unequal sinking, owing to the
variable nature of the soil, consisting of stiff clay mixed with blocks of trap rock, Mr. Roebling
decided to place the bottom of the piers upon a thick platform of timber which formed the roof of
the working chamber, Fig. 1801. The sides were also made of wood, as being easier than iron to
launch and deposit on the exact site. The roof consisted of 5 tiers of beams, 1 feet deep, of yel-
low pine, placed one above the other and crossed, the beams being tightly connected by long bolts.
The working chamber was 167 feet by 102 feet, and 10 feet clear height. The side walls had a V
130] .


section, with a cast-iron edge covered with sheet-iron; the walls had a batter inside outward of l to
1, and 1 in 10 on the outside. Five transverse wooden partitions, 2 feet thick at the bottom, served
to regulate the sinking. “Then the caisson had been put in place, 12 tiers of beams were added on
the roof of the chamber of the Brooklyn pier, and 19 on that of the New York pier, so that the top
rose above water, and the masonry could be built without a coffer-dam lining. The excavation, to
the extent of 19,600 cubic yards, was performed in 5 months by Morris & Cumming’s scoop dredger,
working in two large shafts, dipping into the water at the bottom, and open above. When hard soil '
was met with these shafts were shut, and the excavation performed by manual labor under compressed
air. In the New York caisson the total number of shafts was 9. The blocks of trap rock impeded
the progress considerably; they had to be discovered by boring, and shifted or broken before the
caisson reached them. When under 26 feet of water they could be blown up ; this enabled the rate
of progress, which had been 6 inches per week, to be doubled or trebled. When the caisson had
reached a compact soil, it was possible to reduce the pressure to two-thirds of an atmosphere in ex-
cess of the normal pressure, and water had occasionally to be poured ‘into the open shafts to main-
tain the proper water~level in them. By frequent renewal of the air, a supply was furnished for 120
men and for the lights; and the temperature was kept nearly constant throughout the year at 86°
within the caisson, while in the open air it varied from 108° to 0°. As the load increased as the
caisson went down, the roof of the Brooklyn caisson was eventually supported by 7 2 brick piers, so
that the caisson might not become deeply imbedded in the event of a sudden escape of air. In the
New York caisson two longitudinal partitions were added, which served the same purpose. In the
silty sand which was frequently met with, a discharge-pipe, up which the sand was forced by com-
pressed air, proved very useful, discharging a cubic yard in about two minutes. The New York caisson
(170 feet by 102 feet) was sunk in 5 months; the earthwork removed amounted to 26,000 cubic yards.
7"?4 FOUNDATIONS.

At Bordeaux the air-lock was formed by fixing one circular plate at the top and another at the
bottom of one of the rings of the cast-iron cylinder, so that it was unnecessary to remove it each
time that an additional ring was added. To save loss of air, the air-lock should be opened very sel~
dom, or made very small if required to be opened often. At Argenteuil the air-lock had an annular
form, Fig. 1802, with two compartments 00’, each having an external and an internal door. One
compartment was put in communication with the interior to be filled with the excavated material,
while the other was being emptied by the outer door, so that the loss of air was diminished without
any interruption to the work. Sometimes a double air-lock with one large and one small compart-
ment is used; the large one being only opened to let gangs of workmen pass, and the small one just
big enough to admit a skip and to contain a little crane for moving it. By having a small “air-lock
opened frequently, any sudden alterations
in pressure are diminished. A more com- 1302-
‘ plete arrangement was adopted at Nantes,
Fig. 1803. There a sheet~iron cylinder
was placed on the top of the double shaft r
in which the skips worked, having at one
side a crescent-shaped chamber, a, serving
to pass four men, and also on either side
two concrete receivers, dd', having doors
above and below. There was also a shoot
below for turning the concrete into the





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foundations, and a box, I) c, holding a little ‘ c c _
wagon which emerges at c after having 5 l '
been filled from an upper door b. '
M. Desnoyers gives the following recom- - '
mendations with regard to the choice of
methods of constructing foundations :
1. In still water, to construct the founda- -
tions by means of pumping for depths
under 20 feet. In greater depths, to con-
struct ordinary works on piles if the ground
is firm or has been consolidated by lead-
ing it with earth; otherwise to employ
pumping, and if a permeable stratum is
met with to build on it with a broad base.
For important works, if the soil is water-
tight, it is advisable to adopt the method
of pumping inside a framing, carrying down the foundations to greater depths than 33 feet by the
well-sinking method. If the soil, however, is permeable, dredging and concrete deposited under
water must be resorted to, compressed air being employed for depths greater than 33 feet.
2. In mid-stream, compressed air must be resorted to for foundations more than 33 feet below
water. In less depths the foundations of ordinary works are put in by means of dams or water-
tight frames, if the nature of the silt admits of pumping out the water; but if the silt is permeable,
a mass of concrete is poured into the site inclosed by sheeting. When, however, an important work
has to be executed, it is desirable to use pumps sufficient to overcome the infiltrations. If a perme-
able and easily-dredged stratum lies between the hard bottom and the silt, the method of a water-
tight casing, with a dam at the bottom, should be adopted. To complete these recommendations,
open cylindrical foundations must be included. These may be resorted to, instead of compressed
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air, when the soil is readily dredged or water-tight enough to allow of pumping, and also frequently
in the place of piles or the well-sinking method. The compressed air system is essentially a last
resource, applicable to a bed exposed to scour, and also either difficult to dredge or with bowlders or
other obstacles imbedded in it.
Portable Oqfl‘w-Dam.—Walsh’s portable cofi’er-dam is formed'of water-tight compartments, which,
when the apparatus is to be towed from one point to another, are filled with air only; but when it
is desired to locate the dam, water is admitted into the sections, causing the entire structure to sink
FOUN DING. - 7'75

and rest on the bottom. Fig. 1804 represents the dam in position for the construction of a pier, the
dotted lines indicating the depth of the structure. The forward portion is shaped somewhat like the
bow of a vessel, by connecting together two hinged gates, formed of metal, and each constituting a
compartment similar to those into which the body of the dam is divided. The rear portion of the
structure is provided with similar doors, made so as to secure and fit tightly against the sides of the
pier-end. The manner in which the body is constructed in sections is shown in Figs. 1805 and 1806.
In the latter engraving the rear gates are represented at A ,~ and at B B are the valves which admit
water to the compartments to sink the same. At 0, Fig. 1805, are the plate-piles, which are raised
or lowered by the screws attached to their upper portions. 1) I) are the holding-piles, sliding upon T
irons. Under the body is a keel E. Over the open middle portion is a track to support a dredge,
and pile-drivers and clamping-bars G bind the sides together.
In operation, the sheet- and square piles are first raised so that their lower edges and ends will be
above the bottom of the sections. The latter being emptied, the dam is floated to the desired point
and sunk. The square piles are then forced into the earth to form a solid bearing, the sheet piles
1805.

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being driven in until bed-rock is reached. The water in the middle space is then pumped out, and
building therein is begun. To extend the masonry farther out into the water, the piles are raised
and the dam floated and towed ahead until the rear gates once more embrace the extremity of the
structure. Figs. 1805 and 1806 also show two methods of building a tunnel by the aid of this appa-_
ratus. In Fig. 1805 piles are driven down until their ends meet hardpan, and above them the ma-
sonry of the tunnel is built, as shown, concrete being placed over all. In Fig. 1806 the digging is
carried down to bed-rock, and the masonry is built therefrom upward. The lower part is filled with
concrete up to the level of the tunnel floor.
l'Vorlrs for Reference—See the text-books on civil engineering by Rankine (11th ed., London,
187 6), Malian (2d ed., revised by Wood, New York, 1877), and Wheeler (New York, 1877).
FOUN DING. See Casrme.
FOURDRINIER MACHINE. See PAPER-MAKING.
FRAISING MACHINE. See MILLING MACHINE.
FRAMING. See CARPENTRY.
FRICTION. Friction is the resistance occasioned to the motion of a body when pressed upon the
surface of another body which does not partake of its motion. Under these circumstances, the sur-
faces in contact have a certain tendency to adhere. Not being perfectly smooth, the imperceptible
asperities which maybe supposed to exist on all surfaces, however highly polished, become to some
extent interlocked, and in consequence a certain amount of force is requisite to overcome the mutual
resistance to motion of the two surfaces, and to maintain the sliding motion even when it has been
produced. By increasing the pressure, the resistance to. motion is increased also ; and on the other
hand, by rendering the surfaces more smooth, and by lubrication, its amount is greatly diminished,
but can never be entirely nullified.
Friction ought not strictly to be called a force, unless that term be in this case taken in a negative
sense. The tendency of force, in the rigid meaning of the word, is to produce motion, whereas the
tendency of friction is to destroy motion. An active force may indeed oppose motion in one direc-
tion, but only in virtue of a tendency to produce motion in the opposite direction ; the peculiar char-
acteristic of friction, on the other hand, is that it tends to destroy motion in every direction. It is
essentially a passive resistance, a negative force, produced by pressure, to which it. bears such rela-
tion that its amount may be measured by the same unit and enunciated in the same terms.
Nor is the measure of the friction between two surfaces in contact properly the amount of force
necessary to produce motion, but the amount of pressure necessary to balance the friction, and bring
776 ' ' FRICTION.

the body to a state of indiiference to rest or motion. To understand this, let us suppose that a heavy
hemispherical body rests with its flat surface upon a horizontal plane, and that the plane and the
body are pmfectly smooth: on this supposition there would be no friction, and the smallest possible
force would put the body in motion. This condition being remarked, let us suppose that the surfaces
in contact are of the ordinary kind, and that a weight of 10 lbs. attached to the movable body, and
made to act in the direction of the plane, is found to induce the same state of indifference to rest
and motion as in the assumed case of no friction; we then conclude that 10 lbs. is the measure of
the friction. As it is not always easy to determine when this condition is induced, it is better to
regard the weight as an active force, which may by addition be made more and more intense, till
motion of the body is actually induced. For the sake of convenience we may also speak of friction
as a force, and oppose it to other force: this can induce no erroneous conclusion.
Friction being then considered a passive force, its effect is the result of having other force to resist.
If the measure of the friction of a body upon a plane be 10 lbs., and if an increasing force of 1,
2, 3 lbs., and so on, be applied, the friction increases with the force till the limit is reached; motion
then ensues by the addition of any fraction of weight to the 10 lbs. The force of friction, although
tending to prevent or destroy motion, may also be conceived to act, .
like other force, in a direction opposite to that in which the balan- A B
cing force acts ; that is, in the language of mechanics, if the force ‘
P, applied to balance the friction 1", act in the direction A B, the friction F acts in the direction
B A. If then the body placed upon the horizontal plane, as supposed, be capable of motion in the
two directions A B and B A, the body will remain at rest when acted upon by any force up to 10 lbs.
in either of the directions. If, therefore, we distinguish the forces acting in opposite directions by
the positive and negative symbols '+ and —, then the limits of equilibrium will be expressed by
P : j; 10 lbs., according to the usual mode of representing an equilibrium of ferces.
What is here stated in reference to a heavy body placed upon a horizontal plane, is equally true
of the rubbing parts of every machine: the pressure upon the journals producing resistance to
motion, that is, friction, the equilibrium will subsist between certain limits, and it is only by trans-
gression of those limits on one side that the equilibrium is destroyed and motion established. To
determine accurately those limits in machines is one of the most important problems in mechanics;
and the experiments conducted by the French Academy have furnished data that have long been rec-
ognized as standard. From the results of these experiments certain rules have been deduced that
have been regarded as invariable laws, but which have been brought in question by more recent in-
vestigations. The laws referred to are given below, together with a summary of the results on which
they are based, and references to the later experiments by other investigators.
LAW I.-—The friction bears to the pressure upon the surfaces in contact a ratio which is constant
for the same materials with the same condition of swj'aces. _ a '
To express this somewhat more familiarly: If the surface of one body be pressed upon that of
another with a certain force, and if that force be doubled, the friction will be doubled; and if the
force pressing them together he tripled, the friction will be tripled; and so on. Thus, if a piece of
east-iron weighing 100 lbs. be laid with its plane surface upon a larger surface of brass, level, and
it be found that a certain weight made to act in the direction of the supporting plane is just suffi-
cient to induce in the mass of iron a state of indifference to rest or motion, that weight is the mea-
sure of the friction between the two surfaces; and if these be well polished and clean, and without
lubricant of any kind, the weight which it will be necessary to apply will be 14.7 lbs. If new we
place a weight of 100 lbs. upon the mass of cast-iron, making the gross pressure upon the surfaces
in contact 200 lbs., the weight necessary to balance the friction will be increased in the same ratio ;
that is, F: 14.7 lbs. x 2 : 29.4 lbs. Another weight of 100 lbs., placed on the first, making the
pressure 300 lbs., will increase the measure of friction to 14.7 lbs. x 3 : 44.1 lbs. And so on for
every increment of pressure as expressed by the law.
If new we divide the weight which balances the friction by the weight which measures the pres-
sure upon the surfaces, we obtain a ratio which is manifestly constant, since the pressures upon the
surfaces and the weights balancing the friction, corresponding to these pressures, are respectively.
multiples throughout of the first units 100 lbs. and 14.7 lbs. Thus we have
14.7 lbs. 29.4 lbs. 44.1 lbs.
- . 100 lbs—200 lbs._ 300 lbs.
From this then it appears that, knowing the measure ofthe friction for a given unit of pressure
upon the surfaces in contact, these remaining constant in kind and condition, the measure of the
friction answering to any other pressure may be deduced. In the case assumed we have a common
ratio of .147 as the measure of the friction between the surfaces in contact; this ratio therefore
being known, together with the pressure in the particular case, the measure of the friction for
that case will also be known. Putting P:the pressure upon the rubbing surfaces, F: the


: .147
F
measure of the friction, and f:;; then we have F: f x P.
In this formula the ratio f of the friction to the pressure is termed the coefiicient of friction. Its
value, as already announced, is constant for the same materials and condition of the surfaces in con-
tact, but varies as these vary. Thus in the particular case taken, the value is .147 ; but if the rub-
bing surfaces be wzctaoas, it is reduced to .132; that is, by repetition of the experiments described
above, with this new condition of surfaces, we should find 7
F:f x P: .132 x 100 lbs. : 13.2 lbs.
F :f x P : .132 x 200 lbs. : 26.4 lbs. measures of the friction.
F: f x P: .132 x 300 lbs. : 39.6 lbs.
FRIOTION. * _ '777

If a cast-iron plate be substituted for the brass plate used as the supporting surface, and the sur-
faces be first well polished, clean, and dry, next wetted with water, and lastly be freely lubricated
with hogs’ lard, we have the three values f: .152, f : .314, f: .07, answering to these conditions;
hence, taking P as before, we have, by substitution in the formula F : f x P, the followmg results:
Surfaces wet. Surfaces dry. Surfaces lubricated.
, For 100 lbs . . . . . . . . . . . . . . F: 15.2 lbs. F: 31.4 lbs. F: 7 lbs.
“ 200 lbs. . . . . . . . . . . . . . F: 30.4 lbs. F: 62.8 lbs. F: 14 lbs.
“ 300 lbs . . . . . . . . . . . . . . F: 45.6 lbs. I : 93.2 lbs. F: 21 lbs.
The determination of j, that is, of the coefficient of friction, for different kinds of materials, and
also for different states of their surfaces in contact, is manifestly the business of experiment.
There is no a priori rule by which it can be arrived at in the present state of our knowledge of the
physical properties of bodies.
There is another mode of considering the subject here discussed, which has its expression like-
wise in the subjoined table, and which it becomes us therefore to explain. Let us suppose the
arrangement as in the experiments described, and that A B, Fig. 1807, the supporting surface,
and C' the mass of cast-iron resting upon it.. Again, let the pressure of the mass acting perpendic-
ularly to the surfaces in contact be denoted by P, and let the force Q, parallel to the surfaces, be
applied to slide the body toward A. Then, since the forces P and Q act in directions perpendicular
- to one another, they manifeStly cannot
1807- counteract one another; consequently,
were there no third force F opposed to
Q, the system would be unbalanced,
and there would obviously be motion
P of the mass 0 in the direction of the
secc'md force. The third force F is the
friction, and so long as the force Q
does not exceed its limit, the system
must remain stable. This being under-
7
I


"\c stood, let us suppose that the force P,
Figs. 1808 and 1809, instead of having
G' \ FE its direction perpendicular to the sur-
3 k) A faces in contact, is impressed obliquely;
if then the parallelogram of forces P’
HZOLS' NW Q be completed, the force P, represent-
A ed by the line P ill, is equivalent to
two others represented by P’ M, by
which the sgrfaces are pressed togeth-
er, and Q31, which tends to give mo-
tion to the body in a direction parallel
to the surfaces. Now the actual fric-
tion F of the surfaces must be a cer-
tain fraction of Pill; let it be .31 Q’ =
M F, and complete the parallelogram
P Q', and draw its diagonal P” all.
Since then 111' Q' represents the friction
of the body upon the plane, that is,
the resistance called into action by the
force P111, and since Q 2!! represents
l the whole tendency of P)! to produce
k -._ arr-flg; motion of the body, it follows that the
F Q1 Q M F body will move or not according as
Q fl! is greater or less than Q' ill, that
is, as P P is greater. or less than P" P, or as the angle P J! A is greater or less than the angle
.B .M A. These conditions are shown in the diagrams: in the first there would be motion induced
by the preponderance of force Q Q’ ; in the second, the friction F: ii! Q' being greater than Q )1,
the system would remain at rest.
The angle B 111A is termed the limiting angle of resistance, or more shortly the angle of friction.
P' P"__ ll! Q’,
P M _ P' M
festly the same for surfaces of the same nature, whatever be the actual amount of the impressed
force P, but is different for different surfaces.
From this, then, it appears that the force impressed upon the surface of a solid body, at rest, by
the intervention of another solid body, will be destroyed, whatever be its direction, provided only
the angle which the direction makes with the perpendicular to the surface do not exceed the angle
of friction of that surface; and that this is true, however great the force may be. Also, that if the
direction of the force lie without this angle, it cannot be sustained by the resistance of the surfaces
in contact; and that this is true, however small the force may be.
Law 11.—The measure of friction is independent of the extent of surface, the pressure and the
condition and character of the surfaces remaining the same.
Experiments on sliding friction, made with different materials and with pressures increasing up to










Its tangent is the fraction which is the coefiz‘cient of friction. The angle is mani-
'77 8 FRICTION.

the limits of abrasion, show that the above laws are not universally true, and that the coefficient of
friction does not vary with the pressure and independently of the surface, for all pressures. A
record of these experiments was published in the “Philosophical Transactions” for 1829. Even
before the pressure producing abrasion is reached, it may be so intense as to force out the lubricant,
and thus entirely change the conditions. A familiar example of increase of surface with supposed
advantage is to be found in the enlargement of car-axle journals on American railroads, with the
result, as is generally supposed, of reducing the frictional resistance, on account of the more effect-
ual lubrication that has been possible since the change.
LAW III—The friction is entirely independent of the velocity of continuous motion.
It can safely be asserted that this third law, which is to be found in nearly all modern text-books
on applied mechanics, has been completely disproved by the experiments of Him, Bochet, and Kim-
ball, which are detailed in the Bulletin de la Société Industrielle d0 .Mulltouse, 1854, Annalcs dcs
illines, 1858, 1861, and The American Journal of Science and Arts, March, 1876, and May, 1877,
respectively. Unfortunately, in overthrowing Morin’s law, the experimenters have not furnished a
substitute. Him, who used very light pressures and moderate velocities, announced, as the result
of his experiments, that the coefficient of friction increased with increase of velocity. Bochet’s ex-
periments were made by sliding the wheels of loaded cars on rails, so that the pressures were very
large; and the deduction from his investigations was that the coefficient of friction decreased
as the velocity was increased. Prof. Kintball’s experiments, however, which have been conducted
with a wide range of pressures and velocities, render it probable that each of the laws announced
by the former experimenters is correct for the circumstances under which the trials were made. To
use the last investigator’s own language :
“Morin experimented under conditions which gave him a coefficient very near the maximum, and
thus his results are approximately constant. Bochct experimented with railway trains; his condi
tions were high speeds, hard rubbing surfaces, and great intensity of pressure. All these circunr
stances are favorable to the result he obtained, namely, a coefficient decreasing as the velocity in-
creases. Hirn, on the other hand, employed very light pressures—less than two pounds on a square
inch—and kept his rubbing surfaces so thoroughly lubricated, that the friction was between oil and
oil instead of two metal surfaces; his speeds were not very great. These conditions are precisely
the ones I have found favorable to the results he reached—a coefficient increasing as the velocity
mcreases.
“ The result of my experiments would indicate that the following is the true law, within the range
of my experience : The coefficient of friction at very low velocities is small ; it increases rapidly at
:first, then more gradually as the velocity increases, until at a certain rate, which depends upon the
nature of the surfaces in contact and the intensity of the pressure, a maximum coefficient is reached.
As the velocity continues to increase beyond this point, the coefficient decreases. An increase in
the intensity of the pressure (the number of pounds on a square inch) changes the position of the
maximum coefficient, and makes it correspond to a smaller velocity. The more yielding the mate-
rials between which the friction occurs, the higher is the velocity at which the maximum coefficient
is found. Heating the rubbing surfaces changes the position of the maximum coefficient to a higher
velocity, since by heat the two bodies are made softer, and are caused to yield to pressure with
greater case. For a considerable range of velocities in the vicinity of the maximum coefficient, the
coefficient is sensibly constant.” .
It seems evident from the foregoing that researches on the laws of friction must be greatly
extended before constants that may be accepted without question can be deduced; and the reader
will perceive that the tables which follow, long received as standard authority, contain results that
are not universally true, as already explained.
In estimating the friction of pivots, the coefficient of friction is that of sliding friction multiplied
by a certain constant, depending upon the form of the pivots. The following formula: from
“Des Ingenieur’s Taschenbuch,” Berlin, 1875, show how this constant is calculated. If f is the
coefficient of sliding friction, it may be assumed also as the coefficient of pivot friction, acting with
a __ .3
an arm of gr for a flat pivot with radius 1‘ ,' g X %-%2 for a pivot with an annular base, R and r
. L — '
being the internal and external radii respectively; 5 x 1' for a pivot with a hemispherical base, of
a _ .3
~xFL—9-— >< for a pivot in the form of a frustum of a cone, not hearing on the
3 1t? —- 1'9 SlIl. a
bottom, R and 0' being the two extreme radii in the bearing, and a the angle of inclination;
' gx gig—a for a conical pivot, with radius R, a being the angle of inclination.
If a conical pivot, Fig. 1810, of some soft material, such as chalk, is revolved in a bearing made
of the same material, the bearing having clearance at the bottom as’indicated, it will be found that
the pivot will gradually wear away, until its section is of the form shown by the dotted lines, making
a curve known as the tractrix, and frequently called Schielc’s anti-friction curve. A peculiar prop-
erty of this curve is that tangents drawn from any points to the axis will all be of the same length,
so that a pivot having this section will be pressed equally over its whole bearing surface, thus dis-
tributing the wear. The curve is known as Schiele’s, from the fact that Christian Schiele took
out a patent in 1850 for a method of drawing the curve mechanically, as shown in Fig. 1811. A _
somewhat similar method had, however, been described by Prof. John Leslie, in “Geometrical
Analysis, and Geometry of Curve Lines,” Edinburgh, 1821. In Schiele’s instrument, A is a wooden
radius 1' ;
FRICTION. 77 9

slide, to which the rod B is jointed by a pin 0'. A slide D on the rod carries a drawing pen, and E is
a ruler which acts as a guide for the slide A. To draw the curve, the slide A is placed so that the







rod occupies the position F G, and the slide 1) is then adjusted to the length of tangent required
By moving the slide A along the ruler, the pen in the slide D traces the required curve G H J! 0.
Some applications of the curve are shown in the accompanying figures. Fig. 1812 illustrates a
substitute for the stuffing-box of a locomotive throttle-valve; Fig. 1813
is a section of an end-bearing or pivot; and Fig. 1815 shows the appli- -B.
cation to the grinding surfaces of millstones, the bearings of the stone
also having the same sectional form.
The tractrix can also be constructed by determining a sufficient num-
ber of points, as shown in Fig. 1816. In this figure, the length of the
tangent B O is assumed at pleasure, and laid off at the extremity of a
line, D O, which is divided into a number of equal parts. By making
the divisions of the line D C small, the curve can be constructed by the
‘Q


1816.



l a s n
tangents, as shown, drawing from each point of division a straight line to the point previously deten
mined, and laying off on it the length of the tangent—proceeding in regular order from the starting-
point, which is fixed by the length of the perpendicular CB. By the aid of the numbers on base-
line and curve, the successive steps of the construction can readily be traced by the reader. If t is
vso FRICTION.

A
the length of the tangent in the case of a pivot generated by the revolution 0f such a curve, thearm
with which the coefficient of sliding friction acts is t x f. '
An interesting paper on “ Variable Load, Internal Friction, and Engine Speed and Work,” by Pro-
fessor R. H. Thurston, was read before the A. S. M. E., 1888. Fig. 1816A shows the graphical sum-
mary of the work done to ascertain the method and extent of variation of the friction of the engine with
change of load, other conditions being, so far as possible, retained constant. The lowest curve on
the plate is that obtained from the work On the Jarvis engine, and is considerably lower than any
other, absolutely and relatively. It is a straight line, is parallel to the axis of abscissac, andindicates
constant waste by friction, at all loads and powers. The next curve is that of the 8 x 12 automatic
engine, which is much more variable and less satisfactory as a measure of the true loss ; but it gives
a mean, as shown by the full line, very nearly representative of constant friction; the same is true of
the 7 x 10 traction-engine, and of the '7 x 12 straight-line engine. All give a mean which is practi-
cally independent of the power exerted by the engine. The widest range of work is that obtained
with the compound condensing engine, and extends from zero up to nearly 100 horse-power, the brake
being the measure. This also gives some irregularity of result, but its mean is a constant at all powers,
and is independent of the load on the engine, so far as can be detected in this series of observations.
Finally, the compound tandem engine—a new engine—naturally gives a high measure, comparatively,
of the internal loss by friction; but the law is seen to be nearly the same for variation of load, and
its operation confirms the deductions previously drawn from all other work of this character which
the writer has been able to offer. In both of the compound engines, however, there is some evidence
of a tendency to reduce friction slightly as the power is increased—a change contrary in direction to _
that detected in other cases; but in neither set of examples is this variation great. _
The latest experiments to determine the internal friction of an engine were made by Professor
Carpenter and Mr. G. B. Preston. They first determined the friction of the engine, then dismantled
it part by part, driving the connected parts by a pulley and belt from the main line of shafting over-
head, through a transmitting dynamometer carefully standardized, and thus secured measurements of
the resistance of part after part, until, all the rubbing parts having been thus examined, the sum of
their resistances, at the normal speed of the engine, gave the total internal friction of the engine and
the percentages of the whole due to the resistances of each point of connection or rubbing. An im-
proved dynamometer of the Morin type was used. _ The results are shown in Table I:
TABLE I.—Distribution of .Fi'iction—Straight-Line Engine 6 ft. X 12 ft.
Log of trial with Morin dynamometer.





















, Revolu— H.-P. + 11.-P. cor- Steam-
LBIEZM' Ordinate. in" in lions per g d d Revolu- rected for 230 pressure CONDITION OF ENGINE.
'R" on“ 8' Minute. “e ope ' tions. Revolutions. in Engine.
1... 1.78 34.5 208 1.556 0.007 1.710 Engine complete. Warmed up by steam.
2.. 1.87 36.5 205 1.622 0.008 1.822 .. ()ylinder- head off. Steam - chest cov-
3 _ 1.86 86.5 205 1.622 0.008 1.822 .. ered and pressure-plate 011‘. All cocks
open.
1.20 22.5 230 1.122 0.005 1.122 , . Piston and piston-rod dropped.
5... 1.25 23.25 232 1.169 0.005 1.159
6... 1.27 23.8 244 1.259 0.005 1.189 .. Pressure-plate and steam-chest cover re-
7, _, 1 .28 24.0 2 .5 1 .275 0.005 1.200 40 placed.
23. . _ 2.04 39.0 186 1.573 0.008 1.925 45 Balance-valve converted into slide-valve.
24... 1.90 37.0 186 1 .492 0.008 1 .844 45 Steam-pressure on back of valve.
25.. 1.82 35.0 201 1.525 0.007 1.728 42
26.. 1.81 35.0 214 1.634 0.008 1.75 1 89
27.. 1.92 37.5 201 1 .634 0 .008 1 .868 37
28.. 1.67 34.0 217 1.599 0.007 1.690 74
30. 1 19 22.5 ' 229 1.117 0.005 1.112 _. Slide-valve. piston. and rod still 011‘.
31. 1 80 34.7~ 218 1.642 0.0075 1.732 74
32. 1 .07 19.5 205 0.867 0.004 0.967 .. Main shaft and eccentric.
33 1.03 18.5 207 0.830, 0.004 0.922
34. _ 1.00 17.5 228 0.865 0.004 0.873 .. Eccentric-strap made as loose as possible.
35.. 0.95 16.5 225 0.805 0.004 0.825
36 1.10 19.5 227 0.960 0.004 0.972 .. - Connecting-rod attached to crank-pin.
39. 1 .26 23.0 215 072 —0_.005 1.147 . . Engine complete except piston and rod.
40'. 1.84 35.0 198 1.502 0.008 1.758 75 Slide-valve attached. Cylinder hot.
41. 1.29 24.0 222 1.155 0.005 1.195 .. -
42. 1 92 37.5 211 1.715 0.008. 1.867 67
45. 1.24 23.0 223 1.112 0.005 1 .147 .. Slide-valve dropped. Valve-rod still at-
tached.
47 1.39 26.0 222 1 .251 0.006 1.195 .. Balanced valve. Pressure-plate and cover
43. .. 1.28 23.5 223 1.121 0.005 1.171 .. off.
43. . 1.29 24.0 224 1.165 0.005 1 .299 .. Pressure-plate and cover added.
- 1.22 22.5 228 1.112 0.005 1.222 58 _











The Friction of Metal ‘Coils.-—Coil friction has been used as a powerful means of communicating
or retarding motion. The chief applications have been made in connection with clutches‘and brakes.
FRICTION. 781

The metal coil is either wound round a shaft or the sleeve of a pulley, or contained in a cylinder at-
tached to either. One end is brought into fractional contact with the shaft, sleeve, or cylinder, and
is thus carried round it the surface be in motion, or retarded if the coil itself be in motion and the
surface at rest. The attachment of the “head” of the coil prevents its following the tail until a
1816A.


a.
“GIG s:
0,1,! \




N
considerable tension is put upon the whole coil. Thus, if the coil encloses the shaft or sleeve, it is
made to wind up upon the shaft, becoming of less internal diameter and taking a frictional grip-
throughout its whole length; but if, on the contrary, it is enclosed in a cylinder, it is made to unwind,
and so expand. In either case the result is the same.
782 FURNACES.

Lubricants—The desirable features of a good lubricant or unguent may be briefly stated thus:
It should first of all reduce friction to a minimum, should be perfectly neutral, and of uniform com-
position. It should not become gummy or otherwise altered by exposure to the air, should stand a
high temperature without loss or decomposition, and a low temperature without solidifying or deposit
ing solid matters. The questions of cost and adaptability to the requirements of light or heavy bear-
ings are also important considerations. The finest lubricating oils in the market—those used for
watch, clock, and similar delicate mechanism—are chiefly prepared from sperm-oil by digesting it in trays
with clean lead-shavings for a week or more. Solid stearate of lead is formed, and remains adhering
to the metal, while the oil becomes more fluid and less liable to change or thicken on chilling. Sperm-
oil is used for lubricating sewing-machines and other light machinery. Some of the oils sold for this
purpose contain cotton-seed oil and kerosene, and others are composed largely of mineral, sperm, or
signal oil—a heavy, purified distillate of petroleum. Good heavy lubricating oil is made from heavy
paraffine-oil (a distillate of petroleum). Owing to “cracking” (decomposition of the vapors of the
heavy distillate into lighter products), which takes place in the still, the crude oil contains a large per
cent. of light offensive oils, too thin for lubricating purposes. In Merril’s process these are sepa-
rated by blowing superheated steam through the oils, heated just short of its boiling-point in the
still, the lighter oils being driven ofi, a neutral, nearly odorless, heavy oil, gravity 29° B. to 26° B.,
and boiling at about 575° Fahr., remaining. When mixed with good lard-oil it makes an excellent
and cheap lubricant. Common heavy shop and engine oils are variable mixtures of heavy petroleum
or paraffine oils, lard_oil, whale or fish, palm, and sometimes cotton-seed and resin oils. There are
nearly as many of these composite oils in the market as there are ,dealers in such supplies. The fol-
, lowing is one of them: Petroleum, 30 per cent.; pat-affine-oil (crude), 20 per cent.; lard-oil, 20 per
cent.; palm-oil, 9 per cent. ; cotton-seed oil, 20 per cent. Solid or semi-solid unguents, such as mill
and axle grease, are prepared from a variety of substances. The following are the compositions and
methods of compounding a few of these: '
Frazer’s axle-grease is composed of partially saponified resin-oil—that is, a resin-soap and resin-oil.
In its preparation 4; gal. of N o. 1 and 2% gals. of No. 4 resin-oil are saponified with a solution of Q; lb.
of sal-soda dissolved in 3 pts. of water and 10 lbs. of sifted lime. After standing for 6 hours or
more, this is drawn off from the sediment and thoroughly mixed with 1 gal. of N o. 1, 3} gals. of No.
2, and 43 gals. of No. 3 resin-oil. This resin-oil is obtained by the destructive distillation of com-
mon resin, the products ranging from an extremely light to a heavy fluorescent oil or colophonic
tar. Pitt’s car, mill, and axle grease is prepared as follows: Black oil or petroleum residuum, 40
gals; animal grease, 50 lbs.; resin, powdered, 60 lbs.; soda-lye, 2% gals; salt dissolved in a little
water, 5 lbs. All but the lye are mixed together and heated to about 250° Fahr.
The following are a few of the compositions for lubricating that have been patented: Petroleum
residuum, alkali, ammonia, and saltpctre. Graphite, oil, and caoutchouc. Asbestos and grease.
Lignum-vitze and spermaceti. Ivory-dust and spermaceti. Tin and petroleum. Zinc and caoutchouc.
Plastic bronze and caoutchouc. Tallow, palm_oil, salts of tartar, and boiling water. Oil, lime, graph-
ite, castor-oil. Shorts, soapstone, castor-oil. Petroleum residuum, salt,caustic potash, sal-ammo-
niac, spirit of turpentine, linseed-oil, and sulphur. Petroleum residuum and flour. Petroleum re-
siduum, lard, sulphur, and soapstone. Mixed heavy and light petroleum. Oil, wax, caoutchouc,
resin, and potash. Petroleum residuum, sal-soda, sulphur, and kerosene. Glycerine, graphite,
asbestos, kaolin, manganese, soapstone, sulphide of lead, carbonate of lead, and cork. Saponi-
fied resin, wheat-flour, petroleum, animal fat, and soda. Type-metal and caoutchouc. Anthracite
coal and tallow. Tin oxide and beeswax. Soapstone, magnesia, lime, and oil. Sulphur and pe~
troleuln. Vulcanized caoutchouc, petroleum, and tallow. Paraffinc-oil and milk of lime. Asbestos
and tallow. Spermaceti and India-rubber. Tallow, petroleum, soda, and hair. Mercury, bismuth,
and antimony. Petroleum, sal-soda, lime, tallow, lard, salt, pine-tar, turpentine, camphor, and
alcohol. Sulphur, plumbago, mica, tallow, and oil. Palm-oil, paraffine, tallow, alkali, and asbestos.
Tallow, oil, paraffine, and lime-water. Flax-seed oil, cotton-seed oil, tallow, and lime-water. Petro-
leum, tallow, beeswax, soda, and glauber salt. Animal oil, croton oil, spermaceti, tallow, soda, potash,
glycerine, and ammonia. Sheets of paper of woven fabrics impregnated with graphite, steatite, par-
affine, tallow, size, and soluble gums.
FURNACES. Furnaces, as used in the arts, may be defined as the arrangements under which fuel
is burned to produce heat, for the purpose either of inducing permanent changes in the substances
heated, or of preparing them, by softening or fusion, for subsequent treatment. This excludes two
of the applications of fuel which together take up the larger proportion of that consumed: the
domestic use, namely, for cooking, and for warming, lighting, and ventilating inhabited places (see
GAs, ILLUMINATING, APPARATUS FOR MANUFACTURE or, and S'rovns AND HEA'rmeFURNAcEs); and
that for the generation of motive power (see BOILERS, STEAM).
Furnaces may be divided into those in which solid fuel is intermixed with or directly surrounds
the matters to be heated, and those in which the heating is done, in one way or another, by flame,
without direct contact between the fuel and the object acted upon. The characters of the fuel best
fitted for these two kinds of furnace are essentially different. Where the matters to be acted on,
or the vessels that contain them, are in direct contact with the fuel, as in a smithy fire, a cupola, or
an ordinary coke-furnace for melting steel or brass in crucibles, an intense local heat is required in
the mass of the fuel itself, and any heat developed above its surface is useless. In flame-furnaces,
on the other hand, such as those for glass-melting or for puddling or heating iron, in which the
materials to be heated are not imbedded in the fuel, but placed in a chamber above or at the side of
it, the heat made use of is that of the flame; the heat that is carried into the working-chamber by
the current of gases rising from the fire, together with that due to the further combustion of these
gases on admixture with an additional amount of air. Thus, for furnaces of the first class, the
most suitable fuel is one—such as charcoal, coke, or anthracite—consisting of nearly pure carbon,
FURNACES. 783

free from volatile matter, as this is useless in them as a source of heat, and the driving of it off
renders latent a certain amount of that generated by the combustion of the carbon, and so lowers
the temperature of the fire.
In flame furnaces, a lowering of the temperature at the fire-grate, where the air and the solid fuel
meet, is immaterial, or may be even advantageous, as tending to diminish loss by radiation and to
preserve the furnace from injury by excessive heat. The only use of the heat at the grate is to
generate a full supply of combustible or partly burned gases at a high temperature, which in com-
pleting their combustion, as they pass over the working bed, shall heat as strongly as possible the
matters placed there. The fuel preferred for use in such furnaces is thus either a combustible gas,
or a solid fuel containing hydrogen as well as carbon, such as coal or dried wood, that will produce
on burning a long and powerful flame. A flame, it is true, may be obtained from fuels that contain
little else than carbon and mineral matter, by burning them in a thick bed, so that the greater part
or nearly the whole of the 009 formed in the first instance by the combustion of the carbon is
transformed into 00 as it passes up through the mass, and by introducing with the air as large a
proportion of steam as can be used without lowering the temperature of the fire. The steam is
decomposed by the hot carbon, producing, according to-the temperature and thickness of the fire, a
mixtureof either H and 002 or H and CO. The gases thus generated, together with the mixture of
CO and N produced by the passage of the air itself through the mass of fuel, flow forward into the
working chamber, and there burn, on mixing with a further supply of air introduced above the fire.
I. Fumucss IN WHICH FUEL AND MATTER TO BE HEATED ARE MIXED.-—-C’alcz'nation Furnaces.—
Examples of the simplest form of the class of furnace in which solid fuel is mixed directly with the
matters to be heated are the heaps in which brick-clay is burned to make ballast, and in which iron
and other ores are often calcined. In these, the ore or dried clay, in pieces of convenient size, is
thrown into a heap together with a little coal; and the mass, being lighted at one end, burns through
to the other. In calcining such heaps there is a considerable waste of heat, as a great proportion
of the burned gases from the fire pass off at a high temperature ; and when the calcination is com-
pleted, all the heat that the red-hot mass contains is lost. In an ordinary lime-kiln, a much larger
proportion of the heat produced is utilized, and the amount of this required is proportionately
reduced. (See KILN.)
Crucible Fumaces.--The small furnaces fired with coke that are commonly used for melting steel
or brass in crucibles require no detailed notice. In these the crucible is imbedded in the fuel, and a
rapid combustion and high temperature are maintained round it, by closing the upper part of the
furnace and connecting it to a high chimney. (See Casrmc, CRUCIBLE, and STEEL.)
Forge Furnaces—Where, as in the case of a smithy fire, the top of the furnace cannot be con-
veniently closed in, or where a keener combustion is required than can be obtained by chimney
%raught, the plan is adopted of forcing air into the fire by mechanical means. (See BLOWERS, and
ORGE.
Bias; Furnaces and Cupolas are largely used in smelting the ores of iron, lead, and copper, and in
fusing cast-iron and other substances. In all these, the fuel and the materials to be melted or other-
wise acted on are charged together into the upper end of a vertical shaft, and the combustion is
maintained by air forced in through one or more openings or tuyeres near the bottom. (See BLOW-
Eus,FuuNaoEaIBLasr,andIFURNacns,CuroLaJ
II. FLAME Fuauacss.—These are very varied in form and character. Their useful effect is ob-
tained by bringing a flame or current of highly heated and burning gas into contact with the mat-
ters to be acted on, instead of imbedding these in or mixing them with the solid fuel. '
Reum'bm'atory Furnace—The ordinary reverberatory furnace, with a fire-grate, a flame-chamber
or working chamber, and beyond that a fine leading into the chimney, is well known. An example
is given in Figs. 1828' to 1831. A A is the hearth
and building upon which the furnace is erected. It is lined throughout with fire-bricks, and the hearth is '
formed at a slight inclination, so that the flame and
heat may more effectually react from the arched roof
upon the work placed on it. B B, the roof and sides
of the furnace, also formed of fire-bricks. The roof
is arched throughout its entire length, in order that
the heat may be reflected and concentrated upon the
work placed on the hearth. C C, the sheet-iron sides
of the furnace, by which the brickwork is secured
and retained in its proper form. D .D, the end plates
for binding the side plates together. Instead of being '
riveted to the side plates, they are secured by bolts
and nuts, so that the whole structure may be easily
taken asunder when it is necessary to rebuild the fur-
nace. E, the ash-pit. F F, cross-bearers of wrought-
iron for supporting the furnace-bars a a a. The ends
of the bearers rest in small cast-iron brackets bb,
secured to the sides of the ash-pit 6?,the passage
to the chimney, formed in continuation of the arch of
the roof. H H, the chimney, constructed internally and throughout its entire height of fire-bricks.
I1,corner-pieces of ordinary bricks built upon the angles of the interior chimney to give stabil-
ity to the whole structure, which is further bound together by bolts (1 d d passing through the
small cast-iron pieces a c c. J J, cast-iron sole-plate for supporting the brickwork of the chimney,
and which is itself supported by KK, four strong cast-iron columns resting on a solid foundation


1828.


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FURNACES. 7 85

of mason-work. L, the stoke-hole, through which the fuel is introduced into the furnace. The
mouth of this stoke-hole is so constructed as to admit of its being stopped with a piece of coal
when the furnace is in full operation. M, a small square aperture in the side of the furnace by
which the attendant is enabled to inspect the state of the furnace without interrupting the progress
of the work. It may be stopped with a single brick. N N, the main openings into the furnace,
through which the shaft or other work to be heated is passed. 0, the sliding door by which the
aperture N is guarded. It consists of a square cast-iron frame, lined internally with fire-bricks, and
fitted to slide vertically between guides of angle-iron. .P P, levers working upon the cast-iron
brackets Q Q, surmounting the furnace. They are loaded at the outer ends with counterweights,
and attached by short connecting-rods to the doors 0 0, so as to enable the stoker to raise or lower
the latter with the utmost facility. R, a register or damper surmounting the chimney, for the pur-
pose of regulating the draught of the furnace. It is brought within the command of the attendant
workman by means of a long chain or wire e e, depending from the lever upon which it is hung.
Gas Furnaces—The most important modification of this form of furnace is the regenerative gas
furnace of Messrs. Siemens, for which see FURNACES (GLASS-MELTING), IRON-MAKING PROCESSES, and
STEEL. The Ponsard furnace differs from the Siemens in that the air only is heated by the re-
generator. The gas-producer is placed close to the furnace, and the gas from it taken directly,
without further heating, to the point where it is burned. A theoretically advantageous modification
of this furnace is to supply the gasproducer as well as the working chamber of the furnace with
highly heated air from the regenerater.
The following practical directions are from The Engineer, Nov. 30, I877 :
“The success of a direct-acting gas furnace, or, indeed, of any gas furnace, will greatly depend on
the suitable form and arrangement of the producer—more especially with reference to the peculiar
kind of coal to be burnt. The gas should as much as possible be made to rise up toward the com-
bustion-chamber, more especially in cases where only the natural draught of the chimney is em-
ployed. The simplest means of doing this is to place the producer under the level of the ground.
The brickwork must be very good; the mortar of a fat clay, with a sharp quartzose sand ; good fire-
brick and fire-clay for the parts exposed to great heat. Herr Ramdehr strongly recommends mixing
cheap treacle in the mortar to be used. The number and dimensions of the stoking-holes must be
made to suit the eaking or non-caking properties of the fuel. It is advantageous to make several at
first, which can afterward, in the course of working, be bricked up if found unnecessary. An eye-
piece, best made of a plate of mica set in an ir0n frame, is very useful. A step-grate is generally
best for slack, but an ordinary flat grate, set either horizontally or on an incline, suits caking coal
better. The grate should be made of as small an area as practicable, and its bars cast of good soft
foundry iron, it being of great importance that they should not bend under the heat. In order to
prevent the loss of tar, the need of a tar-trap, the chances of losses of gas, of explosions, and the
deposit of soot, the gas-channels between the producer and gas-chamber should be as short as is con“
sistent with the fire not being in communication with the producer itself. If long gas-channels be
absolutely required, they must be laid 18 inches to 3 feet under the ground; but they always act as
condensers for the tarry products in the gases. The horizontal section of a gas-producer will be gen-
erally square; stoking- and cleaning-doors must be provided for easily removing the ashes. A cir-
cular section is, however, much to be preferred, whenever it can be adopted, as sharp corners catch-
ing the slack are thereby avoided. A damper is necessary, in order to regulate and shut off the gas.
In any case great care should be exercised in setting the gas-channels on a gradual incline between
the producer and the spot where they are to be burnt.
“ The layer of fuel in immediate contact with the grate is set alight, and is the prime agent of the
process ; the layers above gradually going through the three successive stages of drying, coking, and
b.1rning. If the fuel in the producer were pure carbon, burning to carbonic oxide with the exact
modicum of 6 lbs. of air, each pound of carbon would give off 4,400 thermal units, which, divided
by the mean specific-heat times the weight of ‘7 lbs., would give more than 2600° F. as the elevation
of the temperature; but it is more probable that at least 1000° must be struck off this for sundry
losses, bringing the. beat down to 1500° at the very most, in round numbers. The comparatively low
temperature at which the producer can be worked very considerably diminishes the wear and tear of
the bars; and, as compared with the loss of this kind in ordinary furnaces, the saving is generally
one-half in this item. The lower temperature of the clinkers prevents their acting as a flux with the
iron and eating it away.
“ The capital point to be borne in mind is that, if the air be in excess, then carbonic acid is evolved-
the carbon must be in excess to obtain the required carbonic oxide.
“It is evident on consideration that a very important and considerable source of economy in
the use of a gas-producer is that no loss can occur through unconsumed bits of coal dropping
down between the fire-bars into the ash-pit. 13h some producers a steam-jet is employed to induce
a current of air, but the decomposition in this way of steam into its elements is a very uncertain
operation. ‘
“ The combustion-chamber has the function of mixing the gases with the atmospheric air, in order
to oxidize (to burn) them. The apparatus for mixing the air and gases either consists of a suitable
number of concentric double jets—one for the gas, the other for the air—or the air is blown through
a number of small tuyeres, or narrow slits, set at a certain angle against the current of gas as it
streams out of an oblique annular slit; or, lastly, one of the two is caused to impinge against a fire-
brick screen, thereby breaking it up into numerous currents, and bringing them into contact with the
stream of the second fluid as it issues from a concentric outlet. Generally, the best means of com-
bination is to bring the pair of streams at an angle against each other, and as little as possible in a
parallel direction. In order to obtain an intense heat, it is best to let the gas flow out horizontally,
directing the air at a sharp angle on to the stream of gas. The specifically lighter gas strives to rise
50
786 FURNACES.

up through the stream of air, thereby mixing itself so rapidly with it that instantaneous combustion
takes place. By regulating the respective quantities of gas and air, it is very easy to obtain either a.
reducing or an oxidizing flame, as required. Generally speaking, the combustion-chamber should be
easily looked into from the outside. The outlets are best made of equal cross-sectional areas, and
the respective quantities proportioned to each other by means of dampers or valves. It is necessary
to be careful not to let in an excess of atmospheric air, as otherwise the great saving in fuel of at
least one-third or a quarter, compared with the common grate, is lessened.”
Grifiin’s blast gas furnace, for metallurgic operations requiring high heat, is shown in section in
Fig. 1832. Two fire-clay cylinders, a a, form the body of the furnace. 'l'hey rest upon a perforated
1834.
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fire-clay plate 6, into which the gas-burner, c, is introduced. A plumbago crucible, d, sets upon a
perforated plumbago cylinder, 0, and is covered to a considerable depth with quartz pebbles from half
an inch to an inch in diameter; ff are plugs which may be removed to admit of inspection. The
burner is represented in Fig. 1833, and consists of two chambers of cylindrical cast-iron, one for the
reception of air and the other for gas. Tubes, varying in number from 6 to 20 or more, pass from
the air-chamber through the gas-chamber, and through the axes of tubes passing from the latter,
thus securing admixture of the combustible gases. A stand 9, Fig. 1832, supplied with a thumb-
screw, holds the burner at any desired distance below the crucible. The gas is supplied at the usual
pressure, but the air is urged with a bellows or other blowing machine at about 10 times that pres-
sure. In the experiments made by the inventor, the gas and air pipes were of half an inch calibre
and 10 inches long, the gas having a half-inch and the air a five-inch water-pressure. The quantity
of gas used per hour was about 100 cubic feet. Fig. 1832 represents the furnace with the gas-burn-
er in an erect position, but it is perhaps more frequently used at the top, inverted, as shown in Fig.
1834, in which an additional perforated clay plate, h, is laid on the top of the upper clay cylinder.
Into the perforation the burner is introduced, and when in action throws its flame down upon the top
of the crucible, d, which is now placed upon a foundation of clay plates, k k k, raised to the proper
height, and of such a size as to leave a vacant space between them and the clay cylinders, which is
filled with quartz pebbles, and through which the burned gases pass on their exit, which is now
through perforations in the two lower clay plates. The hot gases give up nearly all their heat to ' he
pebbles, and escape at a much lower temperature than would be supposed. The following experi-
ment shows the power of this furnace: A clay
1835. crucible, 3 inches in both diameters, was filled
~ ~ with 24 ounces of cast-iron, and not ccvered.
The flame being thrown directly upon the iron, it
was soon covered with a crust of magnetic oxide.
In 20 minutes the crucible was removed, and a
hole being broken through the crust, 20 ounces of
melted iron was poured out. In the same furnace
16 ounces of copper can be fused in 10 minutes,
commencing with the furnace cold, or in '7 min
utes after it is hot. Gore’s gas furnace is heated
by a burner in which the 'air and gas are more
thoroughly mixed previous to ignition than in Grif-
fin’s, but it is generally used in smaller operations.
Furnaces for Burning Powdered Fuel—Fig. 1835 represents Perret’s furnace for burning any sort
of pulverulent fuel, such as sawdust, coke- or coal-dust, etc. It consists of four stories or chambers
of fire-clay, and an ash-pit beneath. The front is pierced with three openings, the upper pair of
which are for charging the-furnace, and the lower one affords access to the ash-pit. The furnace is
fed with air previously heated by circulation in a chamber in front of the doors, and afterward led
in through the ash-pit. Combustion is thus effected at the elevated temperature due to the heat-
ing of the air and the close approximation of the platforms, and the incineration may be carried to


FURNACES. 787
a“


extreme limit. About 10 kilogrammes of fuel are burned per hour and per square metre of plat-
form surface.
Crampton’s furnace for burning powdered fuel is a remarkable deviation from the ordinary form
of flame furnace. The coal is finely ground, and by a mechanical feeding arrangement is led into a
jet of air from a fan, at a pressure equal to 3 or 4 inches water-column, by which it is carried for-
ward into the furnace. In this the jet of mixed coal-dust and air takes fire and burns like a jet of
combustible gas, except that the flame is solid, and not hol-low like a gas-flame burning in air. (See
IRON-MAKING Pnocsssns.)
Among the directions in which improvements have been effected in flame furnaces of the ordinary
type are the use of the waste heat to raise steam, a system now carried out to a greater or less extent
in all iron works where such furnaces are used. The Newport furnace of Mr. Jeremiah Head (sec Jour-
nal of the Iron and Steel Institute, 1872, p. 220) may be taken as an example of such furnaces. In
this the blast-pressure is obtained by a steam-jet, and the resulting damp air is heated to about 290°
C. by passing it through a cast-iron heating stove, round which the waste flame is led on its way to
the chimney. The hot blast is conducted partly under the fire-grate, and partly to a row of holes in
the furnace roof immediately over the fire, through which a supply of air is thus introduced, sufficient
to complete the combustion of the gases rising from the fire.
Another improvement is the employment of a blast or forced draught under the fire-grate (the air
in it being frequently more or less heated), in order to allow of burning cheaper small coal, and to
give a command, such as that possessed by the regenerative gas furnace, over the pressure in the
working chamber. Price’s retort furnace (for which see IRON-MAKING PROCESSES and Journal of the
Iron and Steel Inslz'lule, 1875, with maps, etc.) is an example of this class.
Arrangements have also been devised for preventing the cooling down of the fire each time that
fresh fuel is put on, and the rush of cold air into the furnace through the opened fire-door when a
pressure is not maintained in it by blast. Frisbie’s feeder, designed for this purpose, consists of
a movable charging-box, which when filled with coal is pushed up into the middle of the fire-grate,
so that the surface of the fire remains always hot; and as the distillation of the gases from the raw
coal goes on continuously, the fire remains uniform in character, and may be readily kept smokeless.
(See Iron, viii., 516.)
Natural Gas in Furnaces—When hydrogen and hydrocarbon gases are found to flow naturally
from bore-holes penetrating to beds of coal or shale, they form a valuable fuel, which is made use
of to a considerable extent. In some parts of Pennsylvania, from bore-holes put down for petroleum,
a supply of gas, consisting chiefly of marsh-gas (0H,) mixed with other hydrocarbons and with hy-
drogen, is permanent and apparently inexhaustible. Messrs. Rogers 82 Burchfield of Leechburg,
Armstrong 00., Pa, were the first to use this gas in their paddling furnaces. The only change neces-
sary in the latter was to brick up the bridge of the furnaces and let the gas in through iron pipes,
supplying air by a blast. Blast-pipes were also inserted in the crown of the furnace in such a way
that the blast should strike the metal at an angle of 90°, blast being let on at the commencement of
the boil. ,A notable economy in iron production has resulted from this utilization. The most remarka-
ble gas wells in the United States are those located in Parker township, Butler 00., Pa. For heat-
ing, the gas is a perfect fuel, causing little waste and protecting the furnace bottoms, while the
transparency of the flame allows the heater to see each pile at any time. The quantity issuing from
a half-inch pipe suffices to heat up and supply a puddling or heating furnace. (Sec Engineering and
Mining Journal, March 18, May 22, and J unc 26, 1875 ; also “Iron Manufacture in America,”
Pearse, Philadelphia, 1876.)
Petroleum Furnace—A petroleum furnace, to work successfully, should be so constructed as to
secure intimate mixture of the gases, complete combustion in the body of the furnace, and a supply
and pressure of the incandescent steam, air, and oil adjustable to the varying working conditions.
The Eamcs furnace, which has given successful results on trial, is constructed as follows : The shape
of the body of the furnace differs but little from the ordinary iron furnace, but in place of the fire-
place and ash-pit are a vapor-generator, a superheater, a mixing chamber, and a combustion-chamber,
while in close proximity, as a very important part of the apparatus, is a small force-pump. The
superheater is a double casting, inclosing the fire, so chambered that the steam which enters it is
brought in contact with ample heating surface before passing into the vapor-generator, about 150 lbs.
of coal per dicm being used in this. The vapor-generator is a cast-iron vessel of about 18 x 30
inches internal dimensions, placed over the superheater, and containing a number of shelves or plates
set one above another, projecting alternately from opposite sides. Next in order is the mixing
chamber, where the steam and oil vapors are mingled with the proper amount of air; and beyond
this, occupying the place of the usual bridge-wall, is the combustion-chamber, which is an indispen-
sable part of the apparatus, though it consists simply of a cellular tier of fire-bricks placed on end
‘and having a horizontal thickness of 18 inches. Within these cells the combustion begins. From
a tank placed in any convenient position the pump draws the petroleum, and forces it, at about
10 lbs. pressure, into the vapor-generator in a very slender stream, where it flows downward in a thin
layer, dropping from shelf to shelf. It thus meets the opposing current of superheated steam which
passes upward from the superheater; thence the combined vapors or gases pass through a pipe to
the mixing chamber to receive the required amount of air, and from this into the cellular combustion-
chamber, where begins the combustion, which is completed in the furnace itself. For the purpose
of guaranteeing absolute safety in the use of this fuel, the pump is fitted with what is called an
equalizing valve, which absolutely regulates the flow of the oil into the generator, and at the same
time interposes an insurmountable obstacle between the generator and oil-tank to any chance reaction
of gases or flame. Pressure-gauges on the oil-feed pipe and on the generator serve to give further
security in the manipulation of the apparatus. Of late years, in repeated instances of continuous
working, the actual efficiency of petroleum in firing boilers has been shown to be from two to three
'7 88 FURNACES, BLAST.

times greater than that of the best solid coal, weight for weight, and in paddling and heating furnaces
from four to six times greater; while in steel-melting furnaces its superiority is still more manifest,
its thermal effects being more decided the higher the temperature required.
See papers on “Liquid and Condensed Fuel,” by Captain Selwyn, t. N ., in Engineering, ix., 310,
and v., 321 ; “A Treatise on Metallurgy,” Crookes and Rohrig, vol. iii., London, 1870 ; and “ Metal-
lurgy (1*‘uel),” Percy, London, 1875.
Heat utilized in li'urnacea—In nearly all furnaces, the amount of heat that is utilized is an ex-
tremely small proportion of the total heat due to the combustion of the fuel ; the greater part being
carried off by the burned gases, or lost by conduction and radiation. M. Gruner calculates that in
the fusion of steel in crucibles in ordinary coke furnaces, the heat utilized does not exceed 1.7 per
cent. of the total amount that the fuel would be capable of giving out if perfectly burned; and that
even the extreme supposition that half the fuel is burned to C0, the heat utilized amounts to only
2.6 per cent. of that evolved. In flame furnaces the proportion of heat utilized is higher, reaching
as a maximum 15 to 20 per cent. of the total heat due to the amount of coal burned, in well-arranged
regenerative gas furnaces for heating iron. In these arrangements in which there is little heat lost
by external cooling, and in which the heat of the products of combustion is most fully utilized, the
useful effect is much higher; thus in large blast furnaces M. Gruner estimates that it is as much as
70 to 80 per cent. of the heat actually developed in the furnace and introduced into it by the blast,
or between 40 and 50 per cent. of the total heat that the fuel could evolve if completely burned;
and in the annular I-Iotl'man brick-kiln (see BRICK-MAKING MAenmnav), it is estimated to amount
also to between 70 and 80 per cent. of that given out by the fuel. The greater the proportion of
heat evolved that is lost in the burned gas, the less the difference is between the temperature of the
flame and that required to be maintained in the working chamber; for as soon as any portion of the
flame is cooled down to the temperature of the matters to be heated, however high this may be, it
can impart no more heat to them, and must be drawn away and replaced by hotter flame from the
fire. Hence a small increase in the initial temperature of the flame, such as that obtained by effect-
ing the combustion of the fuel by means of a moderately heated blast, or a small diminution in the
proportion of heat lost from the working chamber by external cooling, effects a great saving in the
consumption of fuel that is required to do a given amount of work.
The effect of a high flarnctemperature on the proportion of heat utilized is strikingly shown by
the very economical working of furnaces on Dcville’s system, that of burning coal-gas with oxygen
instead of with air. The theoretical temperature of such a flame, if not limited by dissociation,
would probably amount to 7000° or 8000" C., and it is in any case far above the fusing-point of
platinum, which is estimated at about 1900° C. In an example, of which M. Gruner gives particu-
lars (see Annalee (les Mines, 1876), of the fusion of a charge of 250 kilogrammes of platinum by this
method, the cold furnace was heated up, and the metal melted in it, in 1;} hour, with a consumption
of only 848 cubic feet of gas; the proportion of heat actually utilized in the fusion of the metal
being 14 per cent. of that due to the combustion of the gas. Thus, on account of the intense heat
of the oxyhydrogen flame, as good an economical result was obtained in this little furnace as in the
best of flame furnaces used in ordinary metallurgical work; though the proportionate loss of heat
from the surface-cooling of so small a furnace (a little trough not more than 30 inches long) must
have been enormous. (See “Furnaces for producing High Temperatures,” Jt'ng'incm'z'wg, xi., 181.)
The diminished proportion of heat that is lost by surface-cooling in the case of large furnaces, and
the consequent higher temperature of their flame, render them in all cases much more economical in
fuel than furnaces of smaller size. In the case of ordinary puddling furnaces, for instance, where
the coal consumption in those working 500-lb. charges is about 2,350 lbs. per ton of bar produced,
the consumption is reduced to 1,800 lbs. per ton in working 1,000-lb. charges, and to 1,500 lbs. per
ton in still larger furnaces working 1,500~lb. charges. In the welding furnaces in use at the W 001-
wieh Arsenal, the larger the furnace is, the higher by actual experiment is the temperature of the
flame as it passes over the bridge, and the smaller is the amount of coal required per ton of metal
heated. A furnace of ordinary size, heating 6 tons at a charge, consumes about 800 lbs. of coal per
ton; a larger furnace, heating a charge of 13 tons, does the work with 700 lbs. per ton. The largest
furnace of all, capable of heating at once a mass of iron weighing 65 tons, gets this up to a full
welding heat with a coal consumption of only 550 lbs. per ton. ln copper-smelting, glass-making,
and other work, large furnaces are similarly found to use less fuel, in proportion to the work done
in them, than furnaces of smaller size.
As to progress of invention of furnaces, see “The Furnace of the Future,” in Iron, viii., 354-.
For ovens, see BREAD AND BISCUIT MACHINERY. See also Assume; Romans, STEAM; Glimmer;
CnUcInLn; ENGINES, STEAM, PORTABLE AND SEMI-PourAnLE; FURNACES, BLAsr, CaronA, and METAL-
LURGICAL; GAs, ILLUMINATING, APPARATUS roa MANUFACTURE or; GLAss-MAKING; IRON-MAKING Pao-
Oicssns; KILN; STEEL; and WARMING AND VENTILATION. See also the various lists of works for
reference under metallurgical articles. The foregoing article is mainly abridged from a paper on
furnaces by Mr. Hackney, for which see “Science Conferences, Special Loan Collection of Scientific
Apparatus, South Kensington Museum,” London, 1876.
FURNACES, BLAST. A blast furnace is a vertical structure in which ores of iron are reduced
and smelted in contact with appropriate fuel and flux; the combustion of the fuel being accelerated
by blast injected under pressure, and the height of the structure being such as to admit of a thor-
ough admixture and preparation of the stock.
(IYZGSSY‘:(leatiOWA—Jnllst furnaces are classified according to the fuel employed, the heating of the
blast, and the arrangement at the top or tunnel-head. ~
According to the fuel employed, they are known as—a, charcoal furnaces; I), coke furnaces; c,
anthracite furnaces; (l, raw (bituminous) coal furnaces; and the above order may be considered as
representing the average superiority of the various fuels. Mixed fuels are often employed; thus,
FURNACES, BLAST. 789

wood or semi-charred wood or coke has been mixed with charcoal, and in some instances wood char-
coal and peat charcoal are used. Coke is largely mixed with anthracite or with raw coal to increase
the yield of furnaces.
Classified by heating of blast, the terms “hot-blast” and “cold-blast” are applied to furnaces.
Cold-blast furnaces use charcoal exclusively, and their number is annually decreasing. In these the
blast is injected into the furnace directly from the blowing apparatus. Hot-blast furnaces are those
to which stoves or ovens are attached, and the blast is heated so as to intensify the combustion in
the furnace. The term “warm-blast” has been applied to plants where the blast is moderately
heated, say from 250° to 400° F. (120° to 210° 0.). Since the introduction of the fire-brick hot-blast
stoves, those employing a blast heated above 1000° F. (535° C.) have become known as using a
super/tealecl blast.
Classified as to the arrangement of the top or tunnel-head, furnaces are known as open-top or
closed-top. The former either allow the gases a free escape from the tunnel-head, or draw them
away by a superior draught through high chimneys. The latter employ some mechanical means of
closing the top (except when charging stock into the furnaces), so as to more completely control the
gases and convey them away in fines, generally known as down-takes or dome-mum's.
STaucrunEs.—Thc older furnaces are built of heavy stone masonry, pyramidal in form, inclosing the
interior masonry, the lower portion being laid of sand-
stone, and the upper portion of soapstone or slate; some-
times ordinary bricks were employed. In Sweden some
stacks are built of blocks made from furnace cinder, and
instances are recorded where they have been used in the
shaft of the furnace for lining.
Fig. 1836 is a sectional view of an old charcoal fur-
nace. A is the tunnel-head, 30 inches in diameter; B,
the bosh, 8 feet in diameter; 0, top of crucible or hearth,
3 feet square; D, bottom of crucible or hearth, 2 feet
square; E, the-tymp; E the dam; N, the tuyere arch;
H, the in-walls, of slate or soapstone. The masonry be-
low B, of sandstone, constitutes the hearth and boshes.
These furnaces were generally located on hillsides, so
that the stock could be delivered on a level with the
tunnel-head and the iron tapped out at the bottom, the
cinder being allowed to flow continuously over the dam
F. They were generally placed convenient to a water-
power, and the blast was injected through one open tuy-
erc, being supplied from wooden blowing tubs operated
by a water-wheel. If steam was used or the blast heated, the boilers or hot-blast stoves were placed
on top of the structure, close to the tunnel-head, to permit of the employment of the waste gases.
There are instances of such furnaces now in operation, but the more modern are of different con~
struction. They are either a shaft of heavy brick masonry, banded or caged with iron to prevent
rupture, resting upon brick piers (see Fig. 1837), or upon iron columns and mantle-plate (see Figs.
1838 and 1850); or they are wrought-iron shells or casings inclosingr light masonry supported upon
iron columns and mantle-plates. The walls of the crucible and boshes, being exposed, are strength-
ened by buck-staves and binders (see Figs. 1839, 1851, 1852, and 1856). In many cases water-
jackets encircle the crucible, to keep it at a low temperature and prevent the rapid destruction of
the refractory linings. The bottom and all the walls are of fire-brick laid in refractory clay. Blocks
from 3 to 6 inches thick and 12 to 24 inches long are ordinarily employed, but sometimes no special
shapes are used, and furnaces are lined throughout with 9-inch fire-brick. For bottoms, blocks of
fire-clay are laid on end; and various shapes have been made to prevent the blocks from lifting, by
constructing them in a series of wedges, or forming offsets and recesses upon them. Bottoms are
also made of large sandstones neatly jointed, and monolithic bottoms formed of tire-clay well ram-
med and dried are in use. Fig. 1839 illustrates one form of doubled-wedged bottom blocks, resting
on a layer of fire-clay below which is sand.
Small furnaces are blown with 2 or 3 tuyeres; and as many as 16 tuyeres have been inserted in
one large furnace, by placing them in two tiers. This, however, does not meet with general approval
at present. Some large furnaces use only 4 tuyeres, but the greater number employ from 5 to 8.
The sizes of furnaces have ordinarily been compared by the diameter at bosh, 8 to 11 feet being
considered as small, 12 to 16 feet as of medium size; and the large furnaces are those having a
greater diameter at bosh than 16 feet. Latterly, however, since the height of a furnace has been
considered such an important factor in its operation, a more appropriate comparison is made as to
the cubic feet of capacities. The diameters of the boshes of existing furnaces are from 8 to 30
feet, and the heights from 25 to 103 feet, the cubical contents varying from about 1,000 to over
40,000 cubic feet. Most furnaces, however (exclusive of those using charcoal), are included within
the range of 13 to 20 feet diameter of bosh, 40 to 80 feet height, and 3,000 to 20,000 cubic feet
capacity.
SHAPE or Fairness—The proportions of a furnace seriously affect its operation, and instances
can be found of furnaces of equal diameter of bosh and nearly equal capacity, using practically the
same stock, and other circumstances being similar, whose weekly outputs are as 1 to 2; much of
which is directly traceable to the proportions. Attempts have been made to establish universal
formuho for blast-furnace proportions; but they are useful only so far as they indicate certain
limits of possibilities, and they must be decidedly elastic to provide for the behavior of 'the. various
fuels and ores employed or the character of product desired.




790 _ FURNACES, BLAST.

The typical form of blast furnace consists of two frusta of cones placed base to base and resting
upon a short cylinder. The upper frustum forms the shaft of the furnace, the lower frustum the
bushes, and the cylinder the crucible or hearth. Such forms are shown in Figs. 1836 and 1850.
Curves are employed in lieu of straight lines and sharp angles in some furnaces, or a combination of
curves and straight lines, as in Fig. 1839; but the relative proportions of the various parts of the
furnace are of much greater importance than the presence of angles or curves.
All furnaces may be considered as being divided into four zones, as follows: a. The zone of prep-
aration is that portion of the furnace included between the stock-line (i. e., the point at which the
stock is distributed when charged into the furnace) and the bosh, or greatest diameter. 1). The zone











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of reduction extends from the bosh to a plane'3 or 4.- feet above the tuyeres. c. The zone of fusion
includes the portion of the furnace from the bottom of the zone of reduction to the level of tuyeres.
(Z. The well is that part of the crucible which is below the tuyeres, and in which the molten iron
and slag is caught and retained in a murtex of fuel. The relative proportions of these zones are
influenced by the character of ores and fuel employed, the product desired, and the intensity of blast.
To obtain good results, the upper zone should be of such height and capacity as to thoroughly in-
corporate and prepare the stock for the middle zone, by driving off vapors and volatile matter and
partially deoxidizing them. In the middle zone complete reduction and deoxidation should result,
and the material be delivered in proper quantity to the zone of fusion, whose size must depend upon
FURNACES, BLAST. 791

the work to be done and the condition of the blast. The capacity of the zone of preparation depends
upon the relation of stock-line to bosh and the distance between them. The drive of the furnace, or
its rapidity of reducing and smelting ores, is affected by the slope of boshes, which generally ap-
proximates 70° from a horizontal line. The boundaries of the zones being imaginary planes, they
will vary greatly in different furnaces, and in the same furnace will be affected by the operation at
different times. The division as given above is used in designing a furnace and adapting it to the
ores to be employed and the product desired.
YIELD or FURN.\cEs.—In comparing the output of different furnaces, the amount of iron madc-
per week is the generally accepted basis, and the designation of a plant as a IOU-ton, 200-ton, or
300-ton furnace would indicate that the capacity is that number of tons per week. The gross ten
(2,240 lbs.) is the standard of weight, and, except when cast into iron chills for mill purposes, an
allowance of 14 to 30 lbs. for sand is made. A furnace of a given capacity and of appropriate
construction and management will give a greater yield with charcoal than with any other fuel, and
consume less fuel per ton of iron. Other fuels rank in the order before named, viz. : coke, anthra-
cite coal, bituminous coal. _ I
The variations of stock and management, and arrangement of details, affect the amount of prod-
uct, and there is therefore considerable difference in the output of the same sized furnaces; but by
taking an average the following will be found closely to approximate actual practice. The weekly
output of a cold-blast charcoal furnace in tons of pig-iron is equivalent to 45 per cent. of the square
of the diameter at bosh in feet. The weekly output of a hot-blast charcoal furnace is equivalent
to 95 per cent. of the square of the diameter at bosh in feet. Thus, a 9-feot furnace would make 95
per cent. of 9 x 9 r: 77 tons per week. Superior ores and efficient management have in several
instances increased the output per week for a continuous blast to 250 per cent. of the square of the
greatest diameter, and contrary circumstances reduced the product. The average weekly yield of a
coke furnace in tons is about 85 per cent. of the square of the diameter of the bOSll in feet ; but in
some of the large furnaces the output has amounted to 200 per cent. The anthracite and raw-coal
furnaces approximate 80 per cent. of the square of the bosh; but at Pottstown, Pa, a 16-foot
anthracite furnace has yielded 385 tons of metal per week, equivalent to 150 per cent. of the square
of the bosh.
CONSUMPTION or Fern—To produce one ton (2,240 lbs.) of pig iron, the following weights of dif-
ferent fuels are consumed :
Minimum. Average.
Charcoal....... . . . .. . . 1,360 lbs. 2,500 lbs.
Coke . . . . . . . . . . . . .. 2,025 “ 3,000 “
Anthracite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,460 “ 3,300 “
Raw coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 3,000 “ 4,000 “
The mimima given above are the lowest recorded consumption of fuels, and are only attained under
exceptionally favorable circumstances. The percentage of iron in the ore used obviously has a
decided influence upon the yield of various furnaces, and the consumption of fuel per ton of iron;
and in comparing the output and fuel consumption of various furnaces, the richness and chemical
composition of the ores employed must be considered.
FIXTUREs.——In place of the old method of constructing the dam some distance in front of the fur-
nace walls, the dam is now set up to the crucible walls, and the long fore-hearth dispensed with; the
tymp is set in a recess in the walls ; and both dam and tymp are kept cool by coils of pipe in them,
they being cast about the pipe to appropriate pattern; an iron notch or tapping-hole is provided in
the dam. When the tymp is placed above and back of the dam, thus leaving an opening for reach-
ing into the furnace with shovels, etc., the term “open front ” is used ; but where the cinder notch
consists of a water-cooled block similar to a tuyere, the title “closed front ” is applied.
Tuyeres are of various kinds, viz.: the box tuyere (see Fig. 1840), a hollow conical ease closed at
both ends, into which water is allowed to flow at the bottom and escape at the top; the coil tuyere,
a conical coil of pipe through which water circulates; east-coil tuyeres, coils of pipe about which a

BELLY PIPE.
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conical casting has been run; shell-coil tuyeres, coils of pipe supported upon a 'shell of wrought or
cast iron, but independent of it ;. and spray tuyeres, box tuyeres with the back end partly open, into
which perforated water-pipes project. Tuyeres are laid horizontally, and often project considerably




792
FURNACES, BLAST.



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FURNACES, BLAST. 793

into the crucible of the furnace; they are made of iron or of bronze metal. The pipe which con-
veys the blast into the tuyere is known as the belly-pipe. It is projected partially or entirely into the
tuyere, and the diameter of the opening of the small end or nozzle usually determines the volume of
blast. The other end of the belly-pipe is connected on to a bend, in which a sight-hole or pm'cker-
hole is placed, so that the condition of the interior of the furnace can be judged by inspecting it
through the belly-pipe. This also gives a means of cleaning scoria: from the nozzle or tuyere by
means of long pricker rods.
The perforations through the crucible walls into which the tuyeres are inserted are arched with
fire-brick, and in many instances water-cooled arches, or water-breasts as they are termed, are in-
serted. The space between the tuyere and the breast is packed with clay. Fig. 1841 shows an
arrangement of short box tuyere, water-breast, belly-pipe, etc., in which the tuyere snugly fits the
breast and requires no packing, and a series of weights and levers are substituted for the usual key-
bolts to facilitate the removal of the tuyere or change of the size of nozzle.
The blast, after leaving the blowing apparatus, is ordinarily carried into a large vessel or receiver,
and from this a connection is made to the hot-blast stoves. A safety-valve and also an escape-valve,
controllable from the front of the furnace, are placed in this connection. The hot—blast stoves are
placed as close as possible to the furnace, and the heated air is led through a protected bustle-pipe or
circle-pipe, from which connections are made to each tuyere. In these connections blast-cheeks are
placed, so that when the blast is slackened the valves close and permit of gases escaping into the
air, thus preventing explosions in hot-blast stoves, etc. It is also advisable to employ a valve for
each tuyere, to be closed by hand, so that any one can be removed at will. Fig. 1842 illustrates a
modern arrangement of a shell-coil tuyere E, belly-pipe D, stop-valve C, blast-check B, and blast-
pipe A, the tuyere fixtures being held in place by key-bolts.
THE Her Bursa—A retrospect of the growth of the production of pig iron in the past half cen-
tury would be comprised in the invention and introduction of heated blast as applied to iron-smelt-
ing. To compare the original iron box heated over a coal fire, as employed by Neilson, with the
modern blast-heating apparatus, with improved combustion-chambers, gas-burners, air-regulators,
etc., would be equivalent to comparing the yield of the little Blauofen with the improved furnace of
to-day. It is only lately, however, that the true value of the hot blast has been appreciated, it
having been considered simply as a means of in-
creasing the product of a furnace, and its value as
a method of controlling the operation overlooked.
There are three typical forms of hot-blast ovens,
viz.: standing-pipe, suspended-pipe, and fire-brick
stoves. Of the first there is a large number of
styles, but they all agree in consisting of bed pipes
into which vertical pipes are placed. The general
arrangement consists of U-pipes inverted, the blast
passing up one leg and down the other, and being
heated by the combustion of the waste gases from











1846.
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the furnace, in a eombustion-ehamber underneath
the pipe-chamber. Instead of employing invert-
ed U~pipe, single pipes divided by diaphragms, or
double pipes, i. 0., one pipe within another, are
used to a limited extent. Fig. 1843 illustrates a
bin... .4 simple form of standing-pipe hot-blast stove. The
suspended-pipe stoves differ from those just de-
scribed in having the pipe hung from the top.
‘ w U-pipes are employed, and the advantages claimed
J; are greater life of pipes, compact structure, and
_ . _ _ _ ease of making repairs. Fig. 1844 represents a
.Wcnner suspended-pipe stove, eonsrsting of six chambers, each containing eight U-pipes. The stand-
ing pipe and suspended pipe are both placed in fire-brick chambers.
The third class of stove in use is what is known as the fire-brick or regenerative stove, of which
there are two forms. It is necessary that two or more of these stoves should be used, for the essen-


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FURNACES, BLAST.
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tial principle of their operation is that each stove is a mass of fire-brick, which attains a high temper-
ature by the combustion of furnace gases, and gives off its heat to theair afterward driven through
it. As the stove must first be heated up and then impart its heat to the blast, some of the stoves
194, must be receiving their heat while
,n, > » . _ the others are heating the blast. To
' I prevent too great variations of tem-
perature, not less than three stoves
should be used. Figs. 1845 and
1846 represent vertical and horizon-
tal sections of a Siemens-Cowper-
Cochrane stove, consisting of a verti-
cal combustion-chainber, and a mass
of checkerwork made of fire-brick
to expose as great heating surface
as possible. The masonry is in-
closed in a sheet-iron jacket. Figs.
1847 and 1848 are vertical and hori-
, __ , . zontal sections of a W hitwell stove.
outlet .1 r i" M ' ' -, p The essential difference between this
' " ' ‘ ' and the preceding stove is the use
of a series of walls built of fire-
brick, which the blast traverses to
obtain its heat. The regenerative
principle is the same in eitherstove.
The advantages claimed for regen-
erative stoves are th at more intense
heats are possible than with cast-iron
pipe, there is less liability to dam-
age by the heat, and an economy of
fuel is possible. Except in special
instances, however, there has been
no decided advantage shown to re-
sult from a steady work at a tem-
perature above what is possible with
iron-pipe stoves. One especial value
of regenerative stoves is their capa-
city as reservoirs of heat, which can
be used often to great advantage to help a furnace out of “trouble” or bad working.
BELL AND Herman—There are a number of furnaces which are still known as “ open-top,” but
much the larger number are Provided with a “ bell and hopper ” or “cup and cone.” The ordinary
forms are exhibited in Figs. 1856, 1850, and 1851. The hopper is a cup-shaped casting, having a
projecting flange which rests upon the ma-
sonry of the furnace, the aperture below
being somewhat smaller than the diameter
of the bell, which is a conical casting sus-
pended at the apex from an operating beam,
as in Fig. 1851. An improvement is shown
in Fig. 1839, where the aperture in the hop-
per is of greater diameter than the bell, and
there is an offset or shoulder to receive a
lip-ring which forms the lower portion of
the hopper. The advantages of this ar-
rangement are, that it is not necessary to
remove the hopper when a bell is taken
out, and severe explosions are less liable to
move the hopper. The purposes of the bell
and hopper are to close the top and force
the gases down the fines provided for them,
and also to distribute properly the stock run IN snoTIoN.
charged upon the bell. The size of the
bell therefore has a directrelation to the stock-line. Various forms have been employed to accom-
plish proper distribution. Among others is a double bell, Fig. 1849, in which the centre cone does
not drop, but a conical ring closes against it and the hopper. When this ring is lowered, the sup-
position is that the stock is equally distributed over the throat of the furnace. A similar arrange-
ment is employed with the central flue mentioned be-
low. In the usual arrangement, when the bell is low-
ered, the gases from the furnace have a free escape,
and are drawn away from the boilers and hot-blast
stoves. To prevent delay in operating the bell, the
lever is moved by a hand-winch or by steam or com-
pressed air. A cover for the tunnel-head is also per-
fected, in which are openings for dumping charges, provided with sliding covers. These openings
are closed before dropping the bell, and opened when the bell is closed; loss of gases is therefore





GAS CULVRRTS. CHIMNEY
- .
at, v
FLU ES.





FURNACES, BLAST. 795'

prevented. To accomplish the same result and insure more thorough distribution of the stock, the
hopper is placed several feet below the top of the furnace, so that the charge of stock when dumped
from the charging-barrow strikes on the apex of the bell, falling equally upon all sides. When the
charge is ready to be lowered, the tunnel-head is covered by a plate suspended from a beam, which
is removed after the bell is again raised to position. In both cases the covers are operated by steam
or compressed air. In some open-top furnaces, a bell is hung in the throat of the furnace to insure
distribution of the stock.
GAS FLUES.——Th0 gases are taken off below the hell by fines, and in modern plants carried to the
ground in down-comers, which are wroughtiron tubes, usually lined with fire-brick. These are
sometimes of considerable size, even in furnaces of moderate dimensions, and in many large fur-
naces are out of proportion to everything else. Some down-comers are of sufficient capacity to con-
vey five times the quantity of gas which is ever made in the furnace.
The flues into the f urnece are ordinarily circular or arched horizontal openings above the stock-
1850.








line, but in open-top furnaces they are often narrow vertical slits below the stock-line, with an up-
ward inclination.
The central flue above mentioned is sometimes used. This is a vertical wrought-iron pipe, extend-
ing from below the stock-line up through the tunnel~head, and then passing off to the side of the
furnace and thence to the down-comers. The draught from a tall chimney and the stock packed
around the outside of the flue cause the gases to pass through this central fine.
The connection from the down-comer to the hot-blast stoves and boilers is either by wrought—iron
fines above ground or by masonry underground fines; and they usually terminate in gas-burners, by
which the supply of gas and of air can be regulated. ~
Romans—Long horizontal-cylinder boilers, either set singly or two high and placed in nests, are
most in favor with furnacemen. Flue and tubular boilers require more attention, on account of the
amount of dust which accumulates unless the gases are washed previous to burning them. The
ordinary furnace steam-pressure is 50 to '70 lbs. per square inch.
BLOWING Arr.\n.v1'us.—-As the supply of gases is seldom insufficient for both boilers and hot-blast
stoves, water-power is not employed except at the older charcoal furnaces. Steam blowing engines
are chiefly used, and there is quite a variety of them, including horizontal engines working direct or
operated from a steam-engine by gearing, vertical blowing-tubs driven by a horizontal engine, verti-
cal bull engines, and vertical beam engines. The present demand is for vertical bull engines, or
those having a single steam-cylinder placed under a single blowiirr cylinder supported on housings
796 ' FURNACES, BLAST.

or columns, the steam and blowing pistons being secured to the same red, as a horizontal cross-head
which carries connecting-rods for two fly-wheels. Puppet-valves are largely employed. The pres-
sure blown is from three-fourths of a pound 'to 3 lbs. for charcoal, 8 to 7 lbs. for coke, 4 to 14 lbs.
for anthracite, and 2 to 6 lbs. for raw bituminous coal. The best practice now favors running by
the volume of blast rather than by the pressure, and small high-speed engines are in many cases
displacing the more massive engines of slower motion. There is no fixed rule among furnace
managers for the amount of air supplied to various furnaces ; from data collected at a number of
furnaces, the amount of blast varied from less than 200,000 to over 500,000 cubic feet per ton of
pig iron, and from 7 7 to 165 cubic feet per pound of fuel consumed. In every case the number of
cubic feet of air supplied per minute was greater than the cubic feet capacity of the furnace, the
average being as 1’7 to 10. V
CHARGES.-—-A charge or round is a specified amount of fuel (generally a barrow of charcoal or a
net ton of other fuel) and the proportionate amount of ore and flux, which is termed the burden.
Thus a charge for a charcoal furnace would be a barrow (20 bushels) of charcoal, 1,000 lbs. of ore,
and 60 lbs. of limestone. The furnace would be then working on 1,000 lbs. burden, and carry 6 per
cent. of flux. Or an anthracite furnace would charge 2,000 lbs. of coal, 3,600 lbs. of ore, and 1,980
lbs. of limestone ; its burden would be 3,600, carrying 55 per cent. of flux. The number of charges
or rounds in 24 hours indicates the drive of furnaces. Sometimes much larger quantities of fuel than
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2,000 lbs. are used as a basis for the charge. A locked scale, balanced to the weight of barrows and
provided with a series of levers for fuel, ores, and flux, is generally employed to weigh the charges.
The time occupied in the passage of stock through the furnace will average nearly 48 hours, but
it is in some plants 80 hours ; and charcoal furnaces have driven so fast that the stock has not‘re-
Imained in them over 8 hours. This applies to absolute working; for when for any cause a furnace
is stopped for any length of time, the manager either “blows out ” or banks up. In the former
case he endeavors to get everything out of the furnace, and in the latter to keep all in by charging
extra fuel and closing all draughts. In this manner stock may remain in a stack for a long time.
[Iowa's—The old mode of constructing furnaces on a steep hillside, so as to conveniently deliver
the raw materials at the level of the tunnel-head, and convey the pig iron and slag away from the
fore part, has given place to plants erected upon flat or sloping ground convenient to railroads. In
these the raw materials are raised to the level of the tunnel-head by vertical hoists or inclined planes,
considerable ingenuity being displayed in the arrangement of the various parts. The compressed air
produced by the blowing apparatus is often employed for operating the hoist. Hydraulic hoists
and water-balanced lifts are used to a limited extent, but the greater number of furnaces use steam
as the power.
The illustrations herein given represent the various styles of furnace construction employed. Fig.
1839 is a section of a raw bituminous coal furnace in Ohio, with curved boshes and straight in-walls,
and is supported on columns and encased with a sheet~iron jacket. It is 15 feet in diameter at bosh
and 50 feet high; crucible, 7 feet diameter, pierced for ’7 tuyeres.


FURNACES, BLAST. 797
Fig. 1850 is a half elevation and half section of an anthracite furnace at Bethlehem, Pa. It is
supported on columns, and the brickwork is caged with staves and bands of iron. It is 17 feet in
diameter at bosh and 70 feet high; the crucible is 7 feet 6 inches in diameter, and blast is supplied
by 5 tuyeres. The section is of straight lines and angles.
Figs. 1851 and 1852 exhibit the section and elevation of a coke and anthracite furnace at Chicago;


1854.

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the section is entirely of curved lines. The bosh is 17 feet in diameter; the height is 66 feet. The
crucible is 6 feet in diameter, and is blown by 4 tuyeres.
Figs. 1853 and 1854 illustrate the construction of an old-style blast furnace.
Fig. 1855 is a vertical section of a German furnace.
The above fairly illustrate the variations in style and proportions, but there are many modifications
of shape or details.
Efforts have been made to get more intense combustion by injecting petroleum, and considerable
attention has been given to the calcination of the stock in high furnaces. The most prominent in~
stance of this is the Ferric self-coking furnace shown in Fig. 1856, used in Scotland and to a slight
extent elsewhere. The upper portion of the furnace is divided into chambers or retorts, the cross
and side walls containing dues in which part of the gases from the furnace are burned. The raw
7 98 FURNACES, C UPOLA.
coal, ore, and flux are charged into these chambers, and the heat generated by the combustion of the
gases (controllable by air-valves) cokes the coal, roasts the ore, and prepares the flux for action in
the furnace proper below. This illustration shows a water-jacket surrounding the crucible, water-
breasts, plain tuyere fixture, and lined bustle-pipe and down-comer.
Works for Rqf'erenee—J‘ Iron and Steel Manufacture,” Kohn, London, 1868; “Metallurgy of Iron
and Steel,” Osborn, London, 1869; “ Researches on the Action of the Blast Furnace," Schintz, Lon-
don, 1870; “Iron and Heat,” Armour, London, 1871; “Chemical Phenomena of Iron-Smelting,"
Bell, London and New York, 1872-; “ Guide to the Iron Trade or Great Britain,” Griffiths, London,
1873; Wilcy’s “Iron Trade Manual,” New York, 1874; “Studies of Blast-Furnace Phenomena,”
Gruner, Philadelphia, 1874; “Metallurgy of Iron,” Bauerman, London, 1874; “ Metallurgy of Iron
and Steel,” Percy, London, 1875. For descriptions of the most recent advances, the reader is espe-
cially referred to the files of Iron, Journal of the Iron and Steel Institute, Engineering (see series of
papers on “American Iron and Steel Works,” by Holley and Smith, vol. xxv.), Engineer, Iron Age,
American .Ilfmiuj'aeturer, and Engineering and fifining Journal. J. B.
FURNACES, CUPOLA. Furnaces for melting metals prior to casting. In modern practice the
cupola is usually made of boiler-iron in the form of a cylinder or cylindroid, lined withfire-brick. It
is from 10 to 16 feet in height and from 3 to 6 feet in diameter inside, and capable of melting from
5 to 15 tons of metal per hour. The chimney may be of brick, or of boiler-iron lined with fire-brick,
which is more common. A cupola is often spoken of as holding a charge of so many tens of metal ;
but as only a limited quantity of molten metal can be contained in it at one time, its capacity is
more correctly measured by the amount of metal it will melt in a given time. Fig. 1857 is a
perpendicular section of a cupola, to enable the reader to understand the manipulations connected
1857-
/-_._.'


>----- __
1858.







J
with the process of casting. The tuyeres, a a, are seen to enter the cupola from 10 to 16 inches
above its floor. The space just above the tuyeres has the shape of an inverted cone, which has the
effect to hold the contents in such a relation to the blast as is best calculated to make it the most
effectual. The floor of the cupola, b, when in use, is composed of sand 6 or 8 inches in depth, lying
upon the bottom plate 0, which rests upon supports, and may be dumped by their removal. Some
cupolas are chambered at the lower section, the blast entering through a row of holesin the inner
wall. In the upper part of the back of the cupola is the door for receiving the charges. Fig. 1858
shows the exterior of the lower part of a cupola: a a, tuyeres; b 12, small isinglass windows for show-
ing the state of combustion and position of the layer of coal; e, pot for receiving the melted metal;
'0! (1, columns of support. (The smaller upright rods support the movable floor, and stand in the pit
below the cupola.) A cupola is charged by placing a sufficient quantity of kindling-wood upon the
floor, and above this a layer of the best anthracite coal in large lumps, and in sufficient quantity to
fill the cupola to the height of several inches above the entrance of the tuyeres after it has well
settled and the wood has burned away. This precaution must be carefully observed, because if the
charge of iron above the coal should come down to a level with the entrance of the blast, combus-
tion would be checked, the metal become chilled, the process stopped, and the dumping of the charge
necessitated. Upon the layer of coal thus carefully deposited, one of pig-iron is placed, varying
in quantity from 1,000 to 5,000 lbs., according to the size of the cupola and to the rapidity with
which it is proposed to effect the melting; and upon this another layer of coal is deposited, and
afterward succeeding layers of iron and coal. Fluxes are added where occasion requires, according
to the judgment of the founder, pounded marble or limestone being most frequently employed.
The wood is usually ignited when the first layer of coal is deposited, and in from an hour to an hour
and a half the furnace may be tapped.
FURNACES, CUPOLA. 799

In Fig. 1859 is represented an improved cupola for melting iron, highly recommended by Mr.
Edward Kirk in his “ Founding of Metals,” from which work we take the following description :
“The bottom plate should project inside of the lining in a large cupola, so as to make the bottom
doors smaller and easier to handle; and the lining should be sloped out to the edge of the bottom
plate, so that the sand bottom will all fall out when the iron bottom is dropped. This offset also
helps to support the stock, and takes part of the weight off of the iron bottom. The caisson or
shell of a cupola will often rust off, and give way around
the bottom. This is caused by the lining sweating and
the moisture settling to the bottom, and by putting in a
heavy sand bottom, and providing no way for the moist-
, ure in .the sand to escape; this moisture keeps the lower
courses of brick always damp, and causes the caisson to
rust off in a short time. The illustration shows how this
may be avoided by laying the first two courses of brick
out one or two inches from the caisson, so as to form a
small air-chamber all around the cupola, as represented
by the letters A A. Small holes should be put in around
the bottom of the caisson, or through the bottom plate,
to' supply this chamber with fresh air, and allow, the
moisture to escape. A triangular-shaped tuyere is the
best, especially for a small cupola; for it comes up to a
sharp point at the top, and is not nearly so liable to
bridge over as the round or oval-shaped tuyere. There
1859.


is a hollow place in the lining of this cupola, just above
the tuyeres, which indicates the melting point of the cu- ,__ Milwwmfiwm'jmu "
pola. If a cupola is lined up straight, it will burn out _ j-;_ hollow at this point in one or two heats ; and in daubing !, llll’ llllliliiiillllllllllllllllllll
up the cupola for a heat, it should never be daubcd up " straight or too full at this point, but should be left a j mgfifi{[{Elmi“illglligigggfiill
little hollow, as shown in Fig. 1859. Brackets or angle-









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iron should be riveted on to the caisson every three or
four feet, so as to support the lining, and admit of the
» lower part, where the lining burns out the fastest, being
taken out and replaced without taking down the whole
lining. The lining can be taken out and replaced with-
out the brackets by taking out one side of it at a time,
and replacing it with the new lining before taking out
the other side; but after a lining has been taken out and
replaced in this way, it always settles and cracks, and
injures the lining. The stack should be reduced to one
half or less the diameter of the cupola, and should be
drawn in by an arch just above the charging-door. A
cupola contracted suddenly, as this one is, is better than
to have a long tapered contraction, for in this cupola the
heat comes up and strikes the arch, and is thrown down on the iron; the sparks strike this arch, and
are not so liable to be carried out at the top of the stack as in a long contraction by reducing the
diameter of the stack. In this way the heat is more confined and equalized, and will make a more
even iron than a cupola with a large stack when the heat escapes freely up the stack.”
The following table shows the dimensions of an ordinary cupola of this type:






as nun-M
Dimensions of Ordinary Cupola. Feet 11101168-
Outside diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6
Height above hearth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 0
Inside diameter at tuyeres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 0
Inside diameter at hearth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 6
Inside diameter at top (plated with five-sixteenths inch plate 14 feet above
the hearth) . . . . . . . . .~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 0
Diameter of main- blast-pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 15
“ of branch pipes (two) . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . 0 82
“ of tuyere nozzles.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 7
Height of hearth above foundry floor (about) . . . . _ . . . . . . . . . . . . . . . . . . . . . . . 3 0
A cupola of this description has been known to melt- from 10 to 20 tons of iron :1 day, with but
120 lbs. of coke to the ton of metal melted, which consisted of various mixtures of Cleveland hema-
tite and Scotch pig. The diameter was 3 feet 6 inches ; height from tapping-hole to charging-floor, 14
feet. It was supplied with blast from a blower, at a pressure of a quarter of a pound to the square
inch, and melted at the rate of about 5% tons an hour.
The .Maehenzie cupola, 1860. is largely used in this country. It is generally elliptical in plan, '
and the blast, instead of being supplied through tuyeres, is admitted through an opening which
extends completely round the bottom part of the cupola. The blast is led into a chamber surround-
ing the boshes of the cupola, and from thence it escapes through the annular opening into the cupo-
la. The cupola is fitted with a drop bottom, which arrangement is almost universally adopted in
the United States. When first started it is necessary to employ a very light pressure of blast, but as
soc FURNACES, CUPOLA.

the melting proceeds the pressure is brought up to 21} lbs. per square inch. The blast is generally
applied about 40 minutes after the fire is lit, and the iron begins to run about 20 minutes afterward.
American cupolas as a rule are larger in diameter than those of European design, which is an essen-
tial feature when anthracite is used. An arrangement often adopted is to have the sides parallel,
but with a convex-shaped belt of the same material as the lining arranged just above the tuyeres
this belt effecting the same object as the boshes in such forms as those of Ireland or Voisin. ,
Ireland’s cupola is built with boshes, and has a cavity of enlarged diameter below them, so as to
give increased capacity for the liquid iron. In his first patent there are described two ranges of
tuyeres, ordinary ones at the bottom, and smaller but more numerous ones above the boshes, which
latter it was proposed to supply with heated blast. -
Woodward’s steam-jet cupola is worked by means of an induced current caused by a steam-jet
blowing up the chimney of the cupola, instead of by a blast forced in from below. It is claimed that
a considerable saving in fuel is thus effected. Fig. 1861 shows an arrangement of the steam-jet in
connection with a cupola provided with a feeding-hopper, with a sliding door to be worked by a lever,
1360. 1861.


so that continuous working is possible. The steam is arranged to blow through a side flue into the
chimney. The feeding-hopper to the furnace A is represented open, and that of B is shut. There
are eight air-holes in the upper row and three in the lower row.
Hctufon’s cupola is constructed by building a tall stack on the basis of a cupola, and providing the
latter with two rows of large tuyeres; the heat and draught are maintained simply by the ascensive
power of the hot air passing up from the cupola and stack or chimney.
Voisin’s cupola is constructed of double-riveted boiler-plate lined with shaped fire-brick, and the
bottom is arranged to drop. The blast is supplied from a belt completely surrounding the cylinder
of the boshes, and from this belt two sets of tuyeres, four in each set, deliver the necessary supply
of air. The lower set are arranged opposite and at right angles to the main, while the upper set are
diagonal to it. The inventor claims that through this arrangement of the tuyeres the gases, being
burnt in the interior of the cupola, create a second zone of fusion with these gases alone. In other
words, the second set of tuyeres obviate to some extent the evil effect of the formation of carbonic
oxide.
A portable cupola with its fan is shown in elevation, Fig. 1862 It is formed of a cylinder A A,
of sheet-iron one-sixteenth of an inch thick, 2 feet 3 inches in diameter and 4 feet 6 inches high,
'lined with fire-bricks and clay BB, in the usual manner, 4 inches thick. The cupola weighs about
6 cwt., and is easily lifted by the workmen on to a trolly and taken to the place required, when it is
lifted off and placed on a temporary staging. The cupola has a belt or air-chamber at C 0, into
which passes the air from the fan, and it has four tuyeres of 2 inches orifice to admit the air to the
fire. The yield of metal from so small a cupola is great; as much as 31} tons have been run down
in 7 hours by two men turning the handles of the fan, and nearly 4% tons by the use of the engine
in the same time.
TUYERES may be classed under two heads, namely, the coiled tuyere and the water-jacketed tuyere.
The coiled tug/ere is generally made of a coil of wrought-iron tube imbedded in the sides of a
hollow case of east-iron. Sometimes the coils are wound close at the nose of the tuyere, in order
more etfectually to prevent the cast-iron from burning; and sometimes the tuyere itself is formed
entirely of a coil of tube, closely wound from end to end.
The zeatw-jaclcctedtuyere is generally made of wrought-iron, and consists of two conical tubes of
different diameter, connected at each end by rings of wrought-iron welded in, so forming a space
between the two concentric walls of the tuyere, which is filled with water supplied under pressure,
FURNACES, CUPOLA. 801

and generally brought in through a feed-pipe at or near the bottom of the tuyere, and allowed to
escape through a second pipe in the upper side. .
P/wsphor-bronze tuyeres are generally fixed in a casairon casing or box, beyond which they project
into the furnace for the greater part of their length; and they are so arranged that they can be
turned round in the cast-iron plate or box in order to expose a different side of the tuyere to the
action of the materials in the furnace. Greater durability is claimed for phosphor-bronze than for
gun-metal or copper; but each metal possesses the same advantage of preventing adherence of slag,
scoria, or iron to the nozzle of the tuyere, which is the only object to be gained by the use of copper
or its alloys in preference to iron. Additional precautions as to water-supply have to be taken where
such metal is used, as, owing to the low temperature at which it melts, a copper tuyere may be more
rapidly'destroyed than an iron'ene where any overheating is possible; but under favorable conditions
gun-metal, copper, and phosphor-bronze tuyeres have been found very durable, and the advantage
gained by keeping the blast-nozzle always clean and fully open is an important one.
The open-spray tug/ere invented by F. H. Lloyd, Fig. 1863, consists of two concentric conical tubes,
closed at the nozzle but open at the rear end. The water-supply is connected in the usual manner
with a flexible hose, and various systems of spray-pipes are used to suit various shapes of tuyeres
and various conditions of water-supply. The spray-pipes are made either of wrought-iron, brass, or
copper, and a sufficient amount of water is allowed to escape through small holes or slits in the
spray-pipes to protect every part of the tuyere-casing which is exposed to the heat of the furnace.
The spray or jet of water from each hole in the spray-pipe spreads over a considerable surface, and
a small number of holes is, if they are properly placed, sufficient to keep the whole interior surface
of the tuyere-casing constantly wet. Scarcelv any steam is visible, and the waste water passes away,


1962.












after cooling the tuyere, at a temperature little exceeding that at which it entered, unless a large
portion of the tuyere is exposed to violent heat, in which case the temperature of the waste water is
certainly no greater than it would be from a tuyere of the old system placed under the same condi-
tions. The spray is principally directed to the loose end of the tuyere, and beats back to some ex-
tent on the top and sides, which are also protected by a sufficient number of additional sprays from
holes drilled in the spray-pipes. The water falls round the sides and end of the tuyere, and escapes
from the back through the waste-water pipe, as shown in 1863.
The number and position of the tuyere-holes very much depend upon the size of the cupola, the
quality of coke, and the nature of the pig to be employed. For some small cupolas, only one tuyere
is used, which is placed at the back of the cupola, about 15 inches above the bottom. According
as the diameter of the cupola is increased, so must the number of tuyeres be increased around it
in the same horizontal plane, so as to generate a uniform heat at all points in the furnace.
One of the most important modifications of late in the construction of'the cupola has been the
introduction of the falling hinged trap-door, shown in Voisin’s furnace, Fig. 1864, to allow of the
whole contents to be dropped into a pit beneath the cupola, after tapping; by this arrangement the
cupola is much more easily and quickly emptied when “ done work” than by the old and fatiguing
process of “raking out.” When this arrangement can be adopted, that is, when there is the power
to have a clear gangway left beneath the range of cupolas, it is necessary to pay great attention to
the proper arrangement and strength of the supports for the cupolas.
For a very excellent discussion on the subject of cupolas and cupola working (from which the
foregoing is mainly abridged), the reader is referred to “ A Practical Treatise on Casting and Found-
ing,” by E. Spretson, London, 187 8. A large amount of practical data, etc., will be found in “ The
Founding of Metals,” by Edward Kirk, New York, 1878.
51
802 - FURNACES, GLASS—MELTING.

FURNACES, GLASS-MELTIN G. These usually consist of a heating chamber, in which are dis-
posed the pots or crucibles in which the glass is fused.
GLASS-POTS 0R Generates—The various substances which by their fusion produce glass are melted
in large crucibles of refractory earth. These should be capable of supporting for several weeks an
exceedingly high temperature, without splitting or vitrification. This temperature, measured by
means of the thermo-eleetric pyrometer, is not less than from 1000° to 1200° C. Bohemian glass is
liquid at 1050°, crystal at 925°; and the pasty state at which working is best carried on is at about
770°. The bricks \vhich enter into the construction of the furnaces require the same care in their
making as the crucibles. The manufacture of all these appurtenances is in Europe usually carried
on in the glass-works, each manufacturer having as a rule particular ideas as to their proper fabri-
cation to suit his requirements. The most refractory clays are employed, as free as possible from
iron, lime, magnesia, and the alkalies; and in making the crucibles the greatest care is exercised.
In England they are made of the best Stourbridge
clay mixed with about one-fifth part of ground
potsherds. The work is entirely done by hand.
The large pots are about 4 feet in height, 4 feet
in diameter at top and somewhat smaller at the
bottom, and contain about 25 cwt. of melted glass.
Small ones range from 19% to 39 inches in height,
and from 2 to 2.7 inches in thickness, after being
baked. The average durati n of a pot in the fur-
nace is about 8 weeks. In the ease of window
7 and ordinary bottle glass, the pot is a plain round
vessel, open at the top, as shown at the right of
' " l i Fig. 1865 ; but in melting flint-glass, it being
necessary to protect the metal from all external impurities, the top of the pot is made in the form
of an arch or hood, with a small opening on one side near the top, which corresponds to the nose-
hole of the furnace, and from which the workman withdraws the melted glass. .
Peligot gives the following composition of crucibles and pots: Cruciblcs—Fatty clay of Forges,
100 parts; cement, 100 parts; pulverized potsherds, 10 parts. Pots—Fatty clay of Ardennes, 350
kilogrammes; same, calcined, 260 kilogrammes; potsherds, 100 kilogrammes. These ingredients,
moistened with water, are made into a homogeneous paste in a mechanical mixer, and are afterward
kneaded in manner similar to pottery clay. About 300 kilogrammes are required to make a pot.
The material is formed into lumps and allowed to season for several weeks in a moist place, by
which process it acquires the necessary plasticity. The manner of making the pots in France con-
sists in building them up of small cylinders of the prepared clay called pastons or columbz'ns. Gen-
erally a wooden vessel is used as a mould, and this is lined inside with wet cloth. The columbins,
previously prepared and flattened on one side, are placed against the cloth, beginning at the centre
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of the bottom. They are thus built up, range after range; and as they are put in .place they are
rubbed together so as to make them unite. When the top of the moulding vessel is reached, the
whole is removed to a warm apartment, and the interior of the pot is pounded smooth With marble
mallets. It is then left in the mould for several days, after which it is turned out, and any defects
FURNACES, GLASS—MELTING.
803

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804 _ FURNACES, GLASS-MELTING.

on the exterior surface are repaired, The pot is afterward left to dry in a chamber heated to from
30° to 40° C. for from 4 to 8 months. Then it is gradually baked at a red heat.
FURNACE Barons—A glass-furnace after being once fired is always kept in heat until its stoppage
is necessary on account of deterioration. Then it is generally built anew. The bricks, having
therefore to withstand a very high temperature for so long a time, are chosen with great care,
especially those used in forming the vaults and arches. Refractory clay alone does not produce
sufficiently resisting bricks, and hence very pure white sand is added to it. This material is best
obtained from quartziferous rock or pebbles, ground and treated with sulphuric acid to remove all
traces of iron. Vault-bricks should contain from 80 to 85 per cent. of this sand.- Those which
come in contact with the glass which flows over during melting or on the breakage of the pots may
contain very much less. If they are too silicious, they are rapidly scored by the glass which almost
constantly falls from the pot into the furnace. If, on the other hand, they are made of nearly pure
clay, they resist much better the dissolving action of the basic elements of the glass. The following
is a good mixture for vault-bricks : 250 kilogrammes of clay, 250 kilogrammes of calcined clay from
old furnace-vaults, and 100 kilogrammes of purified quartz sand. In Wales a very excellent brick
is made from agglomerated quartz, the material being obtained at Dinas in the Neath valley. It is
nearly pure silex. The rock, reduced to powder, is mixed with about one per cent. of lime and a
quantity of water sufficient to agglutinate the mass, when it is compressed in iron moulds. It is
thus made into bricks, dried, and then baked at a high temperature. The lime acts as a kind of flux
at the surface of the quartz grains and determines their agglomeration. These bricks expand by
heat, while those of clay contract.
FURNACES.-——Tll6 furnaces used in glass-making may be divided into four classes: 1, ordinary fur-
naces; 2, Siemens furnaces; 3, Boetius furnaces; and 4, single-pot furnaces.
Ordinary Fw'naccs.—These are heated either with coal or wood. They are usually of circular,
oval, or rectangular form, and contain from 6 to 12 pots. Access is afforded to each pot by a
separate opening, which is closed during the melting. Figs. 1866 to 1869 represent a four-sided
furnace intended for 6 pots. Fig. 1866 is a horizontal section, Fig. 1867 a perpendicular section
through the teazing arch, Fig. 1868 a perpendicular section through the edges or seats, and
Fig. 1869 a front view with a section of the fritting kiln. There are four side kilns connected
with the main furnace A A, Fig. 1866, in the shape of four wings, viz. : two cooling or annealing
furnaces B B, and two fritting kilns O 0. Above the foundation, in which the drains a: x x
are excavated, the sole-stone w is placed, which forms the bottom of the fire-room. The two fire-
places and grates m m, Fig. 1867, are situated above the ash-pits 31, and are exactly opposite to each
other ; they are supplied with fuel from the arches b b and (Z (1, while the flames from the two extrem-
ities meet in the fire-room ,9, Fig. 1868, and enter together the space a a occupied by the pots 2421- u u,
and, reverberating from the four-sided arch, escape at last through the fines c' c, 8 inches in width,
into the side ovens, of which two can be heated by separate fires K. Fig. 1869; the damper in the
fines c shuts off the flame from the furnace A A when required. The uprights i 2' 2' 2' separate the
working spaces of the glass-blowers, who obtain access to the glass in the pots through the working-
1870.
1871.




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holes 0 e e. Immediately below these are the openings 7* r 9‘, which can be opened for removing the
pots when broken or worn out from the sieges, to which they often adhere. In order to retain the
heat in the furnace, the working-holes are made as narrow as possible, and consequently much
smaller than the pots; when it is necessary to change the latter, they are removed through the side
“ arches, of which there are two in every furnace, kept constantly bricked up except when actually in
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FURNACES, GLASS-MELTING. ' 805
se. Chimneys (I, Fig. 1869) are sometimes erected over one or more of the worklngdioles to carry
off the heat and the vapors from the pots ; these, however, are not essential, and are not often used.
The side-kilns are accessible by the doors 8 S S. Wood is placed on the scaffolding Z to dry. The
cupola or arch v is walled over with ordinary bricks, and the corners are filled with sand and earth.
The round melting-furnaces, although very commonly used, are not so commodinus as those of
quadrangular form under the same circumstances. Figs, 1870 to 1873 represent a furnace of this
1878.

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kind designed for making flint-glass. Fig. 1870 is a ground plan of the melting-furnace. The
pots C' are situated at equal diStances between the pillars or piers E, which support the exterior
dome. At a a are openings in two of the piers for charging with fuel. Fig. 1871 shows how
the heat is carried round the pot in its exit from the furnace. The pots are covered with hood-
shaped tops, and these fit the working-holes of the furnace, so that the smoke and heat cannot
escape in thesame way as in the usual glass furnaces. a is the pot, with the top 6 ; c is the roof of
the furnace; d, the “siege” on which
the pots are placed; and e e, a flue,
low down, which passes between the
furnace and the cone till it reaches
a point f, where it enters the cone
itself. 9', Fig. 1872, is a front view
of the pot and arch of the cone,
which allows the workmen to ap-
proach the opening in the furnace,
against which the mouth of the pot
is placed. h is an opening direct
from the outside into the fine, for the
purpose of keeping it clean. Fig.
1873 is a general view of the melt-
ing-furnace, cone, and working-holes.
It consists of two domes, A A, BB,
one within the other, of which the


u ‘0 v ' ‘° ‘ l l _ inteuor one is flat, and the extei 101


0 l c b of consrderablc altitude, terminating \
in a high chimney. The only con-
nection between the domes is by the
fines G G, which are situated one on
each side of the crucibles, so“ that
they receive the whole body of the
flame as it passes from the fireplace
to the exterior dome, and thence to
the chimney. l____ l__.
The following drawings of a plate-
glass furnace exhibit the manner in which the fusing-pots are arranged, and also how they are
inserted and removed. Fig. 1874 is a horizontal section at the height of the sieges to the right of
a: y, and somewhat lower to the left, through the holes for the cuvettes. 187 5 is a perpendie
ular section through the line a: y. The melting-furnace is surrounded by four side furnaces A A A A,
used for burning and heating the pots, and so arranged that the whole length of the sides with the
siege a is left open and free of access. Thus the two remaining sides are only accessible by the






see ~ FURNACES, GLASS-MELTING.


narrow passages BB, and these are connected with the large apertures b 6. These apertures are
used for the insertion of the pets 0 0, and at the same time for stoking the fire: for the latter pur-
pose they would be too large, and allow too much heat to be lest; they are consequently bricked
up above and closed in front by
slabs of clay, with the exception
1875.


. I /,' - 14
. of the small apertures e e. A
"’7" 7454517242 aj/Zgéé/ié/ajflffiéfi/l/Q .' ,._,/§/’/./4’//" grate is indispensable when coal
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"”.;'j;//,/<,';I ' a, ~ the ordinary fuel. The flame
521/1, .1 _ '
travels from the melting-fur-
nace, after passing between the
sieges and heating the pets 0 C
and the cuvettes it, through the
L__’_ flues o 0 into the side furnaces
A. Two rows of holes are left
in the free sides of the furnace.
/ ., /,. means of thchupper working-
; M " ‘ " - , _, , 14754154" 10 es m m m t e meltin - ots
y " are accessible, for the purgpldses
” " ' ' ' ” n H V of ladling; through ,the two low-
er holes n n the cuvettes are inserted or removed upon the iron slabs p p, which must consequently
be exactly upon the same level as the sieges. All the holes can be closed by movable plates at pleas-
ure. The draught can be regulated through 1' r, and the ash collects in s s. '
Figs. 1876 to 1878 show a ground plan of a melting-furnace for crown glass, and the elevation of
an end and side. a a a. a are the stone pillars which carry the cone; 1) b b b, the walls of the fur-
nace; c c, the grate-bars upon which the fuel lies; d d, the “ sieges,” or position which the melting-
pots occupy, one opposite each opening e e c. g is an elevation of the sides ff, and h an elevation
of the ends tiof the furnace. k k k are temporary openings to enable the workmen to lIISL rt
large iron levers to assist in placing the pots, which are carried on a machine, in a red-hot state,
into the furnace through the other temporary opening l.
The Siemens Gas Fmvzaccs involve two principles: 1. For the direct action of the combustible
that of the products resulting from its distillation is substituted. 2. These products, consisting of
carbonic oxide, carburetted hydrogen, and hydrogen, are directed in company with air, but without
being mingled with the latter, into two chambers filled with fire-brick previously heated to a red heat







1976,



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_—__-___-_.-__ ._-_ ___- --



by the furnace flame. The gases and air are consequently heated by their contact with the bricks.
These chambers are termed “regeneraters,” and the gases, after traversing them, are led mto_the
furnace, adding to the heat which they have already acquired that which is due to chemical actipn.
The flame which is the consequence of the latter starts at a short distance from the bench on which ,
FURNACES, GLASS—MELTING.
807

—fi
the crucibles rest, traverses the furnace, determines the effects due to its high temperature, and on
leaving penetrates into two other rcgenerators, there giving up nearly all its remaining heat, the gases
of combustion escaping from the chimney considerably cooled. Thus the two inlet rcgenerators














,9

1877.
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and the two outlet rcgenerators act inversely.
by the gaseous products, the other by the air.
by the mixture of gases leaving the furnace ;
the brick lining. By means of valves, moved
every [half hour, the four chambers are used
alternately; that is, those previously heated
by the escaping gases are employed to heat
the entering gases and air, and the former
entry regencrators now become those of out-
let. This arrangement will bc understood
from Fig. 1879, which is a vertical section of
furnace and rcgenerators. The gases and air
enter through the two contiguous chambers
on the right, and mingle and burn a little
above them; then escaping, they pass into
the chambers on the left, which they elevate
to a high temperature.
The Boatius Furnace, Fig. 1880, is simpler
and less costly than that just described. The
fuel charged by the two lateral openings fur-
nishes carburcts of hydrogen and other com-
bustible products, and falls on the grates D
in the form of coke. This burns, yielding
carbonic acid, which on traversing the layer
of incandescent coal becomes partially converted into carbonic oxide.


1878.







41;
?//
’









/
..1
1




The first pair are traversed from bottom to top, one
The second pair are traversed from top to bottom
consequently the latter gases raise the temperature of
1879.


The grate allows of the pas-
sage of air only just sufficient to consume the coke. In order to burn the gases formed, air is drawn
in at E and F, and is caused to circulate in its conduits H around the fire, thus becoming heated.
1880.
3
,’. l -‘
‘ . - .
$U-'
‘llil I
> \ \
~~__‘\\\’ . _, s
d “\‘R _\
/
am
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4. 7H 7


It then mixes with the gases, and the
flame produced passes up through the
furnace and escapes by the chimneys
shown. An economy of 30 per cent.
in fuel is claimed for this furnace
over others. It admits of a higher
temperature being obtained, and of
the use of inferior grades of fuel.
Single-Poi Furnaee.—An example
of this construction is shown in Figs.
1881 to 1884. Fig. 1881 is a hori-
zontal projection of the furnace and
crucible. F 1882, section along
the line EF, Fig. 1881; that is to
say, along the flue. Fig. 1883, ver-
tical section along the line CD of
the plan. Fig. 1884, vertical section
along the line A B of the plan. A is
the foundation or support for the cov-
ered crucible B ; (7 C are the walls of
the furnace; D D, openings through
which the coal is thrown on the grate;
E, arch or crown of the furnace; F,
door or opening through which the
crucible B is introduced and taken
out; G, six chimneys; H, an open-
ing; 1, hole to facilitate the placing
of the crucible on its support; K, a bent iron bar for working the fire-clay cylinder; L, a support
with a roller across, on which the bar K is supported ; .M, a hole with a stopper through which the
coal is thrown ; N, aperture with stopper, through which the grate is cleared; O, hood of sheet-iron.
sos FURNACES, GLASS-MELTING.

under which the chimneys terminate; aa, grate of furnace; b, throat of crucible; 0, level of the
melted glass; d, fire-clay cylinder for stirring; 0, opening; f, grate-bars; and 9, door of opening e.
Mr. Siemens has devised a furnace in which the sole is dividedinto three compartments by trans-
1882.




verse partitions. The first serves for fusion, the second for fining, and the third for the collecting
of the glass. In another furnace, in operation in Dresden, the second partition is suppressed and 80
annuli of clay are substituted, in which the glass circulates during the fining. MM. Videau‘ and
Clémandot have constructed a furnace in which a huge melting-vat is substituted for the pots.





/{ tip/NW X
ll GGI ;
ha B AH
A l








Figs. 1885 and 1886 represent M. de la Bastie’s furnace for the manufacture of tempered glass,
Fig. 1885 is a section of the oven and bath, suitable for tempering shaped articles. a is an oven
heated by a furnace I), having its floor 0 made in one piece of a refractory material with a polished
surface; from this a slope d, of the same material, leads into the bath h, which is provided with a n
1885.


lid 2' for the purpose of excluding the air, and a basket kxof fine wire gauze to receive the heated
articles. At the back of the oven a is a chamber into which the articles are first introduced, and
where they are partially heated; they are then pushed through an aperture in the dividing-wall into
theoven a, where the final heating takes place. When the temperature is sufficiently high, the ash-
FURNACES, METALLURGICAL. 809

pit and fire-doors are closed, and rendered air-tight by luting, the fire being maintained by pieces of
fuel introduced through a small aperture in the furnace-door, after which the draught is stopped by
closing the damper. The vertical damper f is then raised, which operation both causes the flame to
pass by the flue g to a second chimney, passing along the slope d and heating it, and also opens the
communication between the oven and the bath, which is filled with the prepared liquid. A fire-truck
p, charged with live fuel, heats the bath to the desired temperature. l is a tube, in which is a ther-
mometer m, for ascertaining the temperature of the bath : by this tube also the contents of the bath
may be added to; n is an overflow-pipe. The plug 0 on the cover may be removed to observe the
interior without wholly uncovering the bath. The workman watches the glass through an eye-hole,
and, when the article has arrived at the proper heat, he pushes it by an iron roa to the slope d,
whence it slides down into the bath, and is received into the basket k. When the glass has cooled
to the temperature of the liquid, the lid is removed, and the basket is taken out with the tempered
glass. The function of the lid is to stop the supply of air, and thus prevent the combustion of the
oleaginous liquid, which might otherwise take place on the introduction of articles raised to a red
heat; the wire basket facilitates the withdrawal of the tempered articles from the bath, and, offering
a yielding surface to the softened glass, the latter incurs no risk of alteration in form. A layer of
sand may be substituted for the basket of wire gauze.
Fig. 1886 represents the same furnace adapted for the annealing of flat plates. Its general con-
struction is the same as above given, the special feature being the rocking-table E and the movable
1886.


furnace-bed B. When the plate which rests on this furnace-bed is sufficiently heated, the bed is
tipped up till it is on a level with the rocking-table, when the plate slides down into the bath, which has
a curve at the bottom to contain any pieces which may be accidentally broken off. When the plate
has been a proper time in the bath, E is tilted up, and, by means of an ingenious adaptation of
levers, the plate is removed and slid out, when the rocking-plate is returned and remains in a posi_
tion to receive the next plate. >
For works for reference on glassmaking, see GLASS, MANUFACTURE OF.
FURNACES, METALLURGICAL, other than for iron and steel. The furnaces chiefly used in the
United States for the roasting of ores of silver, copper, etc., are the Stetefeldt and the Bruckner
revolving-cylinder furnaces.
The Stetqfeldt Furnace, represented in Fig. 1887, is largely employed in the treatment of silver
ore. The percentage of silver chloridized varies according to the character of ore and the care with
which the furnace is managed. Results as high as 97 per cent., the manufacturers state, have been
obtained, while the average chloridations are claimed to range between 87 and 93 per cent. The
furnace can be used for oxidizing as well as for chloridizing roasting, but it is mainly for chloridizing
of silver ores that it has been generally introduced. It may also be used for the oxidizing roasting
of gold-bearing sulphurets, preparatory to extracting gold by Plattner’s process or by amalgamation ;
for oxidizing or chloridizing roasting of sulphuret copper ores, to prepare them for one of the leach-
ing processes; and for the oxidizing roasting and slagging of galena ores—through suitable changes
in its construction—preparatory to their reduction in the blast furnace.
A is the shaft into which the pulverized ore is showered by the feeding machine, placed on the top
of the cast-iron frame B. The shaft is heated by two fireplaces, O. The ash-pits of these are
closed by iron doors, having an opening E, provided with a slide, so that more or less air can be
admitted below the grate, and consequently more or less heat generated. In order to obtain a per-
fect combustion of the gases leaving the fire-box through the slit T, an air-slit U, connected with
the air-channel F, is arranged above the arch of the fire-box. This slit also supplies the air neces-
sary for the oxidation of the sulphur and the base metals. Another advantage of this construction
is, that the arches above the fire-box and fire-bridge are cooled and prevented from burning out. The
roasted ore accumulates in the hopper K, and is discharged into an iron car by pulling the damper
L, which rests on brackets with friction-rollers 111. N is an observation door, and also serves for
cleaning the fire-bridges. O 0 are doors to admit tools in case the roasted ore is sticky and adheres
to the walls. The gases and fine ore-dust, which form a considerable portion of the charge, leave the
shaft throngh the flue G. The doors R are provided toelean this fine, which is necessary with some
810 FURNACES, METALLURGICAL. '
l

ores about once a month. D is an auxiliary fireplace, constructed in the same manner as the fire-
places on the shaft, which is provided to roast the ore-dust escaping through the flue G. in passing
through the chamber H. PP are doors for observation and cleaning. The larger portion of the
roasted dust settles in the chamber V, provided with discharge-hoppers I, from which the charge is
drawn into iron cars by moving the dampers S. The rest of the dust is collected in a system of
dust-chambers Q, connected with a chimney which should rise from 40 to 50 feet above the top of
the shaft. At the end of the dust-chambers is a damper by which the draught of the furnace can
be regulated. The dry kiln can also be used as a dust-chamber, and the waste heat of the furnace
utilized for drying the ore before crushing it. The firing of the furnace is done on one side, and all
discharges are located on the opposite side.
The feeding machine is shown in Fig. 1888. The cast-iron frame A, which is placed on top of the
shaft, is provided with a damper B, which is drawn out when the furnace is in operation, but insert-
ed when the feeding machine stops for any length of time, or if screens have to be replaced. 0 is
a cast-iron grate, to the top of which is fastened the punched screen
1887- D. The latter is made of Russian sheet-iron, or of cast-steel plate,
with holes one-eighth to one-tenth of an inch in diameter. Above
8' the punched screen is placed a frame F, to the bottom of which is
fastened a coarse wire screen F, generally No. 3, made of extra-heavy
iron wire. The frame F rests upon friction-rollers G. The brackets
H, which hold the friction-rollers, can be raised or lowered by set-
screws, so that the wire screen F can be brought more or less close to
the punched screen .D. The brackets K carry an eccentric shaft L,
connected with the shaft 11!, from which the frame F receives an oscil-
lating motion. To the brackets N are fastened transverse stationary
blades 0, which come nearly in contact with the wire screen F, and
can be raised or lowered by the nuts P. These blades keep the pulp
in place when the frame F is in motion, and also act as distributors











, ./ ‘ _ p a I
I;
of the pulp over the whole surface of the screen. The hopper 1 receives the ore from an elevator,
which draws its supply from a hopper into which the pulverized ore is discharged from the crushing
machinery. The ore is generally pulverized through a N o. 40 screen. By means of a set of cone-
pulleys the speed of the flame E can be changed from 20 to 60 strokes per minute, whereby the
amount of ore fed into the furnace is regulated. This can also be done to some extent by changing
the distances between the punched screen 1), the wire screen F, and the blades 0.
The manufacturers give the following example as showing the cost of roasting in a Stetefeldt fur-
nace of 25 tons capacity, in 24 hours, at stated prices for labor, fuel, and salt, such as are generally
paid in mining districts of Nevada:
2firemen,at$4.50 . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . .. 9 00
4 pulp~coolers, at $4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 00
2%}cordsofwood,at$8 . . . . . . . . . . . . . . . . . . .
Wear and tear of screens, etc. . .. . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .___vl~
Labor and fuel for 25 tons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .848 00
Labor and fuel, per ton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . $1 92
7 per cent. salt, at $40 per ton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Expense of chloridizing roasting, per ton . . . . . . . . . . . . . . . . . . . . . . . . . . . .84 72
The Bruclmm' Revolving Furnace, Figs. 1889 and 1890, is also largely employed for the purpose of
roasting and chloridizing silver ores. The exterior of the cylinder is a sheet of boiler iron, 12 feet
long by 5 feet 6 inches in diameter. The ends are partially closed with similar material, leaving in the
centre a circular opening about 2 feet in diameter, bounded by a flange projecting several inches.
Upon one side is placed an opening closed by a hinged door. Upon the outside of the cylinder are
bolted three bands, in which the section of the first is square, and that of the third semicircular; the
second or middle band is a strong spur-gear. Passing through the cylinder are six pipes parallel to one
another, in a plane at an angle of 15° to the axis of the cylinder; these pipes also lie in this plane
at an angle of 30° to 35° to the longitudinal axis of the plane, as shown in Fig. 1890, where the
internal arrangement of the cylinder is seen, a perforated diaphragm being formed through part
of the cylinder by means of perforated plates placed between the above-described pipes, the plates
being held in place by longitudinal grooves upon these pipes. The cylinder is supported upon four
FURNACES, METALLURGICAL. 811

large friction-rollers, two of which are grooved upon their periphery to loosely fit the semicircular
band, thus holding the cylinder longitudinally in place. The other two friction-rollers are made with-
out a groove, and bear upon the square band, thus accommodating themselves to the expansion and
contraction of the cylinder, or any irregularities of form. Rotary motion is given to the cylinder
by means of a pinion placed under the cylinder and gearing into the spur-gear band.
A fire having been kindled in the fire-box, the cylinder is allowed to revolve slowly until heated to
. ill! l1:
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a dull red, and is then brought to rest with the door on top. In this position about 4,000 lbs. of
pulverized ore and 200 to 400 lbs. of salt are introduced ; the door is closed and securely fastened,
and the cylinder is made to revolve at the slower speed of from one-half to one turn per minute.
The fire is so regulated that after an hour’s time the sulphur contained in the ore begins to burn, the
ore in the cylinder being retained at a dull red for some time. (In those ores containing a large
amount of sulphur, little or no additional fuel is required for desulphurization.) Duringr the whole
w-


of this and the subsequent operation. the inclined perforated diaphragm causes the heated ore to
traverse alternately backward and forward the entire length of the cylinder, also sifting it through
the flame, thus insuring a uniform heating, mixing, and exposure to chemical action. The desulphur-
ization being completed, the heat is gradually augmented to a full red. After an hour’s time, or as
soon as a sample taken from the cylinder evolves the odor of chlorine uncontaminated with that of
sulphurous acid, which indicates that the chlorination is complete, the door in the cylinder is opened,
and the cylinder revolved by the more rapid moving gear, and the chloridized ore is quickly dis-
812 FURNACES, METALLURGICAL.

charged, being received into a car, shoot, or other conveyer, according to the construction of the mill.
The total weight of the iron parts is 16,000 lbs. The placing of the foundation and the erection of
brickwork, for fire-box, cylinder-linings, and dust-chambers, will vary greatly according to local cir-
cumstances. The capacity of a cylinder in 24 hours is, as reported by Mr. Charles E. Sherman and
endorsed by B. O. Cutter, from 8 to 10 tons (in very refractory ores the daily average would be less),
the chloridizing being up to 96 per cent. These statements are based upon their experience at the
Caribou Mill, Colorado. A. D. Breed, Esq, proprietor of that mill, gives the actual total cost of
roasting and chloridizing at 85.50 per ton. This low cost renders it feasible to work with profit
very low-grade ores.
Zinc-roasting Furnaces—fig. 1891 represents a vertical section of an improved zinc-ore roasting
and calcining furnace designed by Prof. Pierre de P. Rickctts. The muffle furnace on the right is 42
feet long by 17 feet wide outside. The sole of the mufl‘le measures 39 by 14 feet, and the height of
the arch in the middle is 2 feet 4 inches. There are four flues separated from each other by 9-















1891.
l /, fly, C;;Aw”4nerflisw= -' “R (“fl”'”4m“%: ”’ 9 '
inch walls at the end farthest from the fireplace. These flues connect with a horizontal cross-flue
running along the end of the furnace. This, by means of another fine at right angles to it, commu-
nicates with the calciner on the left. It is also connected by a vertical flue beneath it with the main
flue underground. One of these furnaces is calculated to roast 3 tons of ore in 24 hours, with a
consumption of 2 tons of coal. Should, however, the ore on reaching the end of the muffle not be
completely roasted, it can be taken out and the roasting completed in the reverberatory furnaces used ’
for calcining. The ore is charged through the opening in the arch of the muffle upon the sole below,
where it remains 16 hours, 8 in passing from the charging-deer to tile middle, and 8 in passing from
the middle to the discharge-doors. During this period it is constantly turned over. The sulphur-
ous acid formed during the roasting is conveyed away by two flues at the end of the muffle which
1892.
. > h .
\\ \\\\\\\\\ \\\\\ \\\ \\\\
' 7" . ‘ . \ ii
i

connect with the horizontal underground fine. The roasting furnace can be disconnected from the
calciner at any time by dampers placed at the junction of the fines.
The Hasenclcver furnace, in its latest form, with which the name of Hilbig also is associated, is
used at several European works. In the sectional sketch, Fig. 1892, c' is the hopper into which the
ore is charged; 8, an inclined channel, depressed 33° from horizontal, 1.8 metre wide, 0.5 metre high,
and 9 metres long, heated from below by the flame in the flue d from around the muffle furnace b ;
h h, 50 partitions, which stop short several centimetres above the inclined floor, forcing the ore to
descend in a thin layer, while the gases from the muffle b, passing through openings placed zigzag in
these partitions, are made to traverse the surface of the ore for a long distance, and finally allowed to
escape at s, loaded with sulphurous acid. The inclined channel and the fines are accessible through
side doors. At ,r/ is a hollow, air-cooled, revolving feeder, operated periodically by a water-power, at
each turn of which a certain amount of ore is taken from the bottom of the incline and pushed into
the muffle, While the layer of ore in the incline slips downward. Every two hours the ore is spread
/


FURNACES, METALLURGICAL. 813

out in the muffle by hand, through working-doors, and gradually pushed to the back, where it falls
through an opening upon the hearth a, heated by direct flame. Here it is completely roasted, the
last portions of sulphurous acid escaping with the gases of combustion through e, e, d, and m into
the stack. The Boetius gas-producer l, and the air supplied at n,- give an economical heat to the
hearth, the working-door of which is at f. It will be seen that this arrangement keeps the flame,
gases, smoke, etc., separate from the charge till the roasting is nearly complete, and thus furnishes
sulphurous-acid gas of greater purity (escaping at s) for the manufacture of sulphuric acid. The gas
passes from s first into a cooling chamber, on the iron top of which ore is dried, thus completing the
utilization of the heat. Even blende poor in sulphur (which is the hardest to roast) can be success-
fully treated in this apparatus. A blende containing 20 per cent. of sulphur when charged was found
to contain at g 10 per cent., at the back side of b 6.4 per cent., and at the fire-bridge of a (just be-
fore withdrawal) 1.2 per cent. The further dimensions of the furnace are, in metres: muffle, b, 6.5
long, 1.8 wide, 0.4 high, with five working doors on one side; hearth, a, 5.7 long, 0.4 high; genera-
tor, l, 1.5 high, 0.6 broad at the bottom, 1.4 at the arch.
The Belgian system of distillation is conducted in inclined cylindrical retorts, disposed in rows
above the fireplace, and provided with fire-clay nozzles or condensers, over the outer ends of which
conical tubes (balloons, caps, or “ prolongs ”) of sheet-iron are placed during the operation. The
ordinary form is shown in Fig. 1893, which presents a section from front to rear. In this furnace
the eight retorts a' of the lowest row are left empty, to serve as “ protectors ” and regulators of the
temperature, by means of openings in them, through which the flame may be drawn at will. Above
them are 61 useful retorts, a.
Stone and Water-Jacket Furnaces—There are many ores of silver carrying gold that are too re-
fractory to be treated as free milling ores, by amalgamation in the mortars of the battery where
they have been crushed, or by the Washoe process, where the ore, after it has passed the battery
screens, comes in contact with quicksilver in the pans, with the formation of an amalgam, which is
afterward separated from the earthy matter in settlers. Neither can they be treated by the dry pro~
cess, where the ore crushed dry in the battery mortars is elevated to the top of a Stetefeldt roasting
furnace, to be sifted in a fine powder with salt down through the chloridizing shaft. Consequently
resort must be had to some other method of separation.
The process which, although but a few years in operation, seems to have met with the greatest
success and favor, is that of treating base ores with a certain per cent. of litharge as a flux, if they
do not already contain sufficient
lead for slagging off. In this way 1894‘
a bullion is formed, which collects
and retains the precious metals.
Two general styles of furnaces
have been adopted, termed dis-
tinctively the stone furnace and
the water-jacket, called by some
the hydro-cycle. The stone fur-
nace, as shown in Fig. 1894, is
commonly built of sandstone or
other easily-worked stone that can
be obtained in the vicinity, the
upper structure resting securely
upon corner-piers from 24 to 30
inches square. Springing from
these are arches over the tuyere
cmbrasures, which are construct-
ed so as to admit of the use of
from four to eight tuyeres on the
sides and one opposite the slag-
pot. The interior lining is either
_ of fire-stone or fire-brick, requir-
ing as a rule not less than 200
cubic feet of material. The bot-
tom of the well is sunk from 12
to 18 inches below the point of
slag discharge, to hold about 6
tons, and the tuyeres are located
about 15 inches above the same.
The lead with silver is ladlcd out
of the metal well on the side. At
a height of from 18 to 36 inches
above the tuyeres an offset or
contraction occurs, although the
feeding-floor is generally placed
not less than 12 feet above this point. The stack is commonly run up to a height of 50 feet. Such
a furnace, to treat from 50 to 60 tons per day, will cost from $6,000 to $15,000, according to loca-
tion. This is not meant to include the cost of erecting a light iron flue-connection to flue-stack to
collect the dust, which frequently amounts to 15 per cent. of the ore treated, and assays, according
to the original value of the ore, from $5 to $100 per ton. A number of managers pursue the plan
of working it over, mixed with clay, to a mortar, to aid in fluxing; while others, considering it too


_.
\. 'lJ-u‘l
814
FURNACES, _ METALLURGICAL.

expensive to handle, throw it out as a waste product.
The most essential points to be looked after
in the running of a furnace are: first, to feed uniformly, and the proper portions of ore, litharge,
limestone, and iron ore to secure an even working and no loss; second, to blow just enough air into
1895.


T a .’
I'. “I

















-_
the furnace through the tuyeres to
support a combustion that will pre-
vent clogging in the shaft, or on the
other hand cutting the lining away;
third, to provide an excess of pow-
er for an emergency.
The water-jacket furnace, Fig.
1895, censists of a wrought-iron
stack resting upon a cast; or wrought-
iron frame about the combustion-
chamber, so arranged, in sections of
five or more, that when one gives
out it can be replaced without dis-
turbing the rest. In each of the
sections the water circulates inde-
pendently of the rest, 'and after
reaching a temperature of about
175° F. it passes over the spout into
the tank below, from which it is-
pumped to a tank set so as to se-
cure a head of about 12 feet above
the bottom of the jacket, where the
water is admitted. The interior di-
mensions and capacity for ore treat-
ment are about the same as in the
stone furnaces. This furnace gives
most excellent results when first
lown in, and would continue to do
so under careful management; but
carelessness and irregularity in feed-
ing, with frequent changes of charge,
soon necessitate repairs or renewals
of portions damaged or destroyed.
The advantages which it possesses
over the other style, and which have
led to its more general adoption, are
that it costs only about one-third as
much as a stone furnace of the same
capacity; that it can be erected in
locations where suitable building
materials are scarce; that it can be
repaired without pulling the furnace
to pieces; and that it requires less
labor for working. Many ingenious
devices have been added to the fur-
nace with the view of returning the
valuable flue-dust immediately and continuously to the furnace or to the feeding-floor, where it can
be mixed with just sufficient moistened clay to bring it under the action of the reducing flame.
In the table below are given results from a number of experiments with these two kinds of furnace:
Table showing Results of 'Wm'lcz'ng of Stone and “fatter-Jacket Furnaces.






DETAILS. Stone. Water-Jacket. I
Shape . . . . . . . . . . . . . . .. Oblong.b fippngsolr; oval.
L 3 t0 4 V 0
SIZE! of lead-well.. ..i, 5* to 6 ft-_ 5, 48 to 56 “K ‘
Capacity . . . . . . . . . . . . .. 5 to 6 tons. 6 to 61} tons. i
Tuyeres above slag- ,
discharge . . . . . . . . .. 15 in. 15 in. l
Bottom of well below. 18 to 24 in. 18 to 24 in.
Height of combustion- I
chamber . . . . . . . . . . .. 36 to 56 in. 42 to 54 in.
Height of feed-floor.. . 12 to 15 ft- 12 t0 15 ft. \
Thickness of water- _
jacket. . . . . . . . . . . . . . . . . . . . . . .. g to 1- m. ,
Number of tuyeres. . . 5 to 9 4 to 8 ,
Size of tuyeres . . . . . . . . i 8 in. ' _ 3 in. _ 1
Length of tuyeres .... .i 15 to 30 in. 20 to 3’) in. }
Pressure of air . . . . . . . 1% to 1% 11 to 11} i
Cubic feet of air-dis-1 i
charge . . . . . . . . . . . .. {4,400 to 6,400 4,500 to 7,000
Diameter of air-pipe. . : 1 2





2 in .. 1n. .
‘ Gallons of water daily.i 1 ,000 to 16,000 12,000 to 15,000
DETAILS. Stone. Water-Jacket.
Temperature of water... 120° to 180° 125° to 175°
Height of Stuck . . . . . . . . . 50 ft. 50 ft.
Diameter of stack . . . . . .. 3 x 8 ft. 86 in.
Life of furnace . . . . . . . . . . 4 to 6 months. 8 to 8 months.
Length of dust-flue . . . . . . E . Downcast.
Cost . . . . . . . . . . . . . . . . . . .. $6,000 to $15,000 $2,000 to $5,000
Tons of ore worked per
'24 hours . . . . . . . . . . . . . . 40 to 50 80 to 45
Bushels of charcoal per 80 to 40 25 to 80
ton . . . . . . . . . . . . . . . . . ..
Bushels of coal daily.. . .. 1,200 to 2.000 7 50 to 1.350
(lostofcharcoal per bushel 18 to 80 ots. 18 to 30 cts.
Weight of coal per bushel 18 lbs. 18 lbs
Tons of ore-escape daily. 15 to 18 10 to 15
Percentage of escape. .. 10 to 15 10 to 15
A f d t ( Gold, $10 to $40 . . . . . . . . . . .
881W ° “8 - - ~ - - - -- Silver, $10 to $80 ........ ..
'- Waste in slag and speiss. 75 per cent. 75 per cent.
Cost of smelting, per,
ton . . . . . . . . . . . . . . . . . . i $9 to $15 $8 to $12
FUSES. ' 815

In the stone furnace the result from a charge of 500 lbs. of ore and 250 lbs. of coal and fluxes
would be about 20 per cent. of metal, 10 per cent. of dust, 60 per cent. of slag, and 10 per cent.
of speiss. F. H. McD, (1n part).
FUSES. Devices used to ignite the bursting-charges of hollow projectiles at any desired moment
of their flight, or to communicate fire to the explosive in a mine or blast. As used for projectiles,
they are of three kinds, viz.: time,_percussion, and concussion fuses.
Tms Fuses—The time fuse consists of a column of inflammable composition which, being
ignited by the charge in the gun, burns for a certain space of time, at the end of which it commu-
nicates its "flame to the bursting-charge in the shell. The navy time fuse, represented in Fig. 1896,
is composed of a mealed-powder composition driven into a paper case. This case is inserted in a
metal stock, F, Fig. 1897, which is screwed into the fuse-hole. A safety-plug, P, at the lower
end, prevents the communication of fire to the powder in the shell, in case of the accidental ignition
of the fuse. The jar of concussion consequent upon the explosion of the charge in the bore of the
gun is so great as to detach the plug from the case, so that from the moment the shell leaves 'the
gun the communication is open between the burning composition of the fuse and the bursting-
charge in the shell, and as soon as the composition is consumed the shell explodes. C is the water-
cap, made of copper. On the outer surface of this are pieces of quick-match, the fire from
which, when ignited by the explosion of the charge in the gun, communicates to the powder in channels







1897. 18%
s (I




.. ;\\\\‘ ' " . \_ - \ “I,
\-




/


SECTION.
\\
5
in the cap, and so to the bursting-charge in the shell. The object of the water-cap is to prevent the
entrance of any matter, such as sand or water, over which the shell may ricochet. The safety-cap,
S, is a leaden patch which covers the top of the fuse, and is removed before the shell is inserted in
the gun.
The Bormann Fuse, represented in Figs. 1899 and 1900, consists of a lead—alloy disk, with an inte-
rior canal in which the burning composition is condensed. The upper surface of the disk above the
composition is very thin, so as to yield readily to the cutting tool employed to open it, its whole
external surface corresponding of course to the composition below. It is graduated into seconds
and quarter seconds. The end of the composition at which the enumeration begins communicates
with a- small magazine at the centre of the disk, which is charged with grained powder and closed
on the inner side with a very thin disk of lead, so as to yield in that direction to the explosion.
The thin covering above the composition is cut so as to lay bare the upper surface of the latter and
afford the flame access to it at the part desired. The composition occupies the assigned time in
passing from the incision toward the origin of the graduation, when it traverses the magazine, the
contents of which explode toward the interior, and so fire the charge in the shell.
81 6 ' FUSES.

Pancussron Fuses—A percussion fuse is one which is prepared for action by the discharge, and
put in action by the shock on striking the object. The essential requirements of the device are
that it shall not be ignited by the shock of discharge or on striking the water, that it shall be
ignited by the impact of the shell against the object, and that it may not be liable to explode bV
handling or during transport. ' ‘
The Shenkle Fuse—This is the form used in the U. S. navy. It consists of a metal fuse-stock
inclosing a movable core-piece or steel plunger bearing a musket-cap. The plunger is confined
inside the stock, in which it fits loosely, by a screw or pin which passes through both stock and
plunger, and so prevents motion of the latter. When the projectile is fired, the plunger by its
inertia carries away the pin and presses against the bottom of the fuse-stock. When the motion




\
_ s
\






I


75

'-""\‘-.'_\


3


is arrested, the plunger continuing on strikes the safety-cap in front of it, the cap is exploded, and
fire is communicated to the bursting~charge.
The German Fuse, Fig. 1901.—In this fuse a plunger a h, having a central fire-hole b, is let into
the fuse-hole, and rests against the shoulders c c. This plunger is surmounted by a perforated cap
p, having a terminating point above. The plunger is retained in place by a pin E, which passes
transversely into the fuse-hole, the side of which is put in contact with the point of the cap. The
outer end of the pin projects on the side of the shell, the projection being limited by the line of the
cylindrical portion. The fuse-hole is closed by a screw-cap f f, having a small central screw-hole
into which the fulminatc cap 9 is screwed. When fired from a rifle, the centrifugal force gener-
ated by the revolution of the shell throws out the pin E; the plunger by its inertia is retained at
the bottom of the chamber during the flight of


- "i
r
:
\


1902- the projectile; at the moment of impact the
plunger impinges against the fulminatc, which
\
--. keep the bursting-charge in place in the shell,
,"I m“ a brass thimble h, with a flange on top and a
l '
.% / F“. the fuse-hole and takes against the shoulder a.
.% / “D ' Hotchlciss’s Fuse, Fig. 1902, consists of a
// metal body A, closed at the front end with a
screw-cap B. It has a conical hole at the rear,
which is closed by a lead safety-plug O pressed
in very tightly, so that the plug projects a little
B through the base of the body-case toward the
' inside. The plunger D is composed of lead
cast into a brass casing to strengthen it, and to'
0 prevent the lead from being upset by the shock
of discharge. Two brass wires EF, cast into the
lead on opposite sides of the plunger, hold it suspended in the case, the wires going through the
holes in the bottom of the case, and being held securely in position by the safety-plug. The plun-
ger has a nipple cast into the lead, and is primed with an ordinary percussion cap ; in its axis it has
a powder-chamber G, containing the igniting charge. The operation of the fuse is as follows: The
safety-plug is dislodged backward into the interior of the projectile by the shock of discharge; the
wires then being not held tight in the hole, the plunger is disengaged and rests on the bottom of the
fuse-case, and is free to move in the line of axis. When the flight of the projectile is suddenly
retarded by its striking any object, the plunger, in consequence of its inertia, is driven forward, and
the primer strikes against the screw-cap, thus igniting the powder in the channel, and so firing the
bursting-charge of the projectile.
77w English Royal Laboratory Fuse, Fig. 1903.-—This fuse consists of the following parts: A,
B
a? v 1983. exploding ignites the charge in the shell. To
'7/ E; f small hole in the bottom, is first pressed into
.‘ /'
..l


a
4
2/1
‘I





&
I
l
\ FUSES. 817

the brass stock or body; B, the brass screw-plug closing rear end of fuse; C, the lead plunger; D,
the brass thimble; E, the brass safety-wire; and F, fulminatc. The body has a solid head, hav-
ing on the outside a square recess for the fuse-wrench, and on the inside a sharp pin projecting
from the centre. The screw-plug B has a hole through its centre which is covered by a thin disk
of brass secured on by solder; two small recesses in the bottom of the plug facilitate its inser-
tion with a wrench. The lead plunger 6’ has also a central hole through it, in the front end of
which is placed the fulminatc cap ; the plunger has also two slight projections from its sides, upon
which rests the brass thimble D. Running through holes in the heads of the fuse-body and thim~
ble, and to one side of the centre and resting on top of the plunger, is the twisted safety-wire E.
In order to prevent the easy withdrawal of the safety-wire, a small hole is bored into one side of
the fuse-body and down to the hole through which the wire is inserted, and into this is poured
melted lead. A strong cord facilitates the extraction of the wire before firing. Inserted in a loaded
shell with the safety-wire removed, and meeting with a resisting object in flight, the plunger is thrown
forward, sheering off the shoulders ; the fulminatc, striking the pin, is ignited, the brass disk closing
the hole through the screw-plug is blown out, and the bursting-charge of the shell ignited.
For reports of tests of fuses, see “Report of Chief of Ordnance, U. S. 11.,” 1878. The follow-
ing percussion fuses are recommended as superior to all others : German, Hotchkiss, English Royal
Laboratory, and Shenkle; this being the order of merit.
CONCUSSION Fuses—A concussion fuse is one which is put in action by the discharge, but the
effect of that action is restrained until it strikes any object. The distinction between percussion
and concussion fuses is somewhat arbitrary, and the application of the terms has depended in large
measure upon the sense in which the inventor of any particular fuse chooses to apply them. Such
a fuse, in order to be serviceable, must not only produce explosion on striking, but it must not pro-
duce it on the shock of the firing of the gun charge, nor on that produced by the ricochets of the
projectile in or out of the gun. These fuses have usually consisted of some composition of the
highly explosive fulminates, and the extreme danger of using them has been the chief obstacle to
their adoption.
The Splingarcl Fuse, Fig. 1904, is both a concussion and a time fuse. The appearance of the
paper case is similar to that of the Navy time fuse, but the internal arrangement is different. The
case is filled with fuse composition, and a long cavity is formed in the lower portion of the compo-
sition by driving it around a spindle as in a rocket. This cavity is filled with moist plaster of Paris,
and a long needle is inserted in it, nearly to the bottom of the plaster, forming a tube inclosed in
and supported by the composition. The latter is ignited in the usual way at the top, and as it burns
away leaves a portion of the plaster tube unsupported. \Vhen the shell strikes its object, the stock
breaks off the unsupported part of the tube, and the flame of the composition immediately commu-
nicates with the bursting-charge; if the tube does not break, the composition burns and the burst
ing-charge is ignited as an ordinary time fuse.
The Bacon and McIntyre Fuse, Fig. 1905, is very similar to the foregoing, except that the internal
tube is differently formed. A is an outside paper case; B, the powder composition ; 0, inside paper
case; D, coating of plaster of Paris; E, conical tube; and F, a ball on the tube. The thin cop-
per tube E extends through the centre of the fuse composition, and has a solid copper head F,
secured in its upper end by a little soft solder. The fuse being ignited by the flame from the gun,
the upper part of the composition burns away in the first second or two of time, melting the solder
and leaving the head of the tube free to be displaced by the shock of impact. Under ordinary cir-
cumstances this fuse acts like the time fuse, the stopper F being kept in place by the'plaster of
Paris; but upon impact the plaster breaks, the ball falls, and the flame, passing through the tube,
at once ignites the bursting-charge.
Enncrnrc Fusus on Exrnonsas, for mines, etc., may be divided into two classes: those in which
the heat is obtained by the passage of the electric spark over a. break in the circuit, and those in
Whlill the heat is obtained by the passage of the current over a conductor of great resistance. The
first, called tension fuses, may be used with the Leyden jar, induction coil, or any static electrical
machine. All that is necessary for a fuse or exploder of this class is, that there shall be a break in
a circuit not greater than the spark can easily be made to pass over (one-sixteenth to one-thirty-sec-
0nd of an inch is the usual distance), and that between the two points of the break shall be placed
some composition that will be ignited by the passage of the spark. Gunpowder can be so fired, if
packed closely between the points ; but it is better to use some more sensitive material as a priming.
Fulminating mercury is fired by the spark, and may be used for this purpose, either pure or mixed
with other substances, as in percussion-cap composition. Abel’s composition has thus been used.
It is composed of subsulphide of copper 64 parts, subphosphide of copper 14 parts, and chlorate
of potash 22 parts. The wires of the fuse must be firmly held in a wooden block or similar con-
trivance, in such a manner that the priming cannot be displaced, nor the distance between the
points altered. Outside the priming material is placed fulminating mercury, gunpowder, or other
substance, and the whole is properly inclosed in a wooden or metallic case. The principal diffi-
culty connected with the use of statical electricity for causing explosion is the high insulation of
the conducting-wires that is required. If the insulation is imperfect, the loss is so great as to
render the firing of the fuse uncertain or impossible. -
The second class of electric fuses or exploders are those in which, by the passage of the current,
a portion of the circuit having a great resistance becomes suificiently heated to ignite some explo-
sive or inflammable body in contact with it. These fuses are used with the voltaic battery and the
various dynamo-electric machines, such as Farmer’s, Gramme’s, etc. For convenience they may be
divided into two classes: those in which plumbago, copper sulphide, Abel’s composition, or other
similar highly-resisting substance forms the part of the circuit which is to be heated; and those in
which a fine platgréum wire or other comparatively good conductor occupies that position»
818 . FUSES.

Of the first division are the fuses used in connection with Wheatstonc’s machine and others simi-
lar. They consist essentially of a break in the circuit, which is bridged by a layer of plumbago or
composition which has a certain conducting power, and which will burn when heated. In contact
with this is placed the gunpowder, fulminating mercury, or other substance which is the charge of
the fuse. The difficulties connected with the use of these fuses and the machines for
which they are made are, that good insulation of the leading~wires is necessary, and that 1907,
this, from various causes, is often uncertain. Safe fuses of this sort may be made, since
no very sensitive composition is required as a priming. l
Of the second division are those known as platinum or German-silver wire fuses.
The essential point 111 the construction of these is the placing of a short piece of very




\
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\
-\\§ ’ I ’ 1
\\
\ /
[81!
85>
\\
Q
\
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fine platinum or German-silver wire in the circuit, and in contact with it a priming material which
when fired ignites the fuse-mass; or the wire may be imbedded in the fuse-mass itself, and thus
inflame it directly without the intervention of a priming. This form of electric fuse has many advan-
tages. The current with which it is used is one of great quantity and low intensity, so that the
insulation of the conducting-wires need not be as complete as in the other cases. In 1" act, no insula-
tion is required if the fuse is sufficiently delicate and the whole circuit is not too long.
77w Dynamo-Electric Igniter used in the U. S. navy is represented in Fig. 1906. It consists of a
hard wooden plug a, half an inch in length and about three-sixteenths of an inch in diameter, hav-
ing a score out about its centre, and a longitudinal groove on each side for the reception of the cop-
per wires. The latter are cotton-covered, and are twisted together for about an inch, and stripped
of their insulation almost to the twist. The uncovered parts of the wires are pressed firnzly into
the grooves in the sides of the plug, and are cut ofi so that they project about one eighth of an
inch above the plug. The ends of the wires are now split with a very fine saw in the direction of
the plane passing through them, and the distance between the ends is carefully adjusted to three-
sixteenths'of an inch; after which platinum wire No. 40 is stretched between them to form the
bridge, and is securely soldered to the ends of the split wires i i. A wisp of gun-cotton f is next
wrapped around the platinum wire, and the ends of the copper wires are pinched together sufficiently
to take all strain from them. The plug is inserted in a hollow wooden case bb, 2 inches long,
and is countersunk one-eighth of an inch. The resistance of the wire should not vary five-tenths
either side of 0.4-2 ohm. The upper part of the case is filled with rifle-powder, the top being closed
with a disk of cork, over which is poured some water-proof composition, and the whole is properly
coated with shellac. ~ .
The D,I/'n(mvo-Elcclric Fuse, Fig. 1907, is made by inclosing one of the igniters above described in
a stout paper case about 6 inches in length, which is filled with rifle-powder to give more flame
and consequently a better ignition of the charge. One end of the case is closed by a wooden plug
B, with grooves cut in the sides for the wires, which serves for the bottom, and the other end is
filled with a disk of cork coated with collodion.
The foregoing is mainly abridged from “Naval Ordnance and Gunnery,” Cooke, New York, 1875.
See also BLASTING. '
GAS, r CARBONIC ACID. ‘ 819

FUSEE. A mechanical contrivance chiefly used in chronomcters and watches, in order to main-
tain a uniform force upon the train of wheels, and to compensate for the decreasing power .of the
spring. The spring is inclosed in a cylindrical barrel, and sets the wheels in motion by the ald of a
1909.


s: ___
ullngmlmliali
Ilill


cord or chain wound partly upon the barrel and partly upon a sort of tapering drum called a fusec,
Fig. 1908. As the spring uncoils in the barrel, the pull of the cord decreases in intensity; at the
same time, however, the cord unwinds itself from the fusee, and continually exerts its strain at a
greater distance from .the axis, that is, with a greater lever-
age and with more effect. I
The disk and roller, Fig. 1909, equivalent to the fusee,
consists of a disk A, revolving round an axis perpendicular
to its plane and giving motion to a rolling plate B, fixed
upon an axis which intersects at right angles the axis of the
disk A. Supposing the rotation of the disk to be uniform,
that of the roller B will continually decrease as it is shifted
toward the centre of A, and conversely. This is precisely
the effect produced by a fusee. The roller may be a wheel
furnished with teeth, and may roll upon a spiral rack as
shown in the diagram. As the disk revolves, the pinion P,
Fig. 1910, slides upon the square shaft, and is kept upon the
rack by the action of a guide-roller R, which travels along
the spiral shaded groove.
1910.
//r' I I l\\ \\


GALVANIC BATTERY. See Ense'rao-Gxtvame‘xxn Tnsamc Bxrrsarss.
GALVANOPLASTY. See ELECTRO-METALLURGY.
GAS, CARBONIC ACID. Carbonic acid gas is composed of 1 atom of carbon and 2 atoms of
oxygen. - Its chemical symbol is therefore (JO-2. Compared with air its weight is as 1.529 to 1. 0f
the gases which may be liquefied, carbonic acid is the best for use as a. source of motive power. It
can be readily prepared by pressure in liquefied form, and stored in strong vessels of small compass.
The following table by Regnault shows the tension of the liquid in atmospheres at various tempera-
tures Fahrenheit:
Temperature. Volume. Temperature. Volume.
13° . . . . . . . . . . . . . . . . . . . . . . .. 17.1 + 590 . . . . . . . . . . . . . . . . . . . . .. 52.1
-— 4° . . . . . . . . . . . . . . . . . . . . . . . 19 9 + 68° . . . . . . . . . . . . . . . . . . . . . . 58.8
+ 5°. . . . . . . . . . . . . . . . . . . . 23.1 + 77° . . . . . . . . . . . . . . . . . . . . . . 66.0
+ 14° . . . . . . . . . . . . . . . . . . . . . . . . 26.7 + 86°. . . . . . . . . . . . . . . . . ’73..
+ 23° . . . . . . . . . . . . . . . . . . . . . . . . 808 -_t— 95° . . . . . . . . 82.1
+ 32° . . . . . . . . . . . . . . . . . . . . . . 3o 4 + 104° . . . . . . . . . . . . . . . . . . . .. 910
+41° . . . . . . . . . . . . . . . . . . .. 404 +113° . . . . . . . . . . . . . . . . . . . . .. 1004
+ 500 . . . . . . . . . . . . . . . . . . . . . . . . 46 0

The specific gravity of liquid carbonic acid is as follows:
Temperature. Sp. Gr. ' Temperature. Sp. Gr.
—- 4° . . . . . . . . . . . . . . . . . . . . . . . . 0.90 , + 86° . . . . . . . . . . . . 0.60 (Thilorier)
+ 32° . . . . . . . . . . . . . . . . . . . . . . . . 0.83 l + 32° . . . . . . . . . . . . 0.9470 (Andréef'f)
The expansion of liquid carbonic acid with temperature is at
Temperature. Volume. 1 Temperature. Volume.
4° . . . . . . . . . . . . . . . . . . . . 0.9517 + 50° . . . . . . . . . . . . . 1.0585
+ 32° . . . . . . . . . . . . . . . . . . . . . . 1.000 + 68°.. . . . . . . . . . . . 1.1457 (Regnault)
Carbonic Acid Gas as a Aldon—Carbonic acid gas has been employed for driving the propelling
engines of torpedoes; and experiments in liquefying it, and storing it in flasks, to adapt it for this
purpose, have been carried on at the United States Torpedo Station at Newport, R. I. The following
details* on the subject have been prepared and published by Mr. Walter N. Hill, S. B., chemist of
the station. The liquefying apparatus constructed by Mr. Hill is represented in Figs. 1911 and 1912.
The compressing-pump used is a modification of the Burleigh air-compressor. The generating

* Published by permission of the author.
820 ‘ GA S, CARBON IC ACID.

apparatus was obtained from John Matthews of New York, and is that much used for generating
carbonic acid gas for making soda-water, with some alterations and additions to render it serviceable
for this purpose. I
Fig. 1911 shows the generators, the vessel for receiving, and the coil for cooling the gas. Fig. 1912
shows the compressing-pump and the receivers or flasks, into which the gas is condensed. As used,
1911. Q , e I. r , b


~ - . . . - - -.
..... ~-—_—--... I ; ...-.FF~n-h

\\\\\






the whole forms one complete apparatus, and the gas generated in one end is obtained in the liquid
condition at the other. There are two generators, so that while one is in action the other may be
emptied and recharged. A is a large cast-iron cylinder with rounded ends. This receives the
marble-dust, from which the gas is obtained, and water. E is a wheel by which is revolved a composi-
tion agitator within the cylinder. F is a large valve, through which the spent charge is drawn off.
The acid (sulphuric) is contained in a small cast-iron vessel B, which is supported by a projection
cast on A. There is a small opening in the bottom of the acid-receiver B, which is continued
1912.









I
...-~—
__,-'—’
do,








’ Ellen M-
f /
through the projection on A. This is closed by a plug on the end of a rod, which passes up through
a gland on the top of B. This rod is hinged to the arm a, so that it can be raised _or lowered at
pleasure; and when down, the arm a is prevented from rising by a cam, which works in a frame on
the side. 0 is a vessel of the same size as B, but it has no direct communication with A. This
contains water for washing the gas.
GAS, CARBONIC ACID. 821

When in use, the necessary quantities of marble-dust and water are_poured into A through an
opening which is closed by the cap D ; the corresponding amount of acid is poured into through an
opening, which is then closed by a cap firmly screwed on, and water put into Q, which is also tightly
closed. The plug-valve in B is then lifted by raising the handle a, and a portion of the acid allowed
to run down into A. The valve is then closed by bringing down the handle a, and looking it with
the cam. The acid let down into A acts upon the calcium carbonate (marble-dust), and generates
carbonic acid gas, which passes up the lead pipe b to the cross 0. To one arm of the cross is at-
tached the pressure-gauge (Z, and to another a short lead pipe, which is connected with the top of B
and serves to equalize the pressure in B, so that the valve may be easily worked. The lower branch
of the cross is a pipe which extends to the bottom of O. The gas therefore bubbles up through the
water in C to the upper part of that vessel. From thence, when it is to be compressed, it is drawn
through the pipe e e to the receiver G .
All the castings of the generators are heavily lined with lead to protect them from the action of
the acid. The valves are of brass, heavily tinned. The generators are all tested to 500 lbs. to the
inch, and are capable of supporting a much heavier strain. They are limited to 300 lbs. pressure,
and are provided with ingenious safety escapes. _
From the receiving vessel the gas passes through a lead pipe 9 g into the coil of lead pipe H.
This coil is placed in a tank or box under the floor, which is filled with ice-water flowing from the
freezing mixture in the box LL mentioned below. The other end of the coil is connected to a
strong small vessel, 1. _
Fig. 1912 represents the compressing-pump and the receivers for the liquid. The steam-cyhnder
J has 15 inches stroke by 7 inches diameter. There are two compressing cylinders, k k, of steel,
each 21.} inches in diameter
by 10 inches stroke, provided 1913-
with steel pistons, in which
are small steel valves open-
ing upward. The receivers or
flasks 1?! .M', into which the
gas is condensed, are placed
in the box L L, where they
are surrounded by a mixture
of pounded ice and salt, 1'.
During the compression, the
cooling mixture must be stirred
and pressed against the receiv-
er in order to obtain as much
cooling effect as possible, for
upon this largely depends the
pressure at which liquefaction
takes place. When the flask
or receiver is thoroughly cold
and empty, this pressure is
about 350 lbs., but rises as
the operation goes on, and
large quantities of gas are
rapidly condensed to-500 to 600 lbs., which may be considered as the average range. Sometimes a
higher pressure is attained, of 700 to 800 lbs., when the condensation is very rapid and the cooling
imperfect.
Flasks to contain liquid carbonic acid are shown in Fig. 1913. They are cylinders with rounded
ends. Each is provided with a valve in the centre of one head. When in place in the torpedo they
lie upon their sides. The opening controlled by the valve in each is, therefore, continued into the in-
terior by means of a pipe which turns up against the side. In this way gas passes out only when the
valve is opened. They are four in number: two 7 feet long each (including valve), one 5 feet long,
and one 4 feet long (both with valves included). The outside diameter of each is 12 inches along the
body, and 13% at the heads. They are made of the finest sheet steel (.045 inch thick), in successive
layers, which are firmly fastened together with pure tin. The heads are made from cup-shaped
pieces of steel, which are placed one within the other and sweated together with tin. A flask con-
structed as explained, which was tested to destruction, gave way under a pressure of 1.4 ton (of
2,240 lbs.) to the square inch, or 3,136 lbs. Rupture occurred in the body, and the sheets them.
selves were torn through irregularly without regard to the joints. The heads and junctions of the
heads to the body were not afiected. The strains borne by these flasks may be calculated as follows:
At 1,200 lbs.: longitudinal strain, 19,104 lbs.; tangential strain, 38,800 lbs. At 1,365 lbs.; lon-
gitudinal strain, 21,731 lbs.; tangential strain, 44,152 lbs. These calculations are based upon a
thickness of side of .18 inch. In reality it is nearly five-eighths of an inch, but of this only the steel
is of importance; and, as there are four layers, this amounts to .18 inch. The excess of tin on the
inside, as already remarked, is not required, and does not add to the strength. Taking the tensile
strength of the steel at the low figure of 120,0001bs., it will be seen that the extreme strains are
' well below this point. Finally, the flask which gave way under 3,136 lbs. hydraulic pressure had,
when it ruptured, a tangential strain upon the surface withstanding it of 101,396 lbs. to the inch.
Ritchie’s improved form of N atterer’s apparatus is represented in Fig. 1914. In this apparatus the
gas is conducted into a bronze receiver capable of resisting a pressure of 200 atmospheres, and is
condensed by means of a steel force-pump. The receiver is surrounded by a copper cylinder con~
taining a mixture of ice and salt. When enough of the gas is thus liquefied, it is caused to pass


822 GAS, CARBONIC ACID.

through a tube, terminating in a fine rose of wire gauze and into a lined woolen bag. 0n passing
out, the cold produced by evaporation is so intense as to freeze the liquid carbonic acid, which forms
a deposit resembling snow. By means of the solidified carbonic acid it is possible to freeze mercury
in a white-hot platinum capsule. Water placed in the latter assumes the spheroidal state, in which
it does not really touch the vessel, being separated from it by a layer of steam ; if, new, solid car-
bonic acid mixed with ether is introduced into the water, enough heat is absorbed by the evaporation
of the carbonic acid to freeze a small quantity of mercury placed in the mixture.
Alan'ufactu're of Carbonated Bcvm‘agcs.—There are two systems of apparatus for making “soda
water ” and other carbonated beverages, the continuous and the intermittent. The continuous sys-
tem, being well adapted to making carbonated beverages for filling siphons and bottles, is much
used in Europe, while the intermittent system prevails in the
United States, where beverages are extensively dispensed
from the counter.
The continuous system consists of a generator, in which
the gas is evolved under very moderate pressure ; a gasome-
ter, into which the gas passes and is stored; and a beverage-
carbonating compressor, by which the liquid and gas are
compressed into a receiver and agitated under a pressure of
from 150 to 200 lbs. to the square inch for filling siphons,
or 60 lbs. for filling bottles. In the intermittent system, the
1914.
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pressure is obtained in the generator from the expansive force of the gas evolved by the chemical
action of sulphuric acid on a carbonate. After the required pressure is obtained, the gas is drawn
into a receiver and agitated with the liquid, to carbonate it.
Fig. 1915 represents the Matthews generator, generally used in either system. The chamber A
is filled with a powdered carbonate (preferably ground marble) and water to about two-thirds its
capacity. Sulphuric acid is poured into the acid-chamber B. The gas-washer C is filled with chips
of marble and water to wash and cool the gas. All the openings in the generator are then tightly
closed. The sulphuric acid is allowed to enter the carbonate chamber A, by means of the valve 0,
in small quantities, and the agitator f is turned to mix the carbonate and water with the acid. As
the carbonic acid is evolved, it passes through the pipe 9 to the bottom of the gas-washer, and rises
in minute bubbles through the water and lumps of marble to. the pressure-gauge. When, the re-
quired pressure is obtained, the gas is drawn into the fountain by means of the pipe h. The pipe 2'
GAS, CARBONIC ACID. ‘ ses

connects the top of the acid-chamber with the gas-washer, equalizing the pressure in the two, and
thereby preventing the pressure of the gas in the chamber A from opening the valve e. The valve
e is locked in position by means of the cam j.
Another form of generator is shown in Fig. 1916. In this a mixture of sulphuric acid and water
is introduced through the bung, and the marble-dust is poured in through B. The acid liquor passes
1917. 1918.
1919.






to the bottom of the vessel; but the marble-dust is arrested by a diaphragm .M, furnished with
several slits, through which the marble-dust is made to sift when the shaft S is caused to revolve by
turning the handle E. At the same time the agitator O facilitates the evolution of gas by keeping
the mixture constantly stirred. As soon as a pressure of 105 lbs., indicated by the gauge L, is
reached, the stop-valve of the fountain is opened, and the gas is made to pass into it slowly by
1920. 1921.


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gradually opening the stop-valve D of the gas-washer. When enough gas has come over, the valves
are closed, the pipe is disconnected, and the fountain is made to revolve in its frame for about ten
minutes, to aid the absorption of gas by the water.
Carbonic-acid-gas generators are made either of steel, iron, or copper, and are lined with sheet
lead without seams to prevent corrosion. Those made of steel are the best, as they will resist a
pressure of 2,500 lbs. to the square inch. They cannot be. burst by the chemical action even of a
824 _ GAS, CARBONIC ACID.

full charge of sulphuric acid and carbonate, as the highest pressure that can be thus developed in
the generator does not exceed 1,000 lbs. to the square inch. The best iron generators are made to
resist a pressure of 500 lbs. Copper does not answer so well for high-pressure generators, as it is
weakened by the heat of the chemical action in the generator during the operation. The best genera-
tors are protected from bursting by undue pressure by a safety-cap containing a duplex disk which
will sustain a given amount of pressure. If the pressure in the generator exceeds this amount, the
disk is ruptured and the pressure escapes. Generators are made of different sizes to carbonate from
500 to 600 gallons of- liquid at one operation.
1917 represents the Matthews portable steel fountain for containing and transporting ear-
bonated beverages. It consists of an interior fountain of pure sheet-tin, inclosed in an exterior case
of sheet-steel of great strength and elasticity. The opening for the stop-cock in the fountain is
strengthened by steel washers or rings. The flange of the cock beds down on the bung surmount-
ing the fountain, and is recessed so as to form a matrix to receive a soft metallic or other pack-
ing. The lip of the bung of the fountain fits up into the recess and impinges on the packing, which
is prevented from spreading by the sides of the recess, thus making a perfect joint. The weight of
the steel fountain for holding 10 gallons of beverage is about 40 lbs., while that of the cast-iron
fountain is 180 lbs., and of the tin-washed copper fountain 80 lbs. The fountain is filled to about
two-thirds its capacity, leaving a space for the gas compressed above the beverage to force the latter
out of the fountain. These fountains are also made of wrought-iron and copper.
An improved glass-lined fountain is shown in Fig. 1918, and consists of a glass vessel a, encased
in a shell of steel, iron, or copper. The gas enters between the glass vessel and its metallic case
during the filling of the fountain, and equalizes the pressure inside and outside the glass vessel.
Portable fountains are charged by first filling them with the required quantity of liquid to be car-
bonated, and connecting them with the generator. The carbonic acid gas is let into the foun-
tain at 150 lbs. pressure. The fountain is then shaken to agitate the water and impregnate it
with the gas.
One of the principal parts of the continuous system is the beverage-carbonating compressor shown
in plan in Fig. 1919, and in elevation and section in Figs. 1920 and 1921. The gas and liquid enter
the twin cocks where marked “Gas ” and “ Water.” By, the upward stroke of the reciprocating cylin-
der D, they are forced through the valve L and passages up and into the receiver E, as indicated by
the arrows. The reciprocating action of the cylinder and its passages works the agitator F with a
churning motion. The agitator has one or more volutes to catch and distribute the gas in the water,
and to agitate the latter within the receiver.
1923‘ S is the safety-valve. The pressure used
5- rarely exceeds 200 lbs. to the square inch.
In this machine the feed and the agitator
are operated through the base or lower por-
tion of the receiver, and the discharge- or
feed-pipe passes from the pump into the re-
ceiver and imparts to it a reciprocating ac-
tion by or with the pump, so that- the press-
ure of the gas or the liquid in the receiver
is made to assist the pump in its discharg-
ing or feeding stroke to the receiver, by
acting on the exposed end of the discharge-
or feed-pipe. All the parts exposed to the
beverage are encased with pure block-tin,
and the agitator-shaft is jacketed with pure
silver. All tin-washed surfaces are avoided
a = as not durable.
In bottling carbonated beverages the
Matthews internal gravitating stopper, Fig.
1922, is largely used as a substitute for
corks. This stopper consists of a glass
stem with a rubber cap. The stopper is
forced into the bottle before filling, and can
be used repeatedly to close the bottle. The


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1. pressure of the carbonated liquid presses
” WWWllllllll"williliilllllIlllllllllilmtmllllllllllllll- the rubber cap against the neck of the
*~ a ,-- i _. ~. bottle; the more pressure the tighter the
bottle is closed.
A bottling machine, shown in Fig. 1923,
is required to fill bottles closed with this
stopper. The bottle is placed neck downward in the socket of the machine, and secured by depress-
ing the foot-lever. By raising the hand-lever a vent-tube is elevated in the bottle. A valve operated
by the hand admits the beverage, the air escaping by the vent-valve. As soon as the bottle is filled,
the supply-cock is closed and the hand-lever is depressed, withdrawing the vent-tube from the bottle
and allowing the stopper to fall into its place in the neck of the bottle, which is then released by
elevating the foot-lever, and the operation is completed.
Generators—A vertical carbonate feeding generator, manufactured by John Matthews, of New
York, is represented in Fig. 1923 A. The large cylinder contains the carbonate-chamber above and
the acid-chamber below. The gas-washer is at the side. The carbonate 1s let down from above
and falls as a powder through the acid and water.


GAS, CARBONIC ACID. 825

Gas, carbonic acid, or carbon diet-ide, chemically known as 00,, has so many uses that its collection
and control for convenient handling are attracting the talent of many countries and interesting capital
1928 a.


rubber gaskets; R, acid-valve
handle; 5' S, Agitator-jour
nals; T, gas-pipe connecting
purifiers; U U, lugs or cars;
V V, filling bungs; W W",
brass horns; X X, journal-
box nut for agitator end; Y,
acid-chamber hood; Z, puri-
fier-hood; a, socket-screw for
raising acid-valve; b, brass
core of acid-valve stem; 0,
stuffing - box ; (1, acid - valve
nipple ; e, square socket which
prevents acid-valve from turn-
ing; f, stuffing-nut; y, acid-
valve seat; )1, fitting which
supports acid-valve seat; 2',
clamp-cap of filling-bung; j,
yoke of filling-bung clamp;
k, rubber washer; l, valve of
blow-off cock; m, wheel of
blow-ofi cook; 12, blow-off
cock-valve spindle.
Apparatus for Charging
Ale, Cider, and lVi-ne with
Carbonic-Acid Gas.--Fig.
1923 0 represents an appara-
tus, manufactured by J. W.
Tufts, arranged for charging
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from the whole civilized globe. It is being pumped
from the springs of Europe and America and com-
pressed into portable cylinders containing 10 or more
lbs.; and is collected from chimney-tops as it escapes
from fires in the fines, while in London and America
extensively organized stock companies are collecting it
from the fermenting tanks in large breweries as it
escapes from the brewing of malt, hops, etc.
The J/[anufadure of Carbonated Beverages.—Car-
bonic-acid gas is made from chalk-whiting, shell-lime,
magnesia, magnesite, limestone, dolomite, bicarbonate of
soda, and charcoal. It is asserted that carbonic-acid gas
can be collected without expense from magnesite, dolo-
mite, and bicarbonate of soda, as the by-product will
sell at a price which will cover all costs of materials
and labor where any considerable amount is used.
The construction of the generator shown in Fig.
1923 B, made by James W. Tufts, of Boston, Massa~
chusetts, will be readily understood from the follow»
ing references: A, marble-chamber; B, acid—chamber;
C, purifier; D, agitator-blade; .E', acid-valve; F, Press-
ure-gauge; G, safety-valve; H, blow-off cock; I, clamp
and cap: J, frame; K, equalizing-pipe; L, agitaton
shaft; 11! ill, purifier blow-ofi cocks; N N, agitator
journal-boxes; O, agitator-wheel; P, gas-pipe; Q Q,
19:23 B.
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alez cider, or wine with carbonic-acid gas. The advantages of charging these beverages with gas
artificially produced are generally well understood; but many difliculties have heretofore stood in the
826 GAS, ILLUMINATING, APPARATUS FOR.

way. Ale, cider, and wine after bottling undergo a secondary fermentation, the object of which is
the production of the carbonic-acid gas, which renders the beverages bright and sparkling, and with
out which they are dull, flat, and insipid. Incidentally this secondary fermentation produces various
undesirable products, which form the lees or ullage—no inconsiderable portion of the valuable liquid
—which must be thrown away, as it is both unsightly and disagreeable to the taste, and makes it neces
sary to open the bottle with great care, in order that the sediment shall not be disturbed and diffused
through the beverage. The great cost of natural champagnes is largelyr due to an extensive process
of handling, by means of which they are freed from this sediment or crust. The secondary fermenta-
tion requires time—weeks, and often months—and thus locks up large amounts of capital. By charg
ing with purified carbonic-acid gas, artificially, the secondary fermentation is rendered unnecessary
The beverage is ready for immediate consumption, and no sediment is produced in it.
1928 0.




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The advantages gained are so great that charging artificially, which is now practised in some few
establisl'nnents in this country and in many in England, would doubtless have become general if it
were not for the enormous waste entailed by the processes of bottling under pressure. These bever-
ages, unlike soda-water, foam strongly under the process of bottling, and consequently more is wasted
in venting, by ordinary methods of bottling, than is bottled. _
In the present apparatus the cylinders in which the beverage is charged are elevated six feet or
more above the bottling-table (preferably upon an upper floor). The liquid is drawn from the bottom
while the gas from the vent is returned into the top of the same cylinder, the gas is not allowed to
expand, and the beverage by its own gravity flows gently and without foaming into the bottle. By
means of a newly invented filling-head the inlet and vent are both opened and closed at exactly
the same moment, and consequently it is not necessary to waste any of the fluids during bottling.
Details.-—The improvements in the details of carbonating and bottling machinery within late years
have been very numerous. Among them may be mentioned the Mathews Safety-Cap, which operates
to prevent explosions in generators, andthe Mathews Lead-Lined Gas-Washer, to eliminate traces of
acid taken over from the generator. In both the Mathews and the Tufts manufacture improved
forms of agitators are provided. Full descriptions of all the varied types of apparatus relating to the
manufacture and sale of carbonated beverages will be found in the illustrated descriptive catalogues
of the John Mathews Apparatus 00., of New York, and James W. Tufts,‘of Boston.
Military Uses.---A special gun has been constructed in which carbonic-acid gas furnishes the im-
pelling power. The Patrick torpedo recently adopted by the United States Government is propelled
by carbonic-acid gas generated in the vessel and then superheated to increase its expansive force.
The gas, after superheating, is conducted to a peculiarly designed engine which drives the screw.
This boat has run distances of a mile at the rate of 20 knots per hour.
GAS, ILLUMINATIN G, APPARATUS FOR MANUFACTURE OF. ' All substances, whether
animal, vegetable, or mineral, consisting of carbon, hydrogen, and oxygen, when exposed to a red
heat produce various inflammable elastic fluids capable of furnishing artificial light. Bituminous coal
GAS, ILLUMINATING, APPARATUS FOR. 827

when heated to a certain degree, swells and kindles, and frequently emits remarkably bright streams
of flame ; and after a certain period these appearances cease, and the coal glows with a red light.
The flame produced from coal, oil, wax, tallow, or other bodies which are composed of carbon and
hydrogen, proceeds from the production of carburetted hydrogen gas, evolved from the combustible
body when in an ignited state. If coal, instead of being burnt in the way now stated, is submitted
to a temperature of ignition in close vessels, all its immediate constituent parts may be collected.
The bituminous part is distilled over, in the form of coal-tar, etc., and a large quantity of an aque-
ous fluid is disengaged at the same time, mixed with a portion of essential oil and various ammoniacal
salts. Large quantities of carburetted hydrogen, carbonic oxide, carbonic acid, and sulphuretted
hydrogen also make their appearance, together with small quantities of cyanogen, nitrogen, and free
hydrogen; and the fixed base of the coal alone remains behind in the distillatory apparatus, in the
form of a carbonaceous substance called coke. An analysis of coal is thus effected by the process
of destructive distillation. The principal products obtained, and their several uses, may be repre-
sented as follows: _.
r Benzole.. 5 $61,120} ? USBdqlo make
N aphthal v l 0 no g aim me“
[ Naphtha—used for varnish.
, Xylole—used for small-pox remedy.
(Oils, 30 per cent. . 1 ( Carbolic acid ,3 Used for disinfect-
' Cresylic acid ants.
_ f Gas, illuminating, etc.. Dead on Naphthaline—dyes, etc.
j Tar. . . . . . . . . . . . . . . . . y ' Anthracene, 3’; per 1 Used to_make
8 Ammonia water . . . . . . . cent . . . . . . . . . . . f ahzarme.
Coke, for fuel . . . . . . . . Chrysene—no use as yet.
5 Used for roofing and pavements.
Q Anthracene, 2 per cent.

Pitch, 70 per cent.
For'the manufacture of gas, a coking bituminous coal is greatly preferred, for the reason that it
exists in great abundance, and that a compact porous coke remains after it has undergone fusion,
which can always be sold at a fair price.
The manufacture of coal-gas consists of three distinct operations: Distillation, condensation, and
purification. Distillation is carried on in retorts, which are long, horizontal, semi-cylindrical, D-
shaped vessels of cast-iron, or more generally of clay. These consist of two parts, the body and
the mouth-piece. The temperature to which the retorts are heated before the coal is introduced
varies. For iron retorts, a temperature from 1470° to 1830° F., called a dull cherry-red to a clear
cherry-red heat, is generally adopted. For clay retorts, a deep orange (2010° F .) to a clear orange
(2190° F.), or even white heat (2370° F.), is employed, the coal itself being exposed, when introduced
in either case, to a dull cherry-red heat of 1500° to 1600° F. The temperature to which the coal is
raised, and the length of time it is exposed to heat, are matters of considerable importance. Expe-
rience has demonstrated that it is better to interrupt the process about four hours after the charge
is introduced; for while, at first, condensible vapors rich in carbon are given ofl’, which when passing
out are decomposed, yielding fixed gases possessing high illuminating power, yet if the operation is
allowed to continue too long, little but hydrogen is given off, and this is apt to be mixed with bisul-
phide of carbon, a very bad impurity. It is also necessary that the gas be removed as soon as pos-
sible. It is therefore drawn up a conduit, called the “ascension-pipe,” which is placed near the
mouth-piece, and from thence passes to the hydraulic main. An exhauster is employed to remove
the gas from the retorts, and more particularly to force the gas ahead through the condenser, washer,
and purifiers into the holder, and thus enable more gas to follow from the retort. In the hydraulic
main a portion of the tarry matters becomes deposited. The hydraulic main is a large horizontal tube
which extends the whole length of the retort-house, receiving the dip of pipes of successive benches
of retorts in its passage. This tube is half filled with tar and ammoniacal water, which is always
maintained at a constant level by an overflow to the tar-well, and enables it to act as a contrivance
for sealing the pipes, so that gas will not escape during the drawing and charging of retorts. From
the hydraulic main the gas passes to the condenser, which consists of a series of iron tubes, which
are usually placed in cisterns of cold water or exposed to the air ; by this means the gas is cooled,
and the tarry and aqueous matters held in suspension are deposited. By a simple contrivance the
tar and ammoniacal liquor which separate in the condenser are made to flow into different wells.
The gas passes into a washer, and then into a scrubber, or into the scrubber direct at works where
washers are not used. By this passage of the gas through the washer, where it is made to bubble
through water, and by its exposure to wet surfaces of large extent in the scrubber, the ammonia,
last traces of tar, and considerable of the sulphuretted hydrogen and sulphur compounds are re-
moved. None but a mere trace of ammonia remains after the passage of the gas through the
scrubber.
PURIFICATION.-—FOI1P methods for the purification of gas are used, namely: the “ wet-lime process,”
the “ dry-lime process,” the “ Lauring process," and the “ iron-ore process.” By the first, the gas is
made to pass through milk of lime, which is very effectual in separating the sulphur compounds and
carbonic acid; but this process has been in great measure abandoned, for the reason that there is no
use for the saturated milk of lime, called “blue billy,” which is very foul, and, not oxidizing rapidly,
is useless as a fertilizer. In the “ dry-lime process,” which has superseded the foregoing, dry or
slightly moist hydrate of lime is placed on trays in iron boxes, through which the gas is made to
pass. This process is equally effectual in separating the sulphur compounds and carbonic acid. When
this saturated lime is exposed to the air, it is rapidly oxidized, becoming heated and giving off the
same odor as the wet-lime process, which is very offensive, and was the source of considerable com_
828 GAS, ILLUMINATING, APPARATUS FOR,

plaint by every person who dwelt in the vicinity of gas-works until a system for deodorizing the foul
lime was invented, which cfiects its oxidation in such a manner that the oflensive gases evolved are
not permitted to pass into the atmosphere, but are conducted through a
washing apparatus, and finally through a special purifier, by which they
are rendered comparatively inofiensive. The “Lauring process,” named
after its inventor, was discovered in 1849. It consists in the use of
hydrated sesquioxide of iron, and it is found eifectual in removing the
sulphur compounds from the gas. The scsquioxidc of iron is prepared of
1924. A A







































































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GAS, ILLUMINATING, APPARATUS FOR. 829

~
suitable quality by mixing copperas with slaked lime and sawdust, and. exposing the mixture to the
air, so as to oxidize the protoxide of iron to the sesquioxidc. The resulting mixture contains hydrated
sesquioxide of iron, sulphate of lime (hydrate of lime), and saw-dust. \Vhen this mixture has been
used, it can be exposed to the air, and will not give off any offensive odors. The air, acting upon
the sulphide of iron formed in the purifier, liberates the sulphur, and sesquioxide of iron is again
produced. The mixture can therefore be repeatedly used, until it becomes so impregnated with lib-
erated sulphur as to prevent its acting rapidly on the gas. It has been used for periods of a year
at a time. When saturated, the material can be employed for the manufacture of sulphuric acid, as
it then contains from 40 to 60 per cent. of sulphur.
The iron-ore process involves the use of the natural sesquioxide of iron or “ bog-iron ore.” This
material may also be used over and over again, and when exposed to the air does not evolve oifensive
odors. It has been largely adopted in preference to Lauring’s mixture, as experience has shown
that the sulphate and hydrate of lime present in the latter do not take any appreciable part in the
purification. An improvement on this process was made by Messrs. St. John and Cartwright, and
has been in use nearly seven years at the New York GasWorks, giving entire satisfaction. As the
bog-iron ores of this neighborhood are not sufficiently pulverulent, St. John and Cartwright add to
the ore a quantity of iron borings or turnings, which they convert into artificial hydrated sesquioxide
of iron by moistening the whole with ammoniacal liquor and exposmg the same to the air. Charcoal
is then added to the mass, which consists of natural and artificial oxide. Before placing the mixture
I
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I 1928. A;








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in the purifier, it is moistened with ammoniaeal liquor. Several varieties of the natural sesquioxide
of iron are in use in different parts of Europe.
Arrxna'rus.--Fig. 1924 shows the eneral arrangement and interrelation of the retorts, hydraulic
main, condenser, washer, purifier, an holder or gasometer.
Barents—The proper mode of constructing retorts in which coal is distilled, and the art of apply-
ing them, form objects of primary importance in every gas-light establishment. The forms of the
retorts used are various. Fig. 1925 represents sections of a retort of cast-iron, commonly known as
830
GAS, ILLUMINATING, APPARATUS FOR.

the “D” retort. As clay retorts have been found by experience to be much better than iron retorts,
the latter are going rapidly out of use.
retorts that are now in use vary considerably.


Fire-clay retorts admit of being heated to a higher tempera-
ture than iron retorts, and they are capable of holding their heat much longer.
Single retorts, however, should be 21 by 14 inches
The dimensions of
1929. 1930.
6117/ , . , //
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and 8 or 8% feet long internally, so as to be capable of receiving large charges, and of being easily
drawn—two important considerations, as affecting economy of labor in carbonization.
Retorts which
are called “through retorts ” ought to have about the same internal diameter, and a length of from
18 to 20 feet. The through retorts are open at both ends and closed by mouth-pieces; while the
single retort is closed at one end and open at the other, capable of being closed also by a mouth-piece.
1931.
R
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I
/
pasteboard. E is the hydraulic main.
.Mode of setting Retorts.——In Figs.
1926 to 1931 is represented the old
method of setting a bench of five re-
torts. Fig. 1926 is a front elevation,
Fig. 1927 a transverse section through
cab in Fig. 1928, and Fig. 1928 a lon-
gitudinal section through c d in Fig.
1927. Fig. 1929 is a plan showing
the furnace and side openings below
the fire-tiles on which the lower re-
torts rest, and the bedding of the
lower retorts. Fig. 1930 is a plan
over the three lower retorts, the two
upper retorts being removed. Fig.
1931 is a plan over the even-arch,
showing the fiues, etc.
A A are retorts of the kind called
D. S is the mouth-piece, 10 inches
long, with a socket cast on the top to
receive the stand-pipe. Each Socket
has a neck, as shown in the figure, the
length of which is from 4 to 5 inches.
B is the “ stand-pipe,” through which
the gas as it is generated passes from
the retort. B' is the “bridge-piece ”
connecting the stand- and dip-pipes.
O is the “dip-pipe.” DD are the
bonnets, to be removed when the pipes
require clearing, jointed by putty and
F is a light hollow cast-iron pillar, supporting the hydraulic
main in the centre of each length; it is based upon the cast-iron girder which supports the firing-floor.
G is the pipe through which the gas makes its exit from the hydraulic main to the condensers, fur-
nished with slide-valves to disconnect the mains at each side of the house, when at any time it is
GAS, ILLUMINATING, APPARATUS FOR. 831
found necessary to repair or clear them. H is a small pipe for conveying the surplus tar formed in
the hydraulic main to the tar-well. L is the furnace for heating the retorts ; its breadth is 14 inches,
the length of the fire-bars 24 inches. M M are side openings, 3 inches square, left in the brick-
work, through which the heat of the furnace passes. N N are ask-inch walls, built of fire-bricks, one
between each of the openings m ; they serve to support the fire-tiles T, on which the outside lower
retorts rest. The direction of the flues is shown by arrows. PP are fire-bricks, placed on end, and
a fire-lump upon which the two upper retorts rest. 0 O are openings 3 by 41} inches in the crown of
the main arch communicating with the branch flame. Q is the branch flue, one being built over the
centre of each bench of retorts. R is the main flue, running the entire length of the benches, and
connecting with the chimney, into which all the branches lead. Between this main fine and each
branch are dampers to regulate the draught through the furnaces. 88 are cast-iron plugs, cover-
ing sight-holes through which the heat of the retorts is seen and judged of. Vis the furnace-door,
protected by a fire-lump inside. W is a cast-iron plate, 14; inch thick, on which the fire-door is
hinged, serving also to protect the face of the brickwork which it covers. In the centre, and about
6 inches above the fire-door, a square opening is cast for the admission of an iron spout when it is
required to burn tar. X is a pan at the bottom of the ash-pit, for evaporating ammoniacal liquor,
and the offensive liquid products which could not be disposed of in olden times. Y Y are openings
left in the wall N, by which thev carbon deposited from the furnace is cleared away. The even
represented in Figs. 1926 and 1927 is a good arrangement. The heat from the furnace passes through
the square openings M at each side, and is thus equally divided along the whole length of the retorts;
from between the walls N it rises between the fire-tiles at the outer sides of the lower retorts. The
flame is not sufiered to impinge upon any part, but is equally distributed throughout the oven, and
consequently the retorts work and “burn out ” evenly. The lower retorts, which would otherwise
be exposed to a more direct heat, are carefully guarded by fire-tiles, which at the same time prevent
the bottoms from bulging. The openings 0 at the top of the main arch act more in the manner of
1932. ’ 1933. 1934.
4 x r ‘ \ \ _ .__
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safety-valves than flues, serving to regulate the final exit of the heated air, and, being distributed
along the outer length, they do not draw the flame to one part. The whole interior of the oven, as
well as those parts in contact with the flame, must be constructed of fire-bricks. The main arch,
6 feet in span and half a brick in thickness, is formed of bricks moulded on purpose to suit the
curve, the joint being kept as close as possible. As this arch is permanent, much care should be
taken in its formation.
A bench of iron retorts arranged on this plan, if well and regularly used, ought to last 12 to 14
or even 15 months, and should never be allowed to become cold. The first portion of oxide which
forms upon the surface, when allowed to cool, cracks and falls off, leaving a new surface to be acted
upon the next time it is heated.
Figs. 1932 to 1935 represent a method for setting a bench of three retorts, which has proved very
valuable, each retort having an internal measure of 15 x 12 inches. Fig. 1932 represents the bed,
one half in elevation, the other half having the front wall
removed, in order to show the entrance to fines 0 0, Fig
1933, which extend underneath each retort and communi ' »‘ \ ~ -\ -‘ ‘ ~ ' a \ \ o l s l , \ ~: - cate With the vertical flues, shown in dotted lines in Figs. \ \ ~ * 1933 and 1934, and partly in section in Fig. 1934, and \
marked L, and in Fig. 1935 in plan. The frame of the
furnace-door is secured by a horizontal bar P, and bolted
at both ends to the buckstaves T T, this method being
sometimes adopted instead of bolts imbedded in the brick-
\ v 7 '1 ‘ - \ t \' I _. w 1 - weik. P is the furnace, the sides being formed of large ,. .7 . blocks, wluch, as already stated, are more durable than \\
bricks, the quality of material in both cases being alike.
For carrying repairs into execution, the furnace being “ let x , . .. r . .~ . \ .
down ” and cold, the door and frame are removed, and the S \ . _ . . . I T T . ._ brickwork of the front wall is cut away. -
In Fig. 1934, G- are guard-tiles, to protect the lower retorts from the direct action of the fire at
these points; H is a course of tiles, shown in plan in Fig. 1935, placed so as to form a fine, B, from
\


832 GAS, ILLUMINATING, APPARATUS FOR.

the back of the retort to the front. There is only one fire-bar of 2-ineh square wrought-iron, the
two bearers being of the same material. The fire-bar projects to the level of the front of the wall,
a space existing between the former and the frame of the furnace-door, and through this space, as
well as underneath the furnace, passes the supply of air to the fuel. In the same figure is represent-
ed one of the sight-boxes, as well as a clearing-out box for the flue.
Fig. 1934 is a longitudinal section direct through the centre of the bed, showing the arch J, imme-
diately over the furnace-door, the front wall being 14 inches thick; also the fire-brick lintel .E', with
1986. 1937.
. .1. -...L. -4. __-__
I]
the dead-plate attached to the door-frame, which facilitates elinkering. The top retort is supported
by the piers PP and their respective slabs. L is the flue, at the junction of the two vertical flues.
Fig. 1933 is a section through the line B, all the letters of reference corresponding. The verti-
cal flues, shown in dotted lines, connect the flues O' with the main fine, the damper closing the com-
munication between the beds and the main fine. The latter, for want of space, is omitted.
Fig. 1935 is a plan of the setting, the arch being removed at the points A A, showing the two
vertical flues L L, also the entrances to the two flues B, formed by the tiles H (N in Fig. 1933) which
convey the caloric along the sides of the lower retorts into the fines 0, hence to the vertical fines, as
indicated by the arrows.
Ear-shaped Rater-ta—Fig. 1936 is a front elevation of a bench containing three retorts.
Fig. 1937 is a section taken transversely
Fig. 1938 is a longitudinal section through the centre of the arch.
Fig. 1939 is a plan of Fig. 1938.
The method adopted '1' or setting retorts at the New York GasWorks is illustrated in Figs. 1940 to
1943. The retorts used are neither D-shaped nor oval, but are made up of the two forms, similar to


1988. 1 989.



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a 21% $9.2:
In A. I
the ear-shaped retorts just mentioned. “Their dimensions are 24 by 13 inches, and 8 feet long, set
six in an oven, and almost entirely with tiles and quarries moulded to fit into their respective places
in the setting. The heat ascends from the furnace between the two vertical rows of retorts, passes
over the top, down the outside to the top of the oven, through the horizontal flues nearest to the
furnace on both sides, and thence by way of the vertical shafts into the main flue on the bench.
The average make per mouth-piece is said to be 7,500 cubic feet of gas per day, and the quantity
produced per ton over 10,000 cubic feet, a percentage of cannel coal being used.” ,
vGrAS, ILLUMINATING, APPARATUS FOR. 833‘

Bmnton’s Retort-Jig. 1944 represents a front view of a bench of four retorts, upon Mr. Brunton’s.
principle. A A are the retort-mouths, the lids of which are fitted with stuffing-boxes, for the reason
to be presently described, and permanently jointed in their places with iron cement. BB'are hop-
pers, capable of holding from 20 to 28 lbs. of coal, which, when an air-tight slide-valve 0 is drawn
SID: ELEMTIDN
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ll lllllllllllllllllllllll
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1941 .









GBGTION THROUGH ILO-

I'IWNI' ELEVATIN
BUGKSTAY



END ELE VA TION
EXTERIOR FRONT ELEVA _TION
PlAN

1940.


SECTION AT DJ-l.

SEO‘nou 67 5F ,



hack, falls into the retort through the neck D ; the valve is closed immediately. E is the furnace,
projecting beyond the face of the brickwork in which the retorts are set. F F are handles for work-
ing a. piston contained in the mouth-piece A.
Fig. 1.945 is a transverse section of one-half of a. bench. The retorts G, shown as circular, me}
53
8.34 GAS, ILLUMINATING, APPARATUS FOR.

be varied in form if thought necessary. We believe the pa'tcntee gives the preference to those of a
D-shape. E is the furnace; the direction of the fines is shown by arrows.
Fig. 1946 is a longitudinal section through the centre of the furnace. H is a short pipe, open to
1945. 1944.
i\


the interior of the retort, sealed at the lower end by dipping into water, through which, after a
charge is thrown into the retort from the hopper B, a portion of coke is expelled, by advancing the
piston contained in the mouth-piece. I is the pipe by which the gas, as it is formed, passes to the
1946 hydraulic main. K is a bonnet, to
' be taken ofi at any time when re-
f> quired to examine the interior of
‘ the retort.
Fig. 1947 is a back view of Fig.
1944.
Fig. 1948 is a plan below the re-
torts. (The same letters refer to
corresponding parts in all the fig-
ures.)
The annexed diagram, Fig. 194-9,
will explain the construction of the
piston before alluded to. a is the
piston, drawn back in the proper
position to receive a charge, which,
when the slide-valve is opened, will
fall‘into the space I), and be pro-
pelled forward into the heated part
of the retort by turning the screw
c, which works in a nut cl on the
back of the piston. e is a collar
upon the ‘shaft of the screw, work-
ing between the bottom of the stuffing-box and a washer held in its place by four pins. The stuffing-
box is made tight in the usual way, by screwing the gland f against a gasket. 9 is a shield looselyr
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attached to the front of the piston, to prevent the accumulation of small-coal-dust in the mouth cf
the retort. When the charge is thrust forward, the piston is turned back directly into the mouth,
to preserve it from the action of the heat. That part of the retort adjacent to the fines only is
GAS, ILLUMINATING, APPARATUS FOR. 835


heated, and is consequently the only part liable to much wear and tear. The 'only part requiring
renewal is that of the retort situated between the outer walls of the bench, and weighing about 9
' or 10 cwt. The fuel required to carbonize the coal is about 25 per cent. in coal on the quantity
distilled.
Reciprocating Retort—It has been stated that the first portion of vapor produced by coal when
undergoing destructive distillation in ordinary retorts will, when converted into gas, form that of the
most brilliant quality; and it is to effect this that the following arrangements have been patented.
Fig. 1950 is a back elevation of two pairs of retorts. A‘ A2 A“ A4 are the retorts; BB, the
stand-pipes; C" 02 03 C“, slide-valves for opening and shutting off the communication between the
retorts and hydraulic main; D is the hydraulic main. The front elevation differs but little from it.
Fig. 1951 is a plan of the lower pair of retorts. The operation is as follows: Supposing the en-
tire bench to be at the requisite heat for decomposing the coal, and that they are working six hours’
charges, the lids of the retorts A1 and A3 are removed, and by means of scoops (each half the
length of the retort) the coal is introduced at both ends, and the lids immediately secured in their
places; the slides F‘ and F2 are opened, and 01 and 0“ closed. The bituminous vapors that rise
1949.





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first will pass through the pipes EE, and thence through the entire length of the hot retorts A2 and
A4, and be converted into gas, which will pass to the hydraulic main by the stand-pipes on which
the slide-valves 03 and O4 are fixed, and which remain open. When the distillation has gone on for
half the duration of the charge-via, three hours—the valves 01 and C3 are opened, F1 and F"
shut, and the gas evolved from the retorts A‘ and A3 passes through the stand-pipes attached to
them. The retorts A2 and A4 are now charged, the mouths closed, the valves F1 and F 2 again
opened, and O2 and O4 shut. The operation is now reversed, the first vapors passing through the
two first-charged retorts until their charge is expended, when 0’ and C4 are opened, F1 and F2
closed, and the charge drawn. They are then immediately recharged, and the operation of opening
and closing the valves is repeated.
Retorts on this construction have been worked, and are found to act well, producing gas of aver-
age quality and in greater abundance than by the ordinary method. The reason of the gas being
only of an average quality is, that the carburetted hydrogen made after the production of bituminous
vapor has ceased still passes over the red-hot surface of another retort and deposits some portion of
.its carbon, the rich gas formed by the conversion of the bituminous vapor only serving to make up
the deficiency. If, instead of having only two retorts in a set, the number could be increased to six,
836 GAS, ILLUMINATING, APPARATUS FOR.

-.. ...H. ....a_ ._._,_.__~.---.____....,...- .
and after the first hour the gas be allowed to pass away on the ordinary plan, both the quantity
would be augmented and the quality improved.
Revolving- Web Retort—This retort is arranged so that the coal is acted upon in a thin stratum
and converted into gas at once. -The chemical advantages of this method are many. All the ele~
ments of the coal are liberated nearly at the same time, and unite with one another in such propor~

1952. ‘,
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tions as to form gas of the best illuminating quality, and in greater abundance than when the coal is
carbonized in mass. The condensed bituminous vapor which forms tar in the ordinary process is by
this nearly all converted into olefiant gas. ' '
Fig. 1952 is a longitudinal section through A B in Fig. 1954. Fig. 1955 is a transverse section
through 0 D in Fig. 1952. Fig. 1953, plans of the retort in section, over the top of the retort, the
web, and furnace, respectively. The same letters refer to corresponding parts in all the figures. E
is a hopper containing the coal ; F is the discharging-disk; G is the retort; H is a web on to which
the coal is discharged by the disk F; II are revolving drums carrying the web H ,' K is} the fur-
nace; L L, the fines passing under and over the retorts, and finally into the main fine; .51, the shoot
into which the coke falls, the end of which may either dip into water or be furnished with a tight
door. The retort itself, and the chamber in which the drums work, are made of wrought-iron boiler-
plates, riveted together so as to be quite gas-tight. The only parts subject to wear and tear are the
retort adjoining the fines and the web, both of which are heated; the latter, however, never becomes
so hot that the shape alters The action of this arrangement is as follows: All the coal must be
either ground or beaten small




1953.
“--.... .. . ..__. ...-. _ . . . and screened so that no lumps
" \¢\\~-. . w’ _ _
\ \\ \\ \ remain lai er than cofice ber
\: \ rice, and 2:1: 24 hours’ charge
\ " ‘ ‘\ ‘ ‘ ' must be thrown into the hop-
\\\,. - per and secured by a luted cov-
" _'-_, __ §¢;~_.__."*I er. The discharging-disk, which
' is 9 inches in diameter, with 6
arms, is made to revolve uni-
formly with the drum .below
it, at the rate of 4- revolutions
an hour; for this purpose two
shafts run the entire length of
the retort-beds, on one of which
the drums are fixed; on the
other are the discharging-disks,
connected at one end by a strap.
The diameter of the hexagonal
drums is so regulated that the
coal which falls on the web
from the discharging-lip will at
one revolution have passed the
entire length of the retort. Fif-
teen minutes is sufficient time-
to convert the coal so distrib-
, uted into gas. Each link of
the web is 14 inches long and 24 inches broad, having a surface of 336 square inches, upon which
the contents of one partition of the disk will be discharged, viz., a little more than 124- cubic inches
of coal in a stratum less than three-eighths of an inch thick. Each successive link receives the same
quantity, so that, in one entire revolution of the disk and drum, 745 cubic inches of coal (equal to
21 lbs.) are distributed over a heated surface of 2,016 square inches, and converted into gas. By.
this process 84 lbs., of coal will make 450 cubic feet of gas of the specific gravity .490. , It therefore








GAS, ILLUMINATING, APPARATUS FOR. 837
follows that in 24 hours 18 cwt. of coal will be discharged by each retort, making 10,800 cubic feet
of gas, equal to 12,000 cubic feet per ton. The quantity of gas produced by five D retorts, such as
are shown in Fig. 1926, will be about 14,000 cubic feet in 24 hours, of specific gravity .390 or .400;
and the quantity produced by four of the revolving-web retorts will be 43,200 cubic feet in 24 hours,
of the specific gravity .470 or .490.
1954. 1955.


Mout/tQPicces and bid of Retorts.—The old methods adopted for securing the lid in ordinary retorts
are represented in Figs. 1956, 1957, and 1958. These figures are views of a mouth-piece on a scale
of half an inch to a foot. The mouth-piece was three-quarters of an inch thick, secured to the retort
by bolts and a cement joint made between their flanges.
The mouth-piece is always made of cast-iron, even in the fire-clay retorts, and is fastened in the
ordinary way by means of iron bolts and cement. A gas-tight joint is obtained by using a mixture
of iron filings and gypsum, which is made into a paste with an aqueous solution of sal ammoniac.
Fitted to the mouth-piece is a short tube in which the ascension-pipe sets, for carrying off the gases
and vapors evolved during distillation. In front of the mouth-piece is fitted a lid of wrought or cast
iron. In the ordinary mouth-piece a gas-tight joint is obtained by means of luting, the lid being
pressed down tight by means of a screw and cross-bar into the mouth of the retort. One of the
1958.
1956. 1957.







h—
most important improvements made of late is a method by which lating is rendered unnecessary wher-
ever the exhauster is in use. The lid of the mouth-piece is made so true (as also the mouth-piece
itself) that the pressure of a lever insures a perfectly gas-tight union. This device, known as the
Morton mouth-piece, is shown in Figs. 1959 and 1960. The door is closed by turning the handle B,
which, acting as an eccentric, presses with sufiicient force to produce a gas-tight joint.
Scoops or ShoveLa—TO introduce the coal into the retorts, when a mechanical retort-stoker is not
used, a “scoop” is employed, in preference to a shovel. The scoop is a semi-cylinder made of
thin plate-iron, 6 feet 6 inches long and 12 inches in diameter. with a cross~handle at one end,
represented in Fig. 1961. The charge for the retort is placed in this; one man takes the cross-
handle, and two others at the opposite end lift it with its contents up to the retort; it is then
pushed forward, quite to the bottom, turned round, and withdrawn immediately, and the coal left in
1959.


the retort raked into an even stratum. The lid, previously luted, is now quickly jointed __|_on to the
retort-mouth. It must be obvious that the loss of gas by this simple method is very trifling, the
’ whole operation not occupying more than 40 seconds; whereas, when the shovel is used, the coal is
' thrown in so much by degrees that more gas is lost, owing to the greater length of the operation, and
the heat producing some effect on each separate shovelful; in either case the loss is considerable.
see GAS, ILLUMINATING, APPARATUS FOR.



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GAS, ILLUMINATING, APPARATUS FOR. 839

Previous to drawing the charge, the lids of the retorts are loosened, and a light applied to the issuing
gas, beginning at the upper retorts. This precaution is necessary to prevent explosions. '
Rowland’s Retort-Staking .Machinery.——Rowland’s retort-stoker. or “power retort-worker,” is rep-
resented by Fig. 1962. The following description is from a report of the engineer of the New York
Gas-Light Company: “ It is capable of being, and often is, worked at the rate of drawing and charg-
ing 20 retorts in as many minutes, cleaning them perfectly and depositing the coal evenly therein.
If loaded with the aggregate coal for say 20 retorts, the receptacle will be emptied when the last re
tort is charged, and each individual retort will have received its proper quota, and this without any
attention from the operator whatever. The ability to unequally divide the charges is such that one
retort may receive say 300 lbs. of coal, and the next one 150 lbs., or any number of pounds inter.
mediate to the two sums, by simply turning an index-wheel, which can be accomplished in 20 seconds.
The apparatus is briefly a locomotive carriage traveling by preference upon an elevated rail, although
it would be equally as effective on a surface rail, the former being adopted in order to keep'a floor
space for the coke-trollies. Its functions are to travel the length of the retort-house, automatically
divide the coal into specified quantities, put the same into the retorts, and deliver the coke into the
wagons. The power to perform the various functions is conveyed by means of compressed air, which
performs the triple duty of working the machine, creating ventilation by the exhaust, and tending to
keep the operators cool, and lastly of affording a means of preventing the rake and handle of the
drawing portion of the apparatus from becoming hot and melting, which end is obtained by causing
the air to pass through the handle and hoe, thus carrying off the heat and obviating the constant and
rapid destruction of the rake or hoe, and the handle to which it is attached. The drawing part, of
which the rake (Z (Z is the chief implement, is fixed to a traveler, and can be advanced into and re-
turned from the retort by the chain cc, being in gear with pulleys, the motion of which can be readily
reversed. The first effect of the inward pull of the chain is to lift that part of the traveler to which
the rake is adjusted and fixed (to suit the height of the retorts to be drawn), and the continuation of
the pull takes the rake so lifted in over the charge, as far as the operator thinks fit; he then reverses
the gear, the action of which not only brings the hoe down through the coke to the floor of the re
tort, but brings it out with as much of the charge as had been overreached. There is a very simple
movement by which the operator can swerve the end of the rake to the right or left as it recedes
from the retort, by merely revolving the wheel e to the right or left, as the case requires. Notwith-
standing this deviation from the centre line of the retort being induced by the operator, when the
rake is re-inserted in order to remove every vestige of the charge, it takes automatically as to height
and bearing the same path that it was set to for the first stroke; therefore the fouling of the mouth-
piece is rcndered impossible, without any trouble on the part of the attendant. In fact he has noth-
ing to do but to cause the rake to advance, and set the ‘ monkey’s taii ’ (as the men call it) so as to
determine whether it shall return in a line coinciding with the centre line of the floor of the retort
or to the right or left of the same.
“The charger S is a case or box the shape and length of the retort, but as much smaller as neces-
sary for clearance. It has a sliding bottom, and when loaded with a maximum charge is really full.
If the retort is not in a condition to work off so much coal, the measuring cylinder within the case
M' is set in a few seconds so as to take from the hopper H the quantity that the man in charge of
the retorts considers to be enough. The dropping of the coal into the scoop after it is measured is
carried out in this manner: The sheet N can be adjusted in the same way as the scoop to the height
of any retort in the range. It also automatically moves a few inches upward every time the scoop
is sent in, to allow the heel to pass under its edge, and just before the meter is about to deliver a
charge into the scoop (just withdrawn from the retort) it is lowered a few inches by the motion of
the same cam that raised it. By this time the slot or opening in the measuring cylinder through
which it received the coal from the hopper H is downward, and the charge pours down the shoot N
into the scoop, which has a slotted opening along its arched top into which the shoot fits dust-tight.
A few seconds after this, the measuring cylinder still revolving, the cam on the shaft that carries
this cylinder lifts the shoot N (as before mentioned) above the scoop. The advance-gear is now
thrown in and the loaded scoop inserted. Immediately this is accomplished, a pinion gearing in a
rack underneath the sliding bottom is by a self-acting arrangement set in motion, and runs the bot-
tom back from under the coal, leaving it deposited evenly on the floor of the retort. The body or
case is now by the reverse action of the gear returned to the bottom, and being in aim is ready for
another charge, which by this time is nearly measured out by the meter 21!. The hose-reel R gives
freedom of motion without having to reconnect. The hose is wound on by a counterweight, and off
by the pull of the machine; but to prevent any strain on the hose, a line that winds on and off with
it is made fast to the machine. The air, which is compressed to about 40 lbs. to the square inch,
comes to the hose through the hollow shaft of the reel. When the coal is deposited in front of the
retorts, as is generally the case in large works in this country, the large hopper H is not required, the
coals being lifted to the meter 11! by a chain of buckets, or an equivalent, as the machine advances.”
Retort-Hausa—Figs. 1963 and 1964 represent a retort-house built of brick, for coal-gas, upon the
most simple construction, and well adapted for a town requiring 70,000 cubic feet of gas for the
supply of each night in the winter season. Being without coke-cellar, the charges must be drawn
into wrought-iron barrows, the contents wheeled into the open air, and spread abroad to cool. The
outside walls are calculated to give the greatest security with the least possible material. The piers
a a are 18 inches thick at the base, projecting 4.} inches (on the outside) from the brickwork filling
the space between them. Half way up the walls there is a 4.4-inch offset, which leaves the thick-
ness of the panels 14 inches below and 9 inches above the offset. The roof is of wrought-iron ; the
ventilator is of wood. The retorts are set 5 in one oven, making 40 retorts, which will allow two
extra benches for repairs. In 24 hours, 30 working retorts will carbonize 240 bushels or 180 cwt. of
coal, and produce 78,000 cubic feet of gas. In some places, where little gas is required in the
840 GAS, ILLUMINATING, APPARATUS FOR.

summer season, one-half or even the entire number of retorts may be set three to one oven with
economy.
In the example, Fig. 1964, advantage was taken of sloping ground to form a coke-shed, which
saved a consuierable quantity of brickwork. The charge, as it was drawn, fell through the space in
front of the retorts, and was carried by an inclined plane into the shed behind. This house is con-
siderably larger than that described in the last example, and is furnished with a coal-store. It may
1963. 19,64_ @-


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perhaps be as well to state here that coal from which gas has to be distilled should if possible be
always kept under cover, because, when moisture is present, the hydrogen arising from the decompo-
sition of water will deteriorate the quality of the gas. It is, therefore, a matter of economy to con-
struct a sufficient shed to preserve the coal in a dry state. The house contained 55 retorts, allow-
ing two benches of 5 retorts each for repairs. The coal carbonized by the remaining 45 retorts was
360 bushels or 270 cwt. in 24 hours, producing 117,000 cubic feet of gas.
Grammars—It is necessary to have a good draught, as the coke of the furnace has to be intensely
heated. It is therefore necessary not only to confine the fuel within proper limits, but constantly to
supply it with the requisite amount of oxygen, to be derived from the atmospheric air presented to
the fuel. It is absolutely essential, then, that the chimney be so constructed as to accomplish the
object in view. The utility of the chimney consists not only in its height, but in its area being con-
structed in like proportion, so that the heated air and products of combustion may pass off with free-
dom. Dampers should be placed in the settings, and not in the main flue ; as the object is tohave
a good draught throughout the whole of the settings, and to check each bed carefully by its damper.
The height to which chimneys are built depends on the amount of gas to be made. For small works,
producing from three to four million feet per annum, a chimney 35 feet high, with an opening 16
inches square, is sufficient. The height of the chimney increases according to the capacity of the
works, until it attains a height of 120 feet, with an area of 20 or 25 square feet, which is about as
high as chimneys for gas-works are ever built. (See CHIMNEYS.)
HYDRAULIC MAIN AND ASCENSION-PIPES.-—By the “hydraulic main” is understood a vessel with
which are connected the ascension-tubes leading from the retorts, and it is the first element of the con-
e== =3? rifii-qii
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(lensing apparatus as already described. The hydraulic main is more commonly made of wrought-iron,
as cast-iron breaks too easily. The thickness of the wrought-iron is one-fourth or three-eighths of
an inch, depending somewhat on its diameter. The diameter of the ascension-pipes is on an average
from 4 to 7 inches. The hydraulic main is placed on the top of the furnace, and is supported on
cast-iron stands or crutches, which are mounted on cast-ironpiers placed over the piers of the ovens,
GAS, ILLUMINATING, APPARATUS FOR. 841

so that the main may be distant from the front of the settings, and from the excessive heat there
present.
Fig. 1965 shows the mode of connection between the retorts and the hydraulic main. A is the
ascending or stand-pipe; 0, the dip-tube carried downward into the hydraulic main; D, the main,
and m, the liquid—viz., tar, or, at the first starting of a gas-works, water.
CONDENSER.—-The object of the condenser has already been stated. The form of the most common
air-condenser is represented by Fig. 1966. The inlet-pipe is in connection with the hydraulic main,
the outlet-pipe being connected with the exhauster. The stand-pipes are connected with each other
at the top, and rest in a large cast-iron tank, which, by means of partitions, is divided into compart~
1967.




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ments not communicating with each other, being hydraulically locked; each compartment being fitted
wi h an inlet m and outlet 7?.
Horizontal condensers have lately grown into use, and are considered, when of considerable length,
to be the best means for reducing the temperature of the gas and absorbing its impurities. Fig.
1967 represents a horizontal condenser invented by Mr. D. A. Graham. who claims that by his appa-
ratus he removes about 16 lbs. of sulphuretted hydrogen and 5 lbs. of carbonic acid for every ton of
coal carbonized. The condenser represented is 65 feet long, and consists of 650 feet of 16-inch pipe,
which, with the inlet and outlet pipes, makes
the combined condensing surface equal to
4,000 superficial feet. At the Beckton works,
London, each condenser consists of 2,600
feet of 12-inch pipe for a maximum make
of 2,500,000 feet of gas, or about 3 feet
surface per 1,000 feet, per diem.
Mackenzie’s Surface Condenser is repre-
sented in' Fig. 1968. This condenser has
for its object the gradual cooling of the gas.
Cold water is admitted at a number of places
at the bottom of the condenser, and sur-
rounds the tubes. The gas, being admitted
at the top, comes in contact with a surface
of nearly equal temperature, and moves
slowly downward; the surface constantly
growing colder as it descends, until the de-
sired condensation is etfected. The current
of gas is always downward with the gravi—
tation of the heavy particles, causing the
accumulations to be deposited in the tar-
well below.
Pelouze and Audouz'n’s Mechanical Con-
denser.—-A novel process of condensation
has been devised by MM. Pelouze and Au-
douin, which consists in forcing the gas at
great velocity through numerous small ori-
fices. The jets so formed are brought in
contact with a surface placed near to the
perforations, and against this the globules
held in suspension break and unite, acquir-
ing thus a weight sufl‘icient to cause their
precipitation in the form of liquid against
the sides of the apparatus. The essential portion of the device which forms the condenser proper
consists of a chamber of polygonal section formed of two vertical concentric portions. These parts
are similar, each being composed of two metallic plates placed a short distance apart. The interior
plate is pierced with a large number of small holes disposed symmetrically with relation to the ver-
tical axis of the chamber. In the external plate are made several much larger rectangular orifices,
so arranged as to come opposite the non-perforated parts of the inner plate. It will be obvious that
when the vesicles entrained by the gaseous jets strike the solid portions of the external plate, they
are broken up and run together in liquid form down the surface of that plate, the gas meanwhile
escaping by the rectangular orifices. In the other side of the chamber a similar action occurs, and
this completes the operation. The action of the apparatus depends on the shock of the gaseous






e42 GAS, ILLUMINATING, APPARATUS FOR.

molecules on the plates. The gas passes up into and through a cylindrical chamber, which is sus-
pended and balanced by a counterweight. After traversing the sides of the chamber, the gas finally
escapes by a pipe.
THE Exrmusrsn is usually placed between the condenser and the scrubber, and combined with it
there is a pressure-gauge in direct communication with the hydraulic main. Mr. Joseph A. Sabba-
1969.
mailman
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ton, the engineer of the Manhattan Gas-Works, has shown how great is the advantage of an ex-
hauster with clay retorts. The following is a trial reported by him:
“ Owing to the engine being idle for repairs to the boiler, the exhauster was not in operation dur-
ing 35- days. The amount of gas manufactured was by this reduced 115,000 cubic feet per day, the
average make before the exhauster was stopped being 1,618,000 cubic feet per day. This would
show a difference in favor of the exhauster of about 7.6 per cent., or 7 7 2 cubic feet per ton. After
the exhauster was again started, the average daily make (during a period of five days) was 1,665,000
cubic feet per day. This would show a difi’erence in favor of the exhauster of about 162,000 cubic
feet, or 10.7 per cent., equal to 1,016 cubic feet to the ton of coal. Taking the mean of two trials,
_. the difference in the yield of gas, when clay retorts are used, may be taken at 9 percent. .The
daily amount of coal used in each of the three periods varied but a few pounds, and the inlet-gauge
to the exhauster showed equal vacua during the first and last of the trial.”
illackenzie’s Steam-Jet Erhawster is represented in Fig. 1969. In constructing an instrument of this
kind the object is to get the largest
1970. result with the least expenditure of
f steam. Baking or cooking the tar
must be avoided. Actual test has
proved that the gas can be success-
fully handled by this instrument up
to 12 inches pressure with a min-
imum of steam. The steam, being
thoroughly incorporated with the
gas, takes up a large portion of sul-
phur and ammonia, and if properly
condensed will thoroughly wash the
gas without additional water. If a
surface condenser is used, nearly all
the ammonia now deposited in the
purifiers, with that taken out by :
washing, willbe contained in about
one-tenth the amount of water,
which is important when the am-
monia is saved. The steam passes through the jet-pipe with a velocity due to its pressure, and creates
a current from the retorts in the same direction. The steam, and such impurities as have combined
with it, are taken out by condensation. The amount of steam is regulated by the make of gas operating
a governor, attached directly to the steam-valve. A self-acting by-pass, to allow free passage of the
gas in case the exhauster is not in use, is provided, and valves to admit of ready access to all parts.
u.
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GAS, ILLUMINATING, APPARATUS FOR. 843

Root’a Improved Rotary Exhauster is shown in Fig. 1970. It is in use at several of the large gas-
works in this country. The blower operates by a regular displacement of air, measuring and forcing
forward a definite quantity at each revolution. The power applied is all used either in driving the
machine or forcing forward the air. (For construction, see BLOWERS.)
The herse-power required to drive different sizes of these exhausters is as follows, the weight of
the exhauster being given without'engine or bed-plate: 375 lbs., %; h. p.; 525 lbs., 1} h. p.; 1,650 lbs.,
1 hp. ; 3,500 lbs., 2;} h. p.; 5,575 lbs., 4 h. p. ; 7,950 lbs., 51} h.p.; 10,800 lbs., 8} h. p.
‘ Figs. 1971 and 1972 represent a gas-exhauster designed by Mr. Methven for the Commercial Gas
Company’s Works, London. This machine consists of three vertical wrought-iron cylinders, which
are made to rise and fall in a tank containing water, by the revolution of a treble crank-shaft with
connecting-rods and guides. Each of these cylinders is inverted over a chamber of cast-iron, the
interior of which communicates with the hydraulic main. The top of each chamber is provided with
a flap-valve, which allows the gas to escape into the movable cylinders during the ascent of the latter
by the action of the crank. The cylinders have valves on the top, similar to those in the cast-iron
chambers, which during the descending stroke allow of the discharge of the gas into the upper part
of the external cistern. From the cistern a main leads through the purifiers to the gas-holder, and
the gas is thus pumped out of the retorts and discharged into the gas-holder, independent of any
amount of pressure required to be overcome in its passage.
The velocity of this machine is regulated by the use of conical strap riggers to suit as nearly as
possible the amount of gas being generated; but in order to avoid the possibility of the pressure
upon the hydraulic main becoming less than that of the surrounding atmosphere, and the gas thereby
becoming impoverished by the admixture of atmospheric air, a regulating machine is attached to the
cxhauster, which by self-action maintains that pressure perfectly uniform. The regulator consists of


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a chamber which communicates alike with the inlet and outlet passages of the exhauster, and which
is divided by a valve or conical plug acted upon by a float sustained in water, under the immediate
influence of the exhausting power of the machine. The action of the float is communicated to the
valve with the smallest amount of friction by a lever and connecting-rod with the usual adaptation
of a water-joint; and the effect is that, when the machine from any cause is reducing the pressure
of gas upon the hydraulic main below that of the atmosphere, and thereby causing a partial vacuum
in the retorts, the float of the regulator is by the same means depressed, and the communication be-
tween the inlet and outlet of the exhauster thereby opened to a sufficient extent to restore the equi-
librium. Equilibrium is maintained between the interior of the hydraulic main and the atmosphere
during the various velocities. The pressure has been increased to 48 inches of water without any
sensible variations in the effect upon the gauge. indicatingthe pressure upon the hydraulic main. The
highest speed of this machine is calculated to discharge 60.000 cubic feet of gas per hour at a pres-
sure of 80 inches.
\VASHER.~——Th0 washer used by the Manhattan Gas Company consists of a series of 86 cells, 3
feet square and 10 feet high, each supplied with two jets of water, which enter at the side and are
thrown into spray by impinging against an iron plate ; the gas passes through the entire series. A
system of washer has been invented by Mr. Cattrels, wherein the gas is caused to pass through long
narrow channels situated just beneath the surface of the water; consequently fresh surfaces of
each globule of the gas in its transit are brought into contact with the water, by which means the
ammonia is eliminated. Washers are not so generally used to eliminate ammonia as are scrubbers.
SCRUBBERS.—-Fig. 1973 represents one of Mann’s scrubbers, constructed by Messrs. Walker of
.London. The size is usually so proportioned as to be about one-third its height. For large works
the dimensions are 60 feet in height by 18 feet in diameter. The figure represents two of a set of
five scrubbers used at the London Gas-Works. The penthouse on top of the tower contains the
gearing, the reservoir, and means of controlling the supply of water.
844
GAS, ILLUMINATING, APPARATUS FOR.

“ Within the scrubber is a series of trays which support layers of coke, while at the extreme top
is the contrivance for distributing the water or weak liquor, by means of revolving arms perforated
1973.
[:1 U
a U D
E


with small holes, the motive power be-
ing imparted by means of a cog-wheel
and shaft connecting with an engine.
In order to occasion a still further dis-
tribution of the liquid, the water or
weak liquor distributed by the perfo-
rated arms falls into a layer of brush-
wood, which is also sometimes made to
revolve, and thus the liquor finds its
way on to the first layer of coke in the
form of fine drops. The liquor then
falls slowly through from tier to tier,
becoming stronger and stronger as it
descends.”
The St. John and Rockwell Appa-
ratus, illustrated in Fig. 1974, takes, the
place of condenser, washer, and scrub-
ber, and avoids the use of any water
save that condensed from the gas. The
gas enters the first box, which is made
absolutely tight, except at the dip
tubes; it is then forced down tubes
submerged in the liquid products of
the coal, which are brought forward
by a separate pipe from the hydraulic
main to a given depth. The tubes
have at their lower ends a fine mesh-
work, so that the volume of the gas is
divided many hundred times, insuring
the requisite action. After passing
this series of seals, the gas is then con-
ducted to another of the same char-
acter, and so on, until it has passed
through the four boxes. It then en-
ters the first of the series of upright
pipes, which are provided with a lattice-
work and corrugated plates (as shown
by the open pipe in the figure), and,
after proceeding through the whole
series, makes its exit to the purifier.
The tar is removed by cohesion; the
ammonia and naphthaline by solution.
Prof. Charles F. Chandler tested this apparatus at the works of the Harlem Company for a week,
using' 163,120 lbs. of Pennsylvania and 470,445 lbs. of Murphy Run coal. The yleld averaged
1974.



























> GAS, ILLUMINATING, APPARATUS FOR. 845

10,897 feet of 17.06 candle. gas, which contained, after being purified with oxide of iron, only 2.65
grains of ammonia and 23.58 grains of sulphur in 100 cubic feet.
PURIFIERs.—Malam’s improvement of Phillips’s apparatus is generally employed for either oxide
of iron, lime, sulphate of iron, or other solid compounds used as purifying agents. His arrange-
ment, as generally applied, consists of four purifiers in connection with each other, and with a cen-
B 1975. 0
T


tral valve by which they are controlled in such a manner that, three of them being in operation, the
fourth is shut 011’, thus afiording every facility for discharging the foul material and recharging
the apparatus for purifying.
Fig. 1975 represents two of a set of four purifiers in connection with a central valve, that marked
B in elevation, the other, C, in section. The centre valve is also shown in section, and consists of
1976.





a closed cylindrical vessel E, supported by nine vertical T-pipes, open at the lower ends and stand-
ing on the tank T, which is filled with liquor, and receives any condensation, thus serving as a
siphon for all the connections.
Although, as has been said, lime-purifiers have almost entirely gone out of use, still, as there
remain a few, a description of the old apparatus employed will be of interest.
In Figs. 1976 and 1977 are represented an elevation and plan in section of one of a series of-





thrce “dry~lime” purifiers, through which the gas passes successively; in other words, they are
“worked together,” and, though separate, may be considered as one machine. A is the inlet-pipe
from the wash-vessel, entering at the bottom of the first purifier. B is a plate of sheet-iron, about 2
feet square, placed over the mouth of the inlet-pipe, to separate the stream of gas in some degree, as
well as to prevent any lime from falling into the pipe. 0 O O are the layers of hydrate of lime,
spread upon screens formed of an outside frame, and a number of round rods or wires about five--
846 GAS, ILLUMINATING, APPARATUS FOR.

sixteenths of an inch in diameter, stretched across them in one direction, to afford greater facility
for clearing, with a small interstice between each. , These screens are placed one over another, in
three tiers, from 6 to 8 inches asunder; each tier may consist of four screens for the convenience of
lifting them out'and replacing them. D is the outlet-pipe leading to the second purifier. This
arch-pipe is made of thin plate-iron, sealed at each end by a water-joint; because, when the lid has
to be lifted, this arch-pipe must be removed, and any other kind of joint would be troublesome. .E
is the lid of the purifier, also sealed by a water-joint; e e are round five-eighths rods, keyed at one
end into the keep-ring k, and riveted to each corner of the lid at the other ; a chain is hooked on to
the ring In, and passed over a pulley to a balance-weight, by which, and the rods just mentioned, the
lid is lifted. F F are blank flanges or bonnets, through which, when removed, the pipes are cleared
from any deposited impurity. G G are clamps, to keep the lid of the purifier in its place.
Figs. 1978 and 1979 represent the hydraulic valve just mentioned. A A is a cast- or sheet-iron
tank, 3 feet in diameter and 2 feet 6 inches deep, generally filled with tar to within 6 inches of the
top. B is a light sheet-iron or tin gasometer-shaped vessel of less diameter, divided into three par-
titions by the plates 0, D, and E, of less depth than the rim. F is the pipe from the wash-vessel
or condenser. G is the pipe leading to the first set of purifiers. H is the outlet or return pipe from
them. I is the pipe leading to the meter and gasometers. These pipes, in the present position of
the valve, are all in action. F and G, being in the same partition, communicate with each other, as
do H and I, for the same reason. When the purifiers have to be changed, the vessel B is lifted up,
until the bottom of the partition, at O in the elevation, Fig. 1978, clears the pipes, the outside rim
remaining immersed in the tar (the stops 8 on the guide-rods prevent it from being lifted too high),
and turned partly round until it occupies the position shown by the dotted lines in the plan, Fig.
1979. The guide-rods M pass through openings N. K and L are the pipes connected with the
second set of purifiers thrown into action and into com-
1978- munication with F and I, when the vessel B is shifted to
he position shown by the dotted lines in the plan. PP
is a wooden frame supporting the pulleys and balance-
l weight Q to assist in lifting the vessel B, which while
in action is kept from rising with the pressure of the gas
by a bolt. .
In preparing the lime for the purifiers, it ought to be
beaten, well sifted, and water added until, by compression
in the hand, the lime will just adhere; if any lumps re-


1979






main, their outside only will be acted upon; when broken, they will be found untouched in the inside;
and although such lumps may be used again, it is always better to systematize the process in the
first instance, and prevent even the smallest waste. ‘ ' '
Léme- Water Purifica—Fig. 1980 is an elevational section of a lime-machine, and Fig. 1981 a plan
through a b in Fig. 1980. A is the inlet-pipe through which the gas passes into the chamber B,
which is 4 feet in diameter, jointed to the lid of the purifier, and supported upon two cast-iron beams
C. On to the bottom flange of this chamber a circular ring of thin wrought-iron plate is riveted,
of such diameter that its outside rim will be within 5 inches of the tank of the purifier. D is a
hoop supported from the tank by bolts d cl, etc., having its upper edge level with the before-named
plate, and its lower edge 4 or 5 inches below it. The space left between this hoop and the ring is
three-eighths of an inch, through which the gas (after having overcome the pressure of the column
of water contained in the tank, plus the pressure in the gasometers) will pass, and bubble up
through the lime-water. E is an arm'made to revolve on the spindle S: the parts e e of this arm
continue through the aperture and over the ring, serving to keep the lime from settling or obstruct—
ing the passage of the gas. F'is the outlet for the purified gas. G is a stuffing-box, through which
the spindle 8' passes. H is a mitre-whcel, connected to a water-wheel or steam-engine for turning
the spindle. [is a pipe through which the lime-water is drawn off when it has become saturated
with the impurities of the gas. It will be observed that by this contrivance the water can be
completely drained off, by opening a slide-valve bolted to the flange of the pipe K, without suffering
the gas to escape along with it, because a column of water will remain in the tube I equal to the
height of the bottom of the tank, measured from the inner radius of the curve of the tubes, viz.,
12 inches, which is always more than sufficient to overcome the pressure of the gas in the purifier
when the valve on the inlet-pipe A is closed, which should be done before that at K is opened. L
is a cylindrical vessel, open at the top, for filling the purifier; it also serves to show the quantity
GAS, ILLUMINATING, APPARATUS FOR. 847

of water required ; when the machine is at work the column contained in the vessel will be higher
than that in the tank, in proportion to the pressure of gas in the gasometers, usually about 3 inches.
The lime-water may be mixed in a cistern, and drawn off by a hose into any of the machines,
care being taken to keep the mixture well agitated while passing. The proportions are one measure
of paste-lime to three of water; that is, to every 5 bushels of paste-lime about 120 gallons of water
must be added. The size of the lime-machines ought to be so regulated that they will contain suffi-
cient lime-water to purify the quantity of gas made in 24 hours, without having occasion to fill them
higher than the water-line shown in the engraving. Four lime-machines are necessary, two being
in action and two out, alternately. When that machine is spent through which the gas first passes, it
- is shut off, and a third opened, the
second being left to perform the . p 1980-
duties of the first, and so on. . "
The quantity of lime required for
the complete purification of coal-
gas varies very much with the qual-
ity of the lime and the gas; that
coal which produces the greatest
volume of sulphuretted hydrogen




9
"7.
.41
,
,
,
,
,, . .
,
,
(I
w z
‘5 5‘
,r r
I
, r
If '
i



from the presence of iron pyrites 2}” 1 ,
will require the-most lime. As the best means for arriving at a proper ‘ practical conclusion, we annex the P.” '1 5? ‘
quantities used at different gas-
works in various places. ;
At the Imperial Gas-Works, Lon-
: '; :-'@~ A ; - gees w
don, one bushel of quicklime puri- TI i ‘
fies on an average 10,000 cubic feet
of gas, the price of lime being 7d.
per bushel. The lime is used both
as a hydrate and in the fluid state,
in the following proportions: For the purification of 1,000,000 cubic feet, the produce in the winter
season of 24 hours, 80 bushels mixed as “ dry lime,” and 20 bushels mixed into a fluid: this quan-
tity performs its part thoroughly. At Cheltenham, 11} bushel of quicklime, reduced to the state of
a hydrate, will purify 10,000 cubic feet of gas perfectly; cost per bushel, from 5d. to 6d. At Bir-
mingham, the purification of 1,000 feet costs, in lime and labor, from lid. to Hid“ but in reality not
nearly so much, as the refuse is sold for two-thirds the original cost of the lime. Lias lime is used,
and “dry purifiers.” With the dry-lime purifiers at Chester, 1 cwt. 2 qrs. is required to purify 10,000
cubic feet of gas. The Welsh lime is used, its price being 138. 4d. per ton; therefore the purification
of 10.000feet will cost 1.9. without labor, which is about the average cost.
In making the dry-lime purifiers, that they may present a sufficient surface to the gas which passes
A through them, an excess, rather than
1981' a smaller area, should be given. A
bushel of lime, when reduced to the
state of a hydrate, contains very
nearly 4,500 cubic inches : allow-
ing that this quantity will purify
5,000 cubic feet, it follows that 12.5
square feet of screen surface is re-
quired, the depth of the lime being
2.5 inches. For I‘QtOl'iIS calculated
to produce 300,000 cubic feet of
gas in 24 hours, the purifiers should
present a surface of at least 750
square feet. If three machines are
worked together, each containing
five screens, their dimensions may
be 8 feet by 6 feet, and 3 feet deep,
4 bushels of hydrate of lime being
spread on each screen. The sur-
face presented by three machines
like Fig. 1976, is 324 square feet ;
they were erected for an establish-
ment producing 130,000 cubic feet
of gas in 24 hours.
The work performed by a lime-water purifier is generally computed by its contents in gallons, and
the head of water or pressure opposed to the passage of the gas through it. Taking the latter at a
constant quantity of 8 inches, the computation is easy: 4,500 cubic inches of hydrate of lime
(which, as before stated, is the quantity produced by reducing one bushel or 2,150 cubic inches of
quicklime), mixed with 48 gallons of water, will purify 10,000 cubic feet of gas, if properly applied.
In the example at Fig. 1981, the lime machine contains 316 gallons, which will hold in solution 13
bushels of hydrate of lime, and purify 65,000 cubic feet of gas. Two of these machines will there-
fore do the same work as the three dry-lime purifiers before mentioned, viz., 130,000 cubic feet.
Notwithstanding, however, that the quantity of lime required may be well known, it is necessary










848 GAS, ILLUMINATING, APPARATUS FOR.

_._
to test the gas in its progress through the various purifiers. A saturated solution of the acetate of
lead in distilled water is an excellent test, detecting the presence of the minutest quantity of sul-
phuretted hydrogen, and more convenient than the carbonate, from its complete solubility. Test-
papers may be printed in the following form:
Station and Date.
TA.“ a K... a.
i
__ n__ I
Canon Gas. Fmsr PURIFIER. Snconn Pumrrnu. Tnnw PURlFIEB.
Lime-machine having been charged — hours with -- bushels of —— lime.




Fill a bladder, furnished with a stop-cock, full of gas from the main, before it enters the purifiers,
and also one from each separate purifier, and let the bladders be labeled ; with a camel’s hair pen-
cil paint the square marked Crude Gas with the test solution, and force the gas from the proper
bladder upon it while wet; the paper will immediately be turned black; then paint the square
marked First Purifier, and force the gas into it, and proceed in like manner with the two others;
the paper in the fourth square ought not to be discolored. The squares must not be moistened at
once, because the first impure gas would in that case blacken them all.
Lime for the purpose of purifying coal-gas should be free from foreign matter. That which
slackens the quickest, and produces the greatest heat during the operation, is the best. When dis-
solved in diluted muriatic acid it should not effervesce, and when perfectly pure should leave no
insoluble residue.
THE STATION-METER.--The gas, after passing through the purifier, next enters the station-meter,
the object of which is to measure the quantity of gas made per ton. The difference between the
indications of the consumer’s meter and the station-meter will indicate the loss of gas by leakage.
The difference between the station-meter and the (wet) meter of the consumer is more of size than
anything else, so that a description of one or the other will apply in both cases.
Fig. 1982 is a front elevation in section, and Fig. 1983 is a side elevation, also in section, of a sta-
tion-meter of the capacity of 200 cubic feet, by which 300,000 cubic feet of gas may be measured
and registered in 24 hours. The principal part of the machine consists of a hollow drum of thin
1982. 1988.










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t
sheet-iron A A, revolving upon an axis a, and divided into compartments, so arranged that, as the
gas enters, it shall in revolving successively fill all the chambers, pass through them, and be dis-
charged measured. The part of the drum which contains the gas is in the form of a concentric ring
1 foot 6 inches bread, 6 feet deep, and 7 feet 6 inches in extreme diameter, which will be understood
by reference to the engraving. The plates which form the sides are of the same outer diameter as
the drum, viz., 7 feet 6 inches, but are 2 feet 9 inches broad; they will therefore project within
the smaller diameter, leaving the centre circle (through which the inlet-pipe K passes) 2 feet in
diameter. The surface of the water contained in the drum and outside tank of the meter is 4
inches above the upper circumference of this centre circle, when the drum is in its place; so that
the communication between the outside and inside of the drum is cut off by a head of water of that
height, and continues to be so in every part of the revolution. It is evident, therefore, that the gas
must enter any chamber having its inner hood above the surface of the water. B C' D E represent
the inner hoods, and the direction of the gas from the inlet-pipe is shown by the small arrow at B.
As the chamber fills with gas, it displaces the water, and causes the drum to revolve. Before B
dips into the water, the hood 0 rises above the surface, and opens a communication for the gas into
GAS, ILLUMINATING, APPARATUS FOR. 849

its chamber; and so on with D E, when it will have completed one revolution and measured 200
cubic feet. The same action that allows the free passage of the gas into the chambers causes it to
be expelled from them through the outer hoods F G H I, in the direction of the arrow at F:
each of these outer hoods is sealed alternately in the same manner as the inner hoods, and
opened for the passage of the gas from them, by one constantly being above the water-line. The
direction in which the drum revolves is marked by the arrow over the top of the case. The
bevels of the division-plates d d are arranged so that they will enter the water without effort.
The axis a a on which the drum revolves is supported on friction-rollers; on the front end
of this axis a spur-wheel S is fixed, working into another wheel ’1', having half the number of
teeth ; at every half revolution of the drum it will therefore make an entire revolution; its spindle
passes through a stuffing-box, and is furnished at the opposite end with another wheel V, which
marks 100 feet on the index. From a pinion on the spindle of this last wheel another wheel is
worked, having ten times the number of teeth on the pinion, which will therefore mark thousands.
This last wheel is again furnished with a pinion and works into a third wheel, which will mark tens
of thousands, and so on; the quantities marked on the dials in-
creasing in a tenfold ratio up to hundreds of millions, or higher
if thought necessary.
The entire train of wheel-work is shown in Fig. 1984, where
a is the first spur-wheel, working upon the main axis; 6, the sec- \
0nd wheel, both being inside the meter-case; c, the wheel on the b
opposite end of the shaft of b, which projects through a stuffing-
box on the case, in order to communicate motion to the train of
wheel-work, which must of course be on the outsideof the meter~
case; d, the wheel driving the hand which marks hundreds on the
index, and having 100 teeth (a has likewise the same number of
teeth); e, the pinion on the wheel cl, having 10 teeth ; f, the wheel
driving the hand which marks thousands on the index, having 100
teeth, and driven by the pinion e ,' g, the pinion of the wheel f driving h, which marks tens of thou-
sands on the index; and in like manner any quantity may be registered. If it be required to register
units (and in smaller meters it is useful), the first wheel cl is made to drive a pinion p, having 10
teeth, to the spindle of which the hand marking units is attached.
THE HOLDER, on GASOMETER, serves not only for the storage of the gas, but to cause sufficient pressure
for its distribution through the mains. Gas-holders are of two kinds: the single lift, and the double
lift, or telescopic. The latter require counterpoises, which the simpler form do not, and are more
expensive, but are very extensively used by all large works, especially where ground is valuable. The
simple gasometer consists of an iron vessel, open at the bottom and inverted into a tank of water
below the surface of the ground, having perfect freedom to rise and fall, and guided by upright rods
fixed at several points in the circumference. The holder is so counterbalanced as not to exert a pres-
sure on the gas more than equivalent to a column of water 6 inches high, this pressure being suffi-
cient to force the gas through the mains to the consumers. The diameter and number of the vessels
will vary according to the magnitude of the works to which they are attached and the space to be
occupied by them.
Fig. 1985 represents the half section of a simple gasometer, capable of containing 150,000 cubic
feet, the diameter being 87 feet 6 inches, and the height 25 feet. The sides A A are made of N o. 16
iron plate (Birmingham wire-gauge), weighing 21} lbs. to the square foot, riveted together; the top
B of plate weighing about 3 lbs. to the square foot, or No. 14 gauge. C C, etc., are rings of 3-inch
T-iron, placed 5 feet asunder, and riveted strongly to the sides ; the rivets ought not to be more than
8 inches apart. The top and sides are secured together by 3-inch angle-iron, rolled to fit the curve.
(I d are rings of bar-iron, about half an inch thick and 3 inches deep, fastened to the top by clips,
which are riveted; these rings are placed about 6 feet apart, and strengthened further by diagonal
bars, from one to another, breaking joint. E are stays formed of wrought-iron pipe, about 14; inch
diameter, fixed in the situations represented, their ends being bolted to the T-iron at the sides, and
the rings on the top. G are vertical rods, fixed at the upper and lower ends to the brickwork of the
tank, and passed through eyes fast to the bottom of the side of the gasometer, serving to guide the
vessel in its rise ; their positions are between the standards S, on which are also guide-rods acting in
like manner. The eyes serve“ as stops to prevent the vessel rising out of the water. The standards
5', 8 in number, are each formed of 3 cast-iron frames 6 feet broad at their bases, of the same height
as the gasometer, and jointed together in the form of a T on the plan; they are secured to the stone
plinth by dovetailed lock-nuts, keyed and loaded. H is the wooden curb, which ought always to be
attached to a gasometer; its use is to regulate the flow of gas from one gasometer to another.
While immersed in the water of the tank it acts as a float, and to some extent buoys up the vessel ;
when the gasometer has risen to its full height, it acts as a weight, being partly out of the water,
thus causmg the gas to flow into another gasometer not yet full, and which, having its curb complete-
ly immersed, is under less pressure. I is the inlet-pipe, of the same diameter as that leading from
the retorts, viz., 8 inches. Its mouth above the water-line should be rather higher than the edge of
the tank. K is the outlet-pipe, 12 inches in diameter, entering the gasometer under the same circum-
stances as the iulet-pipc. L are receivers in which the tar or water collects from the mains, being
pu'rnlped lout by a small hand-pump, of which a and I) represent the suction-pipes. P, masonry or
1‘10 mm c.
A gasometer 100 feet in diameter and 39 feet high at the sides, containing 300,000 cubic feet,
weighs about 116 tons 14 cwt. 36 lbs. A gasometer 36 feet in diameter and 12 feet deep contains
12,200 cubic feet, and weighs about 5 tons 2 cwt. 49 lbs.
Fig. 1986 represents an improved gasometer. The largest holder in the world is in London ; it is


54 . .
850 GAS, ILLUMINATING, APPARATUS FOR.

230 feet in diameter, and holds 3,000,000 cubic feet of gas. The largest holder in this country be-
longs to the New York Gas-Light Company; it is 168 feet in diameter, is supported by 16 columns
7 2 feet high, and stands 70 feet high when full. Its capacity is 1,500,000 cubic feet.
.—
c
I
JP












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THE GOVERNOR, 0a PRESSURE REGULATOR, causes the delivery of the gas through the mains at a con~
. stant pressure. An improved governor has been devised by Messrs. Braddock, of Oldham, England,
which for safety has two counterbal~
1936- ance weights, and reverses the position
of the inlet, which delivers the gas on
the top of instead of beneath the cone,
as in other governors. The cone is sus-
pended to a hell by' the same rod which
passes through the central pipe; there
is also another small pipe in connection"
with the outer part of the bell. The
chamber within the bell having the
same area as the cone, the pressure is
always counterbalanced, and oscillation
is prevented.
‘ - Fig. 198'? is an elevation, in section,
and Fig. 1988 a plan, of a governor capable of equalizing the flow of 300,000 cubic feet of gas in 24
hours. A A is a cast-iron tank containing water, 5 feet 4 inches in diameter and 4 feet 6 inches
GAS, ILLUMINATING, APPARATUS FOR. 851

deep, in which the regulating vessel BB floats. C' is a cone of cast-iron, turned true in the lathe,
and suspended by an eye-bolt to the top of the floating vessel. D is the inlet-pipe, having a plate
d on the top, furnished with an aperture, bored out to fit the diameter of the cone at the base, and
which, if raised' to that height, will completely shut off the gas from entering the vessel. E is the
outlet-pipe, its diameter being regulated by the distance to which it has to convey the gas to the
equilibrium-cylinder of the street-mains.
The floating vessel B, when immersed in water, of course loses a portion of its weight equal to
that of the water which it displaces ; and the density of gas contained in it will vary as the immer-
sion. By making the chain F of a proper weight, it may be made to answer the purpose of a regu-
lator of the pressure. Let it be supposed, for example, that the vessel weighs 1,000 lbs., and loses
100 lbs. of that weight when immersed in the water, and that a portion of the chain equal in length
to the height which the vessel rises weighs 50 lbs., and the counterbalance 950 lbs. Then, when
the vessel is immersed, its effective weight is 900 lbs., to which must be added the portion of
chain now acting, as increasing the weight of the vessel, 50 lbs. The sum corresponds with the
actual weight of the counterbalance, 950 lbs. Again, let the vessel be elevated out of the water; its
actual and effective weight then is 1,000 lbs. ; to balance which are opposed the counterpoise, 9501bs.,
and the portion of the chain now removed to the other side of the pulley to counterpoise, and acting
with it, 50 lbs. The sum corresponds with the actual weight of the vessel, 1,000 lbs. The effects
of the vessel and counterpoise being thus opposed to each other, the pressure of the gas contained










therein is equalized. By adding or removing the weight of the counterbalance, an increase or de-
crease of pressure may be effected.
The action of the governor is as follows: The outlet-pipe is connected with the mains, and the
inlet-pipe with the gasometer supplying gas into the machine. It will be evident that, if the density
of the gas in the inlet~pipe becomes by any means increased, a greater quantity of gas must pass be-
tween the sides of theadjusting cone and the aperture in the plate d, the consequence of which will
be that the floating vessel will rise, and therefore contract the area of the opening in d ,- and if, on
the contrary, the gas in the inlet-pipe decreases in density, the vessel will descend ; so that, whatever
density the gas may at any time assume in the gasometers or mains, its pressure in the floating ves-
sel will remain uniform, and consequently the velocity of the gas passing into the mains will be reg-
ular: for when the aperture of the plate d would admit more gas than necessary for the supply to
the mains, the floating vessel rises and diminishes the area of the inlet-pipe; and when, on the con-
trary, the inlet does not allow a sufficient quantity of gas to come from the gasometers, the gas passes
out of the governor.
Pressure- Indicatooa—Jf a governor be not used, it is advisable to have a pressure indicator attached
to the main or mains that leave the works, to serve as a check upon the conduct of the workmen
whose duty it is to regulate the pressure of gas in them according to the demand at certain hours of
the night. It is thus constructed: A small gasometer about 12 inches in diameter is made to move
in a tank of water in such a manner that it shall rise or fall according to the pressure in the mains,
_ with which it is connected by a small pipe; a guide-rod, furnished on the top with a pencil, marks
the exact amount of pressure upon a sheet of paper coiled round a cylinder. ' This cylinder is moved
852 GAS, ILLUMINATING, APPARATUS FOR.

roun'donce in 12'hours by a timepiece. It is evident, therefore, that if the paper be divided by
horizontal lines corresponding to the rise or fall of the gasometer by every tenth of an inch increase
or decrease of the pressure, and if it be divided by vertical lines corresponding to the revolutions of
the timepiece in 12 hours, it will efiect the object required. The gasometer must be formed with an
air-vessel inside, so that when it is totally immersed it shall be in exact equilibrium with the external
atmosphere, and when risen to its full height it shall have a pressure equal to that required to force
the gas through the mains. Say the height to which the gasometer rises is equal to 10 inches, and
the pressure required is 3 inches ; then if the paper be divided into 30 parts by horizontal lines, each
division will indicate one-tenth of an inch.
Pressure-gauges, as the name implies, are instruments by which the velocity with which the gas
flows into the main is ascertained. They are made of glass tubes partially filled with colored water,
and furnished with graduated scales divided into inches and tenths from a point in the centre of the
scale marked zero. When no gas is passing into the main to which one of these instruments is
attached, the columns of water contained in the tubes are in equilibrium with the external air, and
stand at 0. When the gas is admitted, the equilibrium is destroyed ; the gas depresses one column
and raises the other, the total variation being the amount of pressure.
fig. 1989 shows a section of a water-valve. It is formed of an air-tight cylinder A A, containing
a portion of tar or water. B is the inlet-pipe, which communicates with the gasometer. C is the
outlet-pipe, which conveys the gas to the main. DD is an inverted cup, 10 inches deep, furnished
with a rod passing through a stuffing-box, by which it is raised or lowered. When the cup is in the
situation shown in the figure, it is evident that the communication between the outlet and inlet pipes
is shut off by the pressure of a column of water 10 inches high. When the cup is raised above the
mouth of the outlet-pipe by the rack and pinion, a free passage is left for the gas. This description
of valve may be fixed with advantage between the gas-holders and the mains, or between any system
of lime-water purifiers.
Isabell’s Automatic Governor, for regulating the pressure of gas in street mains, is shown in Fig.
1990. The distinguishing feature of this governor consists in automatically changing the position of
the weights to operate the valve and make the desired variations in pressure, as opposed to putting
on and taking off weights by hand of an attendant. The operation of this governor is as follows:
At the inner end of the lever A is suspended a rod which carries a perfectly balanced valve, which
works easily in a proper chamber, located in the outlet-pipe holder. At the outer end of the lever‘
A is pivoted an adjustable bar or track B, on which are placed the rolling weights 0. These
1990.










II'HI



Ii“ .
l
weights are connected by a cord to a sliding bar 1), working between friction-rollers, and driven by a
cam E on the main spindle of a perverful‘cloek, contained in the case G. As the weights are moved
in at the proper time by the action of the clock and cam, the valve below is opened and the pres-
sure gradually increased to the desired point, and held there until the time set for it to be dimin-
. ishcd by the rolling back of the weights and the consequent gradual closing of the valve. ' The cam
E is easily and quickly secured in any position on the spindle, and has stamped upon it the hours of
the day, as shown by the index. It will be at once apparent how any desired effect can be obtained
by changing the position of the cam, or by putting on cams of different proportions.
Works for Reference—3 Treatise on the Manufacture of Coal-Gas,” Richards, London, 1877 ;
“A Treatise on the Science and Practice, on the Manufacture and Distribution of Coal-Gas,” Mus-
pratt’s “Chemistry; ” Muspratt’s “Handbuch der Technische Chemie,” 3d ed., 1875; Bolley,’s “Hand-
buch der chem. Technologie,” 1862.; Wurtz’s “ Dictionnaire de Ohimie,” and “ Neues Handwerter-
bueh der Chemie;” “Le Gaz;" Knapp’s “Lehrbuch der chem. Technologie,” 3d ed., 1865 ; _Wag-
ner’s “ J ahresberieht der chemischen Technologie ; ” Schilling, “ Traité d’Eelairage par le Gaz ; ”*
Matthews’s “History of Gas-Lighting,” 2d ed., 1832; Schilling, “Handbuch fiir Steinkohlengas; ”
Blochmann’s “ Beitrage zur Geschichte der Gasbeleuehtung,” 1871 ; Wilkins, “How to Manage
Gas; ” Sugg, “Gas Manipulations, with a Description of the various Instruments and Apparatus em-
ployed in the Analysis of Coal and Goal-Gas ; ” English “ Abridgments of Specifications of Patents
relating to the Production and Applications of Gas,” 1860; Richards, “ Gas-Consumer’s Guide;”
Accum’s “Practical Treatise on Gaslight,” 4th ed., 1818, and “Description of the Process of Manu-
facturing Coal-Gas,” 1819; D’Hureourt, “ De l’Eclairage du Gaz ; ” Bowditch, “The Analysis, Tech-
nical Valuation, Purification, and Use of Goal-Gas ; ” Thomas Newbigging, “The Gas-Manager’s
GAS, ILLUMINATING, BURN ERS FOR. 853

. Hand-Book ; ” Mason, “Gas-Fitter’s Guide ; ” Bower, “ Gas Engineer’s Book of Reference; ” Hughes,
“ Gas-Works and Manufacturing Coal-Gas;” Clegg, “ On the Manufacture of Goal-Gas;” Colburn,
“ The Gas-Works of London,” and “Gas-Consumer’s Guide.” H. A. M., Jr.
GAS, ILLUMINATING, BURNERS FOR. There are three conditions necessary for the produc-
tion of a perfect burner—that is, one that is “perfectly adapted to the quality of the gas which it is
destined to consume, and which will develop, when burning a regulated quantity, the maximum of
light possible: 1. The gas should issue from the burner at as low a pressure as is possible consist-
ent with the proper flow of gas. 2. The air-supply should be suitably regulated, the amount of
atmospheric oxygen supplied to the flame being exactly proportioned to the richness of the gas. 3.
The burner should be so constructed that the gas is kept as cool as possible up to the point of its
being consumed.” - '
Since the experiments of Christison and Turner in 1825, it has been frequently maintained that
gas gives a larger proportion of light when it is burned in large quantities than in small; in other
words, that the larger the quantity of gas consumed in any kind of burner, the larger will be the
proportion of light obtained-from the gas. Properly conducted investigations made by the Referees
of the London Gas Companies have demonstrated the fallacy of the above doctrine, and have proved
that the observed variations in the illuminating power of gas upon which the conclusion was based
are entirely due to the burners. The correct statement of the matter is, that with every burner there
is a certain point of gas consumption at which the burner gives its maximum of light, and that, if
the consumption be either increased or diminished from that point, the proportion of light obtained
from the gas will be reduced. At the same '
time, even taking each kind of gas-burner at
its best, the difference in the quality of the
gas-burners in general use is so great, that
some of them yield only one-fourth or one-
fifth the light obtainable from burners of
the best construction. The chief point to be
observed, alikein the construction and in
the emplOyment of burners, is the due regu-
lation of the air-supply to the flame. This
depends partly on the size and shape of the
gas-flame—fer, of course, the larger the sur-
face of the flame, the more is it brought in
contact with the air—but still more upon the draught, whereby the same extent of surface will be
more or less exposed to the action of the air. _
There are three kinds of burners in use: the bat-wing burner, with a slit; the fish-tail burner,
with two oblique holes in the end facing each other ; the argand burner, a circular burner with a ring
of small holes, and provided with a gas-chimney and interior supply of air. Burners are made of
brass, iron, or lava (soapstone); the last is far preferable, from the fact that the holes or slits are
not liable to be stepped up by rust.
~ The bat-wing burner, represented at 2, 4, and 5, Fig. 1991, is so called on account of the flame
taking the form of the wing of a hat. The burner consists of a metal, lava, or adamas nib, with
a hole pierced therein within a short distance of the top, across which is a slit from which the gas
1992.


1993. 1994. 1995.
I’-_\ /’_‘\
’\ \.‘~ I 'r“
.' " ‘iisfliat'ér I I ‘.
. .’ /‘~’i§ EEe°B§=~~ \ i
l l I _ \ ‘ l
I f\T E H R. \
\ ‘\ ‘\ ‘ 2FEU \ ‘ I, I
i \ ‘ : PERHOUR : ll , ,
‘\ \\ \ \\ l/“~~—-"‘\\ ; I! I, ll
\ \ \ \ ‘\ .FOOT : I / / I
\ I
\






issues in a thin flame. The bat-wing burner is best adapted for all out-door lights. The slit may
be freed from any obstruction by passing a thin card through the same. The flame is too broad
to be used in globes or shades.
The fish-tail bumer received its name from the shape of the flame. It is formed of the same
854 GAS, ILLUMINATING, BURNERS FOR.

materials as the bat-wing burner, but differs from the latter by the hole, which is bored nearly to
the top, receiving two orifices or small holes, drilled at such an angle that each jet of gas, in issuing,
impinges against the other, forming when lighted a sheet of flame at right angles with the holes.
Figs. 1992 and 1993 represent such a burner. ‘
The argand burner is represented by Figs. 1994 and 1995, and has been already described.
The argand burner is best adapted for ordinary gas; it gives a very steady flame, and consumes
the gas to the best advantage. It is provided with a cut-off or check of very simple construction.
The best burner yet constructed is Sugg’s London burner, shown in Fig. 1995 without its chimney.
For general use 5- or 6-foot lava-tipped check bat-wings are the most economical. ‘
The pressure of the gas is one of the most important considerations. Argauds give most light
under a pressure of one-tenth of an inch, bat-wings and fish-tails under a pressure of three-tenths or
four-tenths of an inch. As gas is supplied to consumers under pressures varying from. 3 or 4 inches
down to one-tenth of an inch, it is very desirable to check the flow of gas when it is excessive. Hence
regulating burners and regulators for checking the flow of gas have been invented. A very simple
method for checking the flow of gas is to screw. a 5- or 6-foot burner over a 3- or 4-"i'oot burner.
The Plass Economic Gas-governing Burner, Figs. 1996 and 1997, may be described as follows: It
consists of a case or shell constructed usually in two parts, a and b, with a flexible automatic disk-
valve 0. An increase of pressure, whether it occurs in the gas-mains or service-pipes, is instantly
communicated to the valve c, which rests upon and contracts the aperture (I through which the gas
enters from the inlet 0 into the chamber f, and, in consequence of the relation which pressure bears
to volume or quantity, the quantity of gas now admitted in a given time is exactly equal to that
which passed when the pressure was less and the opening greater. From the chamber f the gas
passes through the outlets at the lava tip g in the upper shell a, resulting in a rich, clear flame.
1996. g! 1997.



all“







\
\
l “~\\\\\\\\\\\\\\



\\
\\\\\\\\\\\\\\\\\ all
\\
n '
\ \






When the pressure in the mains or house diminishes, the valve a slightly rises; and the aperture d
to the chamber f is again enlarged, admitting of a sufficient volume of gas to correspond with the
now reduced pressure.
The Plass gas-governor, shown in Fig. 1998, is constructed on the same principle as the burner
just described. Fig. 1999 shows the governor properly connected with the meter.
1998.
/..//,:Q7
/




e
\ s
a es s
‘-.
elm" _ - r. , E
2'71 ” @1010], '
Ill/(1100],, I
Ill/’0 :



The Champion Gas-saving Regulator is shown in Fig. 2000. The following is a description of the
same: A, outer ease of cast-iron; B, large inverted cup; 6', east-iron cap; D, brass valve-rod; .E',
discharge-chamber; F, inlet-chamber; G, valve-seat; H, brass coupling connecting regulator with
house-pipe; I, brass coupling connecting regulator with meter; J, brass valve; L, small inverted
GAS, ILLUMINATING, BURNE‘RS FOR. 855

cup; P, opening for valve-rod through which the gas flows into and under cup L; Q, passage for
as to large inverted cup B; V, valve-seat to automatic discharge; W, brass valve; X, valve-rod;
, passage from regulator to inletchamber. The gas flows from the meter into the inlet I through
the opening Pup and under the small inverted cup L, which cup is sealed and made to float in
quicksilver, and is attached to the valve'rod D. This cup is made to rise and fall according to the
increase or decrease of the gas-pressure. When the gas-pressure is greatest, the aperture controlled







by the valve J is made less by the upward movement of the valve. The regulated gas then flows
into the discharge-chamber E, and a portion of it ascends into and under the large inverted cup B,
which is also sealed and made to float in quicksilver, and is alsoattached to the valve-rod .D. This
large cup gives a larger area to the buoyant power, and prevents irregularity in the movement of the
valve. The cups are weighted and adjusted according to the light that may be required. If any
condensation should ever be collected in the regulator, it is automatically discharged by means of the
valve W through the passage Y to the meter.
For economy’s sake, if for no other reason, there should be a governor attached to every meter.
A good street-lamp is shown in Fig. 2001, every practical device being employed to get the full
benefit of the light. It may be described as follows: The glass shade is oval in shape, with the
lower, part open; the glass itself is very thick and strong, but the principal improvement is the use
of two porcelain reflectors, the one on the lower part of the chimney, the other at the centre of the
glass shade or hell, which succeed in throwing down on the pavement considerably more light than
do the street-lamps ordinarily used. Both these reflectors are outside the shade, and thus escape
being blackened by the smoke. The upper one radiates light to a distance, but always downward;
the lower one sends the rays down near the lamp all round, and prevents any shadow being cast. In
a band round the upper part of the lamp, above the lower reflector, the names of the streets are
lettered on ground glass. ‘
INCANDESCENT BURNERS.--Th0 Lowe Bicandescent Gas-Burner, represented in Fig. 2004 A, is in the
form of a cylinder made of a composition in which magnesium predominates. It is claimed to give a
light of 210 candlepower, with a consumption of 3% cub. ft. of gas per hour.
The cylinder to be heated to incandescence is firmly held in place on a metal spindle, which is
slowly revolved by means of an ingenious clock-work in the base of the fixture. The arrangement is
such that by turning off the gas the clock-work is stopped, and by turning on of the gas, it is again
set in motion. The movement of the spindle is so slow that a casual observer would not notice it,
there being only one revolution made in 24 hours. The object of this movement is to continually
present new surface to be heated, as that which is exposed to the high temperature wears away,
similarly to the carbons used in electric lighting, though much more slowly. These burners can be
made of 2,000 candle-power, down to 50 candle-power. ‘
The Clamond Burner uses a metallic basket of magnesia, which is brought to high ineandescence
by ordinary coal~gas. It is said to give a clear white light, and to be economical of gas. ‘
The Welsbach Incandescent Gaslight—The Welsbach incandescent gas-light was invented by Carl
Auer von Welsbaeh, of Vienna, and consists of a mantle (Fig. 2004 n) of incandescent material sus-
pended over a non-luminous gas-flame. This mantle is composed of the oxides of the rare earths,
such as lanthanum, zirconium, yttrium, etc., and is formed by first knitting a cotton web into cylin-
drictl form, saturating it with a solution of these earths, gathering it at the top with a platinum wire,
forming it in the shape desired, and then burning out all the cotton of the webbing, and at the same
time reducing the salts of the earths to oxides. The finished mantle is identically of the same form
as the original cotton webbing. The stitch of the webbing and the composition of the mineral
solution is varied for use on different gases and under different conditions of pressure.
This mantle, which is attached to an iron-wire loop by means of the platinum wire with which it is
gathered, is supported on a gallery above a Bunsen burner, the air-supply of which is made readily
adjustable for use on gases of different qualities. The gas-supply is regulated by the size of the
holes drilled in a metal disk which is placed in the base of the Bunsen burner. The mantle, whether
mounted on the lamp or packed in a pasteboard tube, is saturated with a solution of celluloid varnish,
which, when dried, preserves it against the shocks of transportation.
856 GAS, ILLUMINATING, BURNERS FOR.
All the forms of lamps require a glass chimney or globe to surround the mantle, both for protec-
tion and to increase the draught of the burner.
. Two different sizes of lights are manufactured, con-
suming respectively about 3 and 5 oub. ft. of illuminating gas, and giving candle-powers of about 30
and 50 under ordinary conditions. Fig. 2004c represents the construction of a 3-ft. and Fig. 2004 D
2004 o.





IE!



Three-feet Burner.
of a 5-ft. burner.
The parts indicated by the letters or figures are as follows: A, lever-arm ; 0, po-
sition of gas-check; D, air-shutter; .E', Bunsen burner-tube; F, gallery; G, corrugated cap; H,
gauze tip; K, chimney-guide; and L, detachable shade springs.
A slight variation in form (Fig. 2004 E) is necessary for use on natural gas, the principle, however,
20041).
\\
i "SM biold'er





















._____y;-p
flenmzgraugzi’ \
--* maze 3i!
----—GaZZer_l/ _ ~ ~ ,F-qj-i "TBZ/Lnsen fuZe "
; T -——Ai-r shutter I '
\ ' ‘\67’a,s cheek
“\Basa
Natural as-light.
remaining the same. A bulb-shaped chimney is substituted for the straight cylindrical one, and the
iron-wire support is encased in a clay tube.
The candle-power of the lamps on natural gas is. much
higher, though the consumption is no greater than on artificial gases.
GAS, ILLUMINATING, BURNER-S FOR. 857

For non-luminous fuel-gas the argand principle is substituted for the Bunsen, the mantle being
supported above the jets of gas as they issue from the ring of holes in the tip. The consumption of
these fuel gas-lights varies from '7 to 10 cub. ft., with a candle-power of about 50.
The Welsbach lights have been successfully applied to photography at night. For this purpose
about 42 burners are arranged in three groups, the greater number of lights being in front of the
sitter. The light has the quality of sunlight, and the time of exposure varies with the subject, from
2 to 10 seconds. The finished photographs cannot be
2004F- distinguished from the work produced by sunlight.
///,;¢// // / I //' ["W/ // $447}??? ' 2 REGENERATIVE Gas-Lam’s—This form of as-lamp
/// // ’4’ is come largely into use of late years as a subsgtute for
the electric-lamp. It depends on the principle that the
heat which is usually wasted in ordinary burners is to
a great extent returned to the flame. The manner in
a, which this result is brought about is by intercepting,
by means of a regenerator, the heat passing away with
the products of combustion, and applying the heat thus
saved to raise the temperature of the air which feeds
the flame, thus increasing the temperature of the latter
and its illuminating power; for it may be admitted that
the higher the temperature of a body rendered incan-
descent by heat, the greater is the proportion of light-
rays emitted out of the total amount of energy radiated.
This being the case, the amount of heat carried from
such a source of illumination to the surrounding atmos-
b phere by conduction and convection must be less than
in the case of a burner consuming the same quantity
of gas burning at a lower temperature, which circum-
stance, combined with the well-known economy result-
ing from the use of these burners, accounts to a great
extent for the popularity which regenerative lamps have

attained.
c ' The Siemens Lamp, constructed by Mr. Frederick
9"“ . Siemens, is represented in Fig. 2004 F. After passing


through the governor_A and the tap b, the gas enters
an annular casing; in the lower portion of this, a num-
ber of small tubes are fixed, forming the burner, from
which tubes the gas passes out in separate streams.
By this means combustion of a very perfect character
I takes place, as the air is directed round each separate
- stream of gas and thus enabled to combine most inti_
mately with it. Within the circle of small tubes is a
e _ trumpet-shaped porcelain tube d, and around the out-
~- S side and inside of this the gas burns downward and
‘ slightly upward, as indicated by arrows, thus producing
a steady, powerful flame of beautiful appearance. This
porcelain tube forms the lower portion of the chimney,
around which is placed the regenerator. The products
(50 of combustion, in passing away, heat the regenerator by


conduction, through the metal of the same; and the
air, passing upward and downward between its metallic
surfaces, as also indicated by arrows in the diagram,
carries the heat back to the flame. The lamp is closed below by a glass globe, which, however, need
not be removed for lighting, as a flash-light is provided for that purpose.
These lamps are made of different sizes, with a consumption varying from 10 to 40 cub. ft. of gas per
hour. With London gas they give a light of from 10 to 12 candles per cub. ft. consumed per hour,
which is from four to five times as much as is obtained with ordinary burners. In France the following
results have been obtained from Siemens lamps: With a consumption of 150 litres per hour, the light
of from 1 to 3 carcels; 250 to 300 litres, 6 to 7 carcels; 600 litres, 15 carcels; 805 litres, 20 to 22
carcels; 1,600 litres, 46 to 48 carcels; 2,200 litres, ‘72 carcels.
The regenerative lamps manufactured by the \Velsbach Company are represented in Figs. 2004 e
and 2004 H. These are of two general types, those having outward-burning flames and those having
inward-burning flames. The former (Fig. 2004 G) are intended for outdoor and the latter (Fig. 2004 n)_
for indoor use.
Referring to Fig. 2004 G, the parts are as follows: A, T-cock; B, governor-yoke; C, governor; D,
long-lever cock; E, chain-hooks; F, right and left cross; G, keeper-socket for wind-cap; O or H,
side-arm; I, wind~cap; J, chimney; K, chimney-casing; L, nut for air-injector; Zlf, keeper-screw for air-
injector; N, air-injector; O or H, side-arm; P, air-tube; Q, chain for lever-cock; R lamp-casing; S,
perforated brass cylinder; T, arm on spider; U, long or centre flue; V, screw for holding; IV, upper
chamber; X, spider; Y, screw attaching R to lower chamber; Z, shade-ring; A A, globe-holder;
B B, globe-holder catch; 0' C, globe; D D, chain-ring; E E, extension for shade-ring; F F, bolt
holding upper and lower chambers together; G G, distributing-ring; H H, globe-ring hinge; I 1, lower
chamber; J J; screw attaching deflector to lower chain; K K, deflector; L L, centre flue.
The following are the parts of the indoor lamp represented in Fig. 2004a: A, T-handle stop_
858
GAS, ILLUMINATING, BURN ERS FOR.
B, governor-yoke; G, governor; D, governor adjusting-screw; E, long lever by-pass cock; F,
cock;
lock-nut; G, governor shield; H, tripod; I, chimney-crown; J, centre rod; K, asbestos tube; L,
inner chimney; M, outer chimney; N, lock-nut; 0, hub or regenerator; P, cone-top; Q, canopy;
R, combination deflector-plate; S, globe-holder; T, globe-holder catch; U, burner; V, asbestos cyl-
inder; l/V, flame-plate; X, globe; Y, burner-post; Z, button.
Regenerative lamps all require a volumetric governor to furnish a uniform supply through condi-
tions
Q
CHAIN FOR "OPERATING BURNER Cock-
of varying pressure. The outdoor lamps, when not put up in street lanterns, are provided with











































2004B. 20046.
/A
_B
B /d
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U. ______ ' ' K
—— f , fit ,
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\\ f, P;
Q ~41 .‘f/ g
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| w 1 -- ------ —- ' BB
". ‘ I l - -
-W , '.
1 ~ __ I: :i. _ c'
x Z 3A 3::
. L.
DC
wind-caps and air-injectors, for the steadying of the draught and the proper supply of air to the flame.
These lamps are made in sizes, and consume from 3 to 25 cub. ft. of gas, giving as high as 800-candle-
power illumination. Cast-iron, brass, and sheet-metal go to make up the lamps, while porcelain,
aluminum-bronze, and nickel are used at points where the heat is most intense.
The VVenham Lamp—This is one of the latest types of regenerative apparatus, and is largely used in
France. With a consumption of 10 cub. ft. per hour it has given 126 candles, in a vertical direction
without reflectors; horizontally, 50 candles. But the gas employed in the tests had an illuminating
power about 20 per cent. higher than that usual in Paris. When experimenting in Paris with a No.
GAS, ILLUMINATIN G, DISTRIBUTION OF. 859

lamp in a vertical direction, it showed a consumption of 34.6 litres (1.2 cub. ft.) per carcel obtained.
The Wenham lamp is constructed to give light in a vertical direction; and by adopting a large reflect-
or, the illuminating power is increased 18 per cent. in a vertical line, and 55 per cent. at 80°.
The Delmas Hot-Air Barman—In this device the batswing flame is completely enclosed in a glass,
mounted with a sheet-iron casing, heated by the products of combustion, through which the air
passes on its passage downward to feed the flame; and it thus increases the temperature, improves the
illuminating power, and produces a beautiful steady light.
The Siemens Radiated Heat-Burner causes a heating of the air, which is effected simply by the radi-
ation of the metallic parts of the appliance which are in contact with the flame. These burners pro-
duce the light of 1 carcel (9.5 candles) with a gas consumption of 70 litres (about 2% cub. ft.), and are
therefore, from an economical point of , view, intermediary between the high-power and regenerative
. burners. This degree of economy can be ascertained by an ingenious arrangement of the air-supply
in a burner with holes, which has been made in the laboratory of the Wazemmes Gas Company by M.
Verlé, the engineer, who has invented a very simple burner called the .“ Lillois,” with which the light
of 1 carcel is obtained with a consumption of 70 litres. This produces a tulip-shaped flame, and it
has a specially constructed glass arrangement on the outside for regulating the combustion. ‘
The following tables by Mr. C. M. Lungren, C. E., show the economical results of different methods
of gas-burning as compared with oil-burning:
Expenditure of Energy per Hour for Production of One Candle of Light.










LIGHT. Heat Units per Candle. $21522.“ 1?;(1125 . l
Incandescent gas . . . . . . . . . . . . . . . . . . . . . . . . 84 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 836 8,000 1
“ electric . . . . . . . . . . . . . . . . . . . . . 243 (coal as fuel) . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . '
“ "‘ . . . . . . . . . . . . . . . . . . . .. 101(gasasfuel) . . . . . . . . . . . . . . . . . .
Coal-gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 (18 candle, batswing burner) . . . . . . . l 650 2,, F50 {
“ " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 (18 candle, regenerative lamp) . . . . .. f "‘“ l
Kerosene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25,000 i
Cost to the Consumer.
l
LIGHT. Candles for 1 Cent an Hour. 1 ORE-138.5326. Flt-13301,)” P533026
Incandescent gas . . . . . . . . . . . . . . . . 80 (without incandescent) . . . . . . . . . .. l 50 A
"' "‘ . . . . . . . . . . . . . . . . 66% (with incandescent) . . _ . . . . . . . . . . . i' c‘ l
“ “ . . . . . . . . . . . . . . . . 160 (without incandescent) . . . . . . . . . . . 2-
“ “ . . . . . . . _ . . . . . . . . 133 (with incandescent) . . . . . . . . . . . . . ' ' ‘ ' ac‘ l
"' electric . . . . . . . . . . . 80 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1040. F
“ “ . . . . . . . . . . .. 160 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54c. &
Coal-gas . . . . . . . . . . . . . . . . . . . . . . 66} (18 candle, batwing burner) . . . . . .. . . . 540. . . ..
“‘ " . . . . . . . . . . . . . . . . . . . . . .. 133 ‘- “ r . . . . . .. 270. ‘
“ “ . . . . . . . . . . . . . . . . . . . . . . . 80 (18 candle, regenerative lamp)... .. .. . . 87c.
“ “ . . . . . . . . . . . . . . . . . . . . . .. 160 “ " “ 43-}0. I
Kerosene . . . . . . . . . . . . . . . . . . . . .. 64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15c.
“ . . . . . . . . . . . . . . . . . . . . . .. 80 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12c.





It appears from these figures that at the maximum price at which a fuel-gas of the assumed heat
value can be sold, an incandescent gas-light, fulfilling the two requirements of four candles to the foot,
and a cost of fifty cents a year for the incandescing material, would be as cheap as kerosene at the
lowest figure, while any gain in the stipulated candle-power or decrease in the price of the gas would
give it the position of the cheapest of all artificial lights. _
GAS, ILLUMINATING, DISTRIBUTION OF. Melina—The term “main ” is applied to all cast-
iron conduit-pipes that serve to convey gas from the works to the place or district to be lighted, and
especially applied to those pipes from which smaller ramifications branch. The diameters of the
mains vary from 1% inch to 15 or 18 inches, according to the quantity of gas required to be supplied,
and the distance it has to flow.
The 15inch mains are cast 4 feet 6 inches long, the 2- and 3-inch mains about 6 feet long, and all
the other sizes 9 feet, with a socket at one end and a plain bead at the other.
Sockets.-—Figs. 2002, 2003, and 2004 represent the sections of sockets of different-sized pipes, to a
scale of 15 inch to the foot. Fig. 2004 is that of mains from 9 to 15 and 18 inches in diameter.
The usual thickness of metal is shown by the hatched lines, and is proved to be sufficient. The
depth of these sockets is 4% inches.
Fig. 2003 is a section of the sockets of mains from 4 to 8 inches in diameter; their depth 4 inches.
Fig. 2002 is the thickness of those of a smaller diameter, 3 inches deep.
The thickness of the main pipes ought to be as follows:
1% inch diameter . . . . . . . . . . . . ;} inch thick. 9 inches diameter. . '. . . . . . . . . 9; inch thick.
2 inches “ . . . . . . . . . . . . ;\~ “ “ 10 “ “ . . . . . . . . . . . “ full.
3 “ “ . . . . . . . . . . . a “ full. 12 -“ “ . . . . . . . . . . . “ “
4 u u . . n _ t _ _ _ _ . _ . g u u 13 u u _ . . _ _ _ _ _ . _ . g u u
5 C‘ U . g 4‘ fl (C _ H a U H
6 _u u ' _ g u u 15 u u _ -_ H H
8 (l H . , % ‘C H ‘4 (l 4% H (‘
Joints—To make the joints, spun yarn is driven before the pipes to within 2% inches of the lip of
the socket, and a good fitting of the two pipes being effected, melted lead is poured into the remain-
ing cavity, which when set is calked or hammered in with a blunt square-pointed chisel.
860 GAS, ILLUMINATING, DISTRIBUTION OF.

In order to guard against the danger of water remaining that enters from the external surface into
the pipes, and the deposition of other condensed matter, a reservoir should always be placed at the
lowest point, where two or more descending mains meet and form an angle, to receive the water, etc.,
that may happen to collect at this angular point, an accumulation of which would obstruct the passage
of the gas through the mains. These receivers ought to be at least twice the diameter of the mains
between which they are interposed, and four times that diameter in depth. These receivers afford the
best indication of the sound or leaky state of the system of mains. In all instances where the pipes
are perfectly sound, observation has shown that half a mile of gas-mains, three inches in diameter, does
not deposit more than a quart of condensed vapor or water in the year; on the other hand, when the
mains are leaky, the water of the reservoir requires to be umped out, particularly in wet weather, as
frequently as once a fortnight. The loss of gas by such eakage Is much greater than is generally
imagined. In order to keep the common air out of the faulty mains, a constant influx of gas is often
necessary; this is of course so much gas lost to the economy of the establishment.
Distribution of gas through mains—The velocities of different gases under the same pressure will
be to one another, inversely, as the square roots of their s ecific gravities; therefore a heavy gas will
be discharged through the same opening with a less velocity than that due to a lighter gas. For ex-
ample, if coal gas of the specific gravity '420, and with a pressure of five-tenths of an inch, flows through
a circular orifice one-fourth of an inch in diameter, at the rate of eighty cubic feet per hour, gas having
the specific gravity '400 will flow through the same opening at the rate of 819 per hour, pressure re-
maining the same. For by inverse proportion,
As \/ 400 = 20000
Is to 80, the quantity discharged of the heavy gas,
So is \/ 420 = 20493
To 819, the quantity of lighter gas discharged.
The discharges of the same gas through different open-
ings and under the same pressure, are proportional to Quantities of "as dischar d, bi
the areas of the orifices in circular inches, or to the Diameter reaper how: Pressumg; $111831;
squares of their diameters. Allowing an excess in the 9f mm" m .--
5 inches and


larger openings for the difference of the friction, the parts. By experiment, I By calculation_
results of the annexed experiments will agree very
nearly with this law. '25 80
To obtain the velocities of the same gas from any -50 321 820
other opening, say, - '75 723 720
As the square of given opening, 100 1287 1280
Is to the given quantity discharged, 1125 1625 1620
So is the required opening 125 2010 2000
To the required quantity discharged. 1'50 2885 2880
The quantities of the same gas discharged in equal 600 46150 46080





times by a horizontal pipe under the same pressure and
for dilferent lengths, are to one another in the inverse
ratio of the square roots of the lengths. Hence, when we know the quantity of gas discharged from a
given length of pipe, we may find the quantity discharged by any other length with any pressure, and
of gas of any specific gravity.
Example of the foregoing rule—It is required to find the number of cubic feet that will be discharged
from a horizontal pipe six inches diameter and 1760 yards long, the specific gravity of the gas being
'420, and the pressure equal to five-tenths of an inch perpendicular head of water. We know by
experiment that 44,280 cubic feet will be discharged by a six-inch pipe 3'46 yards long; therefore, by
inverse proportion, say,
As \/ 1760 = 41952, the required length,
Is to 44,280, the known quantity discharged,
So is \/3'46'= 1860, the known length,
.To 19632, the required quantity discharged.
We therefore find that the loss by friction in a pipe a mile long is 441168, the initial velocity being
equal to 46,080 by calculation.
A horizontal main, 16 inches diameter and- 1760 yards long, is laid from the works to the e uilibrium
cylinder: it is required to know how many cubic feet of gas of the specific gravity '390 wil be dis-
charged with a pressure equal to a head of water of 6-10ths of an inch.
We have found by the last example that a six-inch pipe, one mile long, with a pressure of 5-10ihs of
an inch, will deliver 1963 cubicv feet of gas having the specific gravity '420, in one hour. Then say, as
36, the square of the diameter of the six-inch pipe, is to 1963, the quantity of gas delivered, so is 256,
the square of the diameter of the sixteen-inch pipe, to 13,959, the required quantity delivered by a
sixteen-inch, one mile long. For the difference of specific gravity, say,
As J'390 = '197, the specific gravity of the lighter gas, is to 13,959, the quantity delivered of the
specific gravity '420, so is J'420 == '204, the specific gravity of the heavy gas, to 14,455 = the quantity
delivered of the specific gravity '390.
And for the difference of pressure, say,
As J '50 = '707, the first pressure, is to 14,455, the quantity discharged through a sixteen-inch pipe
by that pressure, so is J60 == '7 74, the required pressure, to 15,824, the required quantity, of specific
gravity 3% discharged from a sixneen-incli pipe, with a pressure equal to 6-10ths of an inch head of
water. The actual quantity discharged is about 16,500 cubic feet.
'GAS, ILLUMINATING, DISTRIBUTION OF. 861

An accurate experiment was made by Mr. Clcgg, atthe Pancras Station, on the quantity of gas dis
charged through a four-inch main, six miles in length, with a pressure of three inches perpendicular
head of water. The s ecific gravity of the gas was not taken until some hours after the experiment,
when it was found to ie "398.
,A new four-inch main had to be laid for the purpose of supplying parts of the parish of St. Marylo-
hone with gas; after completing a circle of nearly six miles in circumference, it terminated within the
distance 01' a short street from the point at which it left the works. By completing this distance, tlu-
two ends of the pipe were brought together on exactly the same level. There were no short bends
and all the services and branches were closed The pipe measured exactly six miles in length. The
leakage was ascertained in the first place by shutting the valve adapted to the returned end, and 06
serving the gasometer; it was found to be thirty-three cubic feet at the end of one hour, and was
allowed for. At the commencement of another hour the valve was opened and free passage given to
the gas, which was allowed to escape: by observing the gasometer at the end of this hour, it was found
that 885 cubic feet had been expended; deducting thirty-three cubic feet from this for the leakage,
852 will remain for the actual quantity discharged at the end of six miles. This experiment is valua-
ble to the practical man, both for the unquestionable data it supplies, and for its close approximation
to the rules here laid down.
The quantity discharged by calculation 873 cubic feet
By experiment 852 “

Difl'erence....., .......... .. 21
Tunas 0f the difl'erent quantities of coal gas of the speczfic gravity '420, delivered in one hour, from
horizontal pipes of diferent diameters and lengths, and under dip’erent pressures
QUANTITIES DELIVERED BY A TWO-INCH MAIN 1N CUBIC FEET.


Length of Pressure in inches and parts. Perpendicular head of water.
pipel in
y“ 8' 0-50 0-75 1-00 1-50 2-00 300

10 2896 3558 4135 4923 5792 6950
15 2364 2904 3331 4089 4728 5768
20 2047 2507 2886 3541 4094 4994
25 1830 2241 2580 3165 3660 4465
30 1673 2049 2368 2894 3346 4082
40 1445 1770 2037 2490 2890 3525
50 1294 1585 1824 2238 2588 3157

100 _915 1121 1290 1582 1830 2232
150 748 916 1054 1304 1496 1825
200 647 792 912 1119 1294 1578
250 579 709 816 1010 1158 1412
300 522 639 736 903 1044 1273
400 457 559 644 790 914 1115
500 409 500 576 707 818 997








QUANTITIES DELIVERED BY A SIX—INCH MAIN IN CUBIC FEET.










Pressure in inches and parts. Perpendicular head of water.
‘Length of
"P" m ymds' 0-50 075 1-00 1-50 2-00 3-00
100 8242 10095 11657 14276 16484 20190
150 6730 8242 9517 11657 13460 16484
200 5828 7138 8242 10095 11657 14276
300 4759 5828 6730 8242 9517 11657
440 3929 4813 5557 6806 7858 9626
500 3686 4515 5213 6384 7372 9030
600 3365 4121 4759 5828 6730 8242
700 3115 3816 4406 5396 6230 7632
880 2778 3403 3929 4813 5557 6807
900 2747 3365 3886 4759 5494 6730
1000 2606 3192 3686 4515 5213 6384
1760 1965 2406 2778 3403 1 3929 4813
2640 1604 1965 2269 2778 3208 3929
3520 1389 1702 1965 2406 2778 3403
5280 1134 1389 1604 1965 2269 2778
7040 982 1149 1389 1702 1965 2298
8800 879 1076 1287 1521 1758 2152
l 10000 824 1010 1166 1428 1648 | 2010


862 GAS, ILLUMINATING, DISTRIBUTION OF.

QUANTITIES DELIVERED BY A TWELVE-INCH MAIN 1N CUBIC FEET.




Pressure in inches and parts. Perpendicular head of water.
Length of
pipe ha yards.
050 0'7 5 1'00 150 2'00 3'00
100 32968 40380 46628 57104 65936 80760
150 26920 32968 38068 46628 53840 65936
200 23312 28552 32968 40380 46628 57104
300 19036 23312 26920 32968 38068 46628
440 15716 , 19252 22228 27224 81432 38504
500 14744 18060 20848 25536 29488 36120
600 13460 . 16484 19036 23312 26920 32968
700 12460 15264 17624 21584 24920 30528
880 11112 13612 15716 19252 22228 27224
900 10908 13460 15544 19036 21816 26920
1000 10424 12768 14744 18060 20848 25536
1760 7860 9624 11112 13612 15716 19252
2640 6416 7860 9076 11112 12832 15716
3520 5556 6808 7860 9624 11112 13612
5280 4536 5556 6416 7860 9076 11112
7040 3928 4596 5556 6808 7860 9624
8800 3516 4304 5148 6084 7032 8608
10000 3297' 4038 4663 5710 6594 8076








In the foregoing Tables we have considered the mains as horizontal.
In mains rising above the horizontal line the quantity of gas delivered by them will be greater, and
in mains falling below that line it will be less. In the first instance, the resistance offered to the flow
of gas by the atmospheric pressure will be lessened, and in the latter it will be increased, and will
cause a difference in the necessary pressure for the discharge of the gas of one-tenth of an inch head oi
water for every ten feet rise or fall.
The effect of bends and angles in the main, upon the quantity of gas delivered, isessentially a matter
of experiment: they may be considered as so man mechanical obstructions. The results of the fol-
lowing experiments will show, in some measure, w Iat allowance to make for quadrant, semicircular,
and right-angle bends. A two-inch pipe thirty feet long, perfectly horizontal and free from obstruc-
Zi-wns, delivered 2898 cubic feet of gas in one hour, with a pressure of five-tenths of an inch head of
water The same pipe, disconnected in the middle of its length, and returned by a semicircular bend
to the point at which it left the gasometer, delivered 2754 cubic feet in the same time, being a differ-
ence of nearly one-twentieth in the whole quantity. The semicircular bend was removed and a quad-
rant bend substituted, making the two fifteen-foot lengths of pipe form a right angle with one another;
the quantity delivered was 2834 cubic feet in the hour, a difference of about 1-45th of the first dis-
charge. Again, the pipes were disconnected, and a right-angle bend substituted for the quadrant; the
quantity delivered in the hour was 2824, a difference of 1-39th of the first discharge. ,
Services are wrought-iron tubes, for the purpose of supplying the interior of houses with gas from
the mains; every small tube on to which a burner is fixed, whether for public or private use, is
called a sermce.
In order that the pipes for conveying the gas from the mains and distributing it through the houses
or other buildings to be lighted, may in the first place be neither unnecessarily large or too small, the
following rule is given:
One gas-lamp consuming four cubic feet in an hour, if situated forty feet from the main, requires u
service not less than a quarter of an inch in the bore.
2 lamps, ....... 40 feet from the main, require a three-eighth service.
' 3 “ .......... .. 30 “ “ a three. eighth tube.
4 “ 40 “ “ a half-inch service.
6 “ .......... .. 50 “ “ a five-eighth service.
10 “ .......... .. 100 “ “ a three-quarter service.
15 “ .......... .. 130 “ “ an inch service.
20 “ .......... .. 150 “ “ a service 14 in diameter.
25 “ .......... .. :180 “ “ a 1% service.
30 “ ......... 200 “ “ a service 14 in diameter.
It is desirable that all bends should be circular. No branch ought to proceed from a service of a
quarter of an inch in the bore, and no more than two from a three-eighth service. All pipes, before
they are fixed, must be proved by condensing air into them by means of a hand-syringe while under
water; the leak will be easily detected by the air-bubbles which rise through the water. For con-
ducting the gas from the street-mains into the interior of a house, or any building to be lighted, a
wrought-iron pipe of sufficient diameter is tapped into the main, and carried in a straight line to the
nearest wall of that building. through which it must pass; and on the inside be furnished With a good
atop-cock. If all the fittings rise from the main no'siphon is necessary, but if any part of them fall
below the main a small receiver must be attached to the lowest point, fitted with a screw-plug at the
bottom, so that any moisture may be drawn off. The pipes which convey the gas to the burners
GAS, ~ ILLUMINATING, DISTRIBUTION OF.
863

must be in as'direct a line as possible, to avoid unnecessary expense and obstructions. The union
joints used to connect two services together must be of the same diameter as the pipes, and soldered
firmly on to them.
Gas-fittings ought to be made of the best materials; the





















y should be judiciously arranged, and fixed
by skillful workmen. The choice of a situ-
ation for the main cock is of importance;
it should be placed as near as pessible to
the inside of the wall through which the
gas is admitted from the street-main, and
4 where it will at all times be accessible to
the inmates of the house. The key or
spanner by which it is turned should always
be attached, and the nick which indicates
whether it is open or shut should be dis-
tinctly marked. The cock should be lit-
erally a stop-cock.
Throughout their various ramifications
the pipes should have a slight inclination
toward the point where the main cock is
fixed, and thence to the street-main; this
is to allow the water, which is occasionally
deposited in them, to drain off without in,
2007


water line


side view inlet.


terrupting the passage of the gas. In fit_
tings which are not thus arranged the water
accumulates in some curvature of the pipes,
and occasions an oscillation, or, as it is very
commonly called, jumping of the lights.
Consumer’s Alden—J ‘he consumer’s me-
ter is constructed upon precisely the same
principle as that shown in Fig. 1982, but
the partitions of the drum are difl’crently
arranged, and placed in such a manner
that, as they reach the water, the surface
presented shall be as small as possible,
or the resistance ofif'ered shall be so grad-
ual that the stream of gas flowing through
the machine is uniform and constant. This
is necessary in a meter from which any
number of lamps are immediately sup-
plied; because the most minute diminu-
tion or increase of the volume of gas flowing to them would cause a variation in the light, and pro-
duce an oscillation.
In a stati0n~meter the intervention of the gasometer will remedy this defect.
A variation in the arrangement of the drum, therefore, is a matter of necessity.
As in the former case, the outer circumference or rim of the drum is divided into four partitions,
864 GAS, ILLUMINATING, DISTRIBUTION OF.

separated from each other by partition-plates, not running across directly at right angles with the
face, but beveling from the plane of the water, meeting the wrap of the opposite hood. The sides
of these partitions are also beveled; the space left between each plate forming on one side of the
drum the inlet, and on the other side the outlet for the gas; the area of the latter being greater than
the inlet, to insure perfect freedom of action. The dotted lines show the wrap of the hoods. Fig.
2005 is a view of the front or inlet side of the drum, with the convex cover removed. The outlets
will present the same appearance, but of course reversed. By referring to Figs. 2006 and 2007, the
remaining parts will be understood. The direction of the gas is marked by arrows. The box a, in
which the inlet-valve is contained, is soldered tight, having no communication with the rest of the
case, except through the valve, the position of which is shown by the arrows; b is the inlet-pipe pro-
jecting above the water-line, conveying the gas into the meter by the bent arm 0, rising above the
water between the convex cover and the inlet-hoods; d is a float attached to the inlet-valve, adjusted
so that when the water falls below the centre opening the valve will close, and the gas cease to enter
the meter.
Motion is communicated to the train of wheel-work behind the index from a spiral worm w, fixed
on to the axis of the drum, working into a wheel, the s
scaled by dipping under the water contained in the case.
The following are the principal dimensions of consumers’ meters:
pindle of which passes through the tube t,



Number of Diameter of Depth of Diameter of Centre Open- Hollow Cov- Depth of Depth of Capacity in Cubic
Lights. Drums. Drums. “'ater Circle. ing. er projects— Inner Hoods. Outlet. Feet.
Inches. Inches. Inches Inches. Inches. Inches. Inches.
5 12} 5 3 1i 2' § '2- . 25
10 14 i 61- ° 2 1 5 1 . 5
20 1 'i i- ! § 4} ‘I 1 §~ ~§ 1'} 1 . 00
80 12 1} 10-1- 5 3 ] :1- § 1 § 1 .50
50 21$ 111L 5 3} 1% 1- ]} 2.00
80 25 121- 6‘} 4 ] 1} 1 1'} 8 . 00
100 '1!- 13§~ H- 5 1&- 1 1} 4.00
150 38 201- 9 6 2} 1% 8.00
200 33 24-2- 10 7 $1- 2 2§ 10.00
400 44 8QL 15 10 2‘ 3 20 .00
800 ()0 401- 21 15 43- 5 5? 50 . 00











Dry Gas-lifeters.—The ordinary wet gas-meter described is unexceptionable where fraudulent _
means are not employed for underestimating the amount of gas consumed, but its construction admits
of great deception being practised by dishonest consumers. If, for instance, the water-level in the
meterbe lowered, more gas will pass through than is registered by the instrument; if the case of _
the meter be tilted forward to an angle of from 5° to 13°, according to its construction, and a pro-
portion of the water drawn off, so as to expose the outlet of the measuring chamber, the gas will
pass through it without affecting the index, and without being registered at all. This is constantly
done, and the large amount of gas which is unaccounted for in the calculations kept at the gas-works,
and which is frequently attributed to leakage, is no doubt traceable to this nefarious practice. In
cold weather the water in the meter is liable to freeze, and the passage of the gas is then completely
stopped. The use of a solution of caustic potash or soda has been proposed, which is not so easily












affected by frost, to replace the water in the meter, which will also tend to render the gas more pure,
should either carbonic acid or sulphuretted hydrogen have escaped the general purifiers. The objec-
tions to the use of the wet meter stated above have given rise to great ingenuity in the construction
of a variety of measuring instruments, in which the use of water or any liquid is dispensed with, and
in which the gas is measured by the number of times that a certain bulk will fill a chamber capable
GAS, ILLUMINATING, DISTRIBUTION OF. 865

of undergoing contraction and expansion by the passage of the gas. These alternate contractions
and expansions of the chamber set certain valves and simply constructed arms in motion, which, by
the aid of a few wheels, can be made to turn the hand of a dial, as in the ordinary wet meter.
Messrs. Groll & Richards’s meter consists of a cylinder or case A A, Fig. 2008, divided by a plate
B in the centre into two separate compartments, which are closed at the opposite ends by metal
disks 0 C'. These metal disks serve the purpose of pistons, and are kept in their places by a kind
of universal joint attached to each. The space through which the disks move by the action of the
gas, which affords the means of measurement in this meter, is governed by metal arms and rods,
shown in Fig. 2009, which space, when once adjusted, cannot vary. To avoid the friction attending
a piston working in a cylinder, a band of leather D D is attached, which acts as a hinge, and folds
with the motion of the disk; this band is not instrumental in measuring the gas, so that its contrac-
tion or expansion would only decrease or increase the capacity of the hinge, the disk being still at
liberty to move through the required space only. The leather is also attached in such a manner that
it can only bend in one direction, and this renders it much more durable.
The gas enters the cylinder at the top, from the space occupied by the arms, valves, etc., Fig. 2010,
and forces the disks bodily forward through a
2010- certain space; the motion communicated by the
disks to the arms and rods causes the supply
of gas to be cut off, and admits of its escape by
another valve; at the same moment the gas
is admitted to the other side of the disk, and
this is forced to return to its original position,
traversing, of course, the same space as before.
Each backward and forward motion consequent-


’.' l fer/.1 l a :
, ly indicates the passage of a constant quantity
4 s 1 of gas, and the same apparatus which admits
ill
3*.
umnmntmuuuluinqmmi
and shuts off the supply by means of valves is
connected with clock-work ; and thus the motion
mll ,Tmmmu of the disk, or the quantity of gas which has
" passed through the meter, can be indicated upon
. a ~ 5 a dial-plate, as in the ordinary wet meter.
T m Comparative Advantage of Wet and Dry 111e-
'_' " ters.--IVet meters are simpler in construction
i than dry meters, having no valves except the
' ' float, but they are liable to freeze and stop on
“I *n' j.
' ,r‘rl; ‘H '.
I ,.
multivitamin.
meters are therefore more generally used, al-
though they are more liable to get out of order,
as the wear and tear is greater; but the inac-
curacies from wear or corrosion are generally
in favor of the consumer. The water in wet
meters is sometimes replaced by glycerine or
water in which chloride of calcium is dissolved,
to prevent evaporation, thereby keeping the
liquid all the time at the same level.
The index of the meter, Fig. 2011, is very simple. Each figure or division on the faces indi-
cates as follows: On the right-hand face, 100, 200, 300 cubic feet, etc.; on the middle face, 1,000,
2,000, 3,000, etc. ; on the left-hand face, 10,000, 20,000, 30,000, etc. ; and, in this way, multiplying
by 10 for every additional face. The face in the centre or top indicates the fractions, as 1 foot,
2 feet, and so on, and it is used in testing the governor. \Vhen there are 10 or more burners
lit, the hand may be seen to move; the more burners lit, the faster it will move. Look at the
left-hand face of the index and set down the figure the pointer has passed, which on the above
diagram is 8 ; next look at the middle face, and set down the next, which in the diagram is 9; next
upon the right-hand face, and take the same relative figure, which is 2; and you have the number
892, to which add two ciphers to represent hundreds, and the sum of 89,200 is shown as the present
state of the meter.
Natural Gala—The detrimental qualities of natural gas, says Mr. E. B. Phillipp, in a paper read
before the Ohio Gas-Light Association, which tend to make its use in its crude state unsatisfactory,
are its heavy specific gravity, and the excess of sulphuretted hydrogen, carbonic acid, and carbonic
oxide which it contains. Its heavy specific gravity makes the light flickering and unsteady, when sub-
v
'-
,’ 3.51..”
2011.
BUBIB FEET-



55 '
866 GAS, ILLUMINATING, DISTRIBUTION OF.

fl.
ject to draughts or currents of air; and the excess of sulphuretted hydrogen makes its use unpleasant,
on account of the formation of sulphurous acid in burning. Now, in removing these detrimental
qualities, and in increasing its candle-power, it will successfully compete with any other illuminant,
not only from a protometrical standpoint, but also on account of the low price at which it can be fur-
nished. There are two practical methods of treating natural gas and of removing its detrimental
qualities: one of which is by passing it through a complete coal process, from the retorts through
scrubbers, washers, condensers, and purifiers, into the holder, and enriching it by using oil or naphtha
in the retorts; while another method is to put it through a water-gas process. The latter, on account
of its being the cheapest and best, is to be preferred.
In using the water-gas process no change is made whatever in the construction of the apparatus.
The only real difference in the process is that, instead of using anthracite coal and steam to make
water-gas, natural gas is passed through the apparatus, and simply enriched and purified. The use
of the cupola in the water-gas process is to make, from anthracite coal and steam, carbonic-oxide gas
and free hydrogen, which together form water-gas; and also to carburet or enrich the same by vapor-
ized oil. The use of the cupola in the natural-gas process is merely to carburet or enrich the crude
natural gas by vaporized oil. By this process of carburetting, its specific gravity is changed from 0.57
to 0.40, which makes it of about the same specific gravity as coal-gas. The rest of the machinery
belonging to the water-gas process proper, consisting of the washer, scrubber, and purifiers, is also
used in treating natural gas. The washer removes principally a black, clayey substance, very similar
to lamp-black; the scrubber removes the oily, condensable vapors; the purifiers remove the sulphu-
retted hydrogen and carbonic acid. The result of this method of treating natural gas gives a mer-
chantable, high candle-power, non-condensable illuminant, free from sulphuretted hydrogen and car-
bonic acid, with a specific gravity of 0.40, and with an illuminating power of from 22 to 24 candles,
and which at a low price per thousand cub. ft. completely and signally competes with and supersedes
coal-gas or any other illuminant.
A water-gas plant, with cupola, washer, scrubbers, purifiers, and engine and blower, of a capacity
of 75,000 cub. ft. per 24 hours, costs (complete) between $5,000 and $6,000. This, used in connec-
tion with purifiers, holders, and mains of the coal plant, will make a complete plant for the purpose.
Distribution of Natural Gas.——The four main lines from the gas-fields that comprise the high
pressure or country system of the Chartiers Valley Gas Co. can deliver into the cities of Pittsburg
and Allegheny nearly 200,000,000 cub. ft. of gas every 24 hours. The total length of the high-press-
ure lines is 479,258 ft. -
The method of connecting the wells to the main line is shown by Fig. 2011 A. The casing that is
put in the well extends to the level of the derrick floor. A branch is bolted to this casing, having
2011 A.



one of its outlets pointing straight up the derrick, and the other going off at the side at an angle of
45°. Upon each of these outlets, which are usually 6 in. in diameter, a gate-valve is bolted, the
gate-valve on the upright branch having a pipe bolted to it to conduct the gas to the top of the der-
rick in case it is necessary to blow off the gas. The branch leading out of the side has also a gate-
valve bolted to it, and from this valve a curved pipe leads into a tank placed near the well to separate
and collect any water or oil that may be carried along with the gas as it leaves the well. The pipe which
enters the tank on the left side extends into it 6 in. beyond the centre, and the pipe which leaves the
tank on the right side extends into it and past the inlet-pipe, they overlapping each other 12 in., so
that the gas as it enters the tank has to change its direction in order to get out, and in doing this the
water falls to the bottom of the tank and is blown out at the small valve shown at the side. A by—
GAS, ILLUMINATING, MACHINES FOR PRODUCING. 867.

pass is constructed around the tank, and gate-valves placed on each side and in the centre of the by-
pass, so that the gas can be conducted around the tank in case it needs repairs. A man-hole is placed
at the bottom of the tank and a safety-valve on top. The cut also shows the anchor-rods leading
down on each side of the casing in the derrick. These rods are fastened below to a heavy timber
foundation embedded in the ground, and above to a stirrup over the gate-valve; then, by means of a
right and left hand screw swivel, placed in each rod, the casing is drawn firmly down, so that it will
resist the full pressure on it when the well is shut in. All the fittings used about the wells are enor-
mously heavy, so as to withstand the great pressure of the well when shut in. The reason for con-
necting the wells in this manner is to prevent the great loss of gas by friction in passing the many
Ts and elbows that are generally used in connecting wells to the main line.
As before stated, the Chartiers Co. draws its supply of gas from three separate and distinct fields. As
the gas enters the city it passes through regulating stations, where the pressure is reduced, as a higher
pressure is carried on the lines from the wells to the city limits than within the city. The appliances
for reducing this pressure are shown in Fig. 2011 B. The gas enters the station on the main line
shown in the centre of the cut at the top. From this line two branches are carried off from each
side, and which are carried back again into the main line. In the centre of each one of these
branch pipes or arcs a regulating valve is placed, which is so constructed that the pressure is
reduced to that required by placing the proper weights on
the levers that extend from them. On each side of each of
these regulating valves a gate-valve is placed, in order to shut
oif the gas from each regulator in case they should need re-
pairs, and at the same time not interfere with the flow of gas
through the other valves. The
number of regulating valves and 20110.
their size is such that there is /—-\
always one more valve than will
give the full capacity of the line.
In the main line which passes
through the station-house in the
centre a gate-valve is placed,
which is called the by-pass valve.
During the ordinary operation of
the line this valve is kept closed;
but should any accident occur by
which it would be necessary to
close all the regulating valves,
this by-pass valve would then be
open and the gas would pass di-
rectly through the station. The
main line is increased in size at
the outlet side of the regulating
valves in order to give the gas
more volume, and in this way
make up for the reduced press-
ure. The line as it enters this
station is 20 in. in diameter, and
as it leaves it is 24 in. in diameter. The pressure is reduced from 15 to 25 lbs. per sq. in. The
device for removing gas which may leak from the joints is shown in Fig. 2011 c. It consists in a
sleeve placed over each joint and made gaS-tight. On the inside of the sleeve a space or chamber
is left where all the gas that escapes from the joint is collected. Connected with this chamber at the
top a small pipe leads off and up to the top of a lamp-post situated at the curb. Several of these
pipes are led into one lamp-post, but each joint of the main pipe has its own separate and distinct es-
cape-pipe, which is in no way connected with the others. Each joint on the main pipe is numbered,
and its exact distance measured from the lamp-post. The escape-pipe that leads away from the joint
is marked with a corresponding number at the top of the lamp-post; so if gas is discovered escaping,
by noting the number of the small pipe through which it escapes, the exact location of the leak can
be determined.
There are two distinct systems for supplying natural gas to private houses. The first consists in
laying a system of small pipes, generally about 4 in. in diameter, in the streets and connecting these
small pipes at certain points with the mill-supply lines by regulating valves so set that 5 lbs. of gas is
received into and carried on the small lines. To reduce this pressure, which is too great to be con-
ducted into a house, a regulating and automatic shutoff is put in each house, by which the pressure
is reduced to about 4 oz., which is the proper pressure for gas for burning in private houses.
The system used by the Chartiers Valley Gas Co. consists in laying an entirely different network
of pipes from the mill-supply system, but connected at different points with these lines by means of
regulating valves. The pipes which supply the private houses are, however, made so large that only
a pressure of 4 or 5 oz. need be and is carried on them. The service-pipes are then run direct into
the consumer’s house, no regulating or other device being necessary, as the pipes themselves carry no
greater pressure than is required in the houses. .
GAS, ILLUMINATIN G, MACHINES FOR PRODUCING. When buildings are situated beyond
the reach of the gas—mains of cities, it becomes necessary to find a substitute for coal-gas. One of
the best is the gas produced by bringing a current of air in contact with gasoline. This fluid, being
of a volatile character, readily throws oif carbonaceous vapors, which, combining with the air, pro-



-.~
_
11.“. ' -
“Minn/r
my {-"v.
ui'fyuQQ/il
‘ I




868 GAS, ILLUMINATING, MACHINES FOR PRODUCING.
duce a gas that burns, when properly regulated, without smoke or odor, and furnishes an agreeable
light.
bThe Springfield Gas Illachz'ne is shown in Fig. 2012. An air-pump operated by a weight is used



to produce the air~eurrent. The gaS-generator is a cylinder containing evaporating pans or cham-
bers, in which the gasoline is kept. The generator is always placed in a vault under ground,
removed from the building a safe distance; or it may be buried in the earth. The air-pump is sta-
2013. K
<6 .1.”-
‘o \,
Mfg a}:
with]!



tioned in the cellar of the building to be lighted. Supposing a machine to be set up and connected
by pipes, as shown in Fig. 2012, the generator to be filled with gasoline, and the weight of the
pump wound up, the process of gas-making is as follows: The action of the pump draws a supply

























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gas-generator; in its passage through the generator
gas that is returned by the gas-pipe to the




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of air through the induction-pipe leading to the_
it becomes carburetted, thus forming an illuminating
GAS, ILLUMINATING, MACHINES FOR PRODUCING. 869

burners within the buildin". The machine is automatic in its operations, gas being made only as fast
as consumed. When the burners are shut off, the pump stops and the manufacture of gas ceases, but
immediately commences when they are opened again. The gas-generator is recharged whenever
exhausted, usually once in from three to six months, varying according to the rapidity of the con-
sumption of the gas. Gauges on the generator show at any time the amount of fluid it contains,
and when it needs to be replenished. A double-way cock connecting with both the filling and vent
pipes in the vault is used, so that of necessity a free vent is given while filling, thus preventing any
846‘ PIPE
F:
“,9: 70 UPPER 2015.
9% CHAMBER






backward pressure of the gas upon the pump or strain on the generator. The weight of the pump
does not commonly require winding oftener than once or twice a week, and this takes but a
moment‘s time. There is a retaining power spring within the pump that drives it while the weight
is being wound, operating on the same principle as that of a watch, which enables it to be wound
without stopping its movement. -
Fig. 2013 is a sectional view of the gas-generator, showing its series of evaporating chambers.
The gasoline, as it enters the generator, fills the uppermost chamber first, to the top of the overflow
tube 0; this tube allows of its passage to the next cham-
ber below ; this in turn filling afterward the one below this,
and so on successively until all are filled, and the fluid
appears in the lowest chamber at say two~thirds the height
of the lowest gauge G. The filling-cock then being shut,
the apparatus is ready for use. Air forced by the pump or
hydraulic blower enters the generator at B, passes over the
fluid and through the meshes of fibrous capillary material,
now thoroughly saturated with gasoline, back and forth
through the subdivisions of this chamber, then up through
the tube 0 to the next chamber above, winding through this ME ,msymmm To
in a similar manner, afterward through the chamber still “8 “"‘"“""
above this, and so on; until finally, becoming thoroughly
impregnated with the vapor arising from the gasoline, it is
delivered a rich carburetted air-gas, through the gas-tube K-
to the burners of the building to be lighted.
In Fig. 2014 is shown a “ flat” gas-generator. The modi
fication consists in making the evaporating chambers of
greater diameter and fewer but larger, and so arranging the
connections for the air, gas, and filling pipes that they may
be substantially buried in the earth, only an arc of a circle
projecting into a little brick pit.
Fig. 2015 is a perspective sectional view of the “flat”
generator, showing the wooden division-frames and the capil-
lary webbing stretched upon them; also, by the arrows, the
direction taken by the air in passing through. Fig. 2016 is also a sectional view, as it appears
when charged with gasoline.
Fig. 2017 shows an ingenious improvement in the apparatus, whereby the air-pump is operated
by water and a water~wheel. Where a fall of water is available, it is made use of to operate a
~ “hydraulic blower,” which is substituted for the air-pump driven by weight. The hydraulic blower
is shown in section in Fig. 2018, and consists of two copper vessels, one inverted in the other,
a"
2mm scum?“
870 GAS, ILLUMINATING, PROCESSES OF MANUFACTURE.

to which are attached pipes as shown. The injection-pipe A brings water from the flame or
other source of supply. This pipe is fitted with the nozzle B, through which the water rushes, fall-
ing through the larger pipe 0; in so doing, air is drawn in at the suction-pipe D, and both water
and air fall together into the inverted vessel E, where the air is confined. The water passes off
through the discharge-pipe F. Through the pipe G air is conveyed to the gas-generator. Where a
head of water of 4 feet or more can be obtained, it can be used with perfect satisfaction. The
cost of gas made by this process is from $1 to $1.50 per thousand feet, 6 gallons of gasoline making,
it is claimed, a light fully equal to 1,000 feet of coal-gas.
The Solar Gas-Gmerator is represented by Fig. 2019. A is an air-pump propelled by the
weight B. F is the air-pipe, through which air is forced into the carburetter C, where it unites
with the vapor of gasoline, thus producing the gas, which is carried through the pipe G to the burn-
2019.


ers. D is an iron reservoir for containing a large supply of gasoline. E is the automatic filler,
which regulates the supply of gasoline to the carburetter. H is the filling-pipe, through which
the gasoline is poured into the reservoir. 1 is a vent-pipe to allow the escape of gas while
filling. J J’ are globe valves for the purpose of confining the gasoline to the reservoir and carbu-
retter, whenever alterations may be required. K is a draw-01f cock, which can be opened with an
ordinary wrench. L is a vacuum-pipe for the purpose of preventing a vacuum, which would other-
wise occur in the reservoir and automatic filler. M is a plug for drawing off the water from the air-
pump. N and O are gas-cocks for shutting ofl’ the pressure from the air~pump and generator. P
is the induction-pipe, which supplies air to the air-pump. The reservoir is intended to contain a
supply of gasoline for six months, more or less, according to dimensions selected by the purchaser.
The gasoline is transported in barrels, and poured directly into the reservoir by means of a rubber
hose, one end of which is attached to the barrel by a faucet, and the other to the filling-tube, as
shown at the surface of the ground. The automatic filler performs the important function of supply-
ing gasoline to the carburetter in exact proportion to the consumption of gas; by which means a
most desirable result is secured, not otherwise attainable, viz., uniformity of light. 11. A. M., Jr.
GAS, ILLUMINATING, PROCESSES OF MAN lFAGTURE OF. The principal processes of
manufacture of illuminating gas are given in some detail in the following article, beginning with the
various systems in use by the large gas companies which supply the city of New York.
Manhattan Gas-Light Company’s Panacea—The gas is manufactured directly from coal, three
kinds'of which are used, viz., Westmoreland, Nova Scotia, and cannel. These varieties are mixed
together, the mixture containing about 10 per cent. of cannel coal, which is the enriching material,
furnishing those hydrocarbons desirable for illumination. The mingled coals are introduced into the
retorts, which are 1,000 in number, mostly arranged in benches of five or six. The charges weigh
from 200 to 250 lbs. The retorts previous to the introduction of the coal are heated to from 2100°
to 2300° R, which raises the temperature of the coal to from 1500° to 1600° F. The distillation
takes from 4 to 4% hours, when the retorts are opened, the residue of the coal (coke) is withdrawn,
and new charges of coal are inserted. During the process of distillation, the gas passes up the
stand-pipe, then down the dip-pipe into the hydraulic main. Thence it goes to the large condensers,
which are two in number, and afterward enters the dry scrubbers. Here it passes over a large num.
ber of surfaces, and deposits thereon any tar which it may contain. The gas next proceeds to the
scrubber proper, where it meets with an immense number of moist surfaces which remove the ammo_
nia. Only from 1 to 1% gallon of water is used for 1,000 feet of gas.
The scrubbers are two in number, 85 feet high, the gas-way being 60 feet. Being exposed to the
air and consequently to fluctuations of temperature in winter and summer, the scrubbers are sur-
rounded with an iron Jacket, near the bottom of which are steam-pipes for heating the air in the
jacket, which is kept in circulation by suitable openings at top and bottom. Steam is used only in
winter, to keep the water in the scrubbers from freezing, as generally the colder the water is the bet
ter is its absorbent power.
From the scrubbers the gas is forced through the purifiers, which are 12 in number, containirg
GAS, ILLUMINA'IING, PROCESSES OF MANUFACTURE. 871

’
- from .500 to 600 bushels of lime each. The tops or covers are removed by machinery and trans-
ported on a tramway. The gas is passed through sets of 4 purifiers, whence it is forced into the
meters, which are 15 feet in diameter and 12 feet deep. Finally it passes to the holder ready for
consumption.
About 1,000,000,000 cubic feet of gas is made in a year by this company, the amount daily pro-
duced being from 1,000,000 to" 5,000,000 cubic feet. The candle-power averages (with the city
burner) 17% candles. About 1,700 lbs. of coke is produced from 2,240 lbs. of coal. The exhauster _
is situated in these works between the condenser and scrubbers. The water used at the works is
from a driven well. About 175 tons of coal is used per day. The lime from the purifiers is sold
as a fertilizer at half a cent per bushel.
The New York Gas-light Company’s Procesa—Penn, Rock, and cannel coals are used at the
works of this company. The 'mixture of these three varieties'is introduced into the retorts in
charges of about 240 to 280 lbs. The retorts are charged 5 times in 24 hours, and are arranged in
benches of 6, there being 12 clay retorts with lead lids. The gas after leaving the retorts passes up
the stand-pipe, then down the dip-pipe into the hydraulic main, whence it is forced through two large
multitubular condensers. It then enters a large revolving scrubber 40 feet high, every other tray of
which revolves. The gas is next forced through one lime-purifier containing 600 bushels of lime,
passes through a 30-inch leader to the iron-purifiers, but branches off in two 20-inch pipes on one
side of the purifier, uniting on the other side again in a 30-inch leader. The gas passes through a
set of three iron-purifiers, then to the meter, and finally to the holder ready for consumption. The
exhauster is situated in front of the condenser. The average amount of gas made per day is over
3,000,000 cubic feet. There are a number of holders at the works, two of which have a capacity of
1,500,000 cubic feet each. The greatest pressure of gas at the works is 5.8 to 6 inches, being 1.6
inch at the office. The works are situated at 21st Street and East River, and the gas is not distrib-
uted until it reaches Grand Street (about 2 miles distant); hence the cause of high pressure. The
candle-power of the gas, with the city burner, is 16.5 candles.
The Harlem Company’s Panama—Virginia coal, at $5.25 per ton, is used alone at the works of
this company. There are 52 benches containing sets of 5 retorts. The charge per retort is on an
average 200 lbs., requiring 4 hours for the distillation, 6 charges being introduced in 24 hours. The
gas is drawn from the retorts and ascends the stand-pipe, then descends the dip-pipe into the
hydraulic main, whence it passes into a St. John & Rockwell scrubber. It is then forced through a
. large scrubber about 40 feet high. It next traverses three purifiers containing oxide of iron, and
thence passes to the meter, and to the holder ready for consumption. About 2 gallons of water is
used in the scrubber to about 1,000 cubic feet of gas, the wash-water from which contains 6% ounces
of ammonia to the gallon. About 1,550 lbs. of coke is produced from a ton (2,240 lbs.) of coal.
The pressure of the gas at the works is 3 inches. It is claimed that 11,000 cubic feet of gas is
obtained from a ton of coal. The candle-power of the gas, with the company’s burner, is 171}
candles“ ‘
The Metropolitan Gas Company’s Process—In the works of this company naphtha is substituted
for cannel coal to produce the necessary hydrocarbon. Virginia coal is used in summer and
' Penn or New Castle in winter. There are 560 clay retorts, arranged in benches of 6 each. The
charge is about 240 to 250 lbs. The gas from the retorts passes up the stand-pipe, then down the
dip-pipe into the hydraulic main. It is then drawn into a large multitubular condenser, after pass-
ing through which it is forced through two large scrubbers, one containing ammonia liquor and the
other water. It then goes through a set of three purifiers, which are filled with a layer of sawdust
moistened with acid, then a layer of oxide of iron, and then four layers of lime. From the purifiers
the gas passes to the meter and then to the holder. This gas, which has a candle-power of from 12
to 15 candles, is afterward enriched with naphtha gas, which is prepared in 12- “through retorts,”
which contain iron tubes extending half the depth of the retort. The naphtha is made to pass
back and forth through the tubes until it is thoroughly vaporized, when it escapes out of the pipe
through to the other end of the retort, and is rendered by the intense heat a more or less permanent
gas. It is sometimes mixed with the coal-gas just before the latter enters the condenser, and then
passes with the coal-gas through the condenser, scrubber, etc., to the holder; or the naphtha gas is
itself passed through a separate condenser, scrubber, and meter, and mixed while more or less hot
in the pipes in its passage to the holder. It is claimed at these works that 7 3 cubic feet of naphtha '
gas (of 60-candle power) is obtained from 1 gallon of naphtha, and that from 1 ton (2,240 lbs.) of
coal from 11,000 to 12,000 cubic feet of gas is produced. The largest amount of gas manufactured
per day is 3,200,000 cubic feet in winter and 800,000 cubic feet in summer. The candle-power, with
the company’s burner, is from 18 to 19 candles. The McKenzie exhauster is used after the conden-
ser and scrubber.
The New York llfutual Gas-Light Company’s Process—This company claims to obtain from 1
ton of coal from 16,000 to 18,000 cubic feet of a gas of only 1 to 4 candles luminosity. This, after
proper purification, is enriched by naphtha up to any candle-power, generally about that of 20 can-
dles. The process is as follows: After leaving the retorts the gas passes through the stand-pipe,
the dip-pipe, and the hydraulic main, and then through a 16-inch pipe to 8 large coolers (condensers),
which it successively traverses, and finally enters two large scrubbers, whence it proceeds to the
purifiers. The coolers and scrubbers contain scrap-tin, which gives innumerable surfaces for the gas
to meet. The first purifier contains oxide of iron, which robs the gasof its sulphur compounds.
The gas then passes through purifiers containing lime, which takes up the carbonic acid, and then
goes (to the temporary holders in the form of purified light carburetted hydrogen, heavy carbu-
retted hydrogen, and hydrogen. From the holder the “as passes to the carburetter, where it is
enriched with the vapor of naphtha. It then passes through a long distributing reservoir (hydraulic
main) to the through retorts. On leaving these it traverses the stand-pipe, dip-pipe, and hydrau-
872 GAS, ILLUMINATING, PROCESSES OF MANUFACTURE.

lic main, and lastly is forced through five coolers (condensers) containing as before scrap-tin. The r
candle-power, with the company’s burner, is 20 candles. ‘
The .Zlfanicipal Gas-Light Company’s Panacea—This company uses a new process invented by
Tessie du Motay. Water instead of coal' is used as 'the element for producing the foundation of
the gas, which is afterward enriched by naphtha vapor. The light is remarkable for its Whiteness.
The process is as follows: In a large boiler water is converted into steam, and passes into a large
iron cylinder, known as the “ gasogene generator,” which is filled to three-fourths of its height with
coal. The coal is first heated white-hot by means of a blast, and when in this condition the blast
is turned off and the steam is admitted. Decomposition of the steam at once takes place; hydrogen
gas and carbonous oxide gas are formed, which take up of course the impure gas given off from
the coal. The gas then passes up a stand-pipe and down a dip-pipe into a large rectangular iron
vessel containing water, through which it proceeds to a temporary holder of 125,000 cubic feet
capacity. From the holder the gas goes to the carburetters, where it is enriched with naphtha
vapor volatilized in the carburetter by means of a steam-jacket. It then passes to the thrOugh
retorts, which are highly heated, and on passing through the naphtha is decomposed into higher
hydrocarbons, which tend to make a more stable gas. From the retorts the gas passes up a stand-
pipe and down a dip-pipe into the hydraulic main, whence it passes to the condensers, then through
the scrubbers to the purifiers, then through the meter, and finally to the holder ready for con-
sumption. The exhauster is situated after the condenser and scrubber. The pressure of gas at
the works is 2.7 inches; at 11} mile distant, 14 inches. From 1,000,000 to 3,000,000 cubic feet of
gas is made per day, having with the company’s burner an illuminating power of 22 candles. Six
gas-holders are used, capable of holding 18,000,000 cubic feet of gas. '
The American Hydrocarbon Process—The method formerly known as the Gwynne-Harris process,
2020.


but now as the Allen-Harris or American hydrocarbon process, was successfully introduced into the
city of Poughkeepsie in 1875. Three double retorts of fire-clay are employed; each retort has a
horizontal diaphragm extending from front to rear, dividing it into an upper and lower retort, with
small holes through the rear half of the diaphragm. The three are set in a bench like retorts for
coal-gas, as shown in Fig. 2020. In the bottom of the lower retort chambered tiles are laid, closely
joined and cemented, forming a false bottom. The rear half of the upper surface is perforated with
small holes. Two fire-clay superheaters, 61} by 94; inches in size, and 5 feet in length, having a hole
11} to 2 inches in diameter, extending from the front to near the rear, and returning again to the
front, are laid upon or at the side of each retort in the bench. Near the foot of the bench wall, in
a small chamber about 4 inches square, is placed a drier, consisting of a metal pipe about 5 feet
long, with a smaller one within it, to prevent the possibility of any water or condensed steam from
reaching the red-hot clay superheaters or retorts. The steam is generated by a boiler of suitable
size; and where a rapid production of gas is required, an independent superheater is built alongside
of the boiler, consisting of an oven in which are iron pipes, 5 to 6 inches in diameter, filled with
coiled steel wires or shavings, and passing back and forth in the oven. The steam, by a connecting-
pipe, is sent from the boiler into this superheater, where it is raised to about 700° or 800°, or even
to 900°; from here it passes through the drier, and thence into and through the fire-clay superheat-
ers, which lie in the hottest part of the bench, and by which it is raised to about 2500°. In this
state the steam enters the chambered tiles, and is carried back, and passes up through the small per-
forations, by which it is distributed in finely-divided jets, under and through the incandescent anthra-
cite coal in the lower. retort, and in like manner through the perforations in the diaphragm and the
GAS, ILLUMINATING, PROCESSES OF MANUFACTURE. 873

incandescent anthracite coal in the upper retort. The steam is thus perfectly decomposed, with
great rapidity and at a small cost. As each particle of steam comes in contact with the incandescent
coal, the oxygen in it unites with an atom of carbon, forming carbonic oxide, and its hydrogen is
set free; the result being hydrogen and carbonic oxide, which are the most incondensable of all
gases. To give illuminating power to this gas, where the dailyproduction is large, a separate bench
is set with like retorts, but without any of the above-mentioned fixtures, and without containing any
coal, coke, or other materials. This bench is also kept at a high heat, and into these retorts the
water-gas is sent from two adjoining hydrogen benches ; and at the same time an exceedingly small
stream of naphtha is constantly flowing in, and, being converted into gas, this unites with the water-
gas, and gives it its illuminating power. The gas, thus perfected, passes up the stand-pipe into the
hydraulic main, and thence through the condensers, purifying boxes, and station-meters, to the hold-
er, ready for use.
One bench in which the oil- and water-gases are thus united is sufficient to carburet all the water-
gas from two hydrogen benches; and the three benches will readily make 100,000 cubic feet of gas
per day. The labor of making this gas is very light. The hydrogen retorts are drawn and recharged
once a week with anthracite coal, and every morning the fire is raked back, a few pounds of coal are
thrown in front, and the lid is closed for 24 hours. The steam and oil are admitted into the retorts
by cocks, and require no attention so long as the daily make of gas does not greatly vary ; and even
then it is only a trifling matter to regulate the same, increasing or lessening the quantity of either,
as occasion requires.
In decomposing the steam 17 lbs. of anthracite coal, and in adding the illuminants from 3%,: to 4
gallons of naphtha, to each 1,000 feet of gas, are used. Over 1,500,000 feet of gas has been puri-
fied with 24 bushels of shell-lime, averaging over 65,000 feet per bushel. When the use of rich gas
coals is for any reasons perferred to that of oil, the same are carbonized in the retorts in the oil-
bench, and the water-gas is introduced in the same manner as when oil is used, and the results are
similar. The following is a statement from the Citizens’ Gas Company of Poughkeepsie for the
month of September, 1877 :
Total gas manufactured, 1,592,400 feet. Average daily consumption, 52,970 feet. Average can-
dle-power, 16.73. Materials, etc. : -

18.70 tons stove coal, at $3.90 . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. .. . . .. . . .. . 870 20
11.1144 tons grate coal, at $3.54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 71
13.1880 tons chestnut coal, at $3.74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 62
647 bushelsofleoke,at 52 23
96 bushels of tar, at $0.93 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 28
6,480 gallons of naphtha (average 4.06), at $0.071} . . . . . . . . . . . . . . . . . . . . . . . . 502 20
4 men in works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 00
Total cost.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . $971 24
Cost per 1,000 feet, 61% cents delivered in holder.
One change of purifier, from July 28 to September 5. Gas made, 1,580,200 feet. Lime used, 24
bushels. Average gas purified per bushel of lime, 65,800 feet (shell-lime used).
The cost of 1,000 feet of gas, as shown by this statement, is only 61% cents; but this is higher
than it would be if the works were running their full, capacity. With an average daily consumption
of 80,000 feet, the cost would not be over 50 cents per 1,000 feet, delivered in the holder.
The Lowe Gas Process, Fig. 2021.—This process had a nine months’ trial in the city of Utica
under the direction of Prof. Henry W urtz, and gave excellent results, when, unfortunately, the
works were destroyed by fire. “Fig. 2021 represents a section of one of the sets of apparatus, of
which four are erected at Utiea, although only two are, at the present season, kept at work; these
being more than suliicient to supply the consumption of the town, which, during the month of Octo-
ber, 1875, was close upon 120,000 feet per day. On the left of the engraving is represented the
gas-generator, 9 feet high and 28 inches in internal diameter, half filled with clean anthracite, broken
to rather large ‘ egg size.’ p indicates the man-hole for feeding the coal, almost flush with the second
floor of the building, on which the attendant stands. The apparatus next on the right is called by
the inventor the ‘superhea-ter ’—a name used provisionally, though its functions are but imperfectly
expressed thereby, being rather those of a regenerator. The dimensions of the superheater are 15
feet in height by 28 inches internal diameter. The first step in the process consists in blowing up
the anthracite in the generator to intense ignition, by means of a blast of air entering under the
grate g, at the point marked by the arrow. The highly-heated gaseous products, consisting of car-
bonic oxide and nitrogen, pass down through the pipe f, and, meeting in g another blast of air
from the right, kindle again and blaze up through the mass of loose fire-bricks in the superheater,
heating the latter to an intense temperature. During the first stage of blowing up the generator,
the valve h at the top of the superheater is open, and the blast passes on to the boiler to help make
steam. The second stage is to shut off the air~blast, to close the valve 7:, and to introduce steam
into the side of the generator, through the small pipe marked ‘ Steam’ passing down its right-hand
side. W'ater-gas is now formed, and there is simultaneously fed into the top of the generator, trick-
ling slowly in through the small siphon-tubes m, a certain amount of crude petroleum, of ordinary
density, which, vaporized by the heat as it enters, is swept on to and through the superheater, in
which it undergoes gasifieation; and the whole mixture passes on through a, down to the washer v,
and on to the other arrangements provided for condensation. The amount of gas obtained at each
heat is 3,000 cubic feet or more, according to the degree of heat attained, and the average time of
each such heat, including both stages of blowing up the fire and generating the gas, is one hour; so
that 24 beats, or over 70,000 cubic feet of gas, can be obtained daily from each apparatus.”
874 GASJILLUMINATING, PROCESSES OF MANUFACTURE.

During the tests at Utica it was found that the cost of purification per thousand for labor and
lime together was but 2.788 cents. Prof. Wurtz states that there appears no reason, so far as he
can ascertain, why this low cost of purification should not be maintained. The candle-power of
this gas, during the period of the analyses, was 19% candles for 5 cubic feet per hour. The density
was found to be, mean of three determinations, .571.
After the burning of the Utica works, arrangements were made for another demonstration of this
system with the Philadelphia Gas Trust, at their Manayunk station. The process, as recently “blown
2021.


in” there, showed a decided advance in some particulars over the results obtained at Utica, owing to
some alterations. The generators, of which there were three, were 40 inches in diameter, instead of
30 inches as before._ To each of these there were two—instead of one as formerly—of the stacks
called superheaters, filled with loose fire-brick. The products of combustion were divided between
7/
2022. "































1 m
-,E'|: ' {a}; _ . / ' v .14
A
- t ‘
) \ ____._.___
a3! *
Elii— Kw ul__.__-_--————--"“
these, and when heated up sufficiently one served, as formerly, fer the
thorough fixing of the gases, the other to superheat the steam before
its entrance to the base of the coal-chamber. The temperature
attained by a jet of steam passing down through a column of fire-
' bricks 15 feet high and 30 inches in diameter, standing at a white
heat, is enormous, and produced surprising results. The increased facility of generation was imme-
diately noticed; the delivery of gas, instead of 3,000 feet, which was considered a good result at
Utica, at once attained 8,000 feet to a run of 30 minutes in one generator. Two days later, over
10,000 feet was run, and subsequently 13,400. ,
The Wren Gas Process—The common objection to oil-gas is that it does not come to the consumer
in the shape of a permanent gas. That is, the hydrocarbon is not fully gasified, but is rather in a



GAS, ILLUMINATING, PROCESSES OF MANUFACTURE. 875

semi-vaporous state; consequently the gas leaves a deposit in the pipes, and smokes when burned.
In the Wren system this difficulty is claimed to be obviated by the construction of the retort used,
which is divided by longitudinal partitions into chambers. The oil, entering one of these, is vapor-
ized, and the vapor then passes through the retort from end to end four times in traversing the com-
partments. As a large-sized retort enters 6 feet into the fire, it will be seen that the gas traverses
24 feet of heating surface, and in doing so it changes from a vapor to a permanent gas. Fig. 2022
exhibits the construction of the works. The crude petroleum from the receptacle Fpasses into an
inverted siphon, which communicates with one of the chambers of the retort B, which is imbedded
in the furnace A. It will be noticed that this construction prevents any danger of explosion of the
retort, because, as soon as the stand-pipe chokes, the pressure in the retort meets the oil and stops
the inflow, the oil running over the funnel of the siphon; consequently no more oil can get in and
no more gas can he made until the excessive pressure is relieved. The stand-pipe conducts the gas
to a washing-vat (J, and thence it passes to a receiver I).
The inventor states that the portable form of this apparatus, the retort of which is 6 feet in the
fire, 13 inches high, and 17 inches wide outside, will produce as much as 10 large 9-foot gas retorts,
or 40,000 cubic feet of gas per day of 24 hours. To produce petroleum-gas, the equivalent in illumi-
nating power of 25,000 feet of coal-gas, using the single retort, it is further stated that 300 lbs. of
coal will be consumed in 24 hours’ continuous run. The cost of making the gas is estimated as fol-
lows, prices being those obtaining in 1878: 50 gallons of petroleum, at 6 cents, S3; one-fourth ton
of coal, at $8 per ton, $2; labor, $4; total, $9, or 36 cents per 1,000 feet of 80-candle gas. Gas
made by this process is unaffected by temperature, and retains all its properties over an indefinite
period. It has been stored in a cylinder for four years, and then found to have left no deposit and
not to be impaired in its illuminating properties. It is well adapted for enriching coal-gas of 11-
eandle or other low power. One part of petroleum-gas to 5 parts of coal-gas makes a 17-candle
light; to 4 parts, a 211}-candle light; and to 3 parts, a 30-candle light. It is also suitable for heat-
ing purposes, and especially so for iron- and steel-working, owing to its freedom from sulphur.
The Adams Gas Process.—Each bench contains four full-sized clay retorts. These are connected
in pairs, each pair being a unit, so to speak, for the purposes of the process, the rationale of which
is as follows: Retort No. 1 is charged with gas coal in the ordinary way and heated. Two hours
afterward retort N 0. 2 of the pair is also charged, and the products of the fresh charge, tar, aqueous
vapor, etc., which are given off before the temperature reaches the point when good illuminating gas
is evolved, are led directly into the now highly-heated first retort. ()n the way they are mixed with
superheated steam and petroleum vapor. The mingled gases combine with those in retort No. 1 for
two hours. Then the charge in that retort is drawn, a fresh charge put in, and the first products of
distillation are led into retort No. 2, reversing the former operation. In this way the alternation
continues. The inventor, Prof. H. A. Adams, of New York, claims that the gas thus made reaches
20%. 2024.


over three times" the amount which coal alone is capable of producing in the same number of retorts
of similar size; and he further asserts that the three gases, namely, from petroleum, from water,
and from coal, unite in the retort to form a fixed gas of excellent quality and fine illuminating prop-
erties. From the sectional views, Figs. 2023 and 2024, the construction of his apparatus will readily
be understood. Referring to Fig. 2023, A and B constitute the upper pair and U and D the lower
pair of retorts. As the process is the same in each couple, we shall refer, for eonvvnience, chiefly
to the upper pair. These in front of the bench are connected by the horizontal pipe 1, in which the
mixing of gases is eifeeted. At Fare the steam nozzles, which, as shown in Fig. 2024-, connect by
suitable pipes with the superheater G. These are simply clay retorts or pipes placed in the lower
fines of the furnace, and into which the saturated steam from a boiler is discharged. It will be seen
from Fig. 2023 that the products of distillation from retort A, freshly charged, are passing over into
8‘76 GAS, ILLUMINATING, PROCESSES OF MANUFACTURE.
retort B, which has been in operation for two hours. The steam-jet is seen in operation on the left,
and it will also be noticed that the valve H, which shuts off communication in the pipe E, between
the retorts, is open. In the pipe between the lower retorts it is represented closed. The object of
this valve H is to shut off connection between the retorts when charging one so as not to lose the
gas from the other. At 1, Fig. 2024-, is the reservoir for oil, which escapes in a fine stream, easily
regulated, at the nozzle J, falling into the retort and upon an inclined apron or gutter K. This last
is placed in the mouth of each retort, when the latter is charged with coal, for the purpose of cans-
ing the liquid to flow back into the hotter portion of the retort, and so conducted to the hottest part
of the coal therein. At L are the four stand-pipes which are connected to the rear ends of ‘the
retorts. The object of this arrangement is to compel the gas-tar and aqueous vapors formed in the
front ends of the charges to pass through the red-hot ends of the retorts and escape from red-hot
stand-pipes, being converted into gas during their progress. In order to prevent accumulations of
carbon in the mouths of the pipes, a tubular cutter shown at M is employed. At N are the saddle-
pipes, provided with steam-pipes 0 for conducting steam through them to cleanse them. In order
to remove the fine particles of carbon which the gas contains, it is caused to bubble through the
liquid which seals the dip-pipes P in the hydraulic main. To this end a ring of holes is made near
the end of the dip-pipe, and the main is filled with water and gelatine or other gummy substance
until the fluid level is above the holes. The gas forces its way down through this liquid and escapes
in Jets from the orifices. By means of buckets arranged under the ends of the pipes, as shown at Q,
Fig. 2024-, the holes may be closed, and the gas generated in one retort may be turned into another.
Oil-Gas—An apparatus for obtaining gas by the distillation of oil is represented in Fig. 2025.
To accelerate the evolution of gas, and shorten the time which the gas already produced has to re-
main in the red-hot vessel, the retort a is filled with bricks, or lumps of coke,
l which extend the red-hot surface very materially. The second cylinder 1) serves
both as reservoir and hydraulic main at the same time, and, with this object in
1, view, a and b are connected in two places, d and g. Oil flows from a large cis-
' tern above the apparatus in a constant stream through the tube 0 to b, and b
1,; a is thus kept filled up to a certain level. From I) the oil descends through c to
I a, is converted into gas and tar, and returns through cl to b. The tube d makes
, a short bend, and just enters
, ‘ 2025. below the fluid-level in b, so
, ‘ that the vapors of the decom-






gii i ' a posed 011 must constantly pass
sis ,‘ through the reservoir of 01],
\\\' i \\\\\\\\ i o a
" ' , and deposit their tar. The
\\ ‘ I
l retort a is, therefore, con-
\\§_\\\\ . \\\‘\\\\ , l ,
-_ as: y __ . ~ - - fl. \ stantly supplied, not on y With
' i n j, ‘ .9 oil, but with a mixture of oil
as. '~ r and tar, in such a manner that
i \\\\\\\ :1 . d v 1
I \W l we . , a the con ensed pioducts re-
, __, g _ 7 V ,_,_______;____ _, turn to the retort together
\ , With a fresh quantity of Oil,
\ . — ‘l - .
\is a; “i until they are completely con-
\\\\\ i ' p I: - u n
\ss \ \W K =3;- vertcd into gas. If the ex-
\\,\\\ ;\~“\\<s'sss_:\“ ssss's s“::7»s$§\‘\i§\\\‘§\\: ":2 ls‘s“‘“‘\‘§ls“\‘\\ " ' "
.‘ l {>611 1mm 1318 3121185111 sill'lolng
\ss , u )e, me me a e 111( cr
\\ \\ . . _ ., ... . '
\\\\s\\\sx\\\\\\§‘s\\\\‘s\\\\ part, while the front is kept
“‘~‘“1“"‘~‘1Q§~“\§§§‘\~“3\‘§\“§s l 1 'dl ' "ll
vEIQIEQilgtsggbiifik* coo , iai y any tai wi be
1X1?“‘ssséssssssss \, \\ \\ produced. The gas which col-
\.\‘ s\\\\\ .\\\\\ \\\\c \\\\\\\\\:i \‘\_\:>-_ ~,,~ §\;\ ; - \ ._ _
all:RQQQRXQQKQRQms R\\\\\\R§.\_\\\\\\\.\\‘\\\\‘s\§b\\§§.\\.\\n§‘§!. lGCtS above the Oil 111 b PilSSGS
gexgg on through the tube g. As the
\ \ _ i \\ \. \~ \\ \~ ‘ \\ \\\$ \\ ‘ \ I I I I '
assassstslesssmmes sewsssssss - obJections raised in the case
<>.\\\‘ \\\\\ .\\\\\¥ .\\‘\\‘§ \\\\R\\\\§\\\\Y\\\\\\\\\\\‘§
as:swagesmsmssms\\wssmmwmmsxmsmm 0f coal-gas do not here occur,
.\‘ .\\\\' \\\\\\' \\\\\\~ >.\\\‘ \\\\\ \\\\\ k\\\ .\\\\\Y \\\\\Y ~\\\\\\Y .\\\\\\\‘ .\\\\\‘ .\\\\ '
we“ s |\‘ \\ \ \T was“ \‘ ,. ‘=‘\ \‘ ‘\\\ - cast-iron retorts are solely
. m I. ,_ I- “I __ _ H used in oil-gas works, with the
same firing in other respects,
1' being the grate. According to trustworthy statements, 1 cubic foot (2: about 4 gallons) of oil pro-
duces 600 to 700 cubic feet of gas, which is equivalent to from 90 to 96 per cent. by weight; the
remainder is carbon, which is deposited between the coke or bricks, and some unavoidable loss. The
production of oil-gas is a continuous process, and thus differs from the distillation of coal. The
retorts only require opening new and then, for the removal of the deposit of graphite. Vapors of
the same composition and properties are found in oil-gas as in coal-gas.

Table showing Products of Dis/dilation of Oils.












.___ I
Light Car- _
. Absorbed by buretted C‘ufmnic Hydrogen. Nitrogen.
SUBSTANCES TEMPERATURE OF THE DIB- iSPOClfiO Gravity Chlorine. H 'dro on Oxide.
DISTILLED. TILLATION. of the Gas. 5 g ‘
In 100 parts of Illuminating Gus.
Brigbtrcd h00i7............... 0.464 6 28.2 14.1 45.1 6.6
Oil. “ “ “ . . . . . . . . . . . 0.590 19 32.4 12.2 82.4 4
_ Lowest possible temperature.. 0.758 22.5 50.8 15.6 7.7 4
Train-oil. . . . . Low red heat. . . . . . . . . . . . . . . . . 0.906 88 46.5 0.5 8 8 ,

GAS, ILLUMINATING, PROCESSES OF MANUFACTURE. 877

Rosin-Gas.--If rosin (colophony) were usually fluid, instead of being solid, there would be no
difference between the mode of obtaining gas from it and that practised in the oil-gas manufacture.
As this, however, is not the case, it becomes necessary to render the rosin fluid by some suitable
means, that it may be easily supplied to the retort. The volatile oil from tar is frequently used for
this purpose
The flame from the retort fire, before escaping by the chimney, is caused to heat up a vessel con-
taining rosin. As this melts, it trickles through a sieve into the second division of the vessel, leav-
ing the impurities and the solid portion behind, where it is mixed with an equal part of the oil of
rosin (tar). Thus a solution which will no longer solidify is obtained, and with it the retort is sup-
plied, as with oil in the former case. When the gas has parted with its condensibie vapors in the
coolers, it is in a fit state for consumption, no further purification being required, as is likewise the
case with oil-gas.
One of the best arrangements for rosin-gas, and which has stood the test of practice, is that which
has been extensively carried out by Chaussenot, and is shown in Fig. 2026; the rosin is here melted
by itself, and the oil of tar collected and disposed of as a secondary product.




... x\\\\\*.\\\\\\'.\\\\\\\ .. \
$~\\ ‘
\ . .Jil.
\
. ' ‘ ' ‘ \\ $§\ \\\\\\\' ~\\\\\\‘
‘ ‘ - ' ' ' ' '~ \\.\\\~ \\\\\\\ :.\\\\\\‘ \\\\.
“ ‘ii‘ “">~‘\~; - \ “v we“ ~ \\
\
.\\__
\
\ I'Z-L l: ll; \ a: ’ “:T" l} _ \ \ F? :
\\\\\\ \ ‘- \ _ , - \1
\ \\


Gas from Soap- Water.--Few cases are adapted to give so favorable an idea of the practical value
of gas illumination as the process carried out at the works of I-Iouzeau liiuiron, at Rheims, where
very good gas is obtained from refuse which previously cost something to throw away, and which
now is a source of profit to the manufacturer. This refuse is the soap-water in which woolen stuffs
have been freed from fat. Besides the unchanged fat with which those goods are charged as they
come from the loom, the soap-water contains a solution of olcate and stearate of soda, and com-
pounds of the same acid with lime in suspended flakes, and, lastly, animal matters extracted from
the wool. From all parts of the town the soap-water is collected, and brought to the reservoirs of
the works, where 300 cwts. at a time are treated with 2 per cent. of sulphuric acid (or twice as much
hydrochloric), mixed with equal parts of water. After the lapse of 12 to 18 hours, complete coagu-
lation is effected. The water contains Glauber’s salt (sulphate of soda) in solution; a little gypsum
is formed at the same time, and an impure gray fatty matter rises to the surface. This consists of
the fatty acids, oil, and animal matter, with much water; the greater part of the latter has already
been mechanically separated, and the remainder is removed by melting in copper vessels ; the contents
are then drawn off into a second boiler containing some sulphuric acid, to effect clarification. The
filtration which follows affords a clear oil, and this gives with crude soda (containing sulphuret of
sodium) a very tolerable soap, while sulphurct of iron separates, together with a black solid residue,
containing much fat for distillation in the gas-retorts. The process of distillation is like that prac-
tised with resin: the tar produced the first day is used on the morrow to dissolve and render fluid
‘the solid residue, and so on.
Gas from Animal Matteix—In the distillation of animal matters, bones, flesh, etc., as it has long
8’78 GAS, ILLUMINATING, PROCESSES OF MANUFACTURE.

been practised for the production of bone-charcoal and bone-black, tar (stinking oil, Dippel’s animal
oil) and gases are generated. The illuminating power of the latter has attracted the attention of
manufacturers. Seguin, in particular, has carried on the process on a large scale, making use of the
gases. The material—for instance, the flesh of dead animals—contains 60 per cent. of water, which
must be removed by drying before being placed in the retorts, and the latter should be kept at a
cherry-red heat. The sulphur (a constituent of albumen, fibrine, etc.) is chiefly found in the gas as
sulphuret of carbon, the nitrogen of the flesh as carbonate of ammonia. After being properly
cooled, the gas is first passed through a solution of chloride of calcium, where carbonate of lime and
sal ammoniac are formed, and thence through tubes containing lumps of sulphur, which condense the
sulphuret of carbon to the fluid state, and dissolve in it. The latter would be converted in the flame
into sulphurous acid and carbonic oxide. _
A process is employed to convert the gases arising from rendering-tanks into a good illuminating
gas, as follows: The gas proceeding from the tank is made to pass through a coil which is kept cool
by means of a flow of water; the vapor of water is condensed and runs off, while the gas passes on
through pipes to the bottom of a large tank containing gasoline, through which it bubbles, enriching
itself with the hydrocarbon, and then passes on to the holder, ready for use.
Processes of Water- Gas illanufactare.——These methods can be divided into two classes: 1. Con-
tinuous processes, in which the heat necessary to bring about the interaction of the carbon and steam
is obtained by performing the operation in retorts externally heated in a furnace; and, 2. Intermittent
processes, in which carbon is first heated to incandescence by an air-blast, and then, the air-blast
being cut off, superheated steam isblown in until the temperature is reduced to a point at which the
carbon begins to fail in its action, when the air is again admitted to bring the fuel up to the required
temperature, the process consisting of alternate formation of producer gas with rise of the tempera-
ture, and of water-gas with lowering of the temperature.
Of the first class of generator none have as yet been practically successful, the nearest approach
to this system being the “Meeze,” in which fire-clay retorts in an ordinary setting are employed. In
the centre of each retort is a pipe leading nearly to the rear end of the retort, and containing baffle-plates ;
through this a jet of superheated steam and hydrocarbon vapor is injected, and the mixture passes
the length of the inner tube, and then back through the retort itself—which is also fitted with baffle-
plates—to the front of the retort, whence the fixed gases escape by the stand-pipe to the hydraulic
main, and the rich gas thus formed is used either to enrich coal-gas, or is mixed with water-gas made
in a separate generator. In some forms the water-gas is passed with the oil through the retorts. In
such a process, the complete breaking down of some of the heavy hydrocarbons takes place, and the
superheated steam, acting on the carbon so liberated, forms water-gas ,which bears the lower by-
drocarbons formed with it; but inasmuch as oil is not an economical source of carbon for the pro-
duction of water-gas, this would probably make the cost of production higher than necessary. This '
system has been extensively tried, and indeed used to a certain extent, but the results have not been
altogether satisfactory, one of the troubles which here had to be contended with being choking of
the retorts. Of the intermittent processes, the one most in use in this country is the “Lowe,” in which
the coke or anthracite is heated to incandescence in a generator lined with fire-brick by an air-blast,
the heated products of combustion as they leave the generator and enter the superheaters being supplied
with more air, which causes the combustion of the carbon monoxide present in the producer-gas, and
heats up the fire-brick “ baffles” with which the superheater is filled. When the necessary tempera-
ture of fuel and superheater has been reached, the air-blasts are cut off, and steam is blown through the
generator, forming water-gas, which meets the enriching oil at the top of the first superheater, called
the “ carburetter,” and carries the vapors with it through the main superheater, where the “ fixing”
of the hydrocarbons takes place. ‘
The Springer apparatus differs from the Lowe merely in construction. In this apparatus the super-
heatei is directly above the generator; and there is only one superheating chamber instead of two.
The air-blast is admitted at the bottom, and the producer-gases heat the superheater in the usual way,
and when the required temperature is reached the steam is blown in at the top of the generator, and
is made to pass through the incandescent fuel, the water-gas being led from the bottom of the appa-
ratus to the top, where it enters at the summit of the superheater, meets the oil, and passes down with
it through the chamber, the finished gas escaping at the middle of the apparatus. This same idea of
making the air-blast pass up through the fuel, while in the subsequent operation the steam passes
down, is also to be found in the Loomis plant, and is a distinct advantage, as the fuel is at its hottest
where the blast has entered, and, in order to keep down the percentage of carbon dioxide, it is impor-
tant that the fuel through which the water-gas last passes should be as hot as possible, to insure its
reduction to carbon monoxide. The Flannery apparatus is again but a slight modification of the
Lowe plant, the chief difference being that, as the gas leaves the generator, the oil' is fed into it, and
with the gas passes through a D-sliaped retort-tube, which is arranged round three sides of the top of
the generator; and in this the oil is volatilized, and passes, with the gas, to the bottom of the super-
heater, in which the vapors are converted into permanent gases. The Van Steenbergli plant stands
apart from all other forms of carburetted water-gas plant, in that the upper layer of the fuel itself
forms the superheater, and that no second part of any kind is needed for the fixation of the hydro-
carbons; an arrangement which reduces the apparatus to the simplest form, and leaves no part which
can choke and get out of order—an advantage which will not be underrated by any one who has had
experience of these plants. While, however, this advantage is gained, there is also the drawback
that the apparatus is not fitted for use with crude oils of heavy specific gravity, such as can be dealt
with in the big external superheaters of the Lowe class of water-gas plant, but the lighter grades of
oil must be used in it for carburetting purposes. A valuable series of papers on “Gaseous Illumi-
nants,” by Professor V. B. Lewes, from which the foregoing is extracted, appears in the Scientific
American Supplement, No.7 92 et seq. _
GAS, ILLUMINATING, PROCESSES OF MANUFACTURE. 879

Gas-Holders—The following table gives the weights of various recent examples of gas-holders with
their framing:




Weight of Weight of “'eight of
DESCRIPTION. Holder or Tank-guide Upper-guide Total.
Bell. Framing. Framing.
Tons. Tone. Tons. Tons.
Single-lift holder, 50 ft. diameter, 16 ft. high . . . . . . . . . . . . . . . . .. 18 3 17 38
“ “ ‘72“ “ 18 “ .. . . . . . . . 44 5 40 >59
“ “ 80 “ “ 20 “ . . . . . . . . . . . . . . . . .. 47 5 50 102
“ “ 80 “ “ 23 “ . . . . . . . . . . . . . . . . .. 49 9 53 111
Two-lift telescopic holder, 80 ft. diameter, each lift 20 ft. high . 70 6 82 158
H H at “ 8‘ LB E‘ Eb . . 7 Single-lift holder, 100 ft. diameter, 24 ft. high . . . . . . . . . . . . . . . .. 66 7 75 148
Two-lift telescopic holder, 120 ft. diameter, each lift 24 ft. high. 107 12 86 ~ 205





Mr. William Gadd, of Manchester, England, has devised an apparatus whereby the upper guide-
framing may be dispensed with and the gas-holder securely guided from the bottom circle. The in-
vention, as shown in Fig. 2026 A, consists in placing the
2026A. channel or other guides within the tank at an angle, like
~ the thread of a screw, instead of in the vertical plane, as
has hitherto been the invariable practice. The guide-rollers
attached to the bottom curb of the holder are ranged either
radially or tangentially with the sides of the vessel; and as
they’ work in the channel or rail-guides provided for them,
a helical or screw-like motion is communicated to the float-
ing vessel as it rises and descends in the tank.
The guides attached to the tank sides may be placed at
any angle from 45° upward. The effect is obvious. So
long as the rollers are free to move within the guides, it is
impossible that the holder can tilt so as to get out of the
vertical; the tendency of wind or other pressure exerted
against the sides or on the roof of the vessel being to pro-
duce what may be described (imperfectly, however) as a
locking action, which will sustain the holder in the upright
. position, however great the strain, within the resisting
strength of the rollers and their carriages. '
Automatic Gmv-Retorts.—The object of these is to reduce the labor of charging and discharging
gas-retorts. The system of Messrs. Morris 8: Van Vestraut depends for its successful operation upon
the simple law of gravitation. In this system, when once the coals are raised to a given height, vary-
ing according to the circumstances of each gas-works, the labor of charging and distributing the coal

, ' - - --~-'
/ //////////// ////////7 _/ ,
_ /,,/// ”////////_


\sssssmssms ~


\
&




__ . ' \‘§\\\\>\\\§\\\‘ “
‘ ._‘\ B\ \\\\\\\\\\ \ _\ ~\ _
\ \§ §\\\ \ \
\\ \\
.‘\\ \\ .
\\ \
\


880 " GAS-ENGIN E.

on the floor of the retort and the subsequent drawing is reduced to the most simple operation by the
action of gravity alone. This is mainly efi’ected by setting the retorts at an angle with the horizon,
instead of horizontally, and governing or controlling the velocity of the charge of coal when being
fed into the retort.
In the Morris 81. Van Vestraut system (Fig. 2026 B) the retorts are set at an angle with the horizon
which is near the angle of repose for the class of coals in use. The upper end of the retorts, which
are of the usual pattern, are fitted with the ordinary mouth-piece. At the time of charging, the lower
end of a movable shoot which runs on a light rail in front of
the setting is inserted in the mouth-piece. This shoot is made
0 0 0 0 B 2027' A telescopic, so as to enable it to reach each tier of retorts, and
.__.___ ' 0 0 0 0 at the lower end 1s hinged a shoe-piece or guide. ThlS forms
I an important feature of the Morris & Van Vestraut system,
for by it the velocity with which the coal enters the retort
is controlled. It will no doubt have been seen that the coal
-\ 000 must not be charged at too high a velocity, or the whole of
0 the charge would find its way to the lower end of the retort.
00“' Neither must it be discharged too slowly, or it would cause
an undue accumulation in the mouth of the retort. The shoe
can be set to the required slope, and this, combined with the
“00 angle of the retort, causes the charge of coal to be evenly
‘ distributed over the bottom of the retort. A single shoot is
00"" sufficient to serve a bench of five settings of retorts.
GAS-ENGINE. See ENGINES, Gas AND BINARY Varon.
GAS-FURNACE. See Fumucns, GLASS-MAKING, and law-
“_"‘ a MAKING Paocnssss.
0 GAS—LIGHTER, ELECTRIC. See ELECTRIC GAS-LIGHTER.
GASOMETER. See Gas, ILLUMINATING, Arranarus FOR-
MANUFACTURE OF.
‘ 1 GAS-STOVE. See S'rovss AND HEATING FURNACES.
J GA'l‘LING GUN. See ()RDNANOE (MACHINE GUNS).
'—--,- 2 _ GAUGE, GUN POWDER. See EXPLOSIVES.
GAUGE, WIRE. The American standard wire-gauge is





2 3 a production of Messrs. J. R. Brown & Sharpe, the object
3 “"v-— 9-
4 ——_-6
0‘ M 7
6 ‘6‘
7 “.9
.9
1(1 __
...- 4;, -__ JJ.
15-
,20 being to introduce greater uniformity in the progression of ,
,Qflu—a the sizes. This will be clearly understood by reference to
led. I ’ .. -25 the diagram shown in Fig. 2027, in which the two lines A C
J “050 and B C, meeting at 0, represent the opening of an angular
.36— ,M: wire-gauge. The divisions on the line A 0 show the sizes of
0 wire by the common gauge ; those on the line B O, the sizes
by the new American standard. Wire to be measured by
such a gauge is passed into the angular opening until it
touches on both sides, the line of division at the point of contact denoting the size by wire-gauge
number. Thus No. 13 by the old gauge is No. 15 by the new. The standard gauge, as adopted by
the sheet-brass manufacturers in the United States, is shown in Fig. 2028.
In Fig. 2029 is shown a jeweler’s wire-gauge. One edge of the angular slot is graduated into 250
parts, and figured to give the size in thousandths of an inch. For example, a size of wire which,
passed down half way in the slot, will stop opposite 125, is 110%; of an inch in diameter. The angu-
lar slot has no sharp edge to injure the stock gauged. -
Fig. 2030 represents a twist-drill and steel-wire gauge by the same makers.
GAUGE, WIRE. 881











JEWELEES GAUGE.








'9
p
O
P
P-l
p
N
\
Q
DRILL
Sc STEEL WIRE GAUGE
cage
0...
00,:-
.0“
00
0.1
Om
O
O
O
020
2
34 35 36 3'7 38 39 4O 41
Onitng.nrm\\ nu".
rroviJmuJ- 1.
01308050...
5 27229031323
g OOOOOOOOOOOOQOO
1' 43 44 45 46 47 48 4.9 50 51 52 53 54 55 56 57.5859 60
' 000000000000000000

The difierence between the two gauges, known respectively as the Birmingham or English and the
American, is shown in the table below.
Table of Birmingham and American lizirc- Gauges.

AMERICAN OR NEW BIRMINGHAM OB OLD






















(1'; annmoan on NEW BIRMINGHAM on ow @
p STANDARD. STANDARD. 2 STANDARD. STAN DARD.
q
(5
Difference be- Difi'erence be- #5 Difference be- . Difl'ercnce be-
; Size of each tween consecu~ 8;,“ 0:0“?! tween oonsecu- 5 Size of each tween consecn- 81:38 0:; 88711 tween consecu-
3 Number in tive Numbers 5m, run tive Numbers 3 Number in tive Numbers Sul.eral'n tive Numbers I
g , Decimal Parts in Decimal PM: 2;. an in Decimal ls Decimal Parts in Decimal paring; an in Decimal _ of an Inch. Parts of an In h Parts of an _ of an Inch. Parts of an I 7 h Parts of an
2 Inch. c ' Inch. g Inch. “C ' Inch.
0000 0.460 . . . . . .. 0.454 . 19 0.03589 0.00441 0.042 0.007
000 0.40964 0.05036 0.425 0.029 20 0.03196 0.00393 0.035 0.007
00 0 .36480 ' 0. 04484 0 .380 0. 045 21 0 . 02846 0 . 00350 0 .032 0 . 003
0 0.32495 _ 0.03994 0.340 0.040 22 0.02535 0.00311 0.028 0.004
1 0.28930 0.03556 0.300 0.040 _ 23 0.02257 0.00278 0.025 0.003
2 0. 25763 0 .03167 0 . 284 0 . 016 24 0 . 0201 0 . 002-47 0 . 022 0.003
3 0 . 22942 0.02821 0 . 259 0 . 025 25 0 . 0179 0 . 00220 0 .020 0.002
4 0.20431 0.02511 0.238 _ 0.021 26 0.01594 0.00196 0.018 0.002
5 0.18194 0.02237 0.220 0.018 27 0.01419 0.00174 0.016 0.002
6 0.16202 0.01992 0.203 0.017 23 0.01264 0.00155 0.014 0.002
7 0.14428 0.01774 0.180 0.023 29 0.01126 0.00138 0.013 0.001
8 0.12849 0.01579 0.165 0.015 30 0.01002 0.03123 0.012 0.001
9 0.11443 0.01406 0.148 0.017 31 0.00898 0.00110 0.010 0.002
10 0 . 10189 0 .01254 0 .184 0 . 014 32 0 .00795 0 .00098 0 . 009 0 .001
11 0.09074 0.01105 0.120 0.014 33 0.00708 0.00087 0.008 0.001
12 0.08081 0.00998 0.109 0.011 31 0.0063 0.00078 0.007 0.001
13 0.07196 0.00385 0.095 . 0.014 35 0.00561 0.00069 0.005 0.002
. 1 0.06408 0.00788 0.083 0.012 36 0.005 0.00061 0.0.14 0.001
1 0.05707 0.00702 0.072 0.011 37 0.00445 0.00055 . . . . . . . . . .
16 0.05082 0.00625 0.065 0.007 38 0.00396 0 000-19 . . . . . . . . . .
17 0.04526 0.00556 0.058 0.007 39 0.00353 0 .00013 . . . . . . . . . .
18 0.0403 0.00495 0.049 0.009 40 0.00314 0.00039 . . . . . . . . . . ‘
Dimensions of Sizes of Gauge, m Decimal Parts of an Inch.
Size of Size 01’ Size of Size of Size of Size of
NO. Number in NO. Number in N0. Number in NO. Number in NO. Number in NO. Number in
Decimals. Decimals. Decimals. Decimals. Decimals. Decimals.
1 .227 11 . .188 21 .157 31 .120 41 .095 51 .066
2 219 12 185 22 155 82 115 42 002 52 068
3 212 13 182 23 1'3 33 112 43 088 53 058
4 207 14 180 24 151 34 110 44 085 1' 055
5 204 15 178 25 148 35 108 45 081 55 050
6 201 16 .175 26 146 36 106 46 079 56 045
7 .199 17 .172 27 .148 37 103 47 077 57 042
8 . 197 18 1 28 139 38 1 01 48 075 5b 041
9 1 4 19 164 29 134 39 090 49 070 59 040
10 191 20 161 30 127 40 097 50 069 60 080



















56
882
GAUGE,wuam

Solid cylindrical tools are often made of steel wire, drawn to gauge and to great accuracy of dia-
metrical size. There is, however, a slight degree of variation due to the wear of drawing-dies. In
the table below will be found the gauge numbers and the sizes in decimal parts of an inch of the
Stubs wire. The first column is the size according to the Stubs wire-gauge; the second is the size
in decimal parts of an inch, as given by Mr. Stubs; and the third column represents the average sizes
obtained from actual measurements of the wire, taken during a period of several years by the Morse
Twist-Drill and Machine Company.
Table showing Diameter of Stubs’s Steel Wire, in Fmctional Parts of an Inch.















N 0. OF Measurement NO. OF Measurement NO. OF Measurement
STUBS’S Stubs’s by Morse Twist- STUBS’S Stubs’s by Morse Twist- STUBS’S Stubs’s by Morse Twist—
WIRE- Dimensions. Drill and WIRE- Dimensions. Drill and WlRE- Dimensions. Drill and
GAUGE. Machine Co.‘ GAUGE. Machine Co. GAUGE. Machine 00.
1 . 227 . 228 23 . 153 .154 45 . 081 . 082
2 .219 .221 24 1.151 .152 46 .079 .080
3 .212 .213 25 . 148 .150 47 .077 . 079
4 .207 . 209 26 . 146 .148 48 .075 . 076
5 . 204 . 206 27 . 143 .145 49 . 072 . 078
6 .201 . 204 28 .139 . 141 50 .069 . 070
7 .199 .201 29 .134 .186 51 .066 .067
8 . 197 .199 80 .127 . 129 52 . 063 .064
9 .194 .196 31 .120 .120 53 .058 .060
10 .191 .194 32 .115 .116 E4 .055 .057
11 .188 .191 33 .112 .118 55 .050 .052
12 .185 .188 34 .110 .111 56 .045 .047
13 .182 .185 35 .108 .110 57 .042 .044
14 .180 .182 36 .106 .106 58 .041 ..042
15 .178 .180 37 .103 .104 59 .040 .041
16 .175 .177 38 .101 .101 60 .039 .040
1 7 . 172 . 173 39 .099 . 100 61 .038 . 039
18 .168 . 170 40 .097 .098 62 .037 .038
19 .164 .166 41 .095 .096 63 .036 .037
20 .161 .161 42 .092 .094 64 .035 .036
21 .157 .159 43 . 088 .089 65 . 033 .035
22 .155 .156 44 .085 .056
Table showing Letter Sizes of Stubs’s Wire.
1 A ...... .. .234 I F ...... .. .257 K ..... .. .231 o ..... .. .310 s ..... .343 w ...... . .886
. B . . . . . .. .238 . . . . . .. .261 L . . . . . . . . .290 P . . . . . .. .323 T . . . . . .. .358 X . . . . . .. .397
C . . . . . . . . .242 H . . . . . . . .266 M . . . . . . . .295 Q, . . . . . . . .332 U . . . . . . . .368 Y . . . . . . . .404
D . . . . . .. .246 I . . . . . . .. .272 N . . . . . . . .302 R . . . . . . . .339 V . . . . . .. .877 'Z . . . . . . .. .413
E . . . . . . . .250 J . . . . . . . . .277




Table showing Whitworth’s Standard Wire- Gauge, compared with corresponding Numbers of various
other Wire- Gauges.






















' J, 'U NUMBERS CORRESPONDING TO WHIT- ' J, 'E NUMBERS CORRESPONDING TO WHIT-
E .22 [d 5 won'rn‘s GAUGE. 2 ' .3 won'rn‘s GAUGE.
ii ‘2 21 3
o w a: ' e3 5- I!) ' ' '
43 Qf '35» 23 32 i. .2. 32 O... 51’» .25" 2g» .5, .5,
-= w' 3. 33 .2“ 73. B“ ‘33 ~29}, '5.“ e“ e., ... ,g.
3- 311% 3% 3‘? 32 24 15° ..., .32.. .42 32 2. 4g ,3,
33 333 E»: =3 :2 33 2.. .52 333 £2 5.2 23 33 2..
:3 z in B *5 i: o E z E :> z m i: a Q 3 z 2
001 1 . .. . . 050 50 13 34 17*
.002 2 . .. . .. 035 53 . . c2** 18 .
.003 3 .. . .. .. . .060 00 17* 51 19 ..
.004 4 30 . 1 19 . .065 65 10 49* 21* . .
.005 5 35 . 2 13 . .070 70 15* 47* 22* .
.006 0 .. . .. ' .. . .075 75 . . 45 24* .
.007 7 34 . 17 . .030 30 . . 43* .. . . .
.003 3 33 . 16 . .035 35 14* 42* . . . . .
.009 9 32 . 15 . .090 90 .. 41 25 . ..
.010 10 31 . 14 . .095 95 13 33 20** . . .
.011 11 .. .. .. . .100 100 .. 34 27** . ..
.012 12 30 30 .. . .110 110 12 31* 23 . .
.013 13 29 79 . 12 . .120 120 11 29 31* . ..
.014 14 23 73 11 . .135 135 10 23** 34* . ..
.015 15 .. 77 .. . .150 150 1* 19 30* . .x
.010 16 27 .. .. .. .105 105 8 13** .. . ..
.017 17 . . 76 . . . .180 180 7 5“ . . .
.018 18 26 . . 9 6 .200 200 6** 2 . . .
.019 19 .. 75 3 7 .220 220 5 0* .. .
.020 20 25 74 . . 7 3 .240 240 4* G . . .
.022 22 24 72 10 0 10 .200 230 3 K .
.024 24 23* 71 . . . . 12 .230 230 2* 17* .
.020 20 .. 70 11 5 13 .300 300 1 P* . .
.023 23 22 03 .. . . 14 .325 325 . . 3* . . .
.030 30 . . 03 . . 4 15 .350 350 . . v* . .
.032 32 21 e4 12 .. 1 0 .375 375 00** 11* . . .
.034 34 .. 02 13 3 17 .400 400 . . .. . ..
.036 36 20 61 . . . . 18 .425 425 00(i** . . .
.033 88 . . 59 14 2* 19 .450 450 0000** . ..
.040 40 19* 50 13* 1 20* .475 475 . . . .
.045 45 . . :14 10 .. .. .500 500 . .




GAUGES, MECHANICAL. sss

Nola—The numbers of the Birmingham and other gauges correspond exactly, or within .001 of
an inch, to the numbers on the Whitworth wire-gauge, except those marked *2 which are within .002,
and those marked M, which are beyond .002 of an inch. Below .001, one thousand means .002, two
thousand parts of an inch.
French Wire- Gauge.—
Table showing the French Limoges Gauge (Jauge dc Limoges).







|
Diameter. Diameter. ' BER { Diameter I
Millimetre. Inch. Mlllimctre. Inch. { Millimetre. Inch. 2
'0 .39 .0154 9 1.35 .0532 i 17 l 2.8-1 .112 j
1 45 .0177 10 1.4 .0575 I 18 J a .41» .134 I
2 .56 .0221 11 1.68 .0661 , 19 3.95 .156
8 . 01 .0264 12 1.80 .0706 1 20 4. 510 .11 7
4 79 .0811 13 1.91 .0752 I 21 0.10 .201 ,
5 90 . 0351.- 14 2 .02 . 0795 1' 2.6 5 . 65 . 222 g
6 1 01 .0398 15 2.14 .0843 ‘43 l 0.20 .244 f
7 1 12 .0441 16 2 25 .0580 24 0.30 .263 '
8 1 2 L . 0483







J. R. (in part).
GAUGES, MECHANICAL. Standard gauging implements were introduced about the year 1840,
by the celebrated Swiss engineer, John G. Bodmer. He not only employed gauges in his works to
secure duplicate dimensions, but also invented and put in use many other reforms in manipulation;
among these may be mentioned the decimal or metrical division of measures, a system of detail
drawings classified by symbols, the mode of calculating wheels by diametric pitch, with many other
things which characterize the best modern practice.
The importance of standard dimensions, and the effect which a system of gauging may have in
the construction of machines, will be a matter of some difficulty for a learner to understand. The
interchangeability of parts, which is the immediate object in employing gauges, is plain enough, and
some of the advantages are at once apparent; yet the ultimate effects of such a system extend
much farther than will at first be supposed. The division of labor, that system upon which we
may say our great industrial interests are founded, is in machine-fitting promoted in a. wonderful
degree by the use of gauging implements. If standard dimensions can be maintained, it is easy to
see that the parts of a machine can be constructed by different workmen, or in different shops, and
these parts when assembled all fit together, without that tedious and uncertain plan of try-fitting
which was once generally practised.
The gauging system has been no little retarded by a selfish and mistaken opinion that an engineer-
ing establishment may maintain peculiar standards of its own; in fact, relics of this spirit are yet
to be met with in old machines, where the pitch of screw-threads has been made to fractional parts
of an inch, so that engineers other than the original makers could not well perform repairing or
replace broken parts. One of the effects of employing gauges in machine-fitting is to inspire con-
fidence in workmen. Instead of a fit being regarded as a mysterious result, more the work of
chance than design, men accustomed to gauges come to regard precision as something both attain-
‘ able and indispensable. A learner, after examining a set of well-fitted cylindrical gauges, will form
a new conception of what a fit is, and will afterward have a new standard fixed in his mind.
The variation of dimensions which is sensible to the touch at one ten-thousandth part of an inch
furnishes an example of how important the human senses are even after the utmost precision
attainable by machine action. Pieces may pass beneath the cutters of a milling-machine under con-
ditions which, so far as machinery avails, will produce uniform sizes, yet there is no assurance of
the result until the work is felt by gauges. The eye fails to detect variations in size, even by com-
parison, long before we reach the necessary precision in common fitting. Even by comparison with
figured scales or measuring with rules, the difference between a proper and a spoiled fit is not dis-
cernible by sight. Many of the most accurate measurements are, however, performed by sight, with
vernier calipers for example, the variation being multiplied hundreds or thousands of times by
mechanism, until the least differences can be readily seen. (See Camrsas.) In multiplying the
variations of a measuring implement by mechanism, it is obvious that movable joints must be
employed; it is also obvious that no positive joint, whether cylindrical or flat, could be so accu-
rately fitted as to transmit such slight movement as occurs in gauging or measuring. This diffi-
culty is in most measuring instruments overcome by employing a principle not before alluded to,
but common in many machines, that of elastic compensation. A pair of spring calipers will illus-
trate this principle. The points are always steady, because the spring acting continually in one
direction compensates the loose play that may be in the screw. In a train of tooth-wheels there
is always more or less play between the teeth; and unless the wheels always revolve in one direc-
' tion, and have some constant resistance ofiered to their motion, “backlash” or irregular movement
will take place; but if there is some constant and uniform resistance, such as a spring would
impart, a train of wheels will transmit the slightest motion throughout.
The extreme nicety with which gauging implements are fitted seems at first thought to be
unnecessary; but it must be remembered that a cylindrical joint in ordinary machine-fitting involves
a precision almost beyond the sense of feeling, and that any sensible variation in turning gauges
is enough to spoil a fit. Opposed to the maintenance of standard dimensions are the variations in ~
size due to temperature. This difficulty applies alike to gauging implements and to parts that are
to be tested; yet in this, as in nearly every phenomenon connected with matter, we have succeeded
in turning it to some useful purpose. Bands of iron, such as the tires of wheels when heated, can
884 GAUGES, MECHANICAL.

be shrunk on, and a compressive force and security attained which would be impossible by forcing
the parts together both at the same temperature. Shrinking has, 'however, been almost entirely
abandoned for such joints as can be accurately fitted.
The foregoing remarks are taken from Richards’s “Workshop Manipulation.” The reader will
find examples illustrating their practical application under FIRE-ARMS, Manumerunn or, SEWING-
Macnmns, and in the various articles describing the construction of machine-tools. Sir Joseph
Whitworth, in an address delivered before the Institution of Mechanical Engineers, Manchester, in
1857, referring to the subject of accurate gauging, says:
“ As an illustration of the importance of very small differences of size, I have brought an internal
gauge having a cylindrical aperture .5770 inch diameter, and two external gauges or solid cylinders,
one being .5769 inch and the other .5770 inch diameter. The latter is Why; of an inch larger than
the former, and fits tightly in the internal gauge when both are clean and dry; while the smaller
.5769 inch gauge is so loose in it as to appear not to fit at all. These gauges are finished with great
care, and are made true after being case-hardened. They are so hard that nothing but the diamond
will cut them, except the grinding process to which they have been subjected. The effect of apply-
ing a drop of fine oil to the surfaces of these gauges is very remarkable. It will be observed that
the fit of the larger cylinder becomes more easy, while that of the smaller becomes more tight.
These results show the necessity of proper lubrication. In the case of the external gauge .5770 inch
diameter, the external and internal gauges are so near in size that the one does not go through the
other when dry, and if pressed in there would be danger of the surface particles of the one becoming
imbedded in or among those of the other, which I have seen happen, and then no amount of force
will separate them; but with a small quantity of oil on their surfaces they move easily and smoothly.
In the case of the external gauge .5769 inch diameter, which is TF3“ of an inch smaller in diameter
than the internal gauge, a space of half that quantity is left between the surfaces; this becomes
filled with the oil, and hence the tighter fitting which is experienced. It is therefore obvious both to
the eye and the touch, that the difierence between these two cylinders of film-r, of an inch is an
appreciable and important quantity; and what is now required is a method which shall express
systematically and without confusion a scale applicable to such minute differences and measure-
ments: it should be based on a uniform principle which will accustom the workman to speak of his
measures as aggregates of very small differences; and when a good workman becomes familiar with
such sizes as T-Uflm and Tusk-5b- of an inch, he will not rest satisfied until he can work with correspond-
ing accuracy. He will also be able to judge of their effect under different circumstances, and know
how much to allow in the fitting parts of a machine, according to their relative importance and the
treatment they are likely to receive at the hands of the attendant. For instance, the cylinder of the
moving headstock of a lathe requires as good a fit as possible; but in practice it is found that the
cylinder must be .0005 inch or 51,101 of an inch too small, because it frequently happens that machi-
nery is not kept in a proper state of cleanliness, or from motives of false economy is lubricated with
bad oil. These are two evils which are productive of great mischief. The abrasion caused by ac-
cumulated dust and grit produces increased wear and tear, and soon injures the surfaces in contact;
while bad oil becomes sticky and rancid, and spoils the working of a good fit. And here let me state
what I think is the proper definition of a good fit. A tight fit is not necessarily a good one; but
when the surfaces are true, and a proper allowance is made in the size of the parts working together,
then a good fit is obtained. What constitutes a proper allowance or difference in size depends on
the nature of the case, and the treatment which the machinery will meet with. In machinery sup-
plied to establishments using rape oil there must be greater allowance and looseness in the fits than
would be requisite if better oil, as sperm oil, were used. I need scarcely say how much more ad-
visable it is to have the more accurate fit and use the best oil, than to have a loose fit and use the
inferior oil which, causing more friction, consumes greater power. The deterioration of templets or
patterns of size, from their becoming worn or altered in process of time, is productive of great in-
convenience, as many of us perhaps have experienced. For when an original standard was thus
altered, it was irretrievably lost, because there was no means of ascertaining and recording the exact
measure. It is of great importance to the manufacturer who makes parts of machines in large quan-
2032.


tities to have the means of referring to an accurate fixed measure; it will enable him to reproduce
at any time a facsimile of what he has once made, and so preserve a system of sizes of the fitting
parts unaltered. The greatest care should be taken to make standards of size correctly at first, and
to preserve them unaltered. Errors in the standards are not only propagated in the copies, but are
GAUGES, MECHANICAL. 885

superadded to the errors in the workmanship which will occur in the course of manufacture; and
this is especially likely to occur in cases where one manufacturer supplies parts of machines for the
use of another.” .
Foams or Games—Standard Gauges.——The gauges used as standards for male and female cylin-
drical forms are usually after the pattern shown in Figs. 2031 and 2032. They are made of steel,
hardened and ground to size, the grinding process being so delicately performed as to leave a polish.
In testing such gauges, the heat imparted to them by holding their for any length of time in the
hand will cause a perceptible difference in the size; hence, to insure the greatest practical accu-







,7”
__

racy, it is necessary to test the whole set at an equal temperature. As a test of accuracy, we may
take a female gauge and place therein two or three male gauges, whose diameters added together
will equal that of the female. Thus, in Fig. 2033, the size of the female gauge A being 1% inch, that
of the male B may be 1 inch, and that of 0 half an inch, and the two together should just fit the
female. On the other hand, were we to use, instead of B and C’, two males seven-eighths and five- '
eighths inch respectively, they should fit the female ; or a half inch, a five-eighths inch, and a three-
eighths inch male gauge together should fit the female. By a series of tests of this description, the
accuracy of the whole set may be tested; and by judicious combinations a defect in the size of anv
gauge in the set may be detected. A notable fact with reference to these gauges is that, if we
take a male and female of
corresponding sizes, and
slide the one continuously 2337,
through the other, it will
pass through at a proper
fit; but if we arrest the
progress of the male and
allow it to rest a few mo-
ments, it will become fast in




lllllllllllllllllll n
the female, and require con- 0m 00
siderable force to remove it
again. The wear of these A
gauges takes place most rap-
idly at and near the ends,
because it is difficult in using
them to keep them in lines
true with the bores into GENERAL VIEW.
which they are tried; and


















the movement due to the 2038'
adjustment to line causes E
abrasion. It is indeed an A J I
excellent method of testing ~ 0 0
to place one in the other to B D ‘3
the depth of about one-six- K _
teenth of an inch, as shown 0 O L—
in Fig. 2034, and, holding I I?
the female firmly, lightly ‘* E
press the male first in the .
direction of A and then of PLAN.
B. There are few gauges
which will not, under such a test, show some slight movement, denoting defect.
The Whitworth Mcasu-m'ng Mackina—In Figs. 2035 to 2038 is shown Sir Joseph Whit-worth’s
millionth-measuring machine, the same parts being indicated by the same letters of reference in each
of the views. A standard one-inch bar, D, is here shown in position for being measured. A rigid
casting, A, forms the bed of the machine, and is carried up at each end, formingr two headstocks.
Running from one of these headstoeks to the other is a V-shaped groove, in which the square bars B
and O are laid, and which also receives the other bar, D, of which the length is to be tested. The
sides of the groove and also those of the bars (which are square in section) are worked up as truly
plane as possible, and are kept accurately at right angles to each other, so that, upon whichever side
sec ‘ GAUGES, MECHANICAL.

the bars may rest, theyarc capable of sliding smoothly and with perfect steadiness in the groove.
Their ends also are carefully made square to their sides, and are brought to two planes, one extrem-
ity of each in the case of B and O, and both extremities of D, being turned down so as to present-
circular instead of square faces. Through each headstock runs an accurately pitched micrometer
screw, by which B and O can be driven forward along the groove, as may be seen in the left-hand
portion of the plan, in which the saddle, by which B is protected and partially concealed when the
machine is in use, has been removed. The screw on this side, which has exactly 20 threads to the
inch, is driven by a worm-wheel F of 200 teeth, into which gears a tangent-screw H, having fixed upon
its stem the graduated wheel G. The circumference of this wheel being also divided into 250 parts,
a movement through one division corresponds to a traverse of --1_ x --1—- x —~-
20 200 250
inch on the part of the bar C. Fixed pointers enable the exact distance throng-h which either of the
wheels 11' or G is moved to be read ofi, so that we have thus the means of detecting this extreme-
ly minute difi°erencc in the length of any bars—if, at least, we can fulfill the important condition
of causing the micrometer screws to exert a perfectly equal pressure in every case. The arrange-
ment by which this equality of pressure is secured is one of: very great simplicity and beauty. Be-
tween one extremity of the bar under comparison and the sliding bar a small steel plate with truly
plane and parallel sides is introduced. This plate is called the “feeler” or “gravity piece,” and
its ends EF are drawn out so as to rest upon two supports fixed upon the sides of the bed. When
little or no pressure is exerted upon the bar D, the feeler, if one of its ends be momentarily raised
from the support, falls back again by its own weight; when, on the other hand, the pressure is at all
considerable, it is either incapable of being raised without violence, or when lifted does not return;
the friction, in fact, between its own plane surfaces and those of the bars between which it is placed
forming a delicate measure of the pressure to which they are subjected. When this pressure is just
sufficient to keep the feeler from falling by its own weight, without interfering with its perfectly free
motion when touched, the correct adjustment has been given to the instrument.
Suppose now that a proposed duplicate is to be compared with a standard one-inch bar. The
standard D and the feeler E E are first placed in the positions shoWn in the figure, contact between
' them and the sliding bars being nearly established by turning the wheel F, after which the final
adjustment is given with the wheel G. As soon as the feeler on its end, being lifted, remains sus-
pended instead of falling back on its support, the adjustment is known to be complete, and the posi-
tion of the wheel G is accurately noted. Since the new bar is to be an exact copy of the standard,
the coarse adjustment-wheel F is left untouched, the standard being released by moving the wheel
G only, which is again adjusted when the duplicate of which the length is to be tested has been
laid in the groove. If the position of the wheel then be the same as before,‘it is evident that the
length of the bars is identical; but if not, the exact difference between them is given in millionth
parts of an inch by the number of divisions by which the second reading differs from the first; a
movement through one of these divisions being sufficient to release the feeler, or again to arrest its
fall when the adjustment of G is correct. This degree of delicacy will thus be seen greatly to sur-
pass that of the measurements which have been obtained by reading line measures with the aid of
powerful microscopes. As an instance of the extreme sensitiveness of machines of this kind, it
may be mentioned that the one shown is capable of detecting the expansion in a one-inch bar which
is produced by merely touching it for an instant with the finger; and in a larger machine, if due
precautions be taken to protect it from dust, moisture, and currents of air, momentary contact of the
finger-nail will suffice to produce a measurable amount of expansion in an iron bar 36 inches in
length ; a space corresponding to half a
2039" division on the fine adjustment wheel,
or one two-mil-lionths of an inch, having
been rendered distinctly perceptible by it.
The Hexagon Gauge—This implement
is represented in Fig. 2039, applied to a
bolt-head, the edges A B serving to try
the hexagon sides of the head, and O D
to act as square-edge to the face. The
edge F is used as a straight-edge. When
v this gauge is not available, a bevel-square
, may be set in the following manner :
Take a piece of sheet-iron, true on one
/_- side and on one edge, and let A B, in Fig.
2040, represent the true edge, from which
‘ mark with the gauge the line C D. Then
taking any point, such as 1, in the line C
D, as a centre, at a convenient distance
describe with a pair of compasses the are
F G. Take the compasses, and, with-
out shifting their points at all, rest one
point on the intersection of the lines
0 D and F G, and then mark the are H. If then a line be drawn from the intersection of the
arc F G and the are H to the centre 1, upon which the arcF G was struck, the lines H I, I 0 form
the angle required; and the stock of the bevel-square may be applied to the planed edge A B, and
the blade set to the line I H, as denoted by the dotted lines.
lilachim'st’s Adjustable Gauge—An adjustable gauge is shown in Fig. 2041, in which A and B
zone-millionth of an











GAUGES, MECHANICAL. sea

represent two sliding pieces of steel, and 0' and D screws and nuts. It is obvious that, when the
screws are loosened sufficiently to just let the sliding pieces move by a slight tap, the gauge may be
extended by striking the ends E E, or either of them, their inside edges being rounded off to pre-
vent them from burring. It is better to set them at first a little below the required size, and to per-
form the adjustment by opening them, so as not to require to strike the points at all. The points
should, however, in any event be tempered to a blue. It is an excellent plan to file away the screw-
heads on two sides a little, say one thirty-second of an inch, thus forming a sliding piece under each
head to fit into the slot of the gauge, which will prevent the screws from turning when screwed
or unscrewed, and in the end save much annoyance.
Oarpentm'b Gauge.——The most convenient form of this tool is shown in Fig. 2042, in which A
represents the tightening wedge, standing at a right angle to the rod of the gauge. The advantage
of this design is that it requires only one hand to work it, inasmuch as the wedge may be loosened
2040. 2041.








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.4 %


or tightened by strikingit, as if it were a hammer, against anything that may happen to lie on the
bench. Thus the gauge may be set and adjusted with one hand, while the other is holding the
work, 'as is often necessary when marking small work. For widths above 10 or 11 inches we must
have recourse to the gauge shown in Fig. 2043, called the panel gauge. Its sliding piece may be
7 inches long and the stem 2 feet; the rabbet-ing at A forms a steadying base, the part of the
. v 2045.
A B
)— _ _
D -_
i.) / P _
. Ill» ,,
. . Ida LY
rod about the marking-point being raised to correspond with the distance from the rabbet to the
stem nut. Next we have the cutting gauge, shown in Fig. 2044, in which a steel cutter takes the
place of the marking-point, being wedged in position. It is employed to cut strips of wood, rubber,
cite, of tlliicknesses up to about a quarter of an inch. The cutter-point should be tempered to a dark
s raw co or.
The Trammel Gauge is an exceedingly useful implement, of which but little appears to be gener-
ally known. It is shown, together with its method of~ application, in Fig. 2045. It enables the
operator to strike a true circle upon a round or uneven surface. It is composed of the turned bar
or red of metal A, of about halfran inch diameter, and upon it slides the piece of brass tube B,
upon which is contrived a support for the sliding arm 0, as well as a set—screw for fastening the arm
0' in any desired position. At the end of the arm 0 is placed an arrangement for fastening the
scriber D, so that the scriber may be set at any requisite distance from the red A, by adjusting and
2044.








888 GAUGES, MECHANICAL.

fastening the arm 0, and revolved about while lifted or lowered upon the red A. If the stand E,
pierced with holes for screwing down, is provided, it will be a very useful addition. ,
Suppose it is required
that the end 0 of the
cylindrical branch-pipe B,
in Fig. 2046, shall be fitted
to the main stem A. Take
a planed board and gauge
a line upon it, and at a
point on this line describe
a circle upon it of the size
of the foot of the instru-
ment. Then make two
V-blocks, G G, Fig. 2045,
to carry the branch, place
them with the apex of the
V exactly over'the gauged
line, and place the branch
in the Vs. Then set the
point of the scriber at a
distance from the rod of
the trammel equalto the
diameter of the branch,
which may be readily done
if the size of the rod be
known. Next mark upon
the top of the branch, as
it lies in the Vs, the dis-
tance it requires to be cut
out to form the curve.
Draw the branch forward
until this mark falls ex-
actly under the scriber;
and this adjustment being
made, fix temporarily the
branch to the piece of board whereon it and the Vs rest. Then move the arm 0, Fig. 2045, a .
half circle, and, letting the point of the scriber contact with the branch, draw the necessary line.
It will be found, however, that it is requisite to mark the lines while lifting the arm, to prevent
the scriber from digging into the wood. Thus one side of the branch will be marked. Then turn
it upside down on the Vs, set the joint vertically again, adjust the mark to the scriber-point, and
proceed as before to mark the other side of the branch ; and the lines so drawn will be of the exact
curvature of the body A of the branch-pipe in Fig. 2046.
Ring Gauges are used for testing the diameters of projectiles. Two sizes are used. The projec-
tile must pass through the large ring in every direction, and not at all through the small one. Ring
gauges 2% inches wide in aperture are used for determining the size of broken stone in road-making
under the Macadam system. A jeweler’s ring~gauge is a tapering piece of wood or slip of metal
upon which are marked the sizes for finger-rings.
The Star Gauge is an ingenious device for obtaining the exact dimensions of the bore of cannon.
It is composed of three parts, the staff, the head, and the handle. The staff is a brass tube made


if'ii'l'il'ilfllldzm
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in three pieces, connected together and graduated to inches and quarters, so that the distance of _the
head from the muzzle of the gun may always be known. The inner end of the staff expands into
the head H, Fig. 2047, in which are placed four steel sockets at equal distances apart. _Two of these
are permanently secured and two are movable. A wedge or tapering plate W, the srdes of which
are cylindrical, runs through a slit in the head, and when it is moved forward or backward the sockets
are projected or withdrawn. The tapering of the wedge has a certain known proportion to its length,
so that if it is moved in either direction a given distance, a proportional movement is imparted to the
sockets. There are four steel measuring points P for each caliber of gun. A sliding rod is con~
nected with the wedge and moved by a screw in the handle. The amount of movement of the
GEAR—CUTTIN G MACHINES. 889
measuring points in various places in the bore of the gun is thus registered on an exceedingly fine
scale on the handle; and any deviations of the inner surface of the here from a true cylinder of
standard dimension is‘indieated.
Caliper-Gauge Testing Apparatus.--Fig. 2048 represents a device for testing and correcting fixed
caliper gauges, and also as a reference in any case to prove dimensions within its range. The disks are
separate, ground independently to standard size, and tested by the measuring machine. They are
made of steel, and not hardened. The usual set, as shown, is made to embrace 51 sizes, advancing
by sixteenths from one-eighth of an inch to 21} inches, and by eighths to 4 inches. J. R. (in part).
GEAR—CUTTIN G MACHINES. Machines for cutting the teeth of gear-wheels. Figs. 2049 and
2050 represent Messrs. William Sellers & Co.’s apparatus. The wheels are held upon a stationary
2049.








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l





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HHHHHHH
HHHHHHH Him”,
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mandrel, and a revolving cutter traverses across the wheel-face, cutting through the latter a groove
whose form is determined by that of the cutter.
back, the wheel is revolved the distance required, and the cutting again proceeds.
After a cut is taken, the cutter is traversed rapidly
The essential
parts of such a machine are: a mandrel to hold the work, and having in connection with it a me-
chanical device by means of which this mandrel may be moved through any required fraction of a
revolution; mechanical means of revolving and traversing the cutter; and adjustability of the parts
of the machine to suit the size and shape of the work. In Figs. 2049 and 2050 is shown a machine
automatic in all its motions, and designed for cutting either spur- or bevel-wheels of any size, from 54
inches diameter and 12 inches face downward. A is the revolving spindle, carrying the cutter. The
890' ‘ GEAR—CUTTING MACHINES.

head B, carrying A, slides or traverses upon 0. D is the mandrel, upon which is shown a germ
wheel in Fig. 2049. To cut bevel-wheels, the plane of the slide 0 is set at an angle to the plane of
the mandrelA. This is done by adjusting the position of the standard, which turns upon the bed
on which it rests, and is adjustable to any position; the cone-pulleys, being held to the same cast-
' ing, swing with it, the whole being firmly locked in the adjusted position of the bolts at the base
of the column or standard S. The head H is adjustable to suit the diameter of the wheel to be cut
by sliding along the part of the frame 0. The number of divisions, or in other words the number
of teeth out in a wheel, will depend upon the part of a revolution through which the mandrel D is
revolved at the end of each return traverse of the cutter; and this is arranged to suit the require-
ments by means of a tangent-wheel and worm-screw very carefully and accurately constructed, and
by the additional use of change gear-wheels, and the turning of the handle P one, two, or three
times, as may be called for on the schedule of division. This turning of the handle, however, and
all other motions, are done by the machine itself. Thus, a blank wheel being put in place and the
proper cutter adjusted to depth of teeth, length of stroke of cutter-head, etc., the cutter will pass
across the face of the wheel-cutting space between two teeth, and will ‘
then return at a quick pace to the starting side of the wheel; the
blank will then be turned to present a second space to be cut, and
the cutter will start its proper motion; all the changes being made by
the machine itself, not by the attendant workman. In quantity of
work done it is stated that one machine has been found, on similar
work, to do once and a half the work done by a skillful man on a ll
gear-cutter of equal power operated partially by hand. In practice, ' one man can advantageously attend four of these machines. 1 I; '—
Corlz'ss’s Bevel-Gear Cutting .Machina—In Figs. 2051 to 2063 is -' "'“ -
shown a machine designed and constructed by George H. Corliss of j -_
Providence, R. 1., for the purpose of cutting the teeth of unusually large bevel-gears with a degree of accuracy never before attained. i
It was designed to out i
the teeth of the bevel- 205‘,
wheels employed in
connection with the
shafting at the Centen-
nial Exhibition in Phil-
adelphia. These wheels
were remarkable for the
quietness and smooth-
ness of their action.
They were 5 feet 8%}
inches in diameter, had
54 teeth of 4 inches
pitch, and ran at a
speed of 2,245 feet per
minute, with less vibra-
tion or sound than was
produced by the leather
belts attached to the
pulleys at the opposite
ends of the short sec-
tions of intermediate
shafting driven by the
bevel-wheels. It is
worthy of note that the
most delicate operations
performed in watch-
making were carried on
in close proximity to
these gears, the lathes
and other machines _
standing directly upon the boarded flooring. The essential parts of the machine are as follows: A,
Fig. 205], is a frame carrying and affording journal-bearing to the arbor-shaft or mandrel B, which
carries the wheel B' to be cut by the tool 0. D is a dividing-wheel, constructed so that it can be
moved with mechanical precision through any required portion of a revolution, and having a device
to lock it in any adjusted position. The operation is to cut down one side of a tooth on B', then
move the index-wheel through that part of a revolution which is necessary to revolve B to the
amount of its pitch, and cut down the same relative side of the next tooth, and so on all round the
wheel. The upper part of the frame A forms a quadrant of a circle, and serves to carry the devices
which govern the motion of the radial frame S at that end. This radial frame has for the centre of
motion of all its movement a point denoted by 0', Fig. 2053 ; and 0 being true with the axial line of
B, it represents in all cases the centre to which the lines of the sides of the bevel-teeth converge.
The upper end of the radial arm 8 is adjustable vertically, and is permitted a slight lateral motion,
both movements operating from the point 0. The body of the radial frame 8 serves as a slide-
guide whereon traverses the carriage to which is attached the cutting tool 0. The perimeter of the
quadrant frame A is provided with a slide whereon traverses a carriage adjustable to any required
I ll it“
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GEAR-CUTTING, MACHINES. 891








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892 GEAR—CUTTING MACHINES.

position on the quadrant. This carriage carries and maintains stationary in its adjusted position a
templet of the shape of tooth requiring to be cut. To the end of the radial frame S is attached a
pin; hence, by lowering S while the pin is in contact with the curves of the templet-tooth, the
motion of S at that end will exactly conform to the shape of the templet-tooth, while its motion
will diminish in amount, though remaining constant in direction, as the point 0 is approached. From
this it will be perceived that one former or templet-tooth may be employed to cut wheels of varying
diameters, giving to the teeth of each its proper curves and depth of tooth, all that is necessary to
insure exactitude being to set the various bevel-wheels at their proper distances from the point 0.
The machine is provided with pivoted rack-teeth, to give to the radial frame S the lateral motion
necessary to allow its outer end to conform to the shape or curves of the templet-tooth. It has a
quick return motion for the cutting tool on its back traverse—a device which relieves the cutting tool
from contact with the surface of the tooth on the return stroke, while at the same time it relieves
the pin from contact with the templet-tooth during the elevation of the outer end of S ,' and it has
other ingenious devices, which will be presently explained in detail. The machine is constructed
with every refinement of fit and accuracy of measured dimensions, while at the same time its design
eliminates to a great extent those minute errors which are inseparable from the finest of mechanical
manipulations. Thus the dividing-wheel D is 15 feet in diameter, so that if the bevel-gear wheel
operated upon is 5 feet in diameter, whatever error might exist in the divisions of the indeX-holes
of D will be reduced to one-third as much only in the bevel-wheel. The former or templet-tooth is
9 inches long upon its operative surface, whereas the depth of tooth on a 6-foot bevel-gear wheel
would be about 2% inches only, reducing any possible error in the curves of the templet to a corre-
sponding proportion in the tooth cut. _‘
The machine is operated as follows: The radial frame S is raised (at its outer end) out of the way,
and the mandrel B is moved back. The wheel to be operated upon is bolted to the end of the man-
drel B, its hub fitting into a true bore provided in the mandrel. The bevel-wheel is so chucked upon
the mandrel that,_when the in-
dex-pin is in place in one of the
index-holes of the wheel D, the
tool will be allowed its proper
amount of out upon the side of
the tooth standing beneath it.
The bevel face of the wheel to
be operated upon having been
turned to the proper angle, the
operator lowers the radial frame
or arm S, and so adjusts it and
the distance of the mandrel B
20
53.







(in its relation to the point C)
that the guide or slide surface
of S stands parallel with the
bevel surface of the wheel, and
both the depth and the shape of
the tooth will be cut automati-
cally by the machine to correct
form. This adjustment is easily
made by traversing the cutting
\ 8M8 tool over the turned bevel sur~
” 4 2 3 2 5F1'- face of the bevel-wheel. This
. adjustment completed, the car-
riage holding the templet-tooth is rigidly fastened to the quadrant, and the guide-pin on the end of
S is brought into contact with the templet-tooth at its pitch-line. The tool is then adjusted so that
its cutting point stands even with the pitch-line of the wheel to be 'cut._ The guide-pm upon and
with S is then brought to the top of the templet-tooth, and the machine 18 started._ _The- pinion P,
operated by belt power, revolves, moving the rack R, WhlCh 1n turn operates the shdmg carriage to
GEAR—CUTTING MACHINES. 893
p -._.. V -- -—_._

which the cutting tool is attached. When the carriage, or what is the same thing, when the cutting
tool has traversed the required distance, a rod attached to it operates a belt-shipper, the direction
of rotation of P is reversed, and the carriage and tool travel back, the feed of the tool taking place
. at the end of the back traverse and proceeding from the point or top toward the flank or bottom of
the tooth. The tool cuts while traversing toward the infinite point C, so that the resistance offered by
the cut shall operate to balance the weight of the carriage, the cutting tool and bolder, and the rack.
Such is a general description of this machine, and we may now describe its construction 1n detail,
reference being had to the drawings, of which Fig. 2051 is a sectional side elevation; .Fig._2052, a
sectional front elevation; and Fig. 2053, a plan view of the machine as a whole; while Fig. 2054
is a back view of the device for rotating the dividing or index wheel D. Fig. 2055 is a top


seas.

view, part in section, and Fig. 2056
is a side elevation, of the feeding
and guiding device attached to the
upper end of S. Fig. 2057 is an end
and 2058 a back view of the de-
vice for locking the dividing or index
wheel in position after adjustment.
Fig. 2059 is a top and Fig. 2060 a
side view of the rack R and pinion
P; and Fig. 2061 is a sectional view
of the same. Figs. 2062 and 2063
are two views of the slotted link for
insuring an exact recurrence of the
divisions. In all these drawings sim-
ilar letters of reference indicate sim-
ilar parts. The method of rotating
the index-wheel D is shown in Fig. 2054. The rim of the wheel is provided with cut teeth in gear
with the pinion operated by the hand-wheel H". The circumference of D is provided with 216
equidistant index-holes, and to remove that wheel through any definite portion of its revolution it
is simply necessary to withdraw the pin J, Fig. 2058, from an index-hole, and operate the handle H "
,until the wheel D has rotated the required distance, when J will again enter an index-hole. Thus,
‘if the gear to be cut is to contain 216 teeth, the wheel D will be required to move so that the pin
J falls into the next index-hole at each adjustment; or if the wheel to be cut is to contain 108 teeth,
then at each adjustment J will fall into every other index-hole. After the wheel D is adjusted and
the pin J is in position, J is relieved of the strain due to holding the wheel D against the pressure
of the cut, and also from any lateral vibration by the adjustable jib' L, Figs. 2057 and 2058, which
is caused to bear upon the rim of D, clamping it truly in its adjusted position. To avoid the neces-
sity of counting the number of index-holes to be passed by the pin J at each adjustment of D, and to
eliminate the possibility of error that might occur if the operator was required to count these holes at
each adjustment of D, the ingenious arrangement shown in Figs. 2058, 2062, and 2063 is provided.
The devices for feeding S to the out are as follows: Figs. 2055 and 2056 are views of the parts
at the outer end of S. p is a steel pin pivoted by the stud or bolt 12' round upon its outer end, which
contacts on the down feed of S with the former or templet-tooth g, and of wedge form at its inner
end. The guide g' holding the templet-tooth is secured in its adjusted position to the perimeter of
A. The templet-tooth 9 being curved to the circle of the perimeter of A, the variation in the form
of its curve, due to its curvature, is allowed for in its construction ; for it is evident that the
amount of lateral motion imparted by a given degree of curve in the templet-tooth to the end of S
will be less at the point of attachment of the tool 0’ in proportion as the point of contact of p is
radially removed from the infinite point 0. The carriage fixed to A A, and holding the templet-tooth
g, is provided with the rack R'. A casting bolted to the end of S constitutes a frame carrying the
stud p', the lever M’, the pinion shown at c', and the gear-wheel x. The rod r is moved laterally at
each end of the motion of the carriage S', and, through the medium of ill”, M", and M", operates
the arm carrying the ratchet-tooth 0; thus, as the arm 1' moves in the direction denoted by the
arrow (Fig. 2056), the catch 0' partly rotates the pinion at c’, which moves the gear a: as denoted by
the arrow and the pinion a“, causing S to descend to an amount proportionate to the movement of
.Zll'”, the latter being regulated by the position of the end of M'” in the slot provided in 111’ ’. To
relieve the gears and rack-teeth of the weight of S and its appurtenances, the cord x' is provided; it
passes over a pulley p" (Fig. 2051), and supports a weight beneath the floor.
The method of giving to S the slight lateral movement necessary to relieve the cutting tool
from contact with the work, and the pin p from contact with the templet-tooth, on their respective
back traverses, is as follows: Upon each side of the pin p is a lever h, and to one or the other of
these levers (according to which side of the wheel-tooth is being operated upon) is attached the cord










894 GEAR—CUTTING MACHINES.

a: passing over the pulleys p" p", of which there is a set on each side of the machine, and carrying a
weight beneath the floor. It is obvious that the templet-tooth 9 must stand with its curve in the
same plane as the curve of the tooth being cut ; hence, after all the teeth of the wheel have been
cut on one side, the templet-tooth is turned over and the other sides are cut. Now the cord 2: is
attached to the lever H ,- this is necessary to keep the pin p in contact with the curve of the templet-
, tooth, on whatever side that curve may stand, unless relieved by a separate device which operates
on the return traverse of the cutting tool, and which is arranged as follows: The body of p at 1 is
wedge-shaped, being tapered on its vertical sides from 1 toward the pivot at p', and it operates be-
tween two similarly inclined or wedge-shaped surfaces stationary at 1’, contacting during a part of
its movement with the fixed wedge on the same side of it as the cord to it is fastened. When the
tool begins its up and return traverse, the rod 1' moves in the direction of the arrow, and through




























the medium of M7 and M advances p ; its taper part at I contacts with the fixed wedge, and causes
,0 to swing slightly on the pivot-stud p’, and remove its round end from contact with p; then, as
the motion of r is reversed, the side face of p' at I_ is removed from contact with the fixed wedge,
and the rope at h is permitted to again hold the pin p against 9. To permit of the lateral motion of
S, the teeth of the rack R are pivoted at their centres by steel pins, as in Figs. 2059, 2060, and 2061.
Previous to the introduction of this class of gear-cutter by Mr. Corliss, it was not attempted
to give to bevel gear-wheel teeth the true form of curve, the practice being to operate upon one
side of the space at a time, using two or three cutters, giving a correct form at one or two points
only, and trusting to the wear of the surfaces to give better contact. The bevel-wheels referred to
as having been cut by this machine show upon examination, after their six months of duty, that
the bearing surface on the driving and driven sides of the teeth is smooth and polished, the wear
having been sufficient merely to efface the tool-marks made in cutting the teeth, while on the follow--
ing or follower side of the teeth the tool-marks remain, showing no abrasion or wear.
The Interchange System of Gearing.—The theory of the interchange system of gearing, according
to the solution first given by Professor Willis, in his treatise on the “Principles of Mechanism,” is,
that “in a set of wheels of the same pitch, having a constant generating circle for the flanks and
faces of the teeth, any two wheels of the set will work correctly together ” ; and as a rack is a gear
so infinitely large that its periphery forms a straight line, it follows that, if the rack-teeth are also
GEARING. 895

described with the same circle as that used for the wheels, any one of the set will run correctly with
the rack. The diameter of the generating or describing circle which gives one of the best forms of
teeth for a set of wheels is equal to the radius of the pitch diameter of a Iii-tooth pinion, making a
7t-in. generating circle for one diametral pitch. The flanks of a 15-tooth pinion being radial, a 12-
tooth pinion, which is the smallest generally used in practice, will have the flank of one tooth nearly
parallel to that of the tooth following, thus allowing the space between the teeth to be cut with the
regular gear-cutter. It was thought at the time this system was first brought out that its use would
be very limited, as in the case of change-gears for lathes, and where it was found necessary to con-
struct a train of gear-wheels; but time has shown that it has many advantages over other equally
correct systems not on the interchangeable plan, and it has been constantly growing in favor, until it
is-now almost universally adopted, especially among those using cut gearing. Professor Edward Sang
has also solved the same problem in another way, by taking the rack for the foundation of all curves
for a set of interchange gear-wheels. In the Sang theory, instead of using a constant describing
circle, the rack acts as a constant generator, and the faces and flanks of all teeth throughout the
whole set of wheels are described by it; therefore it is evident that, if the constant generating cir-
cle which is used for a set of wheels according to the Willis theory is also used to turn the teeth of a
rack, this same rack can be used in accordance with the Sang theory to generate another set of
wheels, and any gear of one set will work correctly with the other.
New Forms of Gear-Cutters.——Belgram’s gear-cutter is constructed on the principle that it is pos-
sible to make with any system of interchangeable gears a rack which will correctly gear with any
wheel of the set. Any wheel that gears correctly with this rack must also gear correctly with any
other wheel of the set, and hence must gear correctly with one another. The cutting-tool represents
one tooth of the rack, and has a reciprocating motion in the manner of a shaper tool, while the blank
receives a movement as though it were rolling on a pitch surface. In Swasey’s gear-cutter the tool
is composed of a series of cutters rigidly connected, which revolve and at the same time move longi-
tudinally or endwise at right angles to the axis of the wheel to be cut. Various other gear-cutters
will be found in “Modern Mechanism,” vol. iii. of this work.
Works for Reference.-—“ The Complete Practical Machinist,” Rose; Transactions American Society
of Mechanical gtneers ; “The Teeth of Gears,” Grant; “ Elements of Mechanism,” Goodeve.
GEARIN G. Wheel-work in which motion is transmitted from one wheel to another by means of
teeth upon their peripheries, is called gearing. The axes of a pair of wheels in gear may have dif-
ferent relative positions, and the teeth may act upon each other in different ways. There are in con-
sequence six varieties or classes of gearing, viz.: 1, spur-gearing; 2, bevel-gearing; 3, skew-gear-
ing; 4, screw-gearing; 5, twisted gearing; 6, face-gearing.
In general, if the teeth of wheels in gear be indefinitely increased in number and reduced in size,
they will ultimately become mere lines, or elements of surfaces in contact. These are called the pitch-
surfaces; their relative motions are the same as those of the wheels from which they are thus de-
rived, and their forms and disposition depend upon the class of gearing to which those wheels origi-
nally belonged. In spur, bevel, and skew gearing, the surfaces of the teeth are composed of right
lines ; two engaging teeth of a pair of either kind of wheels touch each other along a right line, and
2064.


the teeth are by the above process reduced to rectilinear elements of the pitch-surfaces. The axes
of spur-wheels are parallel, and the pitch-surfaces arc cylinders; the axes of bevel-wheels intersect,
and the pitch-surfaces are cones whose common vertex is the point of intersection; the axes of
skew-wheels lie in different planes, and the pitch-surfaces are hyperboloids. In all these cases the
pitch-surfaces are tangent along an element ; but in screw-gearing the teeth are of helieoidal form,
and ultimately become helical elements of cylinders which, since the axes are not in the same plane,
are tangent to each other at a single point only. It is this fact which most strikingly marks the dis-
tinction between screw and twisted gearing, which are sometimes confounded with each other. But
in the latter the axes are in the same plane, and the teeth, of helicoidal form, finally reduce to cylin-
drical helices or conical helices upon pitch-surfaces which are tangent along an element. There is
no screw-like action of one wheel upon the other, as there is in screw-gearing, and twisted wheels are
in fact only modified forms of spur or of bevel wheels. In the explanation of their construction
896
GEARI N G.

they will accordingly be treated as such, although the peculiar conformation of the teeth has caused
them to be placed in a distinct class.
These five varieties are those most extensively used in modern machinery, and the general appear-









l/
one here shown.



ance of a pair of wheels and their pitch-surfaces, of
each class, is shown in Figs. 2064 to 2068. Face-
gearing is now rarely met with; the name is derived
from the fact that the wheels were usually formed
with teeth consisting of turned pins projecting from
the faces of circular disks, as shown in Fig. 2069; a
mode of construction well adapted to wooden mill



work, and to that only. In the case illustrated here,
these pins, by indefinite increase in number and dimi-
nation in size, will finally become points in the cir-
cumferences of circles which roll in contact. These
axes are perpendicular to each other, but turned pins
may be inserted in other surfaces than planes, and in
this way such wheels can be made to work together
when the axes have other relative positions than the
All these may be properly said to belong to the same class, the characteristics
being that, whatever the relation of the axes or the general form of the wheels, the teeth are circu-
lar in their transverse sections, touch each other in a single point, and ultimately become points, the
2067.


wheels having no pitch-surfaces properly so called, although in constructing them surfaces of some
kind must be provided in which to secure the teeth. _ .
The following table exhibits in a manner convenient for reference the peculiar features of the dif-



2068.
ferent kinds of gearing above mentioned. The teeth, the forms of whose linear elements are given
in the last column, are supposed to be of sensible magnitude, in order that the circular sections of
GEARING. ' 897

those in the last class may be kept in view. For in facegearing the increase in the number involyes
a diminution in the length as well as in the diameter of the teeth, so that at the limit they vanish





20a).
' '1’
iii?
a» r
$11 ,
.
._ r
W





altogether,-as just explained ; whereas in the other classes the length of the teeth is not affected by
any variation in the height or thickness, and they reduce to lines.









Relative Position of Axes. Pitch-Surfaces. matrix: or
i
1. Spur. . . . . Parallel . . . . . . . . . . . . . . . . . Cylinders. . . . . i
In same plane. _
2. Bevel. . . . Intersecting . . . . . . . . . . . . . . . Cones . . . . . . . . j Rectilinear.
l
8. Skew . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . Hyperbololds. J ,
In (life-rent planes. i
4. Screw. . .. . . . . . . . . . . . . . . . . . . . . . . . . .. Cylinders... . l 1
Parallel . . . . . . . . . . . . . . . . . . . Cylinders ‘ i- Helical.
5. Twisted. In same plane. or 5
' Intersectlng . . . . . . . . . . . . . . . Cones . . . . . . .. 6. Face. . . . . Indifferent . . . . . . . . . . . . . . . . None . . . . . . . . . . .5 Circular.
l

Principles of Forms of Gear-Wheele—The proper action of gear-wheels of any kind evidently
depends upon the forms of the teeth. In order to proceed intelligently in determining these forms,
a clear understanding of the principles involved is necessary ; which can be most readily gained by
first considering two pieces rotating in contact about fixed parallel axes.
In Fig. 2070, let 0 and D be the centres of motion of the two curves in contact at P; then, if
the upper one turn as shown by the arrow, it will drive the lower one before it. Since the point P of
the upper curve moves in a circle about D, the direction of that motion at the instant is perpendicu-
lar to D P, the contact radius, and its linear velocity may be represented by P E. Through P draw
T T the common tangent of the curves, and NN their common normal: then P E may be resolved
into the components PB, PA. Of these the former is ineffective, as, if P moved in the direction.
of the tangent, it would merely slide upon the lower curve. But the normal component PA com-r
pels the lower curve to rotate around 0'. The motion of P considered as a point in this curve will
therefore be perpendicular to (JP; and the magnitude PF of this resultant must be such that its
normal component shall also be PA : [or if this component were greater, the curves would not re-
main in contact, and if less, they would intersect. N ow draw D H perpendicular to NN, thus mak-
ing the triangle D HP similar to EA P ; draw 0 G' perpendicular to N N, making C G P similar
to A PF; also 0 D cutting N N in I, and making 0 G' I similar to H D I.
Let a :: angular velocity of upper curve around D.
“ v'r: “ “ of lower “ “ G.
Then, since angular velocity = bile-“mag, we shall have
2, __ {’5 _ EA, 1
P D D H 1,, __ fill—q _ , PF A v’ ” H “— 1
0:»— -—
57 .100 o
898 ' GEARING.

That is to say, .the angular velocities are to each other inversely as the perpendiculars from the cen-
tres of motion upon the common normal ; or, inversely as the segments into which the common nor—
mal cuts the line of centres. And if it be required that the velocity ratio shall remain constant, it
follows that the common normal must always out the line of centres in the same point.
Now, PB represents the sliding of the driver, P O that of the follower, upon the common tan-
gent; therefore OB, their difference in this instance, represents the sliding of one piece upon the
other. Had 0 and B fallen on opposite sides of N N, this sliding would have been P O + PB.
But it is clear that there will always be a sliding of one upon the other, unless the tangential com-
ponents have the same magnitude and direction. And as the normal component is the same for both
rotations, this can happen only when the resultants P E and P F coincide; in which case the contact-
radii DP and UP, to which those resultants are respectively perpendicular, must also coincide in '
one right line, that is, in the line of centres. In other words, pare rolling contact can exist only when
the point of tangcncg/ is on the line of centres, as in Fig. 2071. Since P and I here fall together, and
the linear motions are identical, we see at once that the angular velocities are inversely as the contact—
radii. And because, if the velocity ratio is to be also constant, these contact-radii must remain con-
stant, it follows that the only curves which can move in rolling contact with a constant velocity ratio are
two circles, whose centres are 0 and D, portions of which are shown in dotted lines in the figure.
These circles may be regarded as cut from the pitch-cylinders of a pair of spur-wheels by the plane of
the paper, supposed to be perpendicular to the axes. N ow the linear motion of the point P in the driver,
coinciding with the tangent, has no normal component, andthercfore no tendency to compel rotation
{ .
- 2071. 2073.




manila"
I .
illlllllll...‘





U @I‘ H: 'l









of the follower; which agrees with the well-known fact that two perfectly smooth cylinders will
merely slip upon each other. Compulsory rotation then requires the addition of teeth to circular
wheels; and if in Fig. 2070 we also regard the circles drawn through I as the sections of pitch-
cylinders, it will be clear that the contact~curves shown in that figure will fulfill the functions of
teeth if they be of such form that their common normal shall always pass through 1.
The principle upon which the finding of such curves depends is illustrated in Fig. 207 2. A piece
with a curved edge, P B D, is fixed upon a plane surface; and HA C is a loose curved ruler which
may roll upon it. The two curves are‘now in contact at P: let the upper one roll to the right as
shown by the arrow; which means that each point in its order of the one shall come into contact
with each point in its order of the other. Thus, PA is equal to PB, and A will come into contact
with B ; PA 0 is equal to P B D, and C will come into contact with D. At the present instant P
is the centre upon which the upper curve is turning. Every point in it or rigidly connected with it is
therefore moving in a circular arc of which P is the centre. Thus the motion of C is at the instant
in the direction 0 E, tangent to that are, or perpendicular to O P. CE is therefore tangent to the
curve C .D, which will be traced on the plane, to which P BD is fastened, and C P is normal to it.
The point C is on the rolling curve ; but this is not necessary. A marking-point, for instance, may
be placed at L ; and it is at the instant moving in‘thc direction L O, perpendicular to L P, and L 0
would be tangent to the curve traced by L upon the plane. At the next instant the point of contact
will change, but that point is always the centre about which the rolling curve is turning. Thus when
A reaches the fixed curve at the point B, the latter will be the instantaneous axis. It is not neces-
sary that PBD should be fixed t we may suppose the upper curve to be fixed, and the lower one to
roll upon it, carrying the attached plane under the tracing-point C ,' or both may be in actual motion,
provided that the relative motions are such that the one measures itself off upon the other. The
principle is that, if one curve move in rolling contact with another, the point of contact is the in-
stantaneous axis, through which passes the normal to any line traced by a point connected with one
upon the plane of the other. .
GEARING. 899

Spun-Gamma.
The application of the above principles to the construction of the teeth of spur-wheels is shown
in Fig._20'73. Let U D be the axes, perpendicular to the paper, and LP B, 0 P G, parts of the
pitch—circles, or sections of the pitch-cylinders, in contact at P. Let E be the centre of another
circle tangent_also at P to the other two, and carrying at P a marking-point. Let these three
circles roll in contact as shown by the arrows, with the same linear velocity. Then, while the
lower pitch-circle turns through the angle PI) G, the upper one will turn through the angle P CB,
and the describing circle through the angle P E A, the arcs P G, P B, and PA being equal; and
meantime the marking-point will have traced the curves G A, BA on the planes of the lower and
upper pitch-circles respectively. Evidently, A G is the epicycloid formed by rolling the describing
circle on the outside of the lower pitch-circle, and A. B is the hypocycloicl generated by rolling the
same describing circle on the inside of the upper pitch-circle. And from what precedes it is clear
that these curves will act together properly as parts of the outlines of teeth. PJ, PI represent
the same curves in contact at P; and the wheel I) being turned to the right, PJ will drive PI be-
fore it, the point of contact being on the arc PA, the common normal passing always through P,
and the velocity ratio being constant, until J and I come together at A. Here the action ends, and,
the rotation being kept up by other teeth, this pair of curves quit contact. While it is not necessary
that a circle should be taken as the describing‘eurve, it is more convenient in practice ; and the teeth
whose forms are thus determined, known as epicycloidal, are those most extensively employed. The
curve A G, which lies without the pitch-circle of its wheel, is technically called the face of the
tooth; and the curve A B, lying within the pitch-circle, is called the flan/r of the tooth to which it
belongs. Usually the teeth of each wheel have both faces and flanks; but as continuous rotation
can be and sometimes is kept up without the aid of other curves than those shown, we will first con-
sider the conditions under which this is possible.
The are of the pitch-circle occupied by a tooth and a space is called the pitch of the teeth ; and a
fractional tooth being impossible, the pitch must be an aliquot part of the circumference. If two
wheels gear together, the pitch must be the same in each, so that the numbers of the teeth must
have the same ratio as the diameters of the pitch-circles. The problem usually presented in practice
is, to construct a pair of wheels which shall work with a given velocity ratio upon axes also given in
position. The distance between the centres, being thus known, is divided into segments having the
given ratio, and the pitch-circles, described with these segments as radii, are divided into as many
equal parts as it is proposed to have teeth. The pitch, being thus found, is again divided into two
parts, one being the thickness of the tooth, the other the breadth of a space. If absolutely accurate
workmanship were possible, these parts might be exactly equal; but as it is not, the space must in
practice be a little greater. The difference is called backlash: if the wheels are to be cast merely, it
is customary to make this a certain fraction (from 11,; to 1%) of the pitch ; but in cut gearing of any
pretensions to accuracy, there is no reason why it should be anything like so large, or why it should
vary with the pitch; it should be as small as the skill of the workman can make it with the tools at
command.
N ow, referring again to Fig. 2073, let us suppose that P G had been determined as the pitch, and
G H as the thickness of a tooth, on the wheel D. Having selected a describing circle and construct-
ed the curve G A, the tooth is then to be completed by drawing the similar but reversed curve H A.
This diagram is so proportioned that these curves intersect at A, and we see that this is the limiting
case; the angle of action P D G is equal to the pitch, and it cannot be made less, or one tooth would
cease to act before the next one began. This determines the necessary length of the face A G; and
since the opposite face also passes through A, it is just possible to make the teeth, which in this case
is pointed, of the requisite length. In this case also the line A D bisects G H, and is the radius of
symmetry. But if, after determining A,.the are G H had been so cut by A D that G F were less
than li’H, the tooth might have been made longer by continuing both faces, thus increasing the angle
of action, or it would be of some thickness at the top, as in the next figure; but if G F had been-
greater than FH, the construction would have been impossible, the two faces intersecting below the
point A. N ow it is clear that a limiting case like this cannot be safely adopted in practice; the least
inaccuracy in workmanship, or a very little wear (to which pointed teeth of this form are especially
liable), will reduce the angle of action, and cause one tooth to quit correct driving contact before the
next one begins to act. We say correct ('Z-l-i-ving contact .- if in Fig. 2073 we remove the second tooth
P J K, the face A G of the first one will push the flank A B out of its way, and so turn the upper
wheel; but the acting curves will not be tangent to each other, nor will the velocity ratio be constant,
but the speed of C will diminish. Each tooth should therefore come into action before the preced-
ing one goes out; that is, the are of action P G should be greater than the pitch, as in Fig. 2074,
which illustrates a case practically feasible.
The construction is as follows: l'Iaving set off from P the equal arcs of action P G, PB, greater
than the pitch, and selected the describing circle, we construct the epicycloidal face GA and the
l'iypoeycloidal flank B A. Drawing A .D, it cuts the lower pitch-circle in .F, and we find G F to be
less than half the thickness of the tooth G H, so that, drawing the reversed face tl'irough H, the
tooth is not pointed, but “topped off” by the circle VA IV. The pitch-circles having been pre-
viously divided, starting at the points G, B, the other teeth of the lower wheel are drawn in their
proper positions, the spaces between them being bounded not by the pitch-circle, but by a circle a
little inside of it, giving a little clearance for the tops of the teeth on the upper wheel, the faces
A. G, etc., being continued within the pitch-circle by tangent radii. Now, as to the tooth of the
upper wheel, B A is the whole of the acting flank; but the space must clearly be made considerably
deeper, to allow the passage of the teeth of the lower wheel. The exact form of this space is im-
material, so long as the spaee is great enough; but it is usual to extend the hypoeycloid B A to S as
shoWn, the bottoms of the spaces being formed by a circle whose centre is O, which allows also a
900 GEARIN G.

clearance between it and the tops of the engaging teeth. When it is possible to construct wheels in
this way, they will fulfill perfectly the requirement of transmitting continuous rotation with a con-
stant velocity ratio. But if the wheel 0, for example, be very small in proportion to D, the teeth
of the latter will require to be very long, and in many if not most cases’this construction will be -
impossible; and in many cases it is not desirable even when possible, for a reason which will appear
from the following considerations: If we suppose D to be the driver, and to turn to the right, the
action begins at P and ends at A, the point of contact continually receding from the line of centres.
But if we suppose O to drive in the opposite direction, the action begins at A and ends at P, and
the point of contact is continually approaching the line of centres. There is during the action an
amount of sliding equal to the difference between the lengths of the acting curves A G, A B; and
it has been found that the friction is greater and more injurious in the latter case than in the former,
the difierence being analogous to that between pushing and drawing a cane over a pavement to which
it is inclined. Of such a pair of wheels, then, the one whose teeth have faces ought always to drive,
and the one with flanks only ought always to be the follower. But in many cases a wheel must be
turned by another, and also drive a third. And besides, it is to be noted that the longer the face
' of the tooth, the greater is the angle between the line of action .PA, Fig. 2073, and the common
tangent of the pitch-circles P T. The pressure as well as the motion acts in this line; and the great-
er this obliquity, the greater will be the component in the line 0 D, that is, the greater will be the
2074.
it

.42 .B
a a. ~
t,
m 2076.
I}
/ . ‘..nll_lj\







I
4
2
\
§
_ pressure on the journals. And finally, the difference between the lengths of the face and the flank
which act together, and therefore the sliding, increases more and more rapidly as we recede from the ~
pitch-circles. This latter fact is sufficient to show that the teeth of wheels ought always to be as
small and numerous as possible ; though this is in many cases also affected by considerations relating
to the pressure to be transmitted and the strength of the materials to be used, with which we have
nothing to do.
It will now readily be seen, that by using another describing circle on the other side of the point
P, as in Fig. 207 5, thus giving both faces and flanks to the teeth of each wheel, two things will be
accomplished: a given angle of action may be secured with shorter faces and therefore less sliding,
and this angle will be divided into an angle of approaching and an angle of receding action, thus
enabling us to use either wheel as the driver. If a wheel has both to drive and to follow, it may be
well to subdivide the angle of action equally; but in case it is to act as a driver only, its arc of
approach may advantageously be made less than its arc of recess, in order to reduce the amount of
the more injurious friction. The diameters of the pitch-circles and the numbers of the teeth being
given, the pitch is determined, and, making the allowance for backlash, we find the thickness of the
tooth. If we then assume the arcs of approach and of recess, we can determine whether the pro-
posed conditions can be satisfied, and if so, the forms of the teeth as well as their heights, by con-
structing the diagram, Fig. 2075-, thus: Let D be the driver, and P 0 its arc of approach, which is


D—

GEARING. 901
O

equal to P L, that of the follower. Taking any point Z on D P as the centre of a describing circle,
draw the epicycloid L R by‘rolling it on the outside of L P B, and the hypocycloid 0 R by rolling it
within GP G. These curves are respectively the face of the follower’s tooth and the flank of the
driver’s. Draw the radius R 0', cutting the pitch-circle of the follower in S : if L S be just half the
thickness of the tooth, the construction is so far possible, but the follower’s teeth will he pointed;
if vL 8 be less than that, the teeth will be “topped off,” but if greater, the size of the describing circle
must be increased or the are of approach diminished. The construction of the remainder is precise-
ly like that of Fig. 2073, above explained. We have here assumed possible conditions, and the
action is readily traced. The arrows indicating the direction of the rotations, the driver’s flank
2077.






t.
begins to act upon the face of the follower at R, and acts upon it until 0 and L come together at P,
the point of contact lying always in the are R P. These two curves now quit contact, and the action
is continued between the face of the driver’s tooth and the flank of the follower’s, ending at A, as
in Fig. 2073. The teeth are completed by extending the flanks, as in Fig. 2074, to form the clearing
spaces, and will present the appearance shown in Fig. 2076.
Nothing has been said thus far about the diameter of the describing circle. In Fig. 2077 are
shown three cases, this diameter being equal to, less, and greater than the radius of the pitch-circle
within which the describing circle rolls. In the first case the hypocyeloid B A becomes a diameter
of the pitch~circle, and the tooth, having radial flanks, is weak at- the root. In the second case the
flank is tangent to the radius B 0 at B, and curves away from it as it recedes from the pitch-circle,
giving a much stronger form of tooth, which is therefore to be preferred for heavy work. In the
third case the flank is still tangent to the radius B C at B, but curves in the opposite direction, the
tooth consequently being not only weak but difficult to make. But with a given are of action the
greatest obliquity of the normal will be less, the greater the diameter of the describing circle; so
that in watchwork or other delicate mechanism the third form might be employed.
It will be noted that the face and the flank, which act in contact, are generated by the same describ-
ing circle. Consequently, if it be required to make a set of wheels such that any two of them shall
gear correctly together, not only must the pitch be the same in all, but the same describing circle
must be used for tracing all the faces and all the flanks. And the diameter of this, for the reason
just pointed out, should not be greater than the radius of the smallest wheel of the set. If it be
0’ "


l

.l.
just equal to that radius, that wheel will have teeth with radial flanks; but these may be materially
strengthened by joining them to the bottoms of the clearing spaces by circular arcs, as in Fig. 2079 ;
Which indeed can be done in any case, as the depth of the space is considerably greater than the
length of the act-ing flank, as shown in Fig. 2074.
902 ‘ GE ARING.
I

From Fig. 2075 it appears that the arc of approach varies with the length of the face of the fol.
lower, the arc of recess with that of the face of the driver. If it be imperative, then, that the lat;
ter are be the greater, the length of the face of a tooth will depend upon whether it is to drive or
be driven. But in the majority of cases in ordinary practice this is not essential; and among mill-
wrights the custom obtains of disregarding this distinction, and making the depth of the tooth,
within and beyond the pitch-line, bear certain definite proportions to the pitch itself. In Fig. 2078
are shown three slightly different proportions. In the first the whole depth is two-thirds of the
pitch, the part within being to that without the pitch-circle as 5 to 4; in the second the whole depth is
four-fifths of the pitch, divided in the proportion of 13 to 11; and in the third we have four-tenths
within and three-tenths without the pitch-circle. By adopting either of these systems of proper-
tioning the teeth, the wheels will work together without risk of a tooth going out of gear too soon,
provided that none of them have less than 15 teeth; but of course the arcs of approach and of
recess will vary according to the numbers of the teeth and the size of the describing circles se-
lected. But as the locus of contact is always the circumference of that describing circle, it is easy
to determine by the diagram, Fig. 207 5, what these arcs are. And as the necessary are of action,
and with it the necessary length of the face, increases with the pitch, it will be found that these
proportions, though good within the limits named, will not answer if the number of teeth in a wheel
be small; and the length of the tooth must be determined in such cases by actual construction, as
above explained. -
Rack and l'V/LG€L-——If one of a pair of wheels become infinitely large, its pitch-circle will become
a right line tangent to that of the other wheel, as O G, Fig. 2079. The similarity of this diagram
to Fig. 2075 is so great, that hardly any explanation is needed. The same or different describing
circles, on opposite sides of the point of contact, are used for generating the acting curves, the teeth
of the wheel having epicycloidal faces and hypocycloidal flanks as before, while both faces and flanks
of the rack-teeth are cycloids. The are of action L P B of the wheel is of course equal to O P G
on the pitch-line of the rack, L P being equal to 0 P, and P B equal to P G, and the necessary
lengths of the faces and flanks are determined, the teeth completed, and the clearing spaces formed
exactly as in Fig. 2075; the only point of difference being, that when the pitch and the are of
action are assumed, and the necessary length of the cycloidal face A G of the rack-tooth has been
found, the possibility of satisfying the conditions is determined by drawing a perpendicular to O G
from A, cutting the pitch-line in F: if F G be less than or equal to half the thickness of a teeth,
the construction is possible; but if greater, it is not. If the describing circles E, Z be of equal
diameters, and the same circle be used for the faces and flanks of a set of wheels, any one of them
will gear correctly with the rack if the pitch be the same.
If, as in Fig. 2080, the upper describing circle be of half the diameter of the pitclrcircle, the
flanks of the wheel-teeth become radial. YVe may assume a similar case below ; but the pitch-circle
of the rack being of infinite diameter, its radius is also infinite, and the describing circle is there-
fore the pitch-line of the rack, which rolling on the upper pitch—circle gives involutes of that circle
for the faces of the wheel-teeth. Thus, let L P, the arc of approach, be equal to O P on the pitch-
line ; then, as the rotation progresses, a marking-point at 0 will trace on the plane of the wheel the
involute 0 L, and on the plane of the rack the traced curve will degenerate into the point 0, which
will meet L at P. The action is therefore had, the wear during approach being confined to this
single point on the rack-tooth, which has no flank proper. A clearing space is however needed, and
0 V may be a circular arc whose centre is P and radius P O, the radius of curvature of the invo-
lute O L at O.
Annular Wheela—An annular or internally-toothed wheel may either drive or be driven. The
construction of the teeth in the former case is illustrated in Fig. 2081. The diameter of the describ-
ing circle E is, for reasons before explained, taken less than the radius of the smaller wheel: both
the face A G of the driver’s tooth and the flank A B of the follower’s lie within the pitch-circle and
are hypocycloidal. Since the pitch-circles both curve in the same direction, the teeth continue longer
in gear than in the case of external contact, and it is usually unnecessary to have any are of
approach; but should it be required, it may be obtained thus: Let P 0 be equal to P L; then a
tracing-point fixed at O in the outer pitch-circle will mark on the plane of the inner one the internal
epicycloid 0 L, and on its own plane merely the point 0, to which therefore the action of the fol-
lower’s face is confined. The possibility of satisfying the assumed conditions is determined exactly
as in the cases already described. Thus, A G is the necessary length of the driver’s face, with the
given describing circle and for the arc of recess P G. Draw D A cutting the pitch- circle in F;
then F G must not be greater than half the thickness of the tooth, which is known if the number
of teeth be assigned. The clearing space of the follower is formed as usual by continuing the
hypocycloidal flank to the requisite depth ; in the annular wheel a short radial line, tangent to the
face A G at G, is drawn to limit this space on the side, the bottom being a circle whose centre is
D. In both wheels the corners of the spaces may be rounded: Now it will be seen that if the
pinion drive, the action will be confined to the arc of recess by cutting down the faces of the teeth
of the wheel to the pitch-line; and by reducing their length to a less extent, and increasing the face
of the pinion’s tooth, the action may be divided in any desired proportion. In all cases, however,
it is better to have no arc of approach if it can be avoided without unduly lengthening the face of
the driving tooth, which increases the obliquity of the line of action and also the sliding: But we
have also just seen that the action of the curve 0 L is confined to the single point 0 on the outer
wheel ; and this is a serious objection to the method above mentioned of forming the teeth when the
pinion is to drive.
A much better way is shown in Fig. 2082, a describing circle E being used whose diameter is equal
to or greater than the radius of the annular wheel, and always greater than the diameter of the pin-
ion. The hypocycloidal face of the wheel-tooth will therefore either be a radius, or, as in the figure,
GEARING. 903

a line curving away from the radius D G ; and the pinion-tooth is also a face instead of a flank, as
it lies without its pitch-circle. The sides of the clearing spaces in the wheel and the pinion may be
any circular arcs tangent to the radii at their extremities, and of less curvature than the faces A B,
A G respectively. It will be noted that in this construction it will in many cases be possible, as in






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the figure, by taking the describing circle of proper diameter, to make the acting faces A B, A G of
very nearly equal length. When this can be done, it is an advantage, as the wear of the two sur-
faces will then be the same.
In laying out annular gearing, when the internal wheel is large, care must be taken that the teeth
are not too long to clear each other; which may require attention to the following consideration: If



.904 ' GEARIN G.

in Fig. 2082 we roll the pinion round within the wheel, the point A of the pinion-tooth will trace an
epitrochoid on the plane of the outer wheel, which may be readily constructed, and obviously must
clear the points of the teeth of the annular wheel. Similarly the highest point of the tooth of that
wheel, in rolling round the pinion, will trace on the plane of the latter an epitrochoid, which must
clear the points of the teeth of the pinion.
Pin-Wheels or Tmndlea—A modification of epicycloidal gearing is shown in Fig. 2083. Let a
1narking~point be fixed at P in the upper pitch-circle ; then it will trace upon the plane of the lower
one, while the latter turns through the angle PD B, the curve BA, the arcs PB, PA being equal.
This curve is simply the epicycloid generated by rolling the upper pitch-circle on the lower; the curve
traced on the plane of the upper degenerates into a point. P F is a curve similar and equal to BA ;
and if we suppose P to be a pin of no sensible diameter, fixed in the wheel 0,. this curve will drive
the pin as shown by the arrow, the action ending at A. Now if PB be the pitch, we canconstruct
the elementary teeth by drawing the reverse faces B A E, P G E, which will drive the pins in either
direction. - These faces intersect in E, thus limiting the height of the tooth when the pitch is as-
sumed. In the diagram E falls within the pitch-circle of the upper wheel, and the face of the teeth
may be made longer than B A, thus making the are of action greater than the pitch : had E fallen
on the circumference of O, we should have had the limiting case, the action on one pin continuing
barely long enough for that on the next to begin.
Practically, the pins must have a sensible diameter, and are made cylindrical, being technically
called staves, which are usually inserted into two circular disks fixed on the axis, thus forming what
in mill-work is called a trundle or lantern. The form of the teeth of the wheel is derived from the
epicycloid, by drawing _a curve at a constant normal distance from it; which is done graphically by
describing any number of circular arcs with a radius equal to that of the pin, the centres being on
the epicycloid, and making the new curve tangent to them all, as in Fig. 2084. -
When the number of teeth, or in other words the pitch, is assigned, it is necessary to ascertain
what diameter can be given to the pins. This is done as in Fig. 2085, thus: Let PB be the pitch
on the driver 1), PA that on the follower C ,' draw PA, biscct PB in G, and draw I) G, producing
it to cut PA in H: then the pin may have any radius less than A H. For, drawing the elementary
tooth PEB, we see that PA is normal to the epicycloid BA E, to the parallel or derived curve,
and to the circumference of the pin. If we assume A .H as the radius of the latter, it is plain that
the highest point of the tooth will be H, and that it will be just quitting contact when the next one
comes into action. With the smaller'radius used in the figure, the derived tooth-outlines would inter-
sect at 1' on the radius D E, and the tooth, if it were desirable to have it pointed, might be extended
to that point. It is however better to have it “topped off” as shown, which may now safely be
done, as the action on A is not yet ended, while the next tooth has begun to drive the pin P. In
the elementary form, Fig. 2083, it is seen that the action is wholly confined to the arc of recess, if
the teeth are given to the driver. When the pins are of sensible diameter, as in Fig. 2085, there is
an arc of approach, but a comparatively small one; so that in practice the pins are invariably given
to the follower.
In the case of the rack, then, the form is materially difierent if it drive from that which it has if
driven. Fig. 2086 shows the construction in the former case; the elementary rack-tooth being the
cycloid traced by the pitch-circle of the wheel rolling on its tangent, from which the practical tooth-
outline is derived as before. In determining the radius of the pin, the line corresponding to the
radius 1) G of Fig. 2085 here becomes perpendicular to the pitch-line of the rack. If the wheel
drive, the pins are given to the rack, and the elementary tooth is the involute of the pitch-circle of the
2087.




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wheel. So also is the derived curve, which it is therefore unnecessary to construct. The appearance
of the combination is shown in Fig. 2087, and it is open to the same objection as that mentioned in
regard to the action of the faces of the wheel-teeth in Fig. 2080 ; that is, the whole wear is confined
to a single point on each pin, so that it makes no difference whether the pin be circular or not, as
it will work equally well if made with flat sides perpendicular to the pitch-line of the rack.
Annular pin-gearing also furnishes two cases differing materially in appearance. If the inner
wheel be the driver, the construction is as shown in Fig. 2088, the elementary tooth PE being the in»
ternal epicycloid generated by rolling the outer pitch-circle uponthe inner, and the radius of the pin
being determined as in Fig. 2085, the lettering corresponding throughout. If the annular wheel
drive, as in Fig. 2089, the face of its elementary tooth is the hypocycloid generated by rolling the
pitch-circle of the pinion within that of the outer wheel; and the general construction will be readily



GEARING. 905

seen by comparing this figure with the preceding one and with Fig. 2085. If the diameter of the
inner wheel be half that of the annular one, the teeth of the latter become radii of the pitch-circle
if the pin be a mathematical point; and when it is made of sensible diameter, the derived outline
of each tooth of the annular Wheel is a line parallel to its primitive radius. The are of action may
\\
in this case be made so long that three or even two pins are sufficient to drive the outer wheel con-
tinuously, the whole combination in the latter case assuming a very curious aspect, as shown in Fig.
2090 ; the pins turning in blocks which slide back and forth in the two slots at right angles to each
other, which are the disguised teeth.
Spwr- Wheels with Involute Teeth—Next to the epicycloidal, the form of tooth most extensively



2080. 2092.
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used is that of the involute of the circle. We have seen that anyr curve carrying a marking-point,
and rolling in contact with both pitch-circles, may be used to generate the acting outlines of the
teeth. Abstractly speaking, that is; for many curves which may be thus generated, although they
sec 2 GEARING.

‘
geometrically satisfy the conditions, are incapable of being practically used. Not so with the invo- '
lute ; but though it can be thus generated, its fitness for the purpose may be much more clearly and
simply shown by deriving it in another way. Let C, D, Fig. 2091, be the centres of the pitch-circles
L P 0, 111 PN, in contact at P. Through P draw A B oblique to C D, the line of centres, and let
fall upon it the perpendiculars 0 B, D A, with which as radii draw the circles B S F, A EB. Sup-
pose these circles to be disks upon which is wound an inextensible band A B, carrying a pencil at A :
if the upper one be turned to the left, it will cause the lower one to turn to the right, and the pencil
to travel in the line of the common tangent, as shown by the arrows ; and in going from A to B, the
pencil will mark upon the planes of the upper and lower wheels respectively the curves A F, EB.
These are the involutes, not of the pitch-circles, but of the base-circles BSF, A E B, whose radii
O B, D A are to each other in the same ratio as C P, D P, the radii of the pitch-circles, by reason
of the similar triangles P C B, PD A. By the mode of generation, the arcs A E, B F are equal to
A P and therefore to each other; and the curves, being simultaneously described by a point which
lies in the common tangent to the base~cirelcs, that is to say, in the common normal to the involutes,
are tangent to each other throughout the generation, and the common normal always cuts 0 D at P.
These curves may therefore be used as teeth for the wheels to which they respectively belong; thus,
A I G, similar to EB, will drive A J F, as indicated by the arrows, with a constant velocity ratio,
the locus of contact being A B. Now, because A B, the line of action, has a constant inclination to
T ”, the common tangent of the pitch-circles, there is always a certain fixed component of pressure
in the line of centres C D. This, tending to cause wear in the bearings, is urged as an objection to
this form of tooth for heavy work; to which the epicycloidal form is not open, as in that the obli-
quity of the common normal varies, and it is perpendicular to C D when the point of contact reaches
P. To offset this, however, this form possesses some advantages The line AB was drawn at
pleasure, and the demonstration in no wise depends upon its inclination; consequently, for the same
pitch-circles an infinite number of base-circles may be used, or for the same base-circles an infinite
number of pitch-circles may be assigned, the only condition being that the diameters shall have the
same ratio in either case. Therefore any two wheels with involute teeth will gear together correctly
if the pitch be the same in each; and further, the velocity ratio will not be affected by changing the
distance between the centres, the effect of which is merely to alter the obliquity of the line of action.
, The backlashmay therefore be reduced to a minimum by bringing the axes as close together as they
can be without causing the teeth to bind; and if by wear of bearings the axes become too wide-
ly separated, the teeth will still gear correctly so long as they engage at all. None of these things
cgn be said in favor of the epicycloidal form; and moreover, the involute is essentially a strong form
0 tooth.
Since the involute does not continue within its circle, it is clear that in Fig. 2091 A F, B E are the
greatest lengths of the acting faces that can be used; and if they are used, the teeth will be pointed,
as A G U, B H W. Considering D as the driver, the action begins at A ; and when I and J meet
at P, the marking-point having traveled from A to P, the curve I A will have the position P V.
The are of approach A V being thus equal to A P, the arc of recess VE must be equal to PB,
since A E, the whole are of action, is equal to A B, as before seen. But $515: :g-“Z;
that is to say, the arcs of approach and of recess, if the teeth be of the greatest possible length,
are to each other as the radii of the pitch-circles, or as the radii of the base-circles, of the driver
and the follower respectively. But as it is not necessary that the full length of the curves should
be used, the arcs of recess and approach may be proportioned at pleasure by properly adjusting the
lengths of the teeth.
The diagram, Fig. 2091, is made without any regard to practical proportions, for the sake of per-
spicuity, the obliquity of A B, as well as the pitch, being plainly excessive. In practice, the angle
between A B and T T should never exceed 20° if it be possible to keep it within that limit, and it
is better that it should be no more than from 15° to 17°; and the laying out of working teeth is
illustrated in Fig. 2092. Through P are first drawn CD, the line of centres, an arc of each pitch-
circlc, and T T, the common tangent, from which is measured the angle of the line of action A B,
which in this case is 17°, by which the radii of the base-circles are determined. Then also through
P are drawn P G- V, PL W, the involutes of the lower and upper base-circles. Supposing the num-
ber of teeth to be assigned, the pitch, and the thickness of the tooth as measured on the pitch-circle,
' are known. N ow, if we assume the height of the teeth of D, taking for instance G as the highest
point, we may find the are of action on the right of CD thus: Through G describe a circular arc
with D as its centre, cutting A B, the locus of contact, in I; then P] will be equal to the arc of
action on the base-circle through A, from which that on the pitch-circle is readily found, subtending
the same angle. Or if that part of the angle of action be assumed, we can by reversing this process
find PI, and thence determine G. Draw GD cutting the pitch-circlc‘in J: then, if PJ be just
half the thickness of the tooth, the latter will be pointed; if less, the teeth may be topped ofi’ as in
the figure, while if greater the assumed conditions cannot be satisfied. By a proceeding exactly
similar, in the case of the upper wheel, we determine the height of its tooth; and, setting off from
P the thickness on each pitch-circle, the opposite sides of the teeth are bounded by similar and re-
verscd involutes. The clearing spaces of the upper wheel may be of any forms which will not touch
the epitrochoids marked on the plane of that wheel by the points in the outer edge of the teeth of
the lower one, and in a Similar manner the forms of those in the lower wheel may be determined.
Rack and Wheel with Involute Thain—We have already met with one case in which the tooth of a
wheel working with a rack, or at least that part of it lying without its pitch-circle, is of the involute
form. This was shown in Fig. 2080; but, as there pointed out, it was the involute of the pitch-cir-
cle, and the action was objectionable as confining the wear to a single point of the rack-tooth. A
GEARING. * 907

better method of constructing involute rack-work is shown in Fig. 2093. Let C be the centre of the
. pitch-circle M P B, and T i ’the pitch-line of the rack. Draw through P, the point of contact, a line
. of action I}? A making any angle with T T; let fall CA perpendicular to EA, producing it to eat
0’ A __ 1’ A
01’ _ .P .D'
the rack moves through the distance PD, the wheel turning also as shown by the arrows, will trace
on the plane of the rack the right line D A, and on that of the wheel the involute B A of the base-
circle A 0. By reversing the rotation and letting,' the pencil travel from 1’ to E, we should evident-
.ly obtain the extension B G of the curve and D F of the right line; and it is equally clear that by
thus reversing the direction, the curve A B (1' will drive the rack to the left with a constant velocity
ratio, the locus of contact being A E. The point A limits the top of the rack-tooth and the bottom
of the acting wheel-tooth, the action in the case above supposed beginning at A and ending at E ;
the latter point being found, if G be assumed, by describing a circle through G to cut the line of
action: by drawing through E a parallel to T T, we find F, the point of the rack-tooth which will
meet G in the action. So if we assume I as the highest point of the rack-tooth, a parallel to T T
through I cuts EA in H, giving H P, which will be equal to the are of action on the right of C P,
measured on the base-circle: on the pitch-circle or on the pitch-line of the rack, it will be JP, found
by drawing HJ perpendicular to E A, cutting T T in J. If I be assumed, D L, found by dropping
from I a perpendicular on T T, must not be greater than half the thickness of a tooth, and should
be less; and the same is true of BR, the intercept on the pitch-circle between Band the radius
0 G. As in Fig. 2091, practical proportions are in this diagram disregarded; the obliquity of the
T Tin D ,' then Therefore a pencil at P, traveling from P to A in a right line while
2093. -
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'line of action should be no greater than in the case of two wheels, and the appearance of a working
rack and wheel of this construction is shown in Fig. 2094.
It may be added that it is possible also to construct annular gearing with involute tooth-lines ; but
the fact is of no practical importance, as the teeth of the outer wheel will assume a form very dim-
cult to make.
To find the Form of a Tooth which shall gear correctly with one whose Form is given—If a tooth
of any reasonable form be given to a wheel, it is possible to find the curves which by rolling upon
the pitch-circle shall generate the given tooth-outline; and, by using the same describing curves in
connection with the pitch-circle of another wheel, to construct a teeth which will work correctly with
the first one. The describing curve may or may not be a circle; but the operation above described
is more laborious, and the result less reliable, than the mechanical method illustrated in Fig. 2095.
Let the form of the assigned tooth, A, be accurately cut out as part of a piece of cardboard of the
form of a sector EE, whose centre is .D, that of the given pitch-circle, 111A N; which is to be
drawn on the tooth, cutting its outline at P. Cut out also another sector, FF, on which describe
the pitch-circle L 0 of the other wheel, and also a' radial line OP. Draw on the first sector the
radius D P; then by making 1’ on the one coincide with P on the other, and setting the two radii
by the same straight-edge, the proper distance between the centres will be fixed, and each sector may
then be fastened to the drawing-board by a pin through its own centre, being thus free to turn. EE
being uppermost, as shown, the outline of the tooth is to be traced on the lower sector. Then turn-
ing it through a small angle, FF is to be turned also through a corresponding angle, which will de-
pend upon the ratio of the diameters of the pitch-circles, and the outline of A traced again. By
marking on each sector the angle subtended by a given length measured on its pitch-circle, and grad-
uating its edge by subdividing this angle into the same number of equal parts on each sector, the
corresponding movements of the two may be readily and accurately adjusted by reference to two
fixed marks on the drawing-board, as shown at R, S. N ow, in every position of A relatively to the
tooth with which it is to gear, it must be tangent to it somewhere. By tracing the outline of A
repeatedly, we simply keep a record of the difierent positions, and by drawing a line tangent to them
all, as thus traced, we must have the form of the tooth to which it was thus tangent. If this opera-
tion be carefully performed, and a sufficient number of positions of A traced, we shall find the space
cos “ GEARING.

on the lower sector, between the adjacent teeth X, Y, covered with fine lines, andthe forms of those
teeth accurately mapped out.
Non-symmetrical Teeth—Were the two sides of the tooth A in Fig. 2095 exactly alike, it would
be unnecessary to map out in the manner described more than the outline of the single tooth X.
Now it is usual to make a wheel-tooth symmetrical about its central radius, the opposite sides being
formed of similar curves, as we have all along supposed to be done. But this is of course not essen-
tial; the fronts and backs of the teeth, being entirely independent of each other, may be formed by
using diiferent describing curves: thus, as in Fig. 2096, we may make teeth of the involute form on
one side and epicycloidal on the other, if for any reason it should be thought desirable.
TWISTED SPUR-GEARING.—If we suppose a pair of ordinary spur-wheels to be split tranverscly into
thin laminae, each of these thin spur-wheels will correctly drive the one with which it is in gear. 11"
p in Fig. 2097 we suppose the laminae of which the lower wheel 1) is composed to be twisted upon
each other to the right, so that each one shall overlap the one below it to the same extent, those of
the other wheel, 0, will be driven round to the left. The original tooth-surfaces of the wheels were
composed of rectilinear elements parallel to the axes; if we suppose these laminae to be of no sensi-
ble thickness, infinite in number, and uniformly twisted or rotated past each other, these rectilinear
elements will become helices. If the laminae be of sensible thickness, we shall have what are called
stepped wheels, those which are fixed upon the same axis, and constitute practically one wheel, being
yet essentially distinct wheels in difiierent phases of action; nor is this fact altered by any diminution
in the thickness of the laminae. When that diminution reaches the limit, and the tooth-surfaces are
composed of helical elements, we have what is known as Hooke’s spiral gearing, to which we have
2095.






ql'D
given a different name, because it is also often but erroneously called screw-gearing. The transmis-
sion of rotation in this form of gearing is due to the successive action of the laminae of one wheel
upon those of the other, each in its own plane, however thin they may be supposed, exactly as one
spur-wheel acts upon another; and not in any manner or degree to the helical form of the elements.
In spur-gearing proper, the common normals to the tooth-surfaces, which being cylindrical are tan-
gent all along an element, all lie in planes perpendicular to the axes. In twisted spur-wheels, the
helicoidal tooth-surfaces, if tangent along any line, touch each other along one ‘which will vary in
form with the amount of twist and also with the actual form of the transverse section or outline of
the tooth, and at any rate partakes more or less of the helical form. The common normals will
therefore not lie in planes perpendicular to the axes; the consequence of which, and of whatever
may be screw-like in the action of the wheels, is to produce, not rotation, but end-pressure in the
lines of the axes. >
The advantage of thus twisting the teeth arises from the fact that different phases of the action
exist in every position of the wheels relatively to each other. The action of a pair of spur-wheels
is at its best when the point of contact is on the line of centres, or more properly, since they have
sensible thickness, when the element of contact is in the plane of the axes. And if a pair of spur-
wheels of any given thickness be twisted through angles measured by the arcs of action, it is clear
that there will always be one point of contact in the plane of the axes. This being the case, it fol-
lows that if desired the transverse sections, or tooth-outlines, may be such that the action of one upon
the other shall begin and end upon the line of centres, continuing but for one instant. This is easily
done, as may be seen in Fig. 2098, where both wheels are shown with radial flanks to the teeth.
' A GEARING. 909

Were the wheels to work in the ordinary Way as spur-wheels, the faces of the teeth of 1) should be
' formed by rolling the upper describing circle uponthe lower pitch-circle; but now they may be of
any form that will'lie within the epicycloids that would be thus generated, but should be tangent to
the radial flanks of D ; and a similar argument holds in relation to the upper wheel. When this is
done, the sliding disappears, and the wheels work in pure rolling contact; but there is at any instant
only a single point of tangency, which must bear all the pressure, and this travels along the wheels
from end to end as they turn. The action is, however, remarkably smooth and noiseless, so that
such wheels are peculiarly fitted for high velocities under moderate pressures.
But, whatever the form of the section, the tooth will ultimately become a helical element of the
pitch-cylinder. In Fig. 2099, AB, CD are the axes of the cylinders E H, E I, tangent along the
' element E L. Let the twist be such that on the lower cylinder the elementary tooth shall be the
helix E F ,f then that upon the upper will be the helix E G, the axial advance being the same, but
the perimetral travel being at rates which are to each other inversely as the diameters of the cylin-
ders, since the arcs whose projections are L F, L G must be equal in length by the mode of deriva-
tion. These helices must coincide when developed upon the common tangent plane; hence, if one
be assumed, the other may be found by developing the first and then wrapping it upon the other

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cylinder. The cylinders in Fig. 2099 are externally tangent, and it is obvious that if the helix on
one be right-handed, that on the other will be left-handed. An annular wheel, with its pinion, may
be also made with twisted teeth in the same manner. In this case, the larger pitch-cylinder being
internally tangent to the smaller, the helices will be either right~handed or left-handed on both.
And it will readily be seen that a wheel gearing with a rack may be modified in the same way: each
lamina of the rack being advanced beyond the succeeding one to the same extent, in twisting the
wheel uniformly, it is clear that the tooth-surfaces of the former will be composed of right lines,
oblique to the plane of rotation. And when the teeth of the wheel ultimately become helical ele-
ments of the pitch-cylinder, those of the rack will become right lines in the tangent-plane, coinciding
with the developments of those helices. The pressure in the direction of the axes, above mentioned,
may be neutralized by making each wheel in two parts, one of which is twisted in one direction, and
the other in the opposite.
ON THE DRAWING. or EPITBOCHOIDAL (leaves—All curves traced by a marking-point carried by one
line which rolls upon another are called epitrochoids; and among them are the cycloid, epicyloid,
hypocycloid, and involute, forming the outlines of the teeth of wheels. The following graphic pro-
910 GEARING.

ccsses will be found of great utility and convenience in many operations besides that of drawing the
curves above mentioned.
I. T 0 find approximately the length of a given circular ure.—Let C, Fig. 2100, be the centre of the
circular are A B. At A draw the tangent A T ,' draw the chord BA, bisect it at D, and produce it ~
to E, making A E : A D. With centre E and radius E B describe an are cutting the tangent in
F. Then A F will be approximately equal in length to the given are A B. It is stated by Prof.
Rankine, from whom these processes are taken, that if the angle A C B, subtended by the given are,
be 60°, A F thus determined will be too short by about gig of its own length. Also, the error
varies as the fourth power of the angle; so that if an arc of 30° be rectified by this process, the
theoretical error will be reduced to Wig—5.
II. On a given circle to lag of an are approximately equal in length to a gii'en straight line—Let \
the given line A B, Fig. 2101, be tangent at A to the given circle. On A B make A D :: 1- A B,-
with D as centre and D B : g A B as radius, describe an are cutting the given circle in F; then
will A E: A B, nearly. The error in this construction is the same as in the preceding one, and
follows the same law. If then A B, when found as above, subtends an angle of more than about
60°, the given line A B may be subdivided, and the arc corresponding to any fraction of it determined.
III. Tofind the radius of a circle on which an arc of a given length shall measure a given angle.—
Let A B, Fig. 2102, be the length of the arc. Draw the indefinite line A G, making the'angle BA G
half the given angle; also draw A H perpendicular to A B. Set off as before A D = i A B, and
with centre D and radius D B describe an are cutting A G in E. Bisect A E by a perpendicular
cutting A H in 0; then A C is the radius sought. For, drawing the arcA E and the radius GE,
the angle B A E, between the chord and the tangent, is half the angle A O E at the centre.
This being only an application of the preceding process, and involving the same error, if the given
angle be over 60°, both'it and the given line should be subdivided. By this method we may readily
find the diameter of a circle when the circumference is given; for, making A B one-sixth of the
given circumference, and the angle B A G equal to 30°, we at once have A E the radius.
The Cgeloicl.—Let the circle whose centre is C, Fig. 2103, roll on the "right line A B, to which it
is tangent at P; then a marking-point at O in the circumference will trace the cycloid 0RD.
Divide the semi-circumference B 0 into equal parts at 1, 2, 3, etc; set off PD equal to this semi-
circumference, and divide it into the same number of equal parts at the points correspondingly num-
bered. The number of subdivisions is immaterial; practically the six shown are sufficient and the
most readily made, PD being found by rectifying P 2 as above explained, and setting off the length
thus determined~three times from P.
The points 1, 2, 3, etc., on the circle,
will come successively into contact
with the points 1’, 2', 3’, etc., on the
\ tangent; and the centre, traveling
in the line parallel to A B, will be
always vertically over the point of
2103.
fl"

\TE‘G contact. Thus, when 0 2 becomes
/' the contact-radius, it will have the
'9 - position E2’; when 04 is the con-
tactfradius, the centre will be at F,
“ fl 3 and so on. But the distance from 0


to the point 2 on the circle is the
same when the centre is at F as when
it is at G: if then» we set off from
the point 2’ on the tangent the chord
2' R : 0 2 on the circle, ER will be
the position of the generating radius
0 O for that position of the circle,
' ' ' and R a point on the cycloid. ,When
0 has reached F, 04 being contact-radius, the generating radius will be F S, the chord 4’ 5’ being
made equal to the chord O4; and in like manner any number of points may be found. When ()
reaches D, the radius 0 0 will have the inverted position G D, to which the cycloid is tangent at D.
The rolling motion of the circle is compounded of a rotation on its axis and a bodily translation
‘in the direction 0 G. We may imagine these motions to take place separately and successively,
instead of simultaneously, and thus find points in the cycloid in another way. If, for instance, we
suppose the circle to be turned round its centre 0' until 0 2 takes the place of O P, this will bring
the generating radius 0 'O to the position 04; if we then push the circle forward through a dis-
tance O E equal to the are 2 P or 04, we shall have the generating radius ER in its correct posi-
tion, parallel to 04. So also if 0 be turned round 0 to the point 2 on the circle, and then pushed
forward to S, the distance 2 S being equal to the are 0 2, then S will be a point on the cycloid.
But a more rapid and accurate method of drawing the curve is by-means of tangent arcs. This
method depends on the fact already stated, that in rolling contact the point of tangcncy is in the
instantaneous axis. Thus, in the original position of the circle, P is the instantaneous centre; and
when the circle begins to roll, every point in or connected with it is at the instant in 'the act of
describing a circle of which P is the centre. If then we describe an are about with radius 0 1’,
the direction of that are is also the direction of 0’s path at that instant. When 02 becomes the
contact-radius, the instantaneous centre will be the point 2’ on A B. But as the chord 0 2 of the
circle does-not change its length, it must then be the instantaneous radius ; therefore, if about 2’ on
the tangent, with radius 2’ R : O 2, we describe an are, it also will coincide in direction with. the
path of 0 at the instant. Now the direction of a chrve at any point is that of its tangentat that


GEARING. \ 911

point; and these arcs being traced by O, which also; traces the cycloid, it follows that the latter
curve is tangent to the arcs.. If then we take as centres the points 1’, 2', 3', etc., on A B, and about
them describe arcs, using as radiithechords 0 1, O 2, etc., the envelope of these arcs, or curve tangent
to'them all, will be the cycloid. And these arcs serve better as guides in drawing the curve than
actual points would, since they do give an indication of its direction, while the points do not. By
making a greater number of subdivisions and striking a greater number of arcs, the cycloid may be
mapped out with any desired degree of precision, though not a single point he found. Should the
point of the curve corresponding to any point of contact, as for instance 2’ on A B, be required, it is
quickly found by erecting the perpendicular 2' E to locate the centre, and cutting the cycloid by an
arc of the describing circle, which will of course give R the extremity of the instantaneous radius
I for the point selected. This instantaneous radius is of course the normal, and TR T perpendicular
to it is the tangent, to the cycloid at R; and the radius of curvature is R L, found by prolonging
and doubling R 2' ; so also MS, twice the instantaneous radius 4’ S, is the radius of curvature at S.
The Epicycloz'd.—-This curve is traced by the rolling of a circle, not upon a bane-line, but upon the
outside of a base-circle. In Fig. 2104, H is the centre of the base-circle, O that of the rolling one,
in the circumference of which is
_O, the marking-point. P being M 2104.
the point of contact at starting,
the radii O P, PH lie in one right '
line; and-as the point of contact 57,
must always lie on the line of cen-
tres, when 0 reaches E the line 6'
E H will cut the base-circle A PB
at 2', the point of contact then, /
and P 2’ must be equal to the are ’ /,"-_
P2 which has rolled over it, and '
the path of 0 will be a circle whose 71 _. . .
centre is H. vThe first step then ' *\-s.
is to subdivide the semi-circumfer- ,
ence P 0 into equal parts at the
points 2, 4 (a greater number be-
ing of course used in practice; but
the analogy to the preceding figure .- /
is so close that what is here shown
will suffice for illustration). On
the left is shown the operation of
rectifying P V, an are equal to
P 2, on the common tangent P T,
and of setting off on the base-cir-
cle an are P W equal to the length
thus found and therefore to P2.
Equal arcs P 2', 2' 4', 4' D, being
then set off from P toward B, we
have PD equal to the half eir- . H
.cumference P 0. Now, when G 2 I Y j
is contact-radius, E must be the '
centre of the describing circle; and making 2’ R : 2 O, we have R, a point in the curve. Other-
wise, the rolling being now compounded of a rotation about 0 and a revolution about H, we may
first turn the circle in its original position until 2 reaches P, which will bring 0 to 4 ; then a circu~
lar are through 4 with centre H will cut the describing circle in its second position at R.
But, again, the method of tangent arcs may be used. When 0 2 becomes contact-radius at E 2’, the
point of contact 2’ is the instantaneous centre, 2’ R equal to 2 O is the instantaneous radius, and
the curve will be tangent to the circular are thus determined; and by repeating this as in the case
of the cycloid, the curve may be most expeditiously mapped out, without finding a point in it. If
the radius of curvature at any point, R for instance, be required, an are described about R with the
radius of the rolling circle will give by its intersection with C’ G the path of the centre, the position
of the latter when the marking-point is at R. Then E H determines 2', the corresponding point- of
contact, and the position R 2’ of the instantaneous radius, normal to the curve. Prolong R 2" inde-
finitely, draw R E the generating radius, and HI parallel to it. Bisect 2' H in K, draw R If and
produce it to cut HI in L, and draw L 11! parallel to HE, which will cut the prolongation of R 2’ in
11!, the centre of curvature. ‘
The Hypocyclot‘d.—This is generated by a marking-point in the circumference of a circle which
rolls on. the inside of another of greater diameter. The construction is illustrated in Fig. 2105,
which is lettered throughout to correspond with Fig. 2104; and the steps of the process being iden-
tical, including the finding of the radius of curvature, no further explanation is necessary.
The Intermal Epicycloz'd.—If one circle be internally tangent to another, and the greater roll upon
the less, a marking-point in its circumference will trace what is called the internal epicycloid, merely
to call attention to the particular mode of generation. For it is to be noted that every epicycloid
may be generated by the rolling upon the same base-circle of either of two circles; and the same is
true of the hypocycloid. Thus, in Fig. 2106, in the diagram on the left, let D be the centre of the
base-circle, and G that of one which by rolling upon it will generate the. epicycloid shown, the tan-
gency being external. Then the same curve will also be traced by the rolling upon D of the circle
E, to which it is internally tangent; the diameter of this larger circle being equal to the sum of the



912 GEARING.

diameters of the other two. Thus every internal epicycloid is also an external one ; but the epitro-
coids traced by points carried by these different describing circles, not on their circumferences, will
not be the same. In the diagram on the right, D is the centre of the large base-circle, within which
are shown two describing circles, the sum of their diameters equaling the diameter of 'D ; and the
2103.
hi,
2106.
_ 1
E
same hypocycloid will be traced by the
rolling of either of them within the out-
er circle. In both these cases, if the
curve be traced in a given direction, the
two circles by which it may be gener-
ated will roll in opposite directiOns.
The Epitrochoz'd.—It is evident that
the marking-point carried by a rolling
circle, or other line, need not be in the
rolling line. Although, as above stated,
the term epitrochoidal is applied in gen-
eral to all lines generated by marking-
points so controlled, yet the name epi-
trochoc'd is also specifically applied in
' the case in which the point is carried
by one circle rolling upon another, and
is not situated in the circumference. If
it be outside the rolling circle, the curve
is called a cw‘tate epitrochoid, and is
looped, as shown in Fig. 2107. If the
marking-point be within the rolling cir-
cle, as in Fig. 2108, the curve is waved,
the marking-point never reaching the
base-circle, and is called prolate. The
epicycloid is therefore, it will be seen,
but a special case, being the boundary
between these two forms; and the mark-
- ing-point just reaching the base-circle,
I there is neither wave nor loop, but the '
curve is tangent to the radius G D, the
adjacent branches forming a cusp. The
construction by points is almost self-evident; the position of the generating radius, being controlled
by the rolling circle, is determined exactly as in the previous cases, and, its length being constant,
points in either of these curves are found as readily as in the others. And it will be at once seen
by these figures that the method by tangent arcs is of perfectly general application, in drawing all
curves capable of being thus generated.
The point of contact at any instant is the
centre of rotation at that instant, and the
distance to the marking-point is the in-
stantaneous radius, with which the tan-
gent arc is to be described.
The Involute of the Circle—This may
be considered in a sense the converse of
the cycloid, being generated by a point
in a right line rolling upon a circle. Or,
what amounts to the same thing, if a pen-
cil be fixed at the end of an inextcnsible
string of no sensible thickness, and the
string be wound upon or unwound from
a circle, being held taut, it will trace the
curve in question. It is easily construct-
ed, as in Fig. 2109. The circumference
being divided into equal parts at the
points 0, 1, 2, etc., a tangent is drawn at each point, and on it is set off the length of the are meas-
ured from the point of starting to the point of tangency. Thus, let the semi-circumference be unwound
to the right, beginning at 0; then the tangent 1 1 is made equal to the are. 0 1, the tangent 2 2 to the
are 0 2, and so on. The method of tangent arcs may also be used here. The points 1, 2, 3, etc., on



J






GEARING. 913

the circle being the instantaneous centres, the tangents 1 1, 2 2, etc., are the instantaneous radii.
These tangents are also not only the normals to the curve, but also the radii of curvature at the cor-
responding points. _
OF CIRCULAR nun DIAMETRAL Prrcm—The term pitch, as has been explained, is used to denote the
distance, measured on the pitch-circle, which is occupied by a tooth and a space ; or in other words,
the are found by dividing the circumference into as many equal parts as there are teeth in the wheel.




\‘\\\\\\\\\\ .
{\\\
\\\\\\\


\‘(\


A"
.\
\\\“
|.\\





We have, then: Pitch x number : circumference; whence, if either two factors be given, we readily
find the third. It is clearly more convenient to express the pitch in whole numbers or manageable
fractions, as 2-inch pitch, 1%411Ch pitch, and so on. But the circumference being 3.1416 times the
diameter, it happens that if this system be adopted, the diameter of the pitch-circle will often involve
an awkward decimal. ‘The pitch as above defined is styled the circular pitch, in order to distinguish
it from what is called the diametral pitch, the use of which is designed to avoid the inconvenient
fractions above mentioned, and otherwise to facilitate the necessary calculations. The diametral
pitch is simply the quotient found by dividing the diameter of the pitch-circle, instead of the circum-
ference, by the number of teeth. Its relation to the circular pitch is clearly seen thus:
diameter x 3.141 6
Circular pitch = ,
number of teeth
Circular pitch diameter
3.1416 _ number of teeth.

Diametral pitch :
In the practical use of this system, values of the diametral pitch are selected, being fractions hav-
ing unity for the numerator and a whole number for a denominator in each case, as a, 15L, {0, 914, etc.
. . . _ number of teeth
The denominators of these fractions are evrdently the corresponding values of ——€_—-——t——’ an
' lame er
are used to designate the wheels; thus, a “ 4-pitch wheel” is one of which the diametral pitch is 4, .
and so on. Suppose, for example, that we wish to know the diameter of a wheel of 40 teeth, of “ 5-_
pitch ”: we have $59- = 8 2 diameter of pitchrcircle. Or if the number of teeth of “ 8-pitch ” in a;
wheel of 17% diameter is desired, we have 8 x 17% :: 140 = number of teeth.
The advantage of this system lies in the obvious fact that it is practically more important to have-
the diameter of the pitch-circle either a whole number or a convenient fraction, than that the cir-_
cular pitch should be either.
Bevan-Gamma. - .
Bevel-wheels are. used for the transmission of motion from one axis to another which intersects it.-.
They are also called conical wheels, because the pitch-surfaces are cones, whose common apex is the-
intcrsection of the axes. It is usually the case in practice that the positions of the axes are given,.
and it is required to make the wheels so as to preserve a given velocity ratio. The first step is to~
find the forms of the pitch-cones. In Fig. 2110, let A B, CD be the axes, meeting at V; and let"
us suppose that two revolutions of the former are to produce three revolutions of the latter. Draw-
a line an, parallel to A B, and at a distance from it measuring 3 on any convenient scale of equal
parts; also a line m m, parallel to O D, and at a distance from it equal to 2 on the same scale. These
lines intersect at P; and drawing VP, we see that it will by revolving around A B generate one
cone, while if it revolve around 0 D it will generate another, the two being tangent along V P; and
these are the pitch-cones required. The line mm is here drawn within the angle B VD : had it
been drawn within the angle A VD, as in Fig. 2111, we should have had a; different pair of cones;
the velocity ratio is the same in either case, but it will be seen that, supposing A B to rotate in the
same direction in both instances, the rotations of O D are in opposite directions. Now, only limited
portions (frusta) of these cones need or can be employed, as shown in the figures; Their distance
from the vertex is immaterial, so far as the theory is concerned ; and this, which also determines the
actual size. of the wheels, is usually decided by considerations connected with the framing of the ma-
chine or the power to be transmitted, with neither of which we have to do in ascertaining the forms
of the teeth. If one shaft canv be carried past the other, however, we see that. we have. the choice
58 -
.914 ‘ GEARING. ‘

between two pairs of wheels, each giving the same velocity ratio, but diifering in regard to the direc-
tions of the rotations. The choice here is also usually determined by the conditions of the machine
in which the wheels are to be used; we will therefore suppose that the pair shown in Fig. 2110 has
been selected, and that the teeth are to be laid out.
The manner in which this is usually done is as follows: In Fig. 2112, VP E, V PH are the pitch-
]3 2111.
. V/ 2-~IIT-~_~m


cones, VP being the common element, which and the axes are in the plane of the paper. Draw
through P a perpendicular to VP, cutting A B at F and CD at G. Then, if PF revolve around
A B, it will generate a cone P FE, whose elements are normal to those of VP E. So also P G by
revolving around G D generates a cone P G H, normal to VPH. These normal cones are now to
be developed. It is clear that if F G
be the trace of a plane perpendicular to
the paper, it will be tangent to both;
and the right-hand part of the diagram
shows the development of the cones upon
it. The vertices appear as the points
I, K ; the base of the upper cone will be
a part of the circle L M, whose radius
is F P, and that of the lower will be a
part of the circle N 0, whose radius is
G P. Upon these circles teeth are to be
laid out as if they were the pitch-circles
of spur-wheels, being usually made of
the epicycloidal form. Were the whole '
' surface of a normal cone developed, all
the teeth laid out, a thin sheet of metal cut to the form thus found, and then wrapped back upon
the cone, we should then have the outlines of the teeth on the larger end of the wheel. But in order
to make the drawings, we need only lay out a single tooth on the development of each cone. how
the pitch is the same on both wheels, and when we have decided on the number of teeth, we know
what it will be. We have then only to rectify such a fraction of the base-circle of either cone, E P
2118.





_A—'_ cash--JI-n
I


I-—-:-— I1_ lic-1.. “C-“l “Ini-
/
,


‘~._-I.- ___-_qq-- —--_I__-- ---__
for instance, as will contain the pitch any convenient number of times, set off _on each circle 1n the
development from the point of contact an are equal in length to this rectification, by the processes
already described, and divide each of these arcs into the same number. of equal parts, to obtain the
correct pitch on the developed bases and construct the teeth Supposing this to" be done, the mode
.of completing the drawing .of the larger wheel is shown in Fig. 2113. .
GEARING. 915

It is evident that, as the teeth project beyond the pitch-cone, both it and the normal cone must be
enlarged beyond the original dimensions. Thus F P must be extended till F D is equal to the ex-
treme radius of the developed tooth, which is projected back upon it, and the blank for the wheel
will consist of a frustum of the cone D VH, joined to a frustum of the normal cone D F H. The
bottom of the space in the development is also projected back upon F P at E, and the top and bottom
of the tooth will be bounded in the section shown in the lower half of the side view by the lines
D G, E K, converging in V. Having decided on the length PR of the teeth, the inner end is lim-
ited by another cone normal to the pitch-cone, generated by a line through R perpendicular to V P.
If a side elevation is to be drawn, the end view must be first constructed. The points D, P, E, in
revolving around the axis, describe circles which correspond to certain circles in the development.
Thus P describes the base of the pitch-cone, which develops into L M. In the end view, whose cen-
tre is 0, this circle is seen in its true size; and the breadth of a tooth or of a space measured on
this circle must be the same as the breadth measured on L M. Similarly the breadth on the outer or
inner circles, described by D and E, must be the same as on the corresponding circles in the develop-
ment. Since the arcs are equal, but the radii different, the chords will not be equal :- practically,
however, the diiference will not be appreciable unless the wheel be of great size or the pitch very
coarse ; and by the processes of rectification and its converse, previously explained, the difference
may be determined graphically if desired. Intermediate circles may be drawn in the development
and in the projections, and similarly used, for determining the breadth of the tooth at other points,
and thus fixing the outline with precision. The form at the inner end is precisely similar but smaller,
and is constructed by drawing radial lines to cut the series of smaller circles described by the points
G, R, K. The radius of any intermediate circle in the development being projected on FD, and a
line drawn from the point thus found toward V, cutting GK, we shall have the point which will





describe the corresponding intermediate circle at the inner end of the tooth. The drawing of one
tooth in the end view being completed, the others are copied in their proper positions, and the various
points projected to the corresponding circles in the side elevation, where, being seen edgewise, they
appear simply as right lines, G J, D H, etc. Since all the elements of the tooth-surfaces converge
in V, it is better here also to determine only the forms of the teeth at the outer end by projection
from the end view, and to draw converging lines toward V to find such outlines as may be visible at
the inner end.
This method of laying out the teeth is, however, only approximately correct. In spur-gearing the
tooth-surface is generated by the element of a describing cylinder rolling in contact with the pitch-
eylinder; and it can be shown that in an analogous manner the tooth-surface should be generated by
the element of a describing cone rolling with the pitch-cone. By following the motion of the describ-
ing element of this auxiliary cone, and finding the points in which in different positions it pierces the
normal cone, we can construct the trace upon the latter of the surface thus generated, or in other
words the outline of the correct tooth. The error of the method first described, then, consists in the
assumption that this outline when developed will be a true epicycloid, hypocycloid, or involute, as the
case may be.
In Fig. 2114, P VH is a pitch-cone, PF H its normal cone, and P V G a describing cone, which
by rolling on the outside of P VH will generate the surface of the face of the tooth. The normal
cone is to be extended as far as may be necessary to determine the line in which the describing cone
intersects it; in the side view this line is P T G, and in the end view, which is a projection on a
plane perpendicular to VF (the axis of the pitch and normal cones), it appears as the curve P T G U.
N ow, taking P V, the common element at starting, for the describing line, it is clear that if the cone
VP G were to turn while the normal cone did not, that element would trace on the latter merely
this line of intersection. But the normal 'cone does turn, and, the ratio of the two velocities being
known, we can easily find the actual trace of VP upon it by the aid of this line of intersection.
916 ‘ GEARING.

Thus, let the lower cone turn until D P appears in the end view as D 1’ ; then the upper cone will '
have turned through the known angle P V1, and the curve 1 1' must meantime have been traced
upon it. So when D P has gone to D 2', P V will have gone to V2, and the curve 2 2’ will have been
traced, and so on.
As an illustration of the extent of the error in the approximate method, we show in Fig. 2115 a
full-size outline of a teeth as determined by it, and also as found by the process just explained.
2115. ' 211v.
'B









,__J












'
/Z.’/////llllllllllll “\‘I \\\\\\\\\\\‘l
in







0
The wheel is one of 30 inches diameter, with 24 teeth. The describing cone was taken of the
diameter which would generate a flank surface most nearly approximating to a plane, the difference
being inappreciable within the limit of the depth of the clearing space; and this being designed to
gear with another wheel exactly similar, the same describing cone was used for the face of the tooth
also. The form of the teeth which would be determined under these conditions by the first method
is shown in dotted lines; the full lines being of the correct form as found by the second method.
The discrepancy is quite marked, and sufficient to make a material difference in the smoothness of
the action and in the durability of the wheels. , ,
It was remarked in connection with Figs. 2110 and 2111 that, with a given pair of axes and a
given velocity ratio, it is always possible to construct two pairs of pitch-cones, 'of which the direc-
tional relations are different. , Of these, one' pair will always be in external contact; but, as shown
in Fig. 2116, the other pair may be such that one of the two shall touch the other internally. In
this case the methods of constructing the teeth will be analogous to those used in annular spur-gear-
ing. Or again, as in Fig. 2117, the common element VP, as determined. by the process described,
may ‘be perpendicular to one of the axes, the pitch-cone thus degenerating into a plane. Thenormal
GEARING. _ 917

cone then becoming a cylinder, its base will develop into a right line, and the construction of the
teeth by the first method will be similar to that applicable in the case of a rack and wheel.
Twidcd Bevel- Wheeler—We may suppose a pair of bevel-wheels to be cut transversely into thin
laminae, as we did in the case of two spur-wheels. Each of these thin wheels will drive its mate, and
as before we may twist them round so that each one shall overlap the next one on the same axis, to
the same angular extent. Supposing the laminae to be of inappreciable thickness, we shall thus
transform the converging rectilinear elements of the tooth-surfaces into conical helices; and if the
teeth be now made indefinitely small and numerous, they will ultimately become such conical helices
lying on the pitch-surfaces, as shown in Fig. 2118. We may thus attain in bevel-gearing the same
advantages that were shown to belong to twisted spur-gearing. Nor would it be diflicult to make the
teeth of this form in any engine in which it is possible to cut bevel-gearing correctly. Spur-wheels,
as is well known, may be cut with precision by a milling-cutter whose outline is that of the space
between two teeth, because the elements of the teeth are parallel to the axis, and the space every-
where of the same size and form. But the space between two teeth of a bevel-wheel continually
changes its size, and though the outlines of parallel sections are all similar, they are of different
curvatures. Consequently the teeth can only be formed accurately by planing, as in the cutting
engine of Corliss, the tool traveling always in a line toward the vertex of the pitch-cone. Now, if
the blank be made to rotate uniformly during each cut, the desired twist may be given to the teeth
with ease and perfect accuracy.
SKEW-GEARING.
When two axes lie in different planes, motion may be and often is transmitted from one to the
other by means of two pairs of bevel-wheels; a third axis being introduced, cutting the other two.
But it-is possible to make a pair of wheels, one upon each shaft, whose teeth shall be composed of
rectilinear elements, touch each other in a right line, and transmit rotation with a constant velocity
ratio directly, thus dispensing with the countershaft and one pair of bevel-wheels. It is usually the
case that the positions of the axes and also the velocity ratio are fixed by the requirements of the
mechanism in which the wheels are to be used.
In Fig. 2119, let A B represent one axis, supposed to be vertical and parallel to the paper; let
G D, also parallel to the paper, represent the other axis. These projections intersect at E, which
point represents the common perpendicular of the axes; this line, being horizontal, will be seen in}
its true length E' A’ in the top view above, where A' represents the vertical and O ’ D’ the inclined
axis. The lines nn, m m are now drawn parallel to A B and G D, at distances from them which
are to each other in the inverse ratio of the given angular velocities; these intersect at P, and P E
will here, as in the case of bevel~wheels, represent in this view the common element of the pitch-
surfaces, which will also be parallel to the paper. Through any point of this line, as G, another
line F H can be drawn perpendicular to it, and so as to out both the axes. Its vertical projection
EH will be perpendicular to G E, because the latter is parallel to the paper; in the horizontal pro-
jection, F, being a point in the vertical axis, will appear as A', and H will appear as H’ in C" D’,
thus giving A’ H’ as the horizontal projection of F H. Now project G to G’, draw G’ I ' parallel
to C" D', and it will be the horizontal projection of G E. This line lies in a plane parallel to both
2120.













2119.
I! .
' I
' i
l i -\\i‘ I
A: l i B :\‘
C i :17 i ' \\E_{__./=/ 1%
- a 2 s -/
A i : : :
l I j .1
l : : :
l l
' i Ti ‘ H
| \ a
l
I : """‘""“'"
....._ .3... K
.Ii : T
' *3 J}


axes, and intersects at I ', their common perpendicular, dividing it into segments proportional to
A’ G', G' H ’, and therefore to F G, GH: by revolving ardund A B it will generate one surface.
and by'revolving around 0' D it will generate another, tangent to the first, which will be the pitch-
surfaces of the wheels. ‘
918 GEARING.

These surfaces are readily constructed, as in Fig. 2120, where the inclined line A B revolves about
the vertical axis, its least distance from which is C' E. Each point in revolving describes a horizon-
tal circle, whose radius is seen in its true length in the top view. It will be seen that the same sur-
face will be generated by a line seen as D F in the front view, and as BA in the top view; for D
and A describe the same circle; so also do G and I ; and the same is true of any two points in
these lines which lie in the same horizontal plane.
The two surfaces generated by the line G E of Fig. 2119 are shown in position in Fig. 2121 ; the
generatrix being prolonged to L, so that the end planes are equidistant from the game-circles, as the
transverse sections through E are called. These surfaces are called hyperboloids of revolution, as
it can be shown that the meridian section of each (as H K L of Fig. 2120) is' a hyperbola. Their
action consists of rolling, with however a sliding in the direction of the common element, because
the two circles which move in contact have not a common tangent. To make this clear, the gorge-
circles of the two pitch-surfaces are shown in Fig. 2119, in dotted lines, in the top view; thein
common point is I ’ ; and if the inclined one turn, it will cause the vertical surface to rotate, the
directional relation being shown by the arrows. In the other view the common point of these two
circles is E; and at the instant the linear velocity of the inclined circumference may be represented
by EM, a tangent to it, of any length; at the same instant that of the other gorge-circle must be
also represented by its tangent EN. The length of the latter is determined by the consideration
that no motion in the direction E G would transmit rotation, which is effected solely by the com-
ponent E 0 of the supposed motion E .M, which is perpendicular to E G, O 1]! being the tangential
or sliding component; and the resultant EN must have the same normal component. Now the
angular velocities will be equal to the linear velocities EM, EN, divided by the radii 1' E ’, I ' A' .;
I I I I
and recollecting that : 1-4—G- = £9 , we will let
I ’ E ' G’ H’ G H
'v : angular velocity about inclined axis (7 D,
. 21’ = angular velocity about vertical axis A B.
Then we have

Ellll
v-FEI v EM'Jur EM FG
}.'.—::--——x—7-~,= x——,or,
0, EN I 21' EN [E EN GH
_I’ A’J
f l JIIEN EFH EH LG EH FG
o a 0 fl : —‘_ X : __, X —_ .
_rom similar trianD es , , E F G H G H E F
_ . _ R EH_EG
But from Similar trianglesE GH, E G . . . . . . . . . . . . . . . _ GR,
FG GS
and from similar trianglesE GF, E GS . . . . . . . . . . . . . . . . . . . —-
EF_EE;
E G G S __ G S .
EkXEG_GR’
which demonstrates the correctness of the process of constructing the surfaces, as previously described.
In practice thin sections or frusta only of the surfaces are used. In Fig. 2122 are shown three
pairs, either or all of which may be used, the hyperboloids being the same as in Fig. 2121. The
$11
2121. I , . ,
. . 5" :0
‘ /
GI
21
whence —, r:
c
L

l
I
0
I
I
I
n
I
I
I
I
Q
——q-_-—-




, 1‘1
C//B
gorge-circles are the mid-planes of the central pair ; but practically the wheels will work better the
farther they are from the gorge-planes, as the transverse obliquity of the common element diminishes
GEARING. 919

as it recedes from them. For the least distance between the axes is a constant, and at an infinite
distancefrcm their common perpendicular the effect of their separation becomes imperceptible, so
that the-wheels will not differ appreciably from common bevel-wheels.
These wheels are now to be furnished with teeth; and the proper surfaces are generated in a
manner exactly analogous to that employed in the cases of spur and bevel gearing. That is to say,
a describing hyperboloid is used, which, moving in contact with both pitch-surfaces, will sweep out,
asv the rotation progresses, a flank for one and a face for the other. If in Fig. 2121 we suppose the
inclined hyperboloid to be the pitch-surface of a wheel intended to work with another equal and
similar to itself, then the vertical one may be considered as the describing surface, which by rolling
upon the other in external contact, as there shown, will generate the face-surface for its tooth. But
if we consider these, as we have hitherto done, to be the pitch-surfaces, from which it is required to
construct the teeth for either of the pairs of wheels shown in Fig. 2122, then the first step is to de-
termine the describing hyperboloid ; and for convenience, this should be such as to roll with either
pitch-surface with a velocity ratio expressible in whole numbers. Now, referring to Fig. 2121, the
angular velocity of the inclined hyperboloid is to that of the vertical one as G S is to G R. Sup-
posing then that, the vertical one and the velocity ratio being given, it had been required to find the
inclined one, we should have proceeded thus: Knowing G S and the velocity ratio, we find the value
of G R, with which as radius describe about G the arc o o, and through E draw 0 D tangent to this
are, thus determining the vertical projection of the required axis. Through G draw F G perpendic-
ular to E G, cutting A B in F and C D in H. The horizontal projection of G E is G' I ’, and that
of F is A’, as before explained, so that the horizontal projection of FG is A’ G' ; produce this
indefinitely, project H up to it in H’, through which point draw C” D’ parallel to G’ I ', and it will
be the horizontal projection of the required axis. If in this way we draw the new or describing
hyperboloid externally tangent to the vertical pitch-surface, it will be internally tangent to the other,
and vice versa. In the case of external tangency the axes are on opposite sides of the common ele-
ment; but the case of internal tangency, in which they are on the same side, may be directly con-
structed as in Fig. 2123; which differs from Fig. 2119 only in this, that the other tangent through
E to the same circle 0 o is taken for the vertical projection of the required axis.
2124.





i --_v
‘_\\ _\\§§
\
’ ' \\
-' i..\\1
?




' —
.

Having in this manner drawn the describing hyperboloid, we have next to find, by means of it, the
tooth-surfaces. The principle of the method of doing this is illustrated in Fig. 2124. The pitch-
surface is the one with the vertical axis; the large circle in the top view is the upper base, and the
ellipse within it is the intersection of the inclined describing hyperboloid by the plane of that base.
Were the describing surface to rotate while the other stood still, the describing line (which in this
case is the element of tangency, A’ B’) would always pierce the plane in some point of that ellipse.
But both hyperboloids turn, and the velocity ratio is known; let then the smaller one rotate till the
describing line, whose point of penetration at starting is A, pierces the plane in the point 1. The
pitch-surface will meantime have turned through the known angle A C 1', and the curve 1—1’ will
have been traced on the plane of the base. So when the point of penetration reaches 2, the radius
(J A will be at O 2', and the curve 2-2’ will have been traced, and so on. It is to be noted that if
the rotation be in the opposite direction, the curve will be different; showing that the two flanks of
920 " GEARING.

the same tooth are not alike, as they may be and usually are in spur and in bevel gearing. By a
process exactly similar we may determine the trace of the tooth-surface outside the pitch-hyper-
boloid, upon the same plane, using a describing hyperboloid externally instead of internally tangent;
and it will be found that the difference between the two faces of the same tooth is still more marked
than in the case of the flanks. These tooth-surfaces are composed of right lines, and, as in bevel-
gearing, the teeth become larger as they are extended in length; but they do not converge to a point,
nor yet are all the elements in the end view of the wheel tangent to the gorge-circle, nor to any other
circle, as sometimes stated: the tooth-surface makes a definite trace on the gorge-plane, which
ought to be determined for the sake of insuring accuracy in the drawing, if, as is most frequently
the case, the frusta employed are at some distance from that plane, like either of the outer pairs in
Fig. 2122. If the central pair be chosen, it will suffice to determine the trace of the tooth-surfaces
on each of the end planes of the frusta; and the curvature of the meridian section being greatest at
the vertex of the hyperbola, it should be carefully constructed and followed.
But if the frusta be remote from the gorge-plane, the teeth will project from a frustum limited
by transverse planes, in a very unsightly manner. The fashioning of the wheel in that case is illus-
trated in Fig. 2125. Let A B be the axis, ED the generatrix, of the hyperboloid, of which E F is
the radius of the gorge, and F G a part of the meridian section; and let H G, K] be the .planes
limiting the frustum chosen. The curvature of the hyperbola diminishes so rapidly as it recedes from
the vertex, that in many cases the arc G I will not difier sensibly from a right line. If then at P,
the middle point of G I, we draw a tangent to the curve, cutting A B in 0, it will 'in revolving de-
scribe a cone G C H tangent to and practically identical with the pitch-surface within the assigned
limits. The tangent may be drawn in this way: ES is the companion generatrix (see Fig. 2120),
and like E D is an asymptote to the hyperbola. Draw through P a parallel to ED, cutting E S in
L ,- on E S make L 111: EL, and P M will be the tangent required. Draw G R, J V perpendicular
to Fill; these will be the elements of two normal cones, by which the wheel is limited, as in the
case of an ordinary bevel-wheel. In this case the intersection of the describing hyperboloid with
the outer normal cone should be first found, and from that, by a process analogous to those of Figs.
2114 and 2124, the tooth-outline on that cone is determined; and by a similar proceeding, that on
the inner normal cone. The parts of the elements of the teeth intercepted between these two cones
are so short that, as before remarked, it will be advisable also to construct the trace of the tooth-
surface on the gorge-plane for the purpose of accurately fixing the positions of these elements. The
process of completing the drawings of the wheel, after the outline of a tooth on eachnormal cone
has been found, is substantially the same as in the case of bevel-wheels. Every point in either out-
line moves in a circle around the axis; these circles are seen as such in an end view, and as right lines
in the side view, of the wheel. The tooth is therefore first drawn in the end view, the others are
copied in position, and the points in the various circles thence projected to their corresponding lines
in the side view.
Now, in Fig. 2125, it will be observed that the blank for the wheel, a portion of which is shown in
outline on the left, is composed of two parts. ()ne of these is a part of the normal cone GRH,
the generatrix R H being extended to O,
the limit of the projecting part or face of
the tooth. The other is a portion of a 00110
whose vertex is not C’, that of the pitch-
cone, as in the case of a bevel-wheel, but
another point N, determined as follows :
When the length of the face of the tooth
has been decided on, the describing line
will have a known position with relation to
the axis of the pitch-surface; and by re-
volving around the latter, it will generate
another hyperboloid. The meridian sec-
tion of this being constructed, a definite
arc of that hyperbola will be intercepted be-
tween R O and V'W, which like G I will be
very nearly straight. Bisect this arc, and
at its middle point draw the tangent O N,
which will generate the cone required.
This is necessary, in order that the teeth
may begin and end contact all along an
element : if it be not done, the result may
be that they will begin and end contact at
a single point, which, sustaining all the
pressure, will be rapidly abraded.
In regard to the division of the pitch?
circles, the state of things at first sight ap-
pears quite contradictory. The ratio of
the radii of those circles which move in.
contact is not the same as the velocity ratio;
nor, again, is the ratio'between the radii of
' any two pairs of circles the same. Yet
it is evident that, because the velocity ratio is constant, the circles must be divided into numbers of
parts having the inverse ratio of the angular velocities, and such points of subdivision will come into
contact. Ordinarily, as shown in Fig. 2122, two pairs of these wheels may be used on the same














GEARING. 921

shafts, equidistant from the gorge-planes. But this is not always possible: for example, in Fig. 2126
we have two tangent hyperboloids, so situated that the projections of the axes on a plane parallel to
both intersect at right angles. This case presents the remarkable feature that the two pitch-surfaces
are tangent to each other ‘ along two right lines, m n, 1' s. N ow from these surfaces we may cut the
' frusta A, B, Fig. 2127, tangent along mn; and at the same time we can make use of the smaller
pair, 0", D, also tangent along m n; the arrows indicating the relative directions of the rotations.
Or, as in Fig. 2128, we may use frusta
which are tangent along the other genera-
trix, rs; and A still turning in the same
direction, B will turn in the opposite direc-
tion. '
As with bevel-wheels, then, we may choose
as to the directional relation; but evident-
ly we cannot use, as in Fig. 2122, a double
pair symmetrically situated in reference to
the gorge-planes. vIt will practically be im-
‘ possible to do this, even before reaching
this condition of double tangency; for the





more nearly we approach it, the nearer will the companion generatriees, and therefore the surfaces,
be to each other at any given distance from the element of tangeney. Consequently the teeth will
interfere with each other unless one pair be made smaller than the other, even when the axes do not
have exactly the relative positions here supposed; but the smaller and more numerous the teeth, the
more nearly may this limit be approached. From this consideration it follows, moreover, that the
use of the central pair of wheels shown in Fig. 2122 will not always be possible, since they are in
fact a double pair of frusta, the gorge-circle in each hyperboloid being the common base of the pair
cut from it. Nevertheless, two wheels may be constructed, and furnished with teeth which will work
together correctly, without interference, the blanks being disks whose mid-planes are the gorge-circles
of Fig. 2126. And these wheels are so similar in appearance to that which would be presented by
one _of the class now under consideration, if furnished with teeth in the direction of one of the gen-
eratrices, that it has been stated that they belong to this class. This, however, is not the case, as
may be more clearly seen from the fact that, if the central frusta can be used at all, there is no limit
to their thickness, or properly speaking their length, as measured on the axes ; the absurdity of which
is evident from a glance at Fig. 2126. The wheels mentioned really belong to the next class of gear-
ing; the teeth are composed of helical instead of rectilinear elements, and are constructed upon
principles and in a manner totally difierent from the foregoing.
SCREW-GEARING.
If the nut of a common screw be split lengthwise through the axis, the form of the section will
be that of a rack fitting between the threads of the screw; and if the latter be turned, the rack will
be driven endlong, as though it were a complete nut. If the rack is of sensible thickness, its teeth
may be just such as would be obtained by splitting out of the nut a piece of the assumed thickness.
The outline of the screw-thread is of no consequence; every point in it describes a helix, and since
this is equally true of the nut, the male and female screws are superficially identical, and there is
absolute contact over so much of the surfaces as we choose to employ. Now the rectilinear motion
of the rack may be regarded as a rotation about an infinitely remote centre. If this centre be
brought nearer, the rectilinear path of any point will become a circle of sensible curvature. Let us
then first consider this as the pitch-circle of a spur-wheel, and construct a rack which shall gear with
it. Then let us make the rack-tooth the outline of a screw-thread, the axis lying in the plane of the
pitch-circle. If the screw thus formed be rotated, it will drive the wheel exactly as if the rack were
moved endlong; because all the meridian sections of the screw are alike, and by construction the
rack-tooth advances in the direction of the axis at a rate proportional to its angular velocity.
This is illustrated in Fig. 2129, by consideration of which it will be seen that the distance of the
axis of the screw from the pitch-line. of the rack is arbitrary; that is to say, the diameter of the
screw may be varied without affecting the velocity ratio, which depends upon its pitch. This in the
figure is the same as that of the teeth of the rack, forming a single-threaded screw, one turn of
which rotates the wheel through an angle measured by the pitch of its teeth; and the screw may be
right- or left-handed, according to the directional relation desired. We may double the pitch, form-
ing a two-threaded screw and doubling the angular velocity of the wheel; and so we may increase
the pitch and the number of threads to any desired extent, observing that the pitch of the screw
922 GEARING.

must be a whole number of times that of the wheel~teeth, and its diameter such as to avoid too great
obliquity of action. ‘
We have thus far supposed the wheel to be merely a thin sheet, or plane. In giving this sensible
thickness, the elements of the teeth cannot be made parallel to the axis, as in a spur-wheel, but must
have an inclination or rather twist, depending on the obliquity of the threads of the screw. One
mode of determining this is as follows : Obviously the pitch-surface of the wheel is a cylinder, and
that of the screw is another, generated by the revolution of the pitch-line of the rack about its axis ;
and the two are tangent at a point. If new the helix on the latter be developed on the common
tangent plane, and then wrapped upon the pitch-cylinder of the wheel, it will become another helix.
If the outline of the wheel-tooth be moved along this helix, parallel to itself, we shall have a twisted
tooth-surface, precisely like that of Hooke’s gearing. It will work correctly with the screw, to whose
surface it is tangent at a point only. If the number of threads of the screw, and also its diameter,
be sufficiently increased, it may be made to have the appearance of another wheel; and if the diame-
ters of the wheel and screw in this way be made equal, they will so closely resemble each other that
this combination has been called a modification of Hooke’s gearing. Erroneously, however; for not
only are the axes here in different planes, not only may the velocity ratio be varied without changing
the diameter of either pitch-circle, but the absolute forms of the teeth of the two wheels are difier-
ent, and must be, in order to transmit the rotation with a perfectly constant velocity ratio by the
screw-like action, which in this case is the eifective means. For instance, the wheel shown in Figs.
2129 and 2131 has teeth of the involute form, the meridian section of the screw being therefore a
rack with sloping teeth, and the screw itself a true oblique helicoid; and such a helicoid it will
always be, whatever the diameter or number of threads: the outlines of these threads or teeth in
all its transverse sections will consequently be Archimedean spirals, and not involutes. While there-
fore it may be that two wheels of Hookc’s form, both having involutc teeth, will work together by
























w



I lli!.|
lllllllllllillL I
~
1
n
-l
|












2131.





the screw-like action if placed in gear with the axes in different planes, the fact remains that the
velocity ratio will not be truly constant. In all screw-gearing proper, it must be kept in mind, the
screw or worm, whatever its size or the number of its threads, is a rack, which virtually advances by
GEARING. 923

rotation, and must be capable of driving the wheel with a constant velocity ratio if it be bodily moved
endlon .
But,gthough the velocity ratio is dependent upon the number of threads given to the screw, and not
upon its diameter, yet it is clear that for any given pair of axes and velocity ratio there must be some
definite ratio between the diameters of the screw and the wheel, involving less sliding than any
other; and this may be found as follows: In Fig. 2130, O D, A B are the axes, A’ E their common
perpendicular. We first proceed exactly as in Fig. 2119 to find the line seen in the front view as
E G, in the top view as 1’ G'. This line would, by revolving around the axes, generate two hyperbo-
loids, which would work together with the given velocity ratio, with no sliding other than that in the
direction of the common element. The radii of the gorge-circles would be A’ 1’, I’ E' : taking these
gorge-circles as the bases of the pitch~cylinders, we have the required proportions for the diameters
of the proposed screw and wheel. For if the supposed hyperboloids were given angular velocities
having any other than the assumed ratio, there would obviously be a certain amount of sliding be-
tween the surfaces, in addition to that in the direction of the common element; and these cylinders
being tangent to those hyperboloids at the gorge-circles, the same is true of them. Furthermore,
E G'- in the front view is the development, upon the common tangent plane of these cylinders, of the
elementary tooth, or helix, upon each surface; and it will be observed that the helices formed by
wrapping it upon the cylinders are both right-handed, the consequent directional relation of the rota-
tions being indicated by the arrows. By making both helices left-handed, this relation will be
reversed; and this again, it will be seen, is consistent with the derivation of the cylinders from the
hyperboloids, since, as has been shown, under the conditions here assumed the latter will be tangent
along the companion generatrix X Z, which being wrapped upon the cylinders will give us the left-
handed helical element, so that the directional relation is optional.
As above stated, the tooth-surface of a wheel, all of whose transverse sections are alike, will be
tangent to the surface of the screw at only one point; so that, though strength is secrp'ed by giving
the wheel definite thickness, yet the action is confined to the single plane passing through the axis of
the screw. But line-contact, instead of mere point contact, can be secured between the thread of the
screw and the wheel-tooth, by constructing the latter as shown in Fig. 2131. The meridian section
of the screw is determined as before, that is, by making it a rack, to gear with a wheel whose diame-
ter is that of the pitch-circle given, as shown on the left; the rack-tooth being straight and sloping,
the wheel-teeth are involutes in this section, which 1s the one made by the plane A B. From this
the screw being constructed, let it be cut by any other plane, as L 0, parallel to A B. This section
is of the form shown on the right, in the side view of the screw; and it may be considered as a
rack-tooth also. It was shown in treating of spur-gearing that, in the case of two wheels, if the
tooth-outline of one be given the other may be found ; and by an analogous process we can ascertain
the form of the wheel-tooth which shall work correctly with this section of the screw as a rack~tooth.
Any number of other parallel planes may be passed, each giving a different rack-tooth and therefore
requiring a different form to be given to the wheel-tooth. We have, then, a wheel whose transverse
sections are not alike, but vary with their distance from the axis of the screw. Each one, however,
having its own point of contact with the screw-surface, the result is a line of contact between the
screw-thread and the wheel-tooth, which line will partake more or less of the helical form. It is
usual to complete the shaping of the wheel-blank by turning off its corners, as the sharp project-
ing points of the teeth would be weak and comparatively useless; so that it is in effect terminated
by cones, as the one whose element is C V in the figure. In making the drawing, it will be seen
that any of the parallel planes used in the construction, as R S, cuts the cone, if at all, in a circle;
and when the wheel-tooth to work with the corresponding rack-tooth cut from the screw by the same
plane has been drawn, its outlines will cut this circle in points of the visible contour of the tooth.
In like manner all other points in that contour may be found, since every transverse section of the
wheel-blank is circular, whether it be beyond the limit of that conical frustum or not, as for instance
that by the plane L O.
The accurate delineation of such a wheel is undeniably tedious; but the making of the wheel
itself is accomplished in a very simple way. A steel screw is first formed, and made into a cutter
by providing it with proper notches ; it is then set to cut the blank, the spaces between the teeth of
which are first “roughed out ” with an ordinary cutter. It will be seen that when the cutting is
finished, the result cannot be other than the wheel above described. For the cutter, being of the
form of the screw, must drive the blank correctly; it must cut away enough metal to pass, and, as it
cannot cut outside of itself, it can remove no more. Every section of the screw by a plane parallel to
and at a given distance from the axis is the same; consequently in every plane of the wheel paral~
101 to A B there must by this operation be formed a wheel-tooth which gears correctly with the sec-
tion of the screw by that plane, considered as a rack-tooth advancing by rotation. In practice, it is
necessary to take more than one cut, and after each cut to put the axes of the wheel and cutter
nearer to each other. The outlines of the elementary rack-teeth and the corresponding wheel-teeth,
then, should be such that this change in the position of the axes does not afTcct the velocity ratio ;
which requires that, as we have shown them, the former should be straight and sloping, the latter of
the involute form. And there is this further practical advantage in this fact, that the cutter and the
finished screw are more easily made in this way than in any other, being simply oblique helicoids, or
V-threaded screws.
OBLIQUE SCREW-GEARING.——Tllus far the axis of the screw has been supposed to lie in a plane
perpendicular to that of the wheel. But, though this is the case most frequently met with, it is not
at all essential that the axes should be thus situated ; that of the screw may cross the plane of rota-
tion of the wheel obliquely. As a preliminary to the construction of the teeth under that condition,
it is to be noted that, though a rack usually moves in the plane of rotation of its wheel, it need not
do so. It is clear that a rack may be moved in a direction parallel to the axis of the wheel, as well
924 GEARING.

as at right angles to it ; and if it receive both motions at once, the rack will travel obliquely across
the plane of the wheel, still working with a constant velocity ratio, as will be seen by a glance at
Fig. 2132. Now a screw, in order to gear obliquely with a wheel, must act in a manner analogous
to that of the rack, as is shown in Fig. 2133. A B is the axis of the screw, CD that of the wheel.
In the top view we have shown simply the pitch-cylinders, with an elementary helix upon that of the
screw. Let us now suppose a thread to be formed upon it, and cut at its lowest points, a, a', by
planes perpendicular to the axis of the wheel. These sections will be similar; and in advancing
from the position a to the position a', it is clear that, in order to maintain a constant velocity ratio,
this section of the thread must always be acting against a section of the wheel by a plane perpendic-
ular to its axis ; and all these sections must be alike, as shown at e, e', and of such form as to work
with a considered as a rack-tooth; for it makes no difference whether a be moved to a' by bodily
pushing the screw in the direction of its axis or by turning it.
In practically laying out the teeth and thread, it will be found most convenient to draw the pitch-
eylinders as in Fig. 2134, the elementary helix being shown as passing through their point of contact
P. Then we may assume the form of the section of the screw-thread by L11, the mid-plane of the
wheel, thus forming our rack-tooth a b, and determine the outline of the wheel-tooth. The position
of every point in the outline of the rack-tooth with respect to the axis of the screw being known,
the helices described by these points may be drawn and the meridian section of the screw ascertained.
In the figure it will be observed that the sides of the rack-tooth are straight and sloping, the teeth
of the wheel being therefore involutes. But the two sides of the rack-tooth are not similarly situa-
ted in relation to the axis, and in consequence the meridian outline of the screw-thread will not be
symmetrical, nor will it be bounded by right lines. Nevertheless, since its acting sections possess the
property, before mentioned, of admitting a change in the distance between the axes without afi'eeting
the velocity ratio, it is necessary that the screw should be formed as above explained if it is re-
quired to cut its own wheel with absolute precision. The determination of its form involves some












2134.
{D
B
Jr 2135.
11 I 7" [3' B
‘ Jr
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a 0 I 1’ M
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Q9- "
labor; but a converse difficulty of equal if not greater magnitude is encountered if we reverse the
process: for if the meridian section of the screw be assumed, we have to determine the form of a
wheel-tooth which shall work with an oblique section of the thread as a rack-tooth; and this also
will result in a non-symmetrical outline, the fronts and backs of the tooth being different, if the
screw-thread be symmetrical in the first place. The wheel, then, having all its transverse sections
alike, is similar to one of those used in Hooke’s gearing, its teeth having a twist dependent on the
obliquity of the screw. And in relation to this, it will be noted that the pitch of the screw is not,
as in the case at first considered, either equal to or necessarily an exact multiple of that of the wheel-
teeth.
The elementary helices on the two pitch-cylinders must evidently coincide when developed on the
common tangent plane; and the mode of determining the pitch of the screw, and also that of the
wheel-helix, when the pitch of the wheel-teeth is given, is shown in Fig. 2135. A B is the axis of
the screw, G D that of the wheel, P the point of contact of the pitch-surfaces, and L JVI the plane
of rotation of the wheel, all as in Fig. 2134, both axes and the common tangent plane being parallel
to the paper. Let P E be the developed pitch of the wheel-teeth ; then make PK, perpendicular to
A B, equal to the circumference of the pitch-cylinder of the screw; draw KE, produce it to out A B
in G, and P G is the pitch; the screw then is single-threaded, one rotation advancing the wheel
through an angle measured by its pitch. If it be desired to make the screw two-threaded, and thus
to double the angular velocity of the wheel, it will not do to double the pitch thus found, as in the
case of the ordinary worm and wheel: we must set off PFequal to twice the developed pitch of
the wheel-teeth, draw KF, and produce it to cut A B in H, giving PH as the pitch of the screw ;
and so on if any other angular velocity is to be given to the wheel. The lines corresponding to PK,
G Kare drawn in Fig. 2133, which will make the application of this construction clear: a line N 0,
drawn through P parallel to G K, as shown also in Fig. 2134, is evidently the development and com-
mon tangent of the elementary helices on both pitch-cylinders which pass through their point of
contact. -
The construction explained in connection with Fig. 2130, in relation to the ordinary worm and
wheel, is also true in the case of oblique screw-gearing. That is to say, if the axes and velocity ratio
GEARING. 925

be given, the screw and wheel which will work with the least sliding are determined by first construct-
ing the rolling hyperboloids which satisfy the assigned conditions, and then taking as the pitch-sur-
faces the cylinders tangent at their gorge-circles; the common element of the hyperboloids being
also taken as the development and common tangent of the elementary helices. Those hyperboloids
in this case having but one line of tangency, the directional relation of the rotations is thereby fixed;
the helix ‘of the screw cannot be made right-handed or left-handed at option, as in Fig. 2130.
Again, it was seen that when the axis of the screw lies in the plane of rotation of the wheel, both
helices must be either right-handed or left-handed. But when it crosses that plane obliquely, it will
be seen from Fig. 2136 that this is not always the case. A B, C' D, L111, PK being the same as in
Fig. 2135, let PE, P F, PR be respectively once, twice, and thrice the developed wheel-pitch; then
P G, PH, PS are the pitches of a single-, a double-, and a treble-threaded screw. Recollecting
that G If, H K, and S K touch the screw-cylinder on its lower side, it will be seen that all the screw-
helices will be right-handed. But as these lines touch the wheel-cylinder on its upper side, it will
also be seen that when S K is wrapped upon that cylinder it will form a right-handed helix, while
G K will form a left-handed one. The proportions in this illustrative diagram are such that HE is
parallel to G D ; it therefore will form no helix at all, but the wheel will be simply a common spur-
wheel, the elements of the tooth-surfaces being parallel to the axis.
From the mode of generation, it is clear that the action will be confined to the plane passing
through the axis of the screw and the common perpendicular of the two axes, represented by A B
in Figs. 2133, 2134, and 2137, each section of the screw-thread by that plane, on the side which is
in gear with the wheel, touching the tooth of the latter in a point whose distance from the pitch-








2137.
2136. S
D
L E 2.2
L P \ 11:
E F 6
I
i
i i
K { I
C | l
l l
: :
: l
I
2138. I
_ "E'
l‘l\--


a...
\\\\\\\\\\\\\\\\\\\\\\



surfaces is determined by the construction of the rack and wheel in Fig. 2134. Consequently the
greatest length of the screw, as in the ordinary worm and wheel, is determined by the distance
through which the teeth of the elementary rack travel while actually in gear with those of the wheel.
This being ascertained and set oif as D Eon the axis A B, Fig. 2137, the screw-blank is terminated
by planes through D and E perpendicular to A B, the outer cylinder being shown in full lines, and
the inner one, or core of the screw, being dotted.
The thickness of the wheel may be determined thus: Through D and Epass planes GH, I K,
perpendicular to the axis; these may limit the teeth of the wheel at their tops, since any further
extension in the direction of the axis would be useless. The wheel-blank need not be cylindrical,
but may have the form shown, which is thus determined: The radius PF, obviously, will be the
distance from the axis of the wheel to the outside of the core of the screw-blank, measured on the
common perpendicular, minus whatever may be allowed for clearance. The plane G D H cuts that
core in an ellipse, of which a part is shown in section in the front view, where A’ B’ is the axis of
the screw, 0 that of the wheel, whose section by this plane is the circle G’ H’, which must evidently
clear the elliptical section. And by a like proceeding with other transverse planes, we may deter-
mine as many points as are necessary in the curve G FI, which practically may be made a circular
arc. Drawing at G and 1 lines normal to this curve, the wheel-blank is terminated, as in Fig. 2137,
by short conical frusta. The tooth-surfaces are, of course, not afiected by this departure from the
cylindrical outline, their transverse sections remaining the same; the depths of the teeth, merely,
increase as they recede from the mid-plane L M.
926 l GEARING.

Oblique Screw and Rack.-—Let A, Fig. 2138, be a common V-threaded screw, whose axis is par-
allel to the paper. If we suppose this screw to be moved, without rotating, in a direction perpen~
dicular to the paper, through some plastic material, the result would be the‘formation of a rack, B,
whose teeth are composed cf parallel elements, which touch the screw at points of its visible con-
tour. If the screw now remain stationary, but free to rotate, we can move the rack perpendicularly
to the paper without turning the screw, or it may be driven endlong by the rotation of the screw, or
it may receive both motions at once. In the latter case the resultant is an oblique travel of the rack
across the plane of rotation, as in Fig. 2132 ; and the degree of obliquity is entirely arbitrary, so long
as it is not so great as to prevent the screw from driving the rack. We have taken the V-threaded
screw, and supposed the rack-teeth to be perpendicular to the paper, only for the sake of simplicity
in illustration. Evidently the same may be done with a screw of any reasonable meridian section,
and in all cases there is a line of contact between each thread of the screw and its rack-tooth.
But again, the screw need not be moved in the direction above supposed in generating the rack,
nor is it the best direction. This will be seen from Fig. 2139, in which A is the outer cylinder or
blank of the screw, upon which the helix is shown; B is that plane section of the rack which is
parallel to the elements of its own teeth and tangent to the cylinder A. Now let us suppose that
the rack is to be driven by the screw as indicated by the arrows. Then, if the screw be formed into
a cutter, the spaces in the rack being “roughed out ” as usual, it is clear that the rack will be driven
by the cutter as it works, and in one revolution it will be driven just far enough for the cutter to
clear itself. In doing this, it is also clear that the helix shown, its point of contact advancing in one
turn from P to G, must, in order to remove the least metal, trace upon the plane B a line which will
be always tangent to the helix. Draw, then, PK perpendicular to O D and equal to the circumfer-
ence of the cylinder, and G K will be the direction of the teeth of the rack, which latter will travel
through the distance PE at each revolution of the screw. The form then of the rack-teeth will be
determined by simply making a drawing of the screw as seen from the direction K G, the outlines
of their normal sections being those of the visible spaces between the adjacent threads, and all the
elements necessarily parallel to G K. If the size of the screw-blank, and the pitch PE of the rack
in the direction of its travel, be given, we may by a converse operation determine the pitch of the
screw. Drawing P 11' as before, set off PE ,' then draw K E and produce it to cut CD in G, thus
giving P G, the required pitch.
FACE-GEARING. ,
This form of gearing was formerly much used in wooden mill~work, but is now seldom met with
in heavy machinery, bevel-gearing being used instead. The latter has the advantage that the teeth
are in contact along a line, thus distributing the pressure and the wear over a considerable surface
during the action ; whereas in the former the teeth touch each other in a single point only, so that
during the whole action the wear is confined to a mere line joining the successive points of tangency.
Yet in light mechanism the facility of forming the teeth in the lathe may make it desirable to employ
this form of gearing. The name is derived from the fact that the turned pins forming the teeth are
often set in the faces of circular disks, as in Fig. 214-0. In this case the teeth are cylindrical pins,
2139. 2140. 2141.
D







and the two wheels are exactly alike in
every particular. The axes are not in the
same plane, but situated like those of the
common worm and wheel; that is to say,
their projections upon a plane parallel to
both intersect at right angles, and the length
of their common perpendicular is equal to
the diameter of the pins. Under these cir-
cumstances it is clear that the angle D (IE will always be equal to the
angle I GH, so long as the pin E of the wheel A is in contact with the
pin H of the wheel 13’. The velocity ratio is therefore perfectly constant.
It will be noted that, the arrows indicating the directions of the rotations,
the length of the pin E must be such that the next pin F of the other
wheel B shall not catch upon its end in going into gear. And it will also be seen that, although
at the instant of coming into contact with the next pin 0 of the driver A, the pin F may also touch
the pin E on the back, it cannot continue to do so. That is to say, it is not possible even theoret
ically to secure entire freedom from backlash.








GEARIN G. 927

The maximum length of one pin having been determined, it is of course the same for all; and it
is next to be observed, that if the number be increased, this length must be diminished ; also, that in
every case there will be a limit beyond which the number cannot be increased without also diminish-
ing the diameter, and in consequence the distance between the axes. It therefore follows that ulti-
mately the axes will intersect at right angles, and the pins will become consecutive points in the cir-
cumferences of two equal circles rolling together like the bases of the pitch-cones of a pair of
mitre-whccls. In other words, as stated in the synopsis at the beginning of this article, there are no
pitch surfaces, these degenerating into lines, and the elementary teeth into points. But if we suppose
the axes to intersect at right angles, cylindrical pins may yet be used on one wheel, and a constant
velocity ratio maintained by making the teeth of the other in the form of surfaces of revolution, if
the meridian outline of the letter be correctly determined. The manner in which this outline is to
be ascertained will be understood by the aid of Fig. 2141, where the two wheels, A and B, are of
the same diameter. Let a be a pin of no sensible diameter in the wheel A, and 0 another in the
wheel B, the distance a c between them being arbitrary. Let the wheels now turn as shown by the
arrows, with a constant velocity ratio; then, when a reaches e, 0 will have gone to g, the arcs as
and cg being equal. The distance between the pins in the two wheels is now changed ; e g is greater
than a c, and it is also lower, that is, nearer to the face of B. The relative positions of the pins may
in a similar manner he obtained in any number of intermediate positions; and it will be seen that if
the vertical line 0 be taken as the axis of a surface of revolution, the radii of whose sections are the
perpendiculars from a upon 0 in those intermediate positions, we shall have the form of a pin or
tooth for B, such that it will be driven by a pin in A, of no sensible diameter, from c to g with a
constant velocity ratio. If we now suppose a to move from c to 6, this tooth will be dn'ven from g
to cl ,' and by repeating the above process we may find the meridian outline required to maintain a
constant velocity ratio during that part of the action.
This process is illustrated more fully in Fig. 2142, in which only the pitch-circles are shown, and
for convenience these are made tangent at c. When the pin a occupies the positions 1, 2, the axis
6 will be at 1’, 2'; by the aid of which, as above explained, the outline ax is obtained, as that of a
2142. . 2143.



teeth which will be correctly driven by a through the are c' g’, which is equal to a. e. In going from
c to b, the pin must drive the tooth to d'; and that the velocity ratio may be constant, the outline
must be that of the curve 6 2.
It will be observed that, the points a, 6 being projected to a', 12' upon the circle BB, which is
equal to A A, we have the equal arcs a’ c', b’ d', subtending equal angles at the centre of B B, the
radii of the upper bases of the teeth on the left and right hands respectively being therefore equal
to a' o, b'p. Now, in Fig. 2143, let 0 be the centre of the circle BB, and let a', c', and o corre-
spond to the points similarly lettered in Fig. 2142. Let 0' e be a chord equal to a' 0’, but nearer to
the vertical line C' T, to which 0' b, e h are parallel, and draw (lg perpendicular to c h. Then, in the
triangles b a' c', h d e, we have the angle at a’ equal to the angle at (I, also a' c’ 1: d 0, but the angle at
It less than the angle at 6. Consequently (I g is greater than a’ o ; that is to say, referring to Fig.
2142, the radius of the tooth will increase from a toward a, the maximum being reached when a’ c’
has the position Us in Fig. 2143, being then bisected by the plane of the axes. And in a similar
manner it may be shown that during the receding action the radius of the tooth will diminish as it
recedes from the plane of centres, or in other words from z toward b in Fig. 2142; as will be seen
by comparing the triangles l m p, r t u, in which 2 m = r t, the angle at r is equal to the angle at l,
but the angle at p is less than the angle at u, whence l n is greater than 1- s. N ow, in Fig. 2143, let
a’ and r be equidistant from T: then in the triangles b a' 0’, Ma, we have a' c' : rt; also in r
=20 C' T: a' be'. But ba' 0', which is equal to CM, is less than 90°, whence Mn is greater
than 90°. Therefore a o is greater than 1- s ; and the same being true for other points equidistant
from T, it follows than in Fig. 2142 all the radii of the tooth a x, except the lowest one, are greater
than those of the teeth 6 z. The consequence of this is that, since the teeth are to be turned in the
lathe, the smaller outline must be selected; and in order to secure receding instead of approaching
action, the cylindrical pins must be given to the driver, and those of the form above discussed to
the follower. In giving sensible diameter to the former, a change is of course made in the elemen-
tary form of the latter. A process is here pursued analogous to that employed in the case of the
pin-wheels described in the section on spur-gearing; that is, a series of circular arcs are described
whose centres are in the elementary outline 62, with the radius assumed as that of the pin; the
curve tangent to those arcs is the meridian outline of the actual tooth.
928 GEARING.

But it is not necessary that the diameters of the pitch-circles shall be equal. In Fig. 2144, BB
is the larger, the cylindrical pins being given to A A, whose centre is C. The mode of constructing
the curves a as, b 2 is precisely the same as in Fig. 2142; and the lettering of the two figures being
made as far as possible to correspond, it can be readily traced, the arcs a e, e I) being respectively
equal to the ares c' g, gd'. The positions of the points a, e, b, and the intermediate ones, on the
circle A A, with relation to the assumed axis a c’ in its progress to cl (1', are evidently precisely the
same as those of the corresponding points on the equal circle A' A', whose centre is c'; the latter
serving better to point out the peculiarities due to the change in the relative diameters of the pitch-
circles A A and BB. These will be clear by the aid of Fig. 2145, in which B is the centre of the
circle B B, 0’ that of the circle A’ A', the two being tangent at e. Let the arcs e 0, ea’ be equal,
and of any length less than 90° on either circle; and let er, eb’ be respectively equal to them,
making a’ m b', 0 n 1- perpendicular to e 0' D. Then, because the arcs e o, e a’ are equal, the chord
a' e is less than the chord o e, and a’ m is less than 0 n. Therefore, drawing through a' a parallel to
e C" .D, it will cut the are 0 e in some point 0'. The linear velocities of the circumferences being
equal, when a' has reached e, 0' will be found at g, e 9 being equal to 0 c' ,' and when (1' reaches 6’,
0' will be at d’, r (1’ being also equal to o 0’. Draw through (1’ another parallel to e 0’ D, and pro-
long a’ b’ to meet it in 1). We then perceive that, whatever the lengths of the arcs e0, ea’, the
distance a' m is always less than a n, and the longer the arcs the greater this difference, which is
equal to that between a r and m b'; and that as d’ always lies beyond 9', b' p will always be greater
than this difference. Now, if, as in Fig. 2144, we assume a’ c' as the axis of a tooth of B B, to work
with a cylindrical pin at a in A A, of no sensible diameter, that tooth will be pointed as shown, the
curve a a: being suited for the arc of approaching action a e, if A A drive as shown by the arrows,










2144.
6'
A A 2145.
/1 / 8 A. liilll
x W W , Q
B a’ k [p L j
A' I
1
j 61'
D
which are here made to correspond with Fig. 2142. The tooth 62, for the are of receding action,
has however at the point I) a radius equal to b’ p. Since, when the teeth are turned in the lathe, the
smallest must be used, it follows that under these conditions the curve am must be employed in
determining the meridian outline of the working tooth, and that in order to secure receding instead
of approaching action the cylindrical pins must be given to the follower.
If the diameter of BB be increased, its curvature will diminish, and at the limit will disappear,
the circle becoming the tangent to A A. The curves a a: and b z will then evidently be equal and
similar, each being the cycloid of which A A is the generating circle; and we have the ease of a
rack driving a pin-wheel. There is in fact a close analogy between the form of gearing now under
consideration and that already described as pin-wheel gearing; for if in face-gearing we suppose the
axes to be parallel, the teeth will be turned pins placed radially in the convex surface of a cylinder,
and their outlines precisely the same as those of a spur-wheel, the cylindrical pins being the same in
both cases.
When the cylindrical pins are given to the larger of two wheels whose axes meet at right angles,
as in Fig. 2146, the case, as will be seen by comparing this diagram with Fig. 2144, is nearly the
converse of the previous one. The rotations being still in the same direction, the pointed tooth ap-
pears on the opposite side of the plane of the axes, and the cylindrical pins must drive, in order to
secure receding action. It will be observed that, as the diameter of A A is increased, the shorter
will the teeth of BB become for a given are of action; and this diameter cannot be indefinitely in-
creased, since at the limit the axes of the cylindrical pins will lie in the plane of rotation of BB.
Still the pin-rack may be made to work, by placing the pins perpendicular to that plane, and making
the axes of the teeth of BB radial, the outlines being involutes of the pitch-circle; but in that
case the wheel must drive, as already explained in treating of spur-gearing.
A process similar to those above described may also be employed when the axes are situated as in
’ GEAItING. 929

Figs. 2140 and 2141, although the diameters of the wheels are unequal, and the forms of teeth for
one ascertained which will gear correctly with cylindrical pins on the other; and that even when the
common perpendicular of the axes is greater than the diameter of the pins. But neither the dis-
tance between the axes nor the difference between the diameters of the wheels can be varied, except
within quite narrow limits, when the axes thus lie in different planes.
It is- not necessary, however, that the pins or teeth of gearing of this form should be inserted
into plane surfaces; of which the suggestion above made in regard to the pin-rack is an illustration,
2146.
6‘




since the radial teeth of the driving wheel would be fixed in the periphery of a cylinder. But if,
as shown in Fig. 2147, the axes intersect at any angle, we may proceed as follows: Draw E 11’,
dividing the angle A E 1) according to the velocity ratio assigned, precisely as in bevel-gearing.
Supposing that cylindrical pins are to be given to the wheel with the vertical axis, draw through
any point F of EK a parallel to A B, as the axis of such a pin; also through F draw F G per-
pendicular to A B, and produce it to meet the other axis CD in the point I: then F1 in revolving
around CD will generate the cone 1"] L. The
teeth of the inclined wheel are to be solids of revo-
lution, whose axes will evidently be elements of
this cone, and they may be fixed in the surface of
another cone N ll! 0, normal to F I L. A pin of
the vertical wheel is shown at F in contact with
such a tooth, of which the form may be thus de-
termined: First let the cylindrical pin be supposed
of no sensible diameter; then, if the vertical wheel
be turned through any angle, the inclined one will
be driven through an angle which is known, since
the eircmnferential velocities of the circles whose
radii are F G, FH must be equal. Consequently,
the relative positions of the axes of the cylindrical
pin and of the required tooth may be determined
at any phase of the action, and their common per-
pendicular found. Having repeated this process a
sufficient number of times, these common perpen-
diculars will evidently be the radii of the‘ transverse sections of the required tooth to work with a
pin of no sensible diameter, from which the meridian section may be constructed, and from it the
outline of a working tooth derived in the usual manner by assigning any diameter at pleasure to the
cylindrical pin.
This arrangement may also be modified as in Fig. 2148, the cylindrical pins being fixed in the
periphery of a cylinder. from which they project radially; the construction of the tooth of the other
wheel being made exactly as in the previous case. And it is hardly necessary to remark that in




59
930 GEARING, FRICTIONAL.

either modification the cylindrical pins may be assigned to the conical wheel and teeth constructed
for the other.
And finally, the same principles and methods may be applied to the construction of what may be
called bevel-face gearing, as shown in Fig. 2149. In this case the action is exactly the same as that
of two rolling cones, the axes of the teeth in one wheel being rectilinear elements of one, while the
pins in the other project normally from the pitch-cone. C. W. MACC.
GEARIN G, FRICTION AL. As used in the lumbering regions in this country to transmit motion
in wood-working machinery, frictional gearing usually consists of smooth-surfaced wheels in contact,
one pulley being made of iron, the other of wood or iron covered with wood. Where it is practica-
ble, the wooden pulley drives the iron, wear of the former being thus saved. For driving heavy ma-
chinery, the wooden drivers are put upon the engine-shaft, and each machine is driven by a separate
countershaft. Two or more of these countershafts are usually driven by contact from the same
wheel. For small machinery the friction—drivers are put upon a line-shaft so as to drive a small
countershaft, whence power is taken by a belt. For the wooden pulley, basswood, cottonwood, and
even white pine, have given good results in driving light machinery. For heavy work, where from
40 to 60 horse-power is transmitted by simple contact, soft maple is preferable. For very small pul-
leys, leather and rubber may be employed. Paper pulleys have yielded excellent results.
All large drivers, say from 4 to 10 feet in diameter and from 12 to 30 inches face, should have
rims of soft maple 6 or 7 inches deep. These should be made up of plank 1% to 2 inches thick, cut
into “ cants ” one-sixth, one-eighth, or one-tenth of a circle, so as to place the grain of the wood as
nearly as practicable in the direction of the circumference. The cants should be closely fitted, put
together with white lead or glue, and strongly nailed and bolted. The wooden rim should be made
up to within about 3 inches of the width of the finished pulley, and be mounted on one or two heavy
iron “spiders” with 6 or 8 radial arms. For pulleys above 6 feet in diameter, there should be 8
arms, and 2 spiders when the width of face is more than 18 inches. Upon the ends of the arms
are flat “pads,” which should be of just sufficient width to extend across the inner face of the
wooden rim as described--that is, 3 inches less than the width of the finished pulley. These pads
are gained into the inner side of the rim, the gains being cut large enough to admit keys under and
beside the pads. When the keys are well driven, strong lag-screws are put through the arm into
the rim. This done, an additional round is put on each side of the rim to cover the bolt-heads and
secure the keys from working out. The pulley is now put in its place on the shaft and keyed, the
edges trued up, and the face turned ofi with the utmost exactness. For small drivers, the best
construction is to make an iron pulley of about 8 inches less diameter and 3 inches less face than
the pulley required. Have 4 lugs about an inch square cast across the face of this pulley. Make a
wooden rim 4 inches deep, with face equal to that of the iron pulley, and the inside diameter equal
to the outer diameter of the iron. Drive the rim snugly on over the rim of the iron pulley, havir g
cut gains to receive the lugs, together with a hard-wood key beside each. Now add a round of cants
upon each side, with their inner diameter less than the first, so as to cover the iron rim. The wood
should be thoroughly seasoned, and the fibre should be in a line with the work.
As to the width of face required in friction-gearing: When the drivers are of maple, a width of
face equal to that required for a good leather belt (single) to do the same work is sufficient. (Sec
BELTING.) The driver-pulleys are similar to belt-pulleys, but much heavier. The arm' should be
straight, and there should be two sets of arms if


_ 2150- the pulley is above 16 inches. A good rule is to
A, _ rm—q m make the thickness of rim 2% per cent. of the di-
v ameter. To secure accuracy, they-should be fitted
a and turned upon the shaft and carefully balanced.

Limited experiments in order to compare fric-
tional gearing with belted pulleys have indicated
that the traction of friction-wheels is greater than
that of belted pulleys, and considerably more than
(I) is usually supposed to be obtained from belts
\








upon pulleys of either wood or iron; and that,
while there is a marked falling off in the adhesion
of the belt as the work increases, that of the fric-
tion augments as the labor becomes greater. Also,
that the difference in the pressure required just
to do the work, and that necessary to do it with-
out slip, advances in an increasing ratio with the
work of the belt; but in the friction-pulley it is
F4 almost constant throughout the whole range of
B experiments. Details of these tests will be found
in the papers from which this abridgment is made.
Bevel Frictional Gearing—In building this gearing, the iron cone or pulley is made similar to a
bevel-pinion, except as to the teeth, instead of which there is a smoothly-turned face. In making
the wooden driver, place a square across the smaller end of the finished iron pulley, and set a bevel
(a 0’



GIB AND COTTER. 931
~_. __--__ ...

to it, as shown at (1) in Fig. 2150. This will give the correct bevel for the face of the driver.
Next, upon any plane surface draw the lines A B and A 0, making the length of A B just equal to
the larger diameter of the iron pulley, and the angle at A a right angle. Then with the square and
bevel draw the lines B (J and A D. The distance A (J is the diameter required for the driver, and
the other dimensions are easily obtained.
To obtain the bevels for pulleys to work on shafts pla'ced at acute angles, draw the lines as in (2),
Fig. 2150. Let A B represent the driving-shaft. Make A 0 equal in length to one-half the diame-
ter of the driving-pulley. Draw the line 0]) at the angle to which the shafts are to be set, and
at a right angle to this line draw GE in length equal to half the diameter of the other pulley.
From the point E, parallel to C1), draw EF, which will represent the other shaft. From the point
of intersection of this and the line A B draw the line G C, which will give the bevels for both pulleys.
If not above 2% feet in diameter, the driver may be built on a hub-flange, a disk of iron of about
two-thirds the diameter of the pulley with a hub projecting on one side. The hub should extend
half an inch beyond the thickness of the wood to receive an annular disk of smaller diameter,
through which the whole may be securely bolted together. Upon the flange around the hub the pul-
ley should be built. The first 2 or 3 inches to form the back should be of hard wood put on radially.
For the remainder, use soft maple. When the wood is built up to sufficient thickness, the other
flange should be put on, and the whole bolted together and turned to the exact diameter and bevel
required. For a large bevel-driver it is best to use an iron centre with arms, and a flanged rim some-
thing like that of a car-wheel. The diameter of the rim or cylinder should be a few inches less than
the smaller diameter of the pulley, and that of the flange something less than the larger diameter.
Upon this wheel the wooden rim is built, as directed, upon the hub-flange, except that the bolts must
be put in as the work progresses, so that subsequent layers will cover the heads; and the pulley is
finished without the smaller flange. Fig. 2151 shows a cross-section of this pulley.
The foregoing is abridged from papers on “Frictional Gearing,” by E. S. Wicklin, in the Scimttific
American, vol. xxvi., 227, ct seq.
Grooved Frictional Gearing.-Robertson’s grooved-surface frictional gearing consists of wheels or
pulleys geared together by frictional contact, in which the driving surfaces are grooved or serrated
annularly, the ridges of one surface entering the grooves of the other. A lateral wedging action is
obtained, which augments the adhesion of the surfaces, as compared with flat friction surfaces, in
the ratio of 9 to 1. That is, the grooved wheels require a force of 3 lbs. acting at their circumfer-
ence to make them slip, for every 2 lbs. applied on the axis ; whereas two flat surface-wheels would
require (2 x 9 = ) 18 lbs. of pressure on the axis to enable them to resist a force of 3 lbs. acting on
the circumference. The grooves are made of V shape, for which 50° is the most suitable angle.
The pitch of the grooves is varied according to the velocity and the power to be transmitted—from
one-eighth to three-quarters of an inch ; the ordinary pitch is three-eighths of an inch. See a paper
by Mr. James Robertson on “ Grooved-Surface Frictional Gearing,” in “ Proceedings of Institution of
Mechanical Engineers,” 1856.
GENEVA STOP. Where a train of wheels is set in motion by a spring inclosed in a barrel, it
becomes of consequence not to over-wind the spring. The Geneva stop, Fig.
2152,\has been contrived with the view of preventing such an occurrence, and
will be found in all watches which have not a fusee. A disk A, furnished with
one projecting tooth P, is fixed upon the axis of the barrel containing the main-
spring, and is turned by the key of the watch. Another disk, B, shaped as in
the drawing, is also fitted to the cover of the barrel, and is turned onward in
one direction through a definite angle every time that the tooth P passes through
one of its openings, being locked or prevented from moving at other times by
the action of the convex surface of the disk A. In this manner each rotation
of A will advance B through a certain space, and the motion will continue until
the convex surface of A meets the convex portion E, which is allowed to re-
main upon the disk B in order to stop the winding up. The winding act-ion
having ceased, the disks will return to their normal positions as the mechanism
runs down. Instead of supposing A to make complete revolutions, let it oscil-
late to and fro through somewhat more than a right angle; then B will oscillate
in like manner, and will beheld firmly by the opposition of the convex to the
concave surface, except during the time that P is moving in the notch.
GIB AND CUTTER. A method of connecting separate parts of a machine. Sometimes one of
the connected pieces is required to move while the other remains stationary; frequently both pieces
have motion imparted to them, as in the case of the connecting~rod of a steam-engine, when the
connection at the end is often made by means of gibs, a cotter, and a strap. Again, both connected
pieces may be stationary, in which case the principle of the connection is the same.
There are three forms of this device: 1. The simple cotter without gibs; 2. A cotter and one gib ;
3. A cotter and two gibs. Of the econd and third forms there are a variety of designs, and various
means are employed to force home the cotter and to keep it there.
The cotter itself is a tapered piece of metal, generally resembling in form and action a wedge,
but with this difference, that the wedge is used to force asunder parts of the same piece or differ-
ent pieces, while the cotter is employed to draw together by means of available parts two or more
pieces of metal. The amount of taper given to the cotter must not exceed the angle of repose of
metal upon metal, which for greased surfaces may be taken at about 4°. Some authorities recom-
mend a taper of 1 in 24 to 1 in 48 for simple cotters, and l in 8 to 1 in 16 when the slacking of the
cotter is prevented by a screwed prolongation of the gib; a common rule is to make the taper one-
half to three-fourths of an inch to each foot of length.
C'ottcr connecting two Pieces without a Gila—In Fig. 2153 is shown an example of the use of a


932 GIG.

cotter without a gib being employed in conjunction with it ; it here maintains the bolt 0 in the hole
made in the piece I) to receive it. The action of the cotter is simply to wedge itself tightly into


















2154
3
-_1__.
r—l""
:11.“
a ‘ b
_._J~-__ _-_é___i
j r--—'----——--~‘ L
EN





the pieces, and maintain its hold by the grip thus induced. It is quite evident that so long as d
keeps its place the bolt 0 cannot be removed from b.
Cotter connecting two Pieces when one Gib is used.-—Fig. 2154 gives two views of a connecting-rod.
A is the cotter, B the gib, and C' the strap. The shape
of the strap is shown more clearly in Fig. 2155, a, b, 2156
and 0 being the openings in it.
Cotter and two G'ibs.-—Fig. 2156 shows a connecting- Al 71 i
.1 I] . 12 .
2155. K ‘






















I B a
I
rod head, held together by a strap, cotter, and two 7 _ 2'-
gibs; the strap is marked s s, the cotter a, and the two ‘3
gibs b respectively. They firmly hold the brasscs at A
the end of the rod in their places. The advantage of
two gibs is, that they keep the strap firmer against the brasses. The screw which forms the lower
part of the gib serves to prevent the cotter from falling or being jerked out when the engine is in
motion. After the strap s is put on the connecting-rod, the gib b is inserted, and then the nut c is
placed so that when the key a is put in the nut can be screwed up. The key is driven home with
the hammer, the nut a being slackened to allow it to come down. When it is made as tight as'is
required, the nut d is put on and screwed up tightly. Then 0 is screwed down, and thus the two pre-
vent the key from becoming slack. rl‘hc hole for the bolt at 0 must be made elliptical, so as to allow
the key to come down without bending the bolt.
The foregoing is abridged from “Principles of Machine Construction,” Tomkins, London and
Glasgow, 1878. '
GIG. See CLOTH-FINISI-IING MACHINERY.
GIN, COTTON. See COTTON-GIN.
GIN, IIOISTING. See Cnanss AND DERRICKS.
GIRDERS. See CARPENTRY.
GLASS, MANUFACTURE OF. Glass is an amorphous substance, hard and brittle at ordinary
temperatures, liquid or soft at a high heat, transparent or translucent, colored or colorless, and pre-
senting a special fracture. It is the result of the combination of silicic acid (silex) with several of
the following bases: potash, soda, lime, magnesia, oxide of lead, oxide of iron, and aluminum. The
various sorts of glass are distinguished with regard to their composition, their mode of fabrication,
and their uses.
Window-pane glass, mirrors, and glass for table use are formed of the same elements associated in
different proportions. These elements are silex, lime, and soda. '
Bohemian glass, which is used in Germany for the production of drinking-vessels, is a silicate with
a potash and lime base. It contains besides, as do all other kinds of glass, a small quantity of alu-
minum and of oxide of iron, obtained either from the crucible in which it is melted, or from the
more or less purified materials employed for its production.
Bottle-gt'ass contains, together with the silex, soda, or potash, lime, magnesia, aluminum, and iron
oxide.
Crystal is a glass having a base of lead oxide and potash. flint-glass, a dense substance used for
optical purposes, and strass, employed in imitating precious stones, are of similar elementary consti.
tution, though the ingredients are in different proportions.
GLASS, MANUFACTURE OF. 933

The enamels contain, in addition to the normal glass ingredients, oxide of tin or arsenious acid,
which gives them the opacity that distinguishes them from all other classes of glass.
Colored iqlasa obtains its tints, which may be infinitely varied, from various metallic oxides, from
some meta s, carbon, and sulphur. Many kinds of colorless glass contain a small quantity of oxide
of manganese, this substance being introduced in order to obtain a whiter glass.
To these may be added the soluble glass, which is a simple silicate of soda or of potash, or a mix-
ture of the two silicates.
The specific gravity of glass varies with its composition, from 2.4 to about 3.6, although optical
glass of greater specific gravity is sometimes made, amounting in some instances to 5. Its density
and also its refractive property are increased with the proportion of oxide of lead it contains. Brits
tleness is a quality that limits the alteration of the shape of glass within narrow bounds, after it has
cooled ; but when softened by heat while it is highly tenacious, no substance is more easily moulded
into any form, and it can be blown by the breath into hollow vessels of which the substance is so
thin that they may almost float in the air. It may also be rapidly drawn out into threads of several
hundred feet in length; and these have been interwoven in fabrics of silk, producing a beautiful
effect. In the soft plastic state it may be cut with knives and scissors like sheets of caoutchouc.
It is then inelastic like wax; but when cooled its fibres on being beaten fly back with a spring, and
hollow balls of the material have, when dropped on the smooth face of an anvil from the height of
10 or 12 feet, been found to rebound without fracture to one-third or one-half the same height. It
has the valuable property of welding perfectly when red-hot, and portions brought together are in-
stantly united. When moderately heated it is readily broken in any direction by the sudden contrac-
tion caused by the application of a cold body to its surface. It is also divided when cold by break-
ing it along lines cut to a slight depth by a diamond, or some other extremely hard~pointed body of
the exact form suited for this purpose; and it may be bored with steel drills, provided these are kept
slightly moistened with water, which forms a paste with the powder produced. Oil of turpentine,
either alone or holding some camphor in solution, is also used for the same purpose. Copper tubes
fed with emery also serve to bore holes in glass. Acids and alkalies act upon glass differently accord-
ing to its composition, and reference should be made to this in storing diiferent liquids in bottles.
Silicate of alumina is readily attacked by acids, and bottles in which this is in excess are soon cor-
roded even by the bitartrate of potash in wine, and by the reaction the liquor itself is contaminated.
A glass that loses its polish by heat is sure to be attacked by acids. Oxide of lead when used in'
largeproportion is liable to be in part reduced to a metallic state by different chemical reagents, and
give a black color to the glass. All glasses are attacked by hydrofluoric acid.
Melting.—-The various materials entering into glass manufacture will be noted as each class of
glass is described. For melting, these are thoroughly ground, mixed together, and sifted, and are
incorporated with from one-quarter to one-third their weight of broken glass before being introduced
into the melting-pots. The latter are previously heated to a white heat in the furnaccgand receive
only two-thirds of a charge at a time, more being added as the first portion melts down. The pot
being at last filled with the melted “ metal,” the heat is raised as rapidly as possible, and the prog-
ress of the operation is judged of by the workman dipping iron rods from time to time into the
mixture and examining the appearance of the drops withdrawn. A nearly homogeneous product,
which becomes transparent on cooling, indicates that the most refractory ingredients have been all
dissolved. Their mixture is facilitated by the continual disengagement of carbonic acid gas, which
in its escape causes the whole to be thrown into ebullition. Some of the gas remains in the mass,
rendering it spongy and full of vesicles. Unless in the manufacture of the finer qualities of glass,
for which the purest materials are employed, there is also a scum called “glass gall ” or “ sandiver "
floating on the surface, consisting of the insoluble matters, and the sulphates of soda and lime not
taken up by the mixture. This is removed by ladling, and the metal is next “ fined,” which is done
by increasing the heat to the highest degree, and keeping the contents of the pots in a state of per-
fect fluidity for from 10 to 30 hours; in this time the bubbles disappear, and the insoluble matters
settle to the bottom. The furnace is then allowed to cool until the metal has become viscid, so that
it may be taken out and worked ; and it is afterward kept at a sufficiently high temperature to main-
tain the glass in this condition, that it may be used as required. For construction of glass furnaces
and pots, see FURNACES, GLASS.
Window-Glass.--'I‘he glass commonly used for window-panes is one of the hardest varieties, and is
of unsuitable quality for shaping into vessels or manufacturing by cutting or grinding. The follow-
ing table shows the composition of several varieties :






l . . s I m“
NAME. Silex. ! Lime. Soda. Potash. i Alumina. I Total.
II v - \ F b a ‘
French glass ......................... .. 69.6 13.4 15.2 g 1.4 .4 l 100
Belgian glass . . . . . . . . . . . . . . . . . . . . . . . . . .. 72 5 18.1 13 ; 1 .4 100
English glass . . . . . . . . . . . . . . . . . . . . . . . . . . 7‘2 .9 13 .2 12 .4 . . ‘ 1 , i 100
"Very white potash glass . . . . . . . . . . . . . . ., 71.2 11.6 2.3 14.2 ‘ 0.4 .3 , 100
Glass easily tarnished, bad quality . . . . . . .I 71.4 3 6 16.2 6.9 1 l .9 | 100
~—-l

The ingredients used are sand, sulphate of soda, and lime in the form of carbonate or slacked lime.
In the north of France and in Belgium these are employed in the following proportions: white sand,
100 parts; sulphate of soda, 35 to 40; limestone, 25 to 35; coke powdered, 1.5 to 2; binoxide of
manganese, 0.5; and glass scrap in variable quantity, usually in the same proportion as sand. Ar-
senious acid is sometimes added to act as a decolorizing agent and to facilitate the fining. English
makers produce a very fine white glass for photography, and for covering pictures in frames, in
934 GLASS, MANUFACTURE OF.


closed pots, with the following ingredients: Fontainebleau or American sand, 100 parts; carbonate
of soda at 90°, 36 ; nitrate of soda, 5; powdered slacked lime, 12 ; and arsenious acid, 0.5.
There are three kinds of glass which come under the general heading of window-glass, namely,
sheet, crown, and plate. All of these differ in their manufacture. Crown-glass is first blown into
a globe or sphere and flattened out into a circular disk ; sheet-glass is formed into a cylinder, which
is opened out into a sheet; and plate-glass is east on huge tables.
Sheet-Glass.—In the manufacture of sheet-glass two furnaces are generally used, one for melting
or making the glass, and the other for reheating it during the process of blowing. The latter is
usually of oblong form, with 4, 5, or 6 holes on each side for as many workmen. On each side of
this furnace is a. pit about 7 feet deep, 16 feet wide, and as long as the furnace; over this at inter-
vals of about 2 feet are erected, in front of each hole of the furnace, wooden stagings or platforms,
upon which the workman stands when swinging
2157. the cylinder to and fro and over his head. The
‘ ‘ 5-,, - manufacture may be divided into three process-
“ul\ es: 1, blowing the cylinder; 2, flattening it out
into a sheet; 3, polishing the sheet. The oper-
ation of blowing is represented in Fig. 2157, and
_ I _
"Jul"
“5*
2158.



begins with the collection of a sufficient quantity
of metal from the pot at the end of the pipe. A,
massive glass ball is thus attached round the
knob of the pipe, which must be pushed for-
ward with a flailing-iron until an annular groove
is produced. When this operation is completed, the blower rounds the ball by rolling it on the-
marver, and distends it slightly by blowing. It then assumes the form represented in Fig. 2158, from
which it will be seen that the mass of glass is thickest in front, as from that part it has to be dis-
tended and lengthened into a cylinder. In the subsequent operations, it first assumes the width of
the future cylinder and then the length. With this object in view, the workman, after having re-
warmed the ball of glass, holds it perpendicularly above his head, and blows into it. The heavy bot-
tom, yielding with lcss ease to the blast, admits of the distention of the width, and a flattened bottle
is formed, Fig. 2159. As soon as the proper width is attained, the pipe is quickly inverted, so that
the ball is undermost, and an incessant swinging motion is then kept up with a constant blast. Fur-
ther distention is thus effected, but from the bottom only, as the thinner sides have by this time cooled,
and in consequence of the swinging motion in the direction of the length, so that the bottle acquires


2163.
2160. 2161.




,__-__-__.._—.—
0
1
the form represented in Fig. 2160 by the time that the glass has so .far cooled as to be no longer
expansible. If the swinging were intermitted, the bottle would be distended in all directions, and
present the form indicated by the circular line. By repeated warming, swinging, and blowmg, the
form Fig. 2161 is gradually produced, which is of the proper length of the cylinder. It is then coni-
eal, and terminated by a semicircle, in the middle of which, at c, is the thinnest part of the vessel.
GLASS, MANUFACTURE OF. ' 935
4

“.- .r... .
When the workman blows air into the pipe, and closes the aperture with his thumb before withdraw-
ing the pipe from his mouth, the air expands and exerts great tension upon the sides of the cylinder;
if the weakest part, at c, is now held in the flame, it will be blown out and burst. The cylinder hav-
ing thus been opened as represented in Fig. 2162, the next object is to extend the somewhat uneven
and thick margin of the aperture, and reduce it to the proper dimensions, while at the same time the
other parts are straightened and acquire a uniform diameter, as is shown in Fig. 2163. Prominent
portions, which may sometimes project, are cut away with the scissors.
According to the size of the cylinder, it may be either blown at once, or it will require to be re-
heated several times. When very long and wide cylinders are blown, the lower portion is liable to
become too thin; an extra portion of glass must then be incorporated with it before the opening
process.
The neck and curvature where the pipe was attached to the cylinder have now to be removed, in
order to spread the whole out in the form of a plate, and the cylinder must be cut open lengthwise.



The cylinder, supported by an assistant upon a wooden rod, is therefore turned round two or three
times in the curve of a bent iron, heated to redness, as shown in Fig. 2164, and a drop of water is
allowed to fall upon the heated line, which fractures the glass and detaches the cap. In a similar
manner, but in a straight direction, a crack is made longitudinally, and the cylinder is then prepared
for spreading or flatting, Fig. 2165. Instead of cracking the cylinder by this means, the cap of the
cylinder is sometimes taken ofi by winding around it a thread of hot glass, and after removing the
latter applying a piece of cold iron to any point which the thread covered. After trimming the other
end by cutting off about 2 inches in length with a diamond, the cylinder is split open longitudinally by
drawing along its inside surface a diamond attached to a long handle and guided by a wooden rule.
Flatting is conducted in furnaces purposely constructed, the principal parts of one of which
are shown in Fig. 2166. The flame first plays upon the flatting-hearth C before entering the anneal-
ing or cooling furnace B, which is also heated directly by the fire, when it escapes through the flue
or channel D, by which the cylinders are introduced to be subsequently removed. The flattener
stands in front of the aperture l, the workman engaged at the cooling-furnace before m; and an
assistant pushes the cylinder 0 o 0 0 along the railway p. The most essential part of the furnace,
however, is the spreading-plate or firming-stone q and q'. This must be perfectly even, without any
roughness or inequalities which would scratch the glass or make it lumpy; it must be unalterable in
the fire, and of a size somewhat larger than the flattened cylinders. A plate of this description is
usually manufactured from fire-proof clay mixed with cement (either ground fragments of burnt clay
of the same kind, or fine sand, or ground quartz), strongly beaten during drying, then burnt, and
lastly ground smooth; it is laid upon
a bed of sand and in contact with a 2166'
second table of the same sort in the ‘ '
cooling-oven. To make quite sure
that no injury shall be sustained by
the plates upon the flatting-stone, it
is customary to cover this previously
with a layer, which is a thick plate of
glass expressly blown for this pur-
pose. These lagers are soon devitri-
fied, which is of no moment so long
as the surface remains smooth; this,
however, does not last long, and fre-
quent renewal of the lager becomes
necessary. Lastly, to prevent the cyl-
inders from attaching themselves to
the lager, the fiattencr, in some manu-
factories, throws a handful of lime
into the furnace, which is carried as
fine dust by the flame and spread over
the lager. The temperature in the
flattingfurnace must only be just suf
ficient to soften the cylinders, while
in the cooling-furnace it must not at- L
tain that point.
The spreading operation is commenced by introducing the cylinders into the warming-tube D. The
further the cylinders are pushed forward by those succeeding them, the more they become heated,
until they begin to soften on reaching the flatting-stone. They are then taken by the workman with





936 GLASS, MANUFACTURE or.

a rectangular bent iron, and placed upon the lager with the cut side uppermost, where they open of
themselves, and are easily straightened and made even. For this latter purpose, a rod of iron, fur-
. nished at the end with a wooden polisher,
Fig. 2167, is employed, and this is dipped
21% into water each time it is used. When all
the curvatures and lumps have been reduced,
the sheet is pushed backward into the an-
nealing-oven, where it cools down and is
placed in an upright leaning position. Be-
tween every 30 or 40 sheets an iron rod s s
is inserted, and the operation is continued
until the whole furnace is filled.
Fig. 2168 is an elevation of a flatting-furnace in section, with three annealing-arches of the ordi-
nary description. Fig. 2169 is a ground plan of the same. In Fig. 2170 are elevations of two end
views of the flatting-furnaee. ab is the spreading-furnace, divided into two compartments by the
partition 0; d d are two sets of fire-bars, on which wood must be burnt; e is the spreading or flat-
ting stone of the furnace, which must be perfectly smooth and even; i is an opening through which
2168.





the cylinder is placed in the furnace previous to being laid on the flatting-stone e ,' h is the opening
through which the workman spreads the cylinder into a flat sheet of glass ; f is the opening through
which the sheet of glass is removed to the table or bed 9, in the compartment 6. The upper side of
the table 9 is made of stone, similar to that employed as the flattening surface. It is fixed to an
iron framework on wheels, and is kept at a proper degree of heat by remaining in the furnace, as
shown in the drawing. The carriage runs on a railway in front of the annealing-arches, where the
sheet is transferred in the usual way.
The cylinder is placed on the flatting-stone, and is split lengthwise by passing a red-hot iron bar It
from end to end, a little charcoal powder being previously sprinkled on the inner surface of the





2169.
w, \\ \\
§ §s M
\\ e .9' [4% i
\ _ J m} [5,3, r-n
\ a“: \ If] :1



Parr—n"
a; -,=\ '
\\\\\ .\\ .
cylinder. It is now spread out into a sheet by pressing the same on the flatting-stone, by mcans oi
. a small block of elder-wood, fixed on an iron bar m. The temperaturehat which the flatting is per-
formed is such that the operation does not occupy more than a minute.
Two improvements have been introduced in this operation. One consists in making part of the
floor of the compartment a to consist of a movable stone about 10 inches in diameter, on which the
2170.


cylinder is placed. It is gradually exposed on all sides to the action of the fire by causing the stone
to revolve on its axis, and thus the objection to the previous plan is avoided, where one side of each
cylinder became so much hotter than the other.
Annealing usually requires from 24 to 36 hours. From the annealing-oven the sheets are taken to
the warehouse, where they are smoothed, polished, assorted, and cut into panes of the required
GLASS, MANUFACTURE OF. 937
dimensions. The former method of grinding and polishing sheet-glass by imbedding the sheets in
plaster of Paris proved inadequate to remove the defects in the glass consequent upon the mode of
manufacture. The chief of these was the undulating or wavy appearance of the surface, called
cockles, which was attributed to the difference of diameter between the inner and outer surfaces of
the cylinder, and which caused objects seen through the glass to be distorted. Notwithstanding the
glass was made very thick, after the superficial roughness was removed the result was a thin sheet
much inferior to plate-glass. The ingenious process devised by Mr. James Chance for producing
patent plate-glass, which is now used in England and most factories on the continent, is one of the
most'important improvements in the manufacture. By removing the thin outer surface of the glass
by this method, an evenness and a polish are secured, even on the thinnest sheet, which make it in
many respects equal to plate-glass, and far superior to the sheet-glass produced by the old process.
The improved method consists in placing the sheet to be ground and polished upon a flat surface
covered with a piece of damp soft leather or cotton cloth. A slight pressure applied to the glass
causes it to adhere to the surface of cotton or leather, and by thus producing a vacuum the entire
sheet is firmly maintained in a flat position by atmospheric pressure. The exposed surfaces of two
sheets fixed in this manner are rubbed against each other in a horizontal position by machinery,_
emery and water being constantly supplied to keep up the friction. Both sides of the sheet are
polished in this manner, with only a slight diminution of the thickness of the glass. After the
removal of the sheets from these surfaces, they resume by their own elasticity their original shape,
which is often more or less curved. The final polish is given to the sheets by a process similar to
that used in polishing plate-glass. In each process through which the glass has passed it was ex-
posed to some imperfection, and some of the sheets bear the peculiar defects of them all and are of
little value; others are suitable for inferior uses, and but few are perfect. The wide difference be-
tween the quality of the best and the worst sheets is indicated by the fact that the former are valued
at three times more than the latter. The same kind of material is used in the production of both
crown- and sheet-glass. The remarkable brilliancy of surface of the former gives to it a certain
advantage over sheet-glass ; but the larger size easily attained in making the latter gives it the su-
premacy in commerce. Of crown-glass it is difficult to obtain panes of 34 x 22 inches, while the
usual size of the sheets of cylinder-glass is 47 x 32 inches, and cylinders are occasionally blown 77
inches in length, requiring about 38 lbs. of glass.
Croum- Glass—Illustrations of the furnace used for melting crown-glass will be found under FUR-
NACES, GLASS.
When a certain weight of glass, a, Fig. 2171, has been collected or gathered from the pets on the end
of the tube 6, it is fashioned into a peculiar form, as shown in the figure, on a solid plate of cast-iron
0, called a‘ marver. Previous to the operation of “marvering,” the workman cools the iron pipe,
which has become heated by being exposed in the melting-furnace. ~The marver c is placed on rollers
for the convenience of moving it from place to place as required. When the mass of glass has as-
sumed the proper form, a boy blows through the iron tube, while the workman continues to roll the
ball upon the marver. During the previous operation of “marvering,” the mass of glass is fashioned
so as to give the outer extremity a conical form, the extreme end of which becomes the outer axis of
the globe during the operation of blowing. This outer axis is called the “bullion,” and during the ex-
panding of the globe the workman rolls this bullion along a straight-edge. The piece of glass, after

1.1
the above operation, is reheated in the blowing-furnace, and expanded by the workman blowing
through the iron pipe, until it is so far cooled as to require another “heat.” When it has been blown
to the proper size, Fig. 2172, 2, it is again exposed to the heat of the furnace, when the workman,
resting the pipe on an iron support, during which time the neck remains cool, causes the glass globe,
by a peculiar motion of the pipe, to assume the shape shown at 3. This last operation is technically
termed “bottoming the piece.” It is then removed to a framing, Fig. 2173, where it rests on its
edge on some ground charcoal and cinders a. Another workman then attaches a strong 11‘011 rod,
with a quantity of melted glass at its end, to the centre of the piece, as at b. The “ blower” now
touches the neck of the piece at c with an iron rod previously dipped in water, and, by a smart blow
on the iron tube cl, detaches the piece, leaving the neck open, as shown at 4, Fig. 2172.
The “piece” is now removed to the “flashing-furnace.” The thick neck is first heated at the
opening, whence a powerful flame is issuing. Fuel is placed on the grating for the purpose of warm-
ing the piece, while the neck is heated from the larger furnace through an opening 1n the Side.
As soon as the neck is sufficiently soft, a boy inserts a flat iron tool through the nose-hole, to smooth
the roughness left in the neck by breaking it off as described above. When the neck has been sulfi-
ciently heated at the nose-hole, the bell-shaped vessel is brought in front of another opening, where
it receives the full heat of the flame, and the pipe is then made to revolve with the greatest possibie


938 ‘GLASS, MANUFACTURE OF.
rapidity. The action of this rotary motion upon the softened glass is easily conceived. The centri~
fugal force communicates to the particles of glass a tendency to fly off at a tangent, and to arrange
themselves in a circular plane perpendicular to the axis of rotation. The mouth, being the softest
part, first expands, and this quickly enlarges until the whole suddenly opens into one sheet of glass,
Fig. 2174, about 6 feet in diameter, which, with the exception of the central portion, is of nearly
2173. 2174.




l
uniform thickness. It is obvious that a sheet of such dimensions must quickly fold together in the
‘ soft state, if the rotary motion is not kept up. The workman, therefore, continues the rotation after
the removal of the sheet from the flame of the furnace, until it reaches the annealing-oven, where
it is placed on a small circular bench, and is detached from the red by means of a pair of strong
shears, leaving a mark called the “bullion,” or bull’s-eye. Another workman, who has charge of
the annealing, now raises the “ ta-
ble” of glass upon a large fork-like
instrument, and carries it to an up-
right position in the annealing-arch,
Fig. 2175. The tables stand thus
on their edges, upon two strong par-
allel iron supports, which run the
whole length of the annealing-kiln.
The glass, after remaining in the
kiln for a considerable time, during
which the cooling has been care-
fully regulated, is withdrawn, so as
to enable a workman to go inside
and hand out each table on the out-
side to an assistant.
This mode of manufacture pos-
sesses at present little more than
retrospective interest, despite the advantage which it offers in the brilliancy of the glass produced.
To make a sheet-glass in which shall be united the brilliant qualities of crown-glass with the cheap-
ness of cylinder-glass is one of the most important problems in glass-making which inventors have
yet to solve.
Plate- GZass.-—The composition of this glass is given by Peligot as follows:







I





MANUFACTURE. Silex. ‘ Lime. I Soda. film“ and
ran Oxide.
, St. Gobain glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 73.2 13.6 12.8 .4
Same, old make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 8.5 19 .5
(
Glass from two English factories; i i I: : 1 English glass, Ravenhead . . . . . . . . . . ., . . . . . . . . 75 6.5 18 i .5
Amelung glass, from Dorpat . . . . . . . . . . . . . . . . . 71 14.3 12.4 I 2.8


The mixture used in the leading glass~houses of Europe is: white sand, 300 parts; soda salt at
85° to 90°, 110 to 120; limestone, 50; glass fragments, 300. In some establishments the limestone
is replaced by 45 parts of slacked lime.
The building or factory for the manufacture of plate-glass is generally of very large size. That of
the British Plate-Glass Works at Ravenhead, where it is called the foundry, is 339 feet long by 155
feet wide; and the famous halle of St. Gobain in France is 174 by 120 feet. In the centre is the
square melting-furnace, with openings on two parallel sides for working purposes, while along two
sides of the great building are arranged annealing-ovens, which are sometimes 30 by 20 feet in order
to receive the immense plates that are to be annealed. Two kinds of pets are used: the ordinary
one, open at the top, for melting the glass; and cisterns or cuvettes, in which the molten glass is
carried to the casting-table. In France the cuvette is usually of a quadrangular form, with a groove
in each of its sides, or, as in the case of the larger cisterns, in two parallel sides, in which the tongs
or iron frame are fitted when the cuvette is moved. Between each two pots in the furnace are placed,
according to their size, one or more cuvettes. In some establishments the cuvette is not now used,
the metal being poured from the pot in which it is melted on to the casting-table. In France 16
hours are allowed for the melting, and the same time for the metal to remain in the cuvettcs; but
the latter term is often extended in order that the aériform bubbles may escape and the excess of
soda become volatilized. Toward the last the temperature is allowed to fall, and the glass then
acquires the slight degree of viscidity suitable for casting. The molten glass is transferred from the
GLASS, MANUFACTURE OF. 930

pots into the adjacent cuvettes by means of wrought~iron ladies with long handles. When the glass
is in the proper condition to be cast, the “tongs carriage,” consisting of two powerful bars of iron
united like two scissors-blades, and resting upon two wheels, is pushed into the opening made in the
furnace, and the cuvette is clamped in the quadrant formed at the extremity of the tongs, two workmen
manipulating the handles at the other extremity. The cistern, thus taken from the furnace full of
molten glass, is placed on another carriage and quickly conveyed to the casting-table, Fig. 2176.
This consists of a massive slab, usually of cast-iron, supported by a frame, and generally placed at
the mouth of the annealing-oven. At the Thames Works in England the casting-plate is 20 feet long,
. 11 feet broad, and 7 inches thick. Formerly these tables were of bronze, and the great slab of St.
Gobain of this alloy weighed 50,0001bs.; but cast-iron was found less liable to crack, and is now
generally used for this purpose. On each side
of the tables are ribs or bars of metal, which
keep the glass within proper limits, and by their
height determine the thickness of the plate. A
copper or bronze cylinder about a foot in diame-
ter, resting upon these bars, extends across the
.table. After being heated by hot coals placed
upon it, the table is carefully cleaned prepara~
tory to casting. The cistern containing the melt-
ed glass is raised from the carriage on which it
was brought from the furnace by means of a
crane, its outside carefully cleaned, and the glass
skimmed with a copper sabre. The cuvette is
now swung round over the table, over which a
roller covered with cloth is drawn to remove all impurities, and the molten glass poured out in front
of the cylinder, which, being rolled from one eXtremity of the table to the other, spreads out the glass
in a sheet of. uniform breadth and thickness. The operation is a beautiful one from the brilliancy
of the great surface of melted glass, and the variety of colors exhibited upon it after the passage of
the roller. While the plate is still red-hot about 2 inches of its end is turned up like a flange, against
which an iron rake-like instrument is placed, and the plate is thrust forward into the annealing-oven,
the temperature of which is that of dull redness. Another plate is now immediately cast upon the
hot table, and the annealing-oven when filled is closed and left for about five days to cool. The pro-
cess of casting is done so systematically and with such dispatch in a well-regulated establishment,
that the glass has been taken from the furnace, east, and put into the annealing-oven in less than
five minutes. From the annealing-oven the plates are taken to the warehouse, where they are care-
fully examined to see how they may be cut to the best advantage.
In different manufaetories and at different times various processes have been in use for grinding
and smoothing the surface of plate-glass, but the principle has been the same in all, viz.: rubbing
the surface to be smoothed with another surface either of glass or iron, and at the same time apply-
ing sand or emery of dilferent degrees of fineness and water between the two impinging surfaces.
One of the most approved methods of grinding and smoothing the plates was introduced into Eng
land in 1856, and adopted in the British Plate-Glass \Vorks. This apparatus consists of a revolving
table, 20 feet in diameter, fixed upon a strong castiron spindle, and capable of running at an aver-
. age speed of 25 revolutions a minute. Above the table frames are arranged to hold the plates of
glass, which are laid in a bed of plaster of Paris, with the face to be polished resting upon the table.
These frames also revolve on their centres by the friction of the table upon the glass, slowly, but so
as to present each side of the plates they hold to an equal amount of rubbing as they are moved
nearer to the centre of the table or farther from it. Sand and water are applied to facilitate grind-
ing down the glass. The grinding by this process is found to be even and equal, and the machinery
to work smoothly and steadily from the facility with which the plates accommodate themselves to the
power applied. After grinding they are smoothed with emery powder of finer and finer qualities, and
are thus prepared for polishing. By the process above described the grinding and smoothing are done
by the same machine; but formerly two sets of apparatus were required for this purpose. By grind-
ing, the surface of the plate is made true, but presents a rough appearance which is removed by the
process of smoothing. At this stage it is somewhat opaque, but this de feet disappears after the final
process of polishing. This is performed chiefly by machinery. The plate of glass having been fixed
upon the table by means of plaster of Paris, the surface is subjected to the action of a series of
wooden blocks covered with felt and attached to a frame by which they are made to move over the
surface of the glass. At the same time a polishing powder, generally red oxide of iron, is applied,
while the friction may be increased by adding weight to the rubbers. Polishing sometimes brings
out defects which were before concealed; the plates are consequently again assorted, and, if need
be, reduced to smaller sizes. Bending the large plates or the smaller sheets of glass for the purpose
of fitting them for bow windows, etc., is an especial branch of the manufacture. A core of refrac-
tory material and suitable shape is introduced upon the floor of the furnace; and upon this is laid
the sheet to be bent, which as it softens by gravity conforms itself to the shape of the bed upon
which it is laid.
The value of plate-glass varies greatly with the size. In the United States the price of a plate of
standard British or French glass, 5 x 3 feet, is about $35; but when the dimensions are double, the
plate being 10 x 6 feet, the price is increased to about $175. A plate 14 x 8 feet is valued at about
$500. -
In Bessemer’s method of casting plate-glass, a reverberatory furnace is employed, Fig. 2177, with a
low arch and descending flue d. The flame, proceeding from the grate a, plays upon the surface of
the materials in thepot e, in the fire~space b. The arch is formed at that part which is most exposed
2176.


94.0 GLASS, MANUFACTURE or.

“
to the heat and the alkaline vapors from the mixture, of hollow bricks c c 0, over which a draught
of cold air is caused to play by connecting the space above the furnace with the ascending main
chimney. The object of this cooling, which is of course attended with a loss of heat, is to prevent
tears, consisting of the fusible product of the action of the alkaline vapors upon the ingredients of
the bricks, from forming on the arch, and falling into the glass during fusion. The pot, e, is of very
large dimensions, as large indeed at the lip on the one side as the width of the plates which it is
proposed to cast with it. It is set upon a siege composed of large masses of fire-stone, and these
are cemented together, as well as the pot upon them, by some bottle-glass, which, in the fused state,
enters the crevices and binds the whole firmly together upon the strong-ribbed cast-iron frame 9.






~__m(l_ _______ K
lllll.l_4‘\1\l I, . ' \ ' “ “/////"~'s\\~ssr<>i> "
\ ._ 7: "4//w\\jg‘\\















\"i .
:1 $1377:









.\ \ s.
This frame moves upon four wheels 7:. on a railway to, which extends beyond the furnace to the
rolling machinery, to be described immediately. Thus pot, siege, and frame are all wheeled in and
out of the furnace at once, as will be seen by reference to the section, Fig. 2178, where 2' j represent
the hollow brick, or masses of stone, by the removal of which a free ingress and egress is allowed
the whole carriage on the continuation of the rail. The pot and carriage fill the entire recess in the
furnace, and the flame playing upon the top does not much affect the iron frame of the carriage
through the bad conducting-stones which form the bed of the pot. 4'0. 2179 is a longitudinal sec-
tion through the middle of the framework and machinery, by means of which the pot and siege are
raised, and the melted glass poured out between the rollers. It shows the pot in an elevated position
and partly emptied.
The mode of operating with this apparatus is as follows : When the glass is in a fit state for east-
ing, the door is removed by a crane from the mouth of the furnace, and by the assistance of an iron
hook the carriage and its pot are easily
2178' , _ , rolled forward upon the rails before men-
tioned to the tilting-frame t. The carriage
f m s. "s \‘r sci-Ores
and its pot are now moved forward until
’/////// \s >///'//»///. Q» .\\I\">\ /// /
74':










‘3
q

the set-screws ill come in contact with the
carriage; the office of these screws is to
Z , regulate the extent to which the lip of the
pot shall overhang the roller 9, so that
when a new pot is used its proper position
l for pouring may be adjusted. The screws
*» M pass through stout lugs N, cast on the
piece at; the handle on X being turned,
the pet will be elevated, as shown in Fig.
. 2179, when the glass passing between the
rollers will be formed into sheets. When
the pot is emptied it is again lowered and
returned to the furnace for a repetition of













.\\'\\\‘\\\\\T\\\\ ~
.~ \»
\\\\ .\\r
, 1,.






,4 m" the preceding operations. The roller ' is
. furnished with a longitudinal rib, w ieh
i L at each revolution cuts the glass off into

lengths.
Flint- Glass.~The best flint-glass is subject to defects, chief among which are undulatory appear-t
ances called strict, resulting from a want of uniform density in the glass, and tending to refraet and
disperse in different directions the rays of light passing through it. These defects are of great im-
portance when the glass is to be used for optical purposes. In 1753 John Dollond, an English
optieian, first began the construction of achromatic object-glasses, formed of two kinds of glass
of different density; for this purpose be used fragments of flint- and of crown-glass, but did not
succeed in making object-glasses with a larger aperturex than 2 or 3 inches in diameter; and when
the need of telescopes of greater magnifying power was strongly felt, it was difficult to produce flint-
glass sufficiently free from striae for a lens 4 inches in diameter. The invention of a means of pro-
ducing flint-glass free from striaa was made by M. Guinand of Brennets, Switzerland, and it consisted
GLASS, MANUFACTURE OF. 941
in working and stirring the material while in a state of fusion, by means of a tool made of the same
material as the crucible or glasspot. He made a hollow cylinder of fire-clay of the same height as
the crucible, closed at its lower extremity and open above, with a flat ledge all round of several
centimetres in width. Having heated this cylinder red-hot, he placed it in the melted glass; then,
by- means of a long bar of iron, bent to a right angle at a distance of some centimetres from its
extremity, which he introduced into the cylinder of fire-clay, he worked and stirred the glass, by










giving the bar a horizontal rotary motion. For the manufacture of flint-glass, and of crown-glass,
he adopted a circular furnace, in the centre of which is placed the crucible or glass-pot, all the parts
of which are exposed to the same temperature; and covered crucibles are adopted, because with
crucibles of this form there is no danger of the glass being spoiled by particles of the fuel, or by
grops or tears from the crown or arch of the furnace. For the construction of this, see FURNACES,
LASS.
Flint-glass, of the usual density, similar to that used for table-sets, decanters, etc., is composed,
ordinarily, of 300 parts of sand, 200 of deutoxide of lead, and 100 of subcarbonate of potash. The
density of this flint-glass is from 3.1 to 3.2. The following composition, expressed in kilogrammes,
gives the quantity necessary to fill the crucible: sand, 100 kilogrammes; deutoxide of lead, 100
kilogrammes; subcarbonatc of potash, 3O kilogrannnes. This composition gives a very white flint-
glass, of a density of from 3.5 to 3.6, and which is perfectly suitable for opticians.
The details of the operation are as follows: The crucible is to be heated in a special furnace kept
for the purpose, and when at a white heat it is to be introduced in the usual manner into the melt-
ing-furnace, which has been brought to the same temperature. This operation cools the furnace and
the crucible. The furnace must be reheated in order to bring it to the highest possible temperature
before introducing the materials. This takes about three hours. The throat of the crucible, which
has been closed with two stoppers to prevent the entrance of smoke, is then opened, and about 10
kilograunnes introduced; one hour after, about 20 kilogrammes more; then, two hours after, 40
kilogrammes. Each time the crucible must be recloscd with the greatest care, and nothing must be
put in until the coal on the grate ceases to give out any smoke. At the end of from 8 to 10 hours
the whole of the composition will have been introduced. The crucible is left without being opened
for about 4 hours; then the stoppers are removed for the purpose of introducing the cylinder of fire-
clay, which has been heated separately to a white heat in the same furnace, and kept at that tem-
perature until placed in the crucible; care is to be taken to keep it perfectly clean and free from
ashes. At this period the flint-glass is melted, but it still contains bubbles. Nevertheless, the bent
iron bar is introduced into the cylinder, and the first stirring is given, which serves to coat the cylin-
der with glass, and to effect a more intimate mixture. In about 3 minutes the iron bar is white-hot;
it is taken out,_and the ledge of the cylinder is placed on the edge of the crucible. This cylinder,
being specifically lighter than the glass, floats slightly inclined, because its upper ledge is outside
of the glass. The two stoppers are so replaced as not to push the ledge of the cylinder into the
glass, and the stirring up of the fire is recommenced. Five hours afterward a fresh stirring up with
a single iron bar takes place, the glass is already well refined, and then from hour to hour there is a.
stirring, each time with a single iron bar; great care being taken that at each stirring there shall be
no smoke in the furnace, and that the lower doors of the furnace are closed. After having thus
used 6 iron bars, from 25 to 30 centimetres in thickness of coal is thrown on the grate, which forms
a mass quickly reduced to coke, and which allows the furnace to 0001 without exposing the grate
942 GLASS, MANUFACTURE OF.

uncovered. The various openings of the furnace are unclosed; the whole furnace and the crucible
thus gradually and slowly cool. This operation tends to cause the bubbles which are not yet dis-
engaged to rise to the surface. At the end of two hours this operation is finished, and the furnace
is again brought to the melting heat. After five hours of the highest temperature, the glass has re-
sumed its greatest fluidity, the bubbles have disappeared, the grates are completely closed below,
and the great stirring (brassage) commences; that is to say, as soon as one iron bar is hot, another
is substituted for it, and so on for about two hours. At the end of this time the material has
acquired a certain consistence, and the stirring is not executed without difficulty; then the last iron
bar is taken out, and the cylinder is removed from the crucible, which is very carefully closed, as
well as the chimneys and openings, except a small hole of two centimetres to permit the escape of
the gas which may have remained in the fuel. When the disengagement of gas ceases, the furnace
is entirely closed, and it is suffered to cool, which takes about 8 days. The door of the furnace is
then removed, and the crucible with its contents taken out, usually in a single mass, except some
fragments which become detached round it. The only object now is to make use of this mass and
these fragments, the mode of doing which we will explain directly, after having given the details of
the operation for crown-glass, which, as may be supposed, has a great analogy with the preceding.
ilfaiiitfaciurc of Crown-Glass.—After many experiments, the following composition is found to be
the best: white sand, 120 kilogrammes; subearbonate of potash, 35 kilogrammes; subcarbonate of
soda, 2O kilogrammes; chalk, 15 kilogrammes; arsenic, 1 kilogramme.
The crucible having been placed in the furnace, as for flint-glass, the introduction of all the
materials is to be completed in about 8 hours, 4 or 5 hours after which the cylinder is to be intro-
duced, and the first stirring takes place; then, every 2 hours, a stirring with a single iron bar; 6 are
to be executed in this way. The- furnace is to cool very slowly for 2 hours, after which it is to be
reheated for '7 hours, this glass regaining its heat with much more difficulty than flint-glass. The
great stirring then takes place, which lasts about an hour and a quarter. The crucible, the chimneys,
and the openings are closed as for flint-glass, and the whole is left to cool. Parallel faces are made
on the sides of the mass, whether of flint- or crown-glass, in order to examine the interior to deter-
mine the mode of division. It is then sawed into slices. Faces are also polished on the fragments
for the purpose of examining them, and disks are made of them in accordance with their weight.
For this purpose, they are first heated in a furnace and then introduced into a muflie, where only the
heat necessary to mould them is given. If the fragment is irregular, it is partially rounded by the
nippers and then moulded in a press, after which it is annealed.
Urystal.-—This glass is sometimes termed flint-glass in England. It is chiefly netable as contain“-
ing lead, the presence of which renders the glass more fusible and of higher refracting power, while
giving to it a special sonority which renders it easily distinguishable. The following table shows the
composition of various kinds of cry stal glass, according to Peligot:












, O_.d f l 0 .d f Oxide of
, MANUFACTURE. S.lex. ‘“ 6 ° Potash. Soda. a: 'mina. "“ '3 ° Manga- Lime. Totals.
y Lead. Iron. new.
i
{ Voneche crystal . . . . . . . . . . . . . . . . .. 61 33 6 l 1(30
, Baccarat crystal . . . . . . . . . . . . . . . . . . .. 51.1 38.3 7.6 1 7 .5 3 5 100
; Choisy-le-Roi crystal . . . . . . . . . . . . . . ., 54.2 34.6 9.2 9 .5 4 99.8
' English crystal . . . . . . . . . . . . . . . . . . . . . l 57.5 32.5 9 1 .. 100
English crystal (Faraday’s analysis). ‘ 5-1.9 33.3 13.8 . . . .. 99
Moulded English crystal . . . . . . . . . . .. 1 61.3 22.3 7.1 7.5 .7 1 99.9
I

In large French establishments the usual composition of crystal is a, sand, 300 parts; minium,
240 to 250; potash, 190 to 200. In England the following composition is used: sand, 300; minium,
150 to 180; potash, 220 to 270. For the manufacture of this glass into various objects, see GLASS-
WARE, MANUFACTURE or. .
Demi-Crystal.—This is a variety of glass largely used for vials, flasks, and cheap tableware.
Peligot, among various compositions, gives the following: sand well washed, 300 parts; soda, puri-
fied and hydrated, from 55° to 60°, 130 parts; slacked lime, 50 parts.
Bohemian Glass—This celebrated glass is almost as cheap as demi-crystal, while it is as brilliant
and homogeneous as crystal itself. Peligot gives the following analyses of three samples:



___i ' I
NUMBER. ‘ _ Silcx. Potash. I Lime. 112i Totals.
1 77— 14 s 1 100
2 76 l (i 7 1 1 00
3 75 13 9 3 100




The following is the composition used at the glass-works near Gratzen, Bohemia: pulverized
quartz, 100 parts; slacked lime, 17 ; carbonate of potash, 32; oxide of manganese, 1 ; white arsenic,
3 ; together with from one-third to one-half the weight of the foregoing composition in glass scrap.
Slag-Glass.—The use of blast-furnace slag for the manufacture of glass has been proposed by Mr.
Bashley Britten (sec Engineering, xxii., 283). The slag is run directly into Siemens furnaces. Two
of these furnaces are so provided that they can be rclined or repaired alternately without stopping
work. In working, these converting tanks are kept supplied with silica in excess; this may be in the
usual form of sand, but flints, coarse sifted gravel, or fragments of quartz or any other silicious
stone, are to be preferred when readily obtainable, as they form a more permeable mass, and are
readily dissolved in contact with the basic slag. It is convenient thatthe fresh supplies of silica
GLASS, MANUFACTURE OF. 943

should be introduced when no slag is running, in order that it may become heated in the interval to
avoid chilling the slag when it is admitted; as the slag is introduced it is fed by a hopper or other
means with the alkali. N o stirring or mechanical agitation is needed, as the ingredients mingle of
themselves; and, as they combine and become glass, this, being of a denser nature than the crude
materials, sinks below them and forms a substratum of clear glass, with the yet imperfect glass and
undissolved silica floating on its surface. The clear glass, as it is wanted, is tapped from the bottom
of the tank, and received in a ladle holding a ten or more. This ladle is lifted by a crane, and is
drawn along a tramway to the glass-house, situate as near as circumstances permit; when brought
opposite to the opening at the back of the working-out furnaces, the ladle is tilted on its trunnions,
and the glass is poured into the tank by a spout. The glass can then be used at once as it is, or its
color or other quality may be changed by adding to it what is needed for that purpose.
The Bastie Toughened Glass—By the process of tempering devised by M. de la Bastie, the hard
ness of glass is very much increased. The operation consists in immersing the hot glass in a bath
of oils, grease, wax, or resinous substance, the temperature of which is above that of boiling water.
Hardened glass will stand blows of about double the energy of those which will shatter ordinary
glass of similar thickness. Its resistance to shearing stress is about three times that of common
glass. On rupture, however, it disaggregates. It may be etched with hydrofluoric acid, or engraved
with the sand-blast, without becoming impaired in point of strength. It cannot be cut with a dia-
mond, as the removal of a portion determines the rupture of the entire piece. It is in use for photo-
graphic negatives, articles of table furniture, and lamp-chimneys, and has withstood the action of a
cupel furnace at white heat for several days. The furnaces used by M. de la Bastie are described
under FURNACES, GLASS. (See Popular Science Monthly, vii., 558. For tests of tempered glass, see
Scientific American, xxxii., 402.)
Colored and Ornamental Glass.—Colored glass is produced either upon strass for imitations of
precious stones, or by introducing the various oxides used for coloring into the materials of flint or
other kinds of glass. In the latter case the coloring matter is thoroughly fused with the glass, which
therefore becomes colored throughout its entire body. Pigments are also applied to the surface of
glass, and sometimes by their greater fusibility are burnt or melted in. Flint-glass may be employed
for vessels ornamented with colors, and to 6 ewt. of it the following ingredients are added for produc-
ing the respective colors: soft white enamel, 24 lbs. arsenic, 6 lbs. antimony; hard white enamel,
200 lbs. putty, prepared from tin and lead; blue transparent glass, 2 lbs. oxide of cobalt; azure-
blue, about 6 lbs. oxide of, copper; ruby-red, 4 oz. oxide of gold; amethyst or purple, 20 lbs. oxide
of manganese; common orange, 12 lbs. iron ore and 4 lbs. manganese; emerald-green, 12 lbs. cop-
per scales and 12 lbs. iron ore; gold topaz color, 3 lbs. oxide of uranium. The colors produced by
the metallic oxides are found to vary with the degree of heat employed. All the colors of the spec-
trum may be obtained with oxide of iron; and these various effects do not seem to depend upon the
different degrees of oxidation, but are thought to result from variations in molecular arrangement,
induced perhaps by the action of light. By another process the surface alone of the glass may be
colored. This is done by first gathering with the blowpipe a lump of clear glass, which after being
rolled upon the marver is dipped into a pot of melted colored glass, forming a lump of colorless
glass enveloped in a coating of colored glass. This is blown into a globe or cylinder and opened out
into a sheet or plate in the usual manner, one surface of which is clear and the other colored. Ves-
sels of various kinds having colored surfaces on the outside may be produced in a similar manner.
By cutting through the thin layer of colored glass to the colorless layer, a great variety of colored
ornamental glass may be produced. By gathering first a lump of colored glass and then coating this
with melted clear glass, the external surface of the vessel will be colorless and the inner layer
colored. “ Casing ” is a somewhat similar process. The article of flint-glass when partially blown
is inserted into a thin shell of colored glass, prepared at the same time for its reception, and the
blowing is continued till the inner one fills the shell, with which it is afterward well incorporated by
softening in the furnace and further blowing. Several partial casings of different colors may be
thus applied.
In making etched enameled glass, the enamel substance is ground to an impalpable powder, and
laid with a brush in a pasty state upon the glass. After the paste is dried, the ornament is etched
out by machinery or by hand, and the glass is then softened till the enamel is vitrified and incorpora-
ted with it. From this it is removed to the annealing-kiln. The flocked variety of enameled glass
is prepared by the same method, except that a fine, smooth, opaque surface, like satin, much softer
and smoother than that of ground glass, is previously given to the whole surface before the enamel
is applied. This variety has in great part supplanted the other, and is justly much admired for the
softening of the light diffused through it, and for the delicacy and beauty of the elaborate and artis-
tic designs with which it is ornamented.
Works for Reference—Among the most valuable treatises on the subject of glass are “Curiosities
of Glass-Making,” by Apsley Pellatt (London, 1849), and “ Guide du Verrier,” by G. Bontemps
(Paris, 1868), both of these authors having been for many years extensively engaged in the manufac-
ture of glass. Among other works are those of Neri, “ The Art of Glass” (translated, London,
1662); Shaw, “ The Chemistry of Porcelain, Glass, and Pottery” (London, 1837); Henry Chance,
“On the Manufacture of Crown and Sheet Glass,” London, 1856, and “ On the Manufacture of
Glass,” 1868 ; Peligot, “ L’Art de la Verrerie,” Paris, 1862 ; Turgan, “ Les grandes Usines de
France,” Paris, 1862—’70; Cochin, “La Manufacture des Glaces de Saint-Cobain de 1665 a 1865,"
Paris, 1865; Gafiield, “Action of Sunlight on Glass,” reprinted from the “American Journal of
Science and Arts,” New Haven, 1867 ; Sauzay, “La Verrerie,” Paris, 1868, and “Wonders of Glass-
Making in all Ages,” London and New York, 1870; and “Rapports du Jury International” of the
Paris Universal Exposition of 1867, vol. cxi. (Paris, 1868). See also “Le Verre, son Histoirc et sa
Fabrication,” Peligot, Paris, 1877. *
944 GLASS, ORNAMENTATION OF.

GLASS, ORNAMENTATION OF. The Venetians and Bohemians have long been celebrated for
their skill and ingenuity in the production of ornamented glass. Examples of their handiwork are
given in Figs. 2180 and 2181, Fig. 2180 representing a Venetian bottle, and Fig. 2181 a Bohemian
drinking-glass. Many ingenious effects produced are imitations of ancient manufacture, of which
many wonderful specimens are preserved in European museums. The process of drawing out tubes
is an interesting one. The workman, having gathered a lump of glass on the end of a blow-pipe, ex-
pands it into a globular form with very thick walls. Another workman having attached a punty to the
opposite end, the two men separate from each other as quickly as possible, thus elongating the glass
into a tube. The globe immediately contracts across the centre, which, being drawn out to the size of
the tube desired, cools, so that the hotter and softer portions next yield in their dimensions, and so on
until a tube of 100 feet or more hangs between the men. It is kept constantly rotating in the hands,
and is straightened as it cools and sets by placing it on the ground. It is cut into suitable lengths
while hot by taking hold of it with cold tongs. The diameter of the bore retains its proportion to the
thickness of the glass; hence thin tubes must be drawn
from globes blown to large size, or from small ones
containing very little metal. In producing canes the
glass is drawn out without being blown. Tubes thus
drawn out from colored glass are converted into beads
by other curious processes. This branch of the man- ,
ufaeture is extensively practised at Murano. The . ‘ ,
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tubes are drawn out 150 feet in length, and to the diameter of a goose-quill, those for the smallest
beads by the workmen receding from each other at a pretty rapid trot. The tubes are cut into
lengths of about 27 inches and assorted for size and color. Women or boys then take several
together in the left hand, and run them on the face of an anvil up to a certain measure, and with a
blunt steel edge break off the ends all of the same length, which is commonly about twice the diam-
eter of the tubes; the bits fall into a box. These are next worked about in a moistened mixture of
wood-ashes and sand, with which the cylindrical pieces become filled; and they are then introduced
with more sand into a hollow cylindrical vessel, which is placed in a furnace and made to revolve.
The glass softens, but the paste within the bits prevents their sides from being compressed; they
become spherical, and their edges are smoothed and polished by the friction. When taken from the
fire and cleaned from the sand, they are ready to be put up for the market.
The Venetian filigree glass, which consists of spirally-twisted white and colored enamel glasses
eased in transparent glass, is much used for the stems of wine-glasses, goblets, etc. ; and when ar-
ra‘nged side by side in alternate colors, it is manufactured into tazzas, vases, and other ornamental
GLASS, ORN AMEN TATION OF. 945

articles. In making this kind of glass, pieces of plain, colored, or opaque white cane, of uniform
length, are arranged on end, the different colors alternating, around the interior of a cylindrical
mould (Fig. 2182). The selection and arrangement of colors depend upon the taste of the manufac-
turer. The mould and the pieces having been subjected to a moderate heat, a solid ball of trans-
parent flint-glass, attached to the end of a blow-pipe or punty, is placed within the mould, the vari-
ous canes forming an external coating to the glass, to which they become welded. The ball is now
taken from the mould, reheated, and marvered till
the adhering canesare rolled into one uniform mass. 2182-
This being covered with a gathering of clear glass,
the lumps thus formed, with the ornamental work
in the interior, may be drawn into canes of any size,
and presenting either the natural or the spiral ar-
rangement, the latter being effected by the work-
men rotating the glass in opposite directions while
drawing it out into a cane. By variously arranging
the colors in this process, and by skillful manipu-
lations, many wonderful and ingenious effects are
produced. Beautiful vases are also made by the
above process, the glass when prepared being blown
into that form instead of being drawn into canes.
The millejiori consists of a variety of ends of va-
riously-colored tubes, cut in the form of lozenges,
which, having been arranged to represent flowers or other ornamental design, are enveloped and
massed together with transparent glass. The lump is then worked into the required form, a very
common one being hemispherical for use as paper weights. Portraits and even watches and barome-
ters have been represented in the interior of glass; but in this case these articles and the glass have
not formed a homogeneous mass, the former being arranged in a cavity of the latter.
Mosaic glass is produced by arranging vertically side by side threads or small canes of variously-
colored opaque or transparent glass, of uniform lengths, so that the ends shall form a ground repre-
senting flowers, arabesques, or any mosaic design. This mass is now submitted to a heat sufficient
to fuse the whole, all the sides at the same time being pressed together so as to exclude the air from
the interstices of the threads. The result is a homogeneous solid cane or cylinder, which, being cut
at right angles or laterally, yields a number of layers or copies of the same uniform design. This
process was practised with great skill by the ancients, who are supposed to have produced pictures in
this way; but in existing specimens, the pieces have been so accurately united, by intense heat or
otherwise, that the junctures cannot even be discovered by a powerful magnifying glass.
Vitro (li trino represents fine lace-work with intersecting lines of white enamel or transparent
glass, forming a series of diamond-shaped sections, each containing an air-bubble of uniform size.
In making this, a lump of glass is blown in a mould, around the inner sides of which are arranged I
pieces of canes of the required colors, as described in the case of filigree glass, which, adhering to
the glass, form ribs or flutes on its external surface. The lump, having been twisted to give the
spiral arrangement to the adhering canes, is formed into a conical shape and opened at the base.
This forms the inner case of the 'v-itro (li triao. A corresponding outer case is formed in the same
manner, which being turned inside out, the projecting canes appear on the inside of the cup with a
reversed spiral arrangement. One case is now placed within the other, and both being reheated are
collapsed together, forming uniform air-bubbles between each white enamel-crossed section. The
two cases, thus welded into one, may be formed into the bowl of a wine-glass or other vessel.
Frosted glass, like the preceding, is one of the few specimens of Venetian work not made by the
ancients; and although the process of making it is exceedingly simple, it was considered a lost art
until recently practised at the Falcon Glass Works in England. The appearance of irregularly-
veined, marble-like projecting dislocations, with intervening fissures, is produced by immersing the
hot glass in cold water, quickly withdsawing it, reheating the ball of glass, and simultaneously ex-
panding it by blowing. "
Cameo incrustrttion is also of modern origin, having been first introduced by the Bohemians The
figure intended for incrustation must be made of materials requiring a. higher degree of heat for
their fusion than the glass to be used. The figure, having been heated, is introduced into a cylindri-
cal-shaped piece of glass, attached at one end to a blow-pipe and open at the other. The open end
is then closed, leaving the figure in the interior of the hollow pocket. The air is now exhausted
through the hollow tube, which produces a collapse and causes the glass and figure to form into a
homogeneous mass. In making “paper weights,” thin sections of little ornamented rods are placed
in a circular iron mould or bed, in the form of the required design. A workman presses a piece of
hot glass on the end of a punty into the mould and takes up the design. Then another workman
drops a piece of hot glass on the opposite side of the design. The whole is now taken to the fur»
nace, where the parts are welded into a hemispherical form, which magnifies the interior design and
presents a fine picture inclosed within the transparent setting.
In making spun glass, the workman heats one end of a tube of glass, white or colored, by the
flame of a lamp, and, seizing the softened end with a pair of pincers, draws out a long thread. Ow-
ing to the extreme ductility of glass, these threads can be drawn to an extraordinary fineness and
length. In some cases spun glass has been made to imitate the hair of animals.
YTackle-glass“ (ca-rre craquelé) is clear glass covered with an opaque layer of powdered or broken
glass, producing a rough surface. This kind of glass is largely made in Bohemia. The broken glass
is spread upon an iron plate, and the object to which it is to adhere is, while yet pasty, rolled upon
the fragments. The ordinary blowing process follows.



60
946 GLASS, ORNAMENTATION OF.

aq—
Aventu-rine glass is a very beautiful imitation of the quartz of that name. It is yellowish in
color, and through it are interspersed immense numbers of brilliant tetrahedric crystals of copper,
protoxide of copper, or the silicate of that oxide. When polished, this glass is often set in precious
metal for jewelry. The crystals are“ produced in the glass while it is yet liquid. As copper, iron,
and tin exist among the numerous elements which compose glass, it is probable that this crystalliza-
tion is attributable to the reduction of the copper oxide by the last-mentioned metals.
Ola-011w aecntur-ine is made of sand, carbonate of soda, lime-spar, and bichromate of potash. It
contains from 6 to 7 per cent. of oxide of chromium, about half of which is combined with the glass,
giving it a beautiful greenish color, and the remainder exists dispersed throughout the material in
the form of brilliant crystals. This glass is also used for jewelry.
Paste, or strass, which is used to imitate diamonds, and which constitutes all the cheap gems known
under a multiplicity of sensational names intended to delude the ignorant, is a superior quality of
lead-glass, of the following composition, according to Dumas: silex, 38.2 ; oxide of lead, 53; potash,
7.8; alumina, 1 ; borax and arsenic acid, traces; total, 100. These are about the same ingredients
as enter into the fabrication of crystal. It is very soft, and is easily cut or scratched by other varie-
ties of glass. Its distinguishing characteristic is remarlmble brilliancy. To convert clear paste into
imitations of gems other than the diamond, metallic oxides are added. Thus the artificial topaz con-
sists of 1,000 parts white strass, 40 parts antimony glass, and 1 part purple of Cassius; ruby, the
same, but heated longer and containing a little more gold; emerald, 1,000 parts white strass, 8 oxide
of copper, and .2 part oxide of chromium; sapphire, 1,000 parts strass and 15 oxide of cobalt;
unrelhyst, 1,000 parts strass, 8 oxide of manganese, 1 oxide of cobalt, and 2 purple of Cassius.
Glass pearls are largely manufactured in Venice, under the name of r'assadcs or 'rocat'lles, in the
same manner as already described for beads. Very beautiful imitation pearls called barogues are
made in Paris, of exceedingly thin glass lined with gelatine and a nacreous matter obtained from
fish-scales.
Glass rllosaécs.—-To make mosaic pictures in glass, small cubes of enamel are used. In the Vatican
factories in Rome this material is produced in upward of 26,000 different shades. The work is
begun by the designer, who traces on pasteboard in colors the design to be reproduced. The mosaic-
setter then fills a shallow tray of lead, of the same size as the cartoon, with plaster, and draws the
design in outline on the surface of the latter. The plaster is then gradually removed bit by bit, and
the pieces of enamel which match the colors on the design are inserted in its place, the hollows being
previously covered with moistened sand of a greasy nature produced from a volcanic earth found on
Vesuvius. Where the cubes of enamel have to turn corners, they are ground to fit on a steel disk
supplied with emery and water. When the cubes are all set in place, a sheet of paper or cloth is
pasted over their surface, care being taken that all are caused to adhere. The lead tray is then
reversed, the earth backing removed, and a mortar composed of Roman cement, lime, and pozzuolana
is applied. When this sets, the enamel cubes are solidly fixed, and it only remains to wash off the
paper or remove the cloth, and insert the mosaic in its frame or in the wall which it is to decorate.
Cutting and Engraving of Glass—Four kinds of grinding-wheels are used in glass-cutting: 1, a
wheel of wrought or soft cast-iron; 2, a wheel of sandstone; 3, a wooden wheel; and 4, a cork
wheel. In France, where this operation is carried to the greatest degree of perfection, a so-called
“company of cutters” includes three workmen, namely, the ébauc/um', iaz'llcw', and polisscw‘, or
designer, cutter, and polisher. The designer is usually the chief of the company. He prepares the
design, and roughs it out on the object by means of the iron wheel, which is rotated either by a foot-
treadle or by a motor. The wheel is mounted vertically, and is surmounted by a conical hopper
filled with sand and water nearly in the state of mud. This falls upon the wheel, and is entrained
by its rotation. The designer applies the object to the wheel, so that the friction of the sand grinds
away the surface at the desired points. The object now passes to the cutter, who in his turn pre-
sents the piece to the sandstone wheel, which smooths away the asperities left by the sand. Finally
the object goes to the polisher, who finishes its surface by application of the wooden wheel and
pumice powder, and lastly of the cork wheel and colcothar.
The wheels employed by the cutters are quite large, often measuring 20 inches in diameter and
over. Those used by engravers; on the contrary, are small, rarely exceeding an inch or two, and
decreasing down to minute disks scarcely larger than the head of a pin. These wheels are of steel,
copper, sandstone, and an alloy of lead and tin. Emery powder is used in a very. fine state, and the
lathe is operated by the foot of the workman. This mode of engraving has been largely supplanted,
especially for coarse work, by the use of the sand-blast. (See SAND-BLAST.)
Stained Glass—G]ass-painting, which is more properly a process of staining, differs from all other
styles of pictorial art, except the painting of porcelain. The colors are different, being wholly of
mineral composition, and are not merely laid on the outside, but fixed by being fused into the mate-
rial, undergoing in the operation chemical changes that develop the brilliancy and transparency
of which the compounds are susceptible. The colors are mixed with a flux of much easier fusion
than the glass, and with some vehicle, as boiled oil or spirits of turpentine. The mixture is usually
laid on with a brush as in ordinary painting; and the glass being then exposed to heat, the flux
melts and sinks into the body. None of the clear bright colors are perceived until the work is com-
pleted, and the artist consequently labors under great disadvantage in applying the materials that
are to produce them. Ile is guided either by lines drawn on the back side, which show through, or
by a cartoon or drawing on paper placed there. In the early use of stained glass for windows, es-
pecially in churches, brilliant colors were hiv‘hly esteemed, and great success was attained in the
methods of coloring. A bright-red color was imparted by the ancients with the protoxide of copper.
In later times it was found impracticable to succeed with this on account of the tendency of the
copper to pass to a peroxide and produce a green tinge; but the practice has been again introduced
with success by the Tyne Company in England, at Choisy in France, and in other places. The dis-
GLASS-WARE, MANUFACTURE OF. 947

_
covery of the preparation of gold and tin, called purple of Cassius, also afforded another means of
producing a brilliant red.
The process of producing a painted glass window is an interesting one. The artist first makes
an outline on a small scale of the stonework of the window, within which he sketches the design,
indicating the colors to be used and the general treatment of the subject. A full-sized drawing or '
cartoon is next made, from which a “ cutting drawing” is traced, showing the lines where the strips
of lead are to go, and omitting all other details. On this latter drawing, on which the colors of the
design are indicated by outlines, the pieces of different-colored glass are laid and cut with a diamond,
each piece being cut out of that particular color or tint required. The artist now arranges the pieces
of different colors in their proper places on the cartoon, and traces the outline of the design upon
them. On being heated in an oven, the opaque lines vitrify and are formed indelibly on the surface
of the glass. After the outlines have been thus “ burnt” on, the glass is taken again to the painter,
who covers the cartoon with a sheet of colorless glass, or if large a portion of it at a time. Thus
having the cartoon for a guide, he arranges in their proper places on the sheet of colorless glass the
pieces on which the outlines have been traced, and secures them firmly with drops of melted resin
and beeswax, or other suitable Substance. The sheet of colorless glass, with the pieces thus ar-
ranged adhering to it, is placed upon an easel, and the shadows of the picture are put on with the
same material as that used in tracing the outlines. The shading, however, is not traced from the
cartoon, as were the outlines, but is done by the skill and experience of the painter. When the
shading is completed, and the tints of yellow, if any are required, are put on, the pieces of glass are
detached from the colorless sheet and again subjected to heat, for the purpose of “burning in ” the
shadows. If more work by the painter is required, the process is repeated, the glass being thus
subjected to heat in some instances six or seven times. The work of the painter being completed,
the finished pieces are taken by the “leader,” who, having arranged them by the aid of the “cutting
drawing” so as to form the entire design, fastens them together by means of strips of grooved lead
skillfully fitted around the edges of the several pieces. If the window is a large one, as is generally
the case, it is divided into parts of convenient size, which are fitted together when the window is put
in its place. Bars of iron are also sometimes placed across the window at the line of junction and
at other convenient intervals. This general process of producing mosaic stained-glass windows has
been in use from the earliest times, though it may have been modified in some of its details; and
until some other method of imparting colors to glass without detracting from its transparency and
brilliancy is discovered, the opaque lead lines in the design must be accepted as a necessity.
Gilding on Glass.—This operation is performed by the same means as the similar operations on
pottery; with the dili‘erence, however, that as vitreous products are much more fusible than ceramic
materials, the proportions of vehicles to be added to the gold or to the coloring oxides are much
greater.
D A new process of gilding by M. Dodon is thus given by the lfimilcur (10 la Geo-antique: Gold,
chemically pure, is dissolve‘d in aqua regia (1 part nitric and 3 parts hydrochloric acid). The solu-
tion effected, the excess of acids is evaporated on a water-bath till crystallization of the chloride of
gold takes place; it is then taken off and diluted with distilled water of such quantity as to make a
solution containing 1 gramme of gold to 200 cubic centimetres of liquid; a solution of caustic soda
is then added until the liquid exhibits an alkaline reaction. The solution of gold is now ready for
reduction. As a reducing agent an alcoholic solution of common illuminating gas is used, prepared
by simply attaching a rubber tube to a gas-jet and passing the current of gas for about an hour
through a quart of alcohol. This liquid (which should be kept in a closed vessel‘; is added in quan-
tities of from 2 to 3 cubic centimetres to 200 cubic centimetres of the alkaline solution of gold
before mentioned; the liquid soon begins to turn to a dark-green color, and at length produces the
metallic layer of gold of known reflecting power. As an improvement on the process, as well as for
canvenience in executing it, there may be added to the alcoholic solution of gas an equal quantity of
glycerine (28° to 30° B.) previously diluted with its own volume of distilled water. If the gold em-
ployed is an alloy, the foreign metals must in all cases be first removed; and especially the least
traces of silver, because the very smallest quantity of this metal totally prevents the regular and
uniform deposition of the gold.
Iridescent Glass, as manufactured under the patent of Mr. Thomas W. Webb, is produced as fol-
lows: Chloride of tin or tin salt is burned in a furnace, and the glass, having an affinity for it when
hot, receives the fumes, and so at once an iridescent surface is produced. To give greater depth to
the color or tints, nitrate of barium and strontium is used in small proportions. Very remarkable
effects of iridesccnce also are produced in glass by long burial in the earth, as is evidenced by the
collection of ancient Phmnician glass exhumed in the island of Cyprus by General Di Cesnola. Long
exposure to ammoniacal vapors gives a somewhat similar result.
Electroplating of Glass—Professor A. \V. Wright has succeeded in depositing most beautiful films
of gold, silver, platinum, and bismuth on thin glass by electro-metallurgical means. For a descrip~
tion of this process, see ELECTRO-METALLURGY.
Various applications of glass will he found under the following headings: For method of ruling
glass to produce diffraction-gratings, sec DIVIDING MACHINES; for its electrical uses, see ELECTRICAL
MACHINES, Sra'rrc. As to cutting glass panes, sec DIAMOND.
GLASS—WARE, MANUFACTURE OF. The tools used by makers of glass-ware are few and
simple, the various operations depending for success principally upon acquired dexterity, skill, and
judgment. The implements are represented in Fig. 2183. The first in importance is the pipe or blow-
ing tube, shown at 1, made of wrought-iron, 4 or 5 feet long, with a bore from a quarter of an inch
to an inch in diameter, a little larger at the mouth end than at the other. It is a long hand, partly
covered with wood, with which, the end being heated red-hot, the workman reaches into the pot of
melted matter and gathers up the quantity he requires, and which afterward holds the article in the
948 GLASS—WARE, MANUFACTURE OF.

manipulations to which he subjects it; and it is at the same time the air-tube through which the
breath is forced to expand the vessel, or through which water is sometimes blown to produce the
same effect by the steam it generates. A solid rod of iron, called a punty or pontil, serves to receive
. the article upon its end when freed from the pipe, adhesion being secured by the softness of the
glass or by a little red-hot lump already attached to the punty. Spring tongs (5), like sugar-tongs,
are used to take up bits of melted glass; and a heavier pair, called pucellas (2), furnished with broad
but blunt blades, serve to give shape tothe articles as the instrument in the right hand of the work-
man is pressed upon their surface, while, seated upon his bench, he causes with his left hand the
rod holding the article to roll up and down the two long iron arms of his seat, upon which it is laid
horizontally before him. At the same time the vessel is also shaped from the interior as well, and
is occasionally applied to the opening of the furnace to soften it entirely, or only in some part to
which greater distention is given by blowing. The pucellas are sometimes provided with blades of
wood, as at 4. Another important instrument is a pair of shears (3), with which a skillful workman
will cut off with one clip the top of a wine-glass, as he twirls it round with the rod to which it is
attached held in the left hand. The edge, softened in the fire, is then smoothed and polished. Be-
sides these, a wooden utensil called a battledore (6) is employed, with which the glass is flattened by
beating when necessary; compasses and calipers and a measure stick are at hand for measuring; and
a slender rod of iron forked at one end is used to take up the articles, and carry them when shaped
to the annealingoven, in which they are left for some time to be tempered. The marver (Fr.
marbre, marble) is a smooth polished cast-iron slab, upon the surface of which the workman rolls
the glass at the end of his tube in order to give it a perfectly circular form.
W'z'ne- Glasses.-—The manufacture of goblets, tumblers, and similar articles of table-ware may be
illustrated by describing how a wine-glass in three parts is made. The workman, having gathered









~ éiilllilgililililflllliliu lllllllllifiiiillllll' t_;'_ _ ""



on the end. of a blow-pipe the requisite amount of glass, as shown at 1, Fig. 2184, rolls it on the
marver and expands it by blowing into the tube until it assumes the form shown at 2, and afterward,
being flattened at the end with the battledore, that at 3. A lump of glass is now attached to the
flat end of the bowl (4), which the workman with the pucellas, While rotating the pipe on the long
arms of the chair in which he sits, transforms into the shape shown at 5. A globe is now attached
to the end of this stem (6), which is afterward opened and flattened into the form represented at 7.
A punty tipped with a small knob of hot glass is next stuck to the foot of the wine-glass, which is
severed from the bloW-pipe at the dotted line shown at 8. The top of the glass is then trimmed
with shears (9), after which it is flashed and finished as at 10. It is now severed from the end of
the punty by a sharp blow, and carried by a boy to the annealing-oven on the end of a forked rod.
Pressed Glass.—In the manufacture of articles by pressing, a hollow mould is used of steel or
iron, with its interior surface so designed as to give the object the required shape and figuration.
This mould may be in one piece or consist of several parts, which are opened when the moulded
glass is taken out. The process will be illustrated by describing the production of a tumbler. A
lump of glass is gathered from the pot on the end of a punty by the “gatherer,” and being held
over the open mould, a sufficient quantity is cut off with a pair of scissors by another workman and
drops into the mould. This is now pushed under a hand-press, Fig. 2185, and a smooth iron plun-
' ger is brought down into the mould with such force that the hot glass is made to fill the entire space
between the inside of the mould and the plunger, whose size and shape are the same as those of the
interior of the tumbler. The plunger being raised up, the mould is taken from the press and turned
over, when the tumbler is made to drop out bottom side up. A punty with a piece of hot glass at
one end is now attached to the bottom of the tumbler, which is heated at another furnace and
smoothed by being skillfully rubbed with a wooden tool while rotated on the arms of the workman’s
chair; after which it is taken on a fork to the annealing-oven. By this process articles can be pro-
duced with a rapidity not attainable in the case of blown glass, and therefore with less cost; but the
latter is generally preferred.
GLASS-WARE, MANUFACTURE OF. 949

The construction of a mould for large objects, such as decanters, is represented in Fig. 2186, and
a section of it in Fig. 2187. The bottom e and the sides a of the body form the lower and larger
part of the mould, and are held together by screws; the upper smaller part consists of two halves,
meeting in the line 7.2, which open after the fashion of a pair of tongs when turned upon the hinge
(I. That they may not be extended more than is necessary, the two wings are impeded by the plugs
0 fixed to the ring I. The workman introduces the glass globe 9, attached to the pipe, into the body



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i
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g; -‘.\\‘\\\ \\. r


of the mould, the neck portion being thrown open, and blows with great force into the globe, as soon
as the neck portion has been closed by an attendant, and fixed by the screw m (the female screw
belonging to which projects at n). The glass is forced by the pressure against the sides of the
mould, and extends in the form of a cap at q, above the margin, where the pipe is detached in the
direction of xx. The cylinder h, and another similar one, more at the back, are intended for the
insertion of wooden handles. Massive pieces, such as plates, are formed by pouring melted glass
between two plates of metal composing the mould, and the excess of glass is squeezed out from the
crevices by applying weights to the mould.
All articles of flint-glass, whether blown, moulded, or pressed, require annealing previous to cutting
or grinding. As they are frequently constructed of very different thickness, two kilns, which can be
heated to different’temperatures, are requisite; the larger and thicker pieces require that the kiln
should be much hotter than is necessary for thinner pieces. These kilns are long, low buildings,
arched over on the top. The various articles are all placed on sheet-iron trays. These trays are put
into the kiln through the opening in front, and are all connected together by hooks, by which means
they can be moved by a chain, worked by windlass or similar machinery, to the farther end of the
kiln, and are thus gradually withdrawn from the hottest part, and, having arrived at the farther
extremity, are removed at a temperature little above that of the atmosphere.
Moulded or pressed glass never exhibits its full amount of lustre, nor even the degree of sharpness
of the metallic mould; the glass, which is never limpid in its liquid state, is first cooled by contact
with the metallic surface, and is thus prevented from penetrating into the sharp comers of the
mould, nor does it even accommodate itself perfectly to the flat sides. For this reason, the surface
of moulded glass is not even, but always more or less curved, and the edges are not sharp ; but the
use of moulds as a preparatory step to grinding is of great" advantage to the grinder, as the vessel
acquires a perfectly regular form, and, although in a crude state, presents all the prominent and
receding facets to be perfected at the lathe.
Bottles—In choosing ingredients for this kind of glass, economy is the chief object. The follow-
ing examples are calculated for 100 lbs. of sand: For champagne bottles, according to J ahkel—200 -
lbs. feldspar, 20 lbs. lime, 15 lbs. commOn salt, 125 lbs. iron slag; ordinary green bottle-glass—72-
lbs. lime, 278-280 lbs. lixiviated wood- ashes; English bottle-glass—IOO lbs. lixiviated ashes, 40-90
lbs. kelp, 30-40 lbs.‘wood-ashes, 80—100 lbs. clay, 100 lbs. cullet. As soon as the working-holes
are opened, the workmanattachcs as much melted glassto the end of a blow-pipe as he considers
necessary for the production of a single bottle. By dipping the previously warmed pipe into the
pot, a little glass remains attached; after turning this in the air before the hole until it is cooled,
and blowing slightly into it to render it hollow, a fresh layer of glass may be attached to it in the
pot; to this a third is added in the same manner, until the ball at the end of the pipe has accu-
mulated to a sufi'icient size. That this ball may become uniformly tractable in the subsequent form‘
ing, it is held by the workman in the flame of the furnace through the working-hole; it is then
brought into one of the round concavities of the marver (constructed either from a stone, marble, or
cast-iron plate), where the ball gradually assumes the form of a pear-shaped vessel, Fig. 2184. It
acquires this shape by the constant rotary motion given by the workman to the pipe, while the cool-
ing and stiffening of the mass is rendered 1miform by the marver, and it is prevented from shrinking
together by constantly blowing into the pipe with very little force. The mass of metal (metal is the
technical term applied to glass during working) must be equably distributed round the axis of the
pipe, and advanced in front of its mouth, being connected with it only by a short neck.
Thus far advanced, the glass has again become cool, and it is rewarmcd by insertion into the work-
950 GLASS—WARE, MANUFACTURE 0F.

ing-hole, in such a manner that the front part receives the chief portion of the heat and becomes the
softer. The pear-shaped vessel is now lengthened by the blower, and its form is approached to that
of a bottle by a threefold operation: by blowing into the tube with greater force, by swinging back-
ward and forward in the manner of a pendulum, and by a simultaneous constant rotary motion of
the pipe round its axis. The globular form, which the glass tends to assume under the influence of
the blowing, is converted into a long thin egg-shape by the swinging motion, Fig. 2189. The rota-
tion round the axis of the pipe is an essential part of every operation in glass-blowing. The glow-
ing mass of glass creates a powerful current of air in an upward direction, and the lower portion
becomes cooled in consequence much more than the upper. This naturally creates an inequality in
the resistance offered to the blowing, and the upper portion would be more expanded than the lower
if the cooling influence were not allowed to act upon all parts of the surface alike by the revolving
motion of the pipe; and this is particularly the case when the pipe has to. be held in a horizontal
position. The mould a (a simple cylindrical hollow block of wood or iron) is placed at the side of
the workman who is blowing the pear-shaped vessel; into this he inserts the vessel as soon as it has
acquired the proper thickness, in the manner represented at Fig. 2190, and by blowing forcibly into
the tube, he presses the glass firmly against the sides of the mould, while, by a kind of jerking mo-
tion, the neck is drawn out to the proper length. The unfinished bottle is again warmed in the
working-hole in such a manner that the lower part only is heated, while the other parts remain com-
paratively cool. In the mean time, another workman or a boy has attached a small quantity of glass
to another pipe or rod of iron, called the punty, which is also kept hot in the workinghole. Both
workmen now stand opposite to each other; and while the pipes are kept constantly turning, the
punty is forcibly pressed against the middle of the lower part of the bottle, which is thus forced
inward, andan even edge is produced, upon which the bottle may stand steadily. The bottle remains
for some moments between the two instru-
ments, Fig. 2191, until, by the application
of cold iron or a drop of water, the neck
can be separated from the pipe. This sepa-
ration is an operation of constant recurrence
in the glass-house, and is effected by a sud-
den change of temperature produced at the
point of separation in the hardened glass,
either by the cold application of a drop of
water, or by the powerful heat of a red-hot
iron or thread of liquid glass from the pot.
The point of separation must often be re-
heated in order to fly on the application of
cold water. The bottle is now supported by
the punty, as shown at a, Fig. 2191, so that
the neck can be warmed, and the sharp edges
melted round without softening the other
parts. A rotating motion is now given to
the red-hot neck, the pipe being rolled back-
ward and forward upon the knees of the
workman. The rim for strengthening the
neck is formed from a drop of glass taken
from the pot by the edge of the flask and
wrapped round the mouth in the form of a
thick thread. The bottle, which is new fin_
ished, Fig. 2192, is immediately carried by the punty-rod to the annealing-oven by a boy, pushed into
its proper place, and the punty_rod is lastly detached from the bottom of the bottle by a sudden sharp
jerk. The place where the punty was attached is perceptible in every bottle blown in this manner
by the sharp edges where the fracture occurred.
Large round bottles are blown without the use of a mould; and when of very large size, like the
carboys for sulphuric acid, the aid of steam is called in, by spurting a mouthful of water into the
interior, and holding the mouth of the pipe with the thumb.
Moulds are used of such construction as to secure the formation of a bottle, perfect, both as
regards form and capacity, at one single operation, without reliance upon the workman’s correctness
of sight. The use of moulds of this description, like that of Rickets, which is easily managed,
affords a great saving of time, and renders the repeated heating of the bottles unnecessary.
The mould consists of a body which forms the belly of the bottle and of four other parts, a fixed
bottom-piece with a movable piston for forming the concavity, and two movable pieces for the neck.
Two treadles set these different parts in motion. As soon as the workman has introduced the
hollow lengthened globe into the belly of the mould, by pressing with his foot upon the first treadlc,
he brings up the neck-piece, then forces the glass into contact with all parts of the mould by a pow-
erful blast, and finishes the bottle by working the second treadle, which forces the pestle against the
bottom. 0n the removal of the pipe, the rim of the neck is all that remains to be perfected.
Champagne bottles require to be made more than usually strong in consequence of the pressure
exerted by the carbonic acid inclosed within them, and they are particularly liable to fracture during
the bottle-fermentation of the wine. Yet they will often withstand a pressure of 40 atmospheres
and upward (: 600 lbs. on the square inch). '
The fllanufacture of Mirrors.--Plate-glass has to undergo three operations before it is silvered.v
The first is smoothing. The rough plates are fastened with plaster upon a stone or cast-iron table.
By means of a long beam of iron suspended from the ceiling and moved circularly, masses of wood
2188. 2189 2190.









. \- \;
: . \1i-\ -
, figs




GLASS—WARE, MANUFACTURE OF. 951

attached to said beam and faced with cast-iron are rubbed over the glass. On the surface of the
latter coarse quartz sand is thrown and a constant fine stream of water is supplied. The coarse
sand is subsequently replaced by a finer material, and this last by coarse emery. As soon as one
side of the glass is finished, the plate is turned over and the other side similarly treated. Another
method, largely used in France and England, consists in attaching the plates to a circular table of
15 or 18 feet diameter, which is rotated about a central pivot. Above the glass are placed heavy
plates of wood faced with cast-iron. These plates, which are rotated by motion imparted from the
table, but in an opposite direction, have counterweights, so that their pressure upon the glass may
be adjusted; by means of this double movement the operation is greatly expedited. Sand and emery
are interposed as already described.
The second process is rubbing with fine emery, made into a paste with water, in order to remove
fine scratches. The glass rests on a table, and upon a wet cloth to prevent its sliding. Another
plate of glass is deposited above it, and the two surfaces are thus rubbed together by suitable
machinery.
The third process is polishing, and this is done by means of eolcothar or red peroxide of iron, in
a pure and fine state. The polishing apparatus is represented in Fig. 2193. The glass is fastened
2193.


.
i'fvxmmrr'm .o , .
.


‘ /
i“ y ' // to the movable tables E, which reciprocate in a direction relatively perpendicular to that of the
//
brushes H H’, which reciprocate above and rub upon the glass. The brushes are moved by the
geared mechanism shown. About 10 hours is required to polish about 50 superficial feet of glass.
The method of coating the plates is as follows: A large stone table, ground perfectly smooth, is
so arranged as to be easily canted a little on one side by means of a screw set beneath it. Around
the edges of the table is a groove, in which mercury may flow and drop from one corner into bowls.
The table is first made perfectly horizontal, and then tin-foil is carefully laid over it, covering a
greater space than the glass to be coated. A strip of glass is placed along each of three sides of the
foil to prevent the mercury from flowing elf. The metal is then poured from ladles upon the foil
till it is nearly a quarter of an inch deep, and its tendency to flow is checked by its affinity for the
tin-foil and the mechanical obstruction of the slips of glass. The plate of glass, cleaned with espe-
cial care, is dexterously slid on from the open side, and its advancing edge is kept in the mercury,
so that no air or floating oxide of the metal or other impurities can get between the glass and the
clean surface of the mercury. When exactly in its place, it is held till one edge of the table has
been elevated 10° or 12° and the superfluous mercury has run off. Heavy weights are placed on the
glass, and it is left for several hours. It is then turned over and placed upon a frame, the side
covered with the amalgam, which adheres to it, being uppermost. In this position the amalgam
becomes hard, and the plate can then be set on edge; but for several weeks it is necessary to guard
against turning it over, as until the amalgam is thoroughly dried the coating is easily injured.
Several serious difficulties attend this process. The health of the workmen is so affected by the
fumes of the mercury that they can rarely follow the business more than a few years; for this no
remedy has been found so effectual as thorough ventilation and the frequent use of sulphur baths.
The glass plates are liable to be broken by the weights placed upon them; and the coating of amal-
gam is frequently spoiled by the drops of mercury removing portions of it as they trickle down, or
by its crystallizing, or by mechanical abrasion. Many methods of silvering have been contrived and
patented with the view of obviating these defects, some of which are important. In 1855 a patent
was granted in England to Tony Pctitjean for a method of precipitating silver, gold, or platinum
upon glass, so as to form a coating upon it, by the use of two solutions, the effect of which when
mixed upon the glass is to decompose each other. The solutions be employed were different com-
pounds of 'ammonio-nitrate of silver, tartaric acid, and distilled water; and they were placed upon
the plate while this was at the temperature of l50° F. The precipitated silver within 20 minutes
covered the glass, to which it adhered; and the solution being then turned off, all that remained to
complete the mirror was to wash the surface, and when dry cover it with a coat of varnish to protect
it from injury. The silvering thus obtained is not so white, and is rarely so free from blemishes, as
952 GLUE.

the amalgam coating. In 1849 Mr. Drayton made known a similar method, an improvement upon
a process which he patented in 1843. He employed ammonia 1 oz., nitrate of silver 2 oz., water 3
oz., and alcohol 3 oz. ; these, being carefully mixed, were all allowed to stand a few hours, when to
each ounce of the liquid was added an ounce of saccharine matter, as of grape-sugar, dissolved in
equal portions of spirit and water. Liebig invented a method of coating glass with silver, in which,
after the silver coating is laid on, it is covered with a coating of copper precipitated upon it by the
galvanic current, or is protected by varnish. Silver mirrors are now extensively made in New York.
For platinizing glass, R. Bettger recommends the following process: Pour rosemary oil upon the dry
chloride of platinum in a porcelain dish, and knead it well until all parts are moistened; then rub
this up with five times its weight of lavender oil, and leave the liquid a short time to clarify. The
objects to be platinized are to be thinly coated with the preparation, and afterward heated for a
few minutes in a muffle or over a Bunsen burner. The brilliancy of aluminum has caused the sug-
gestion of its application to the coating of mirrors; but no successful experiments have yet been
made with it for this purpose.
Large mirrors are made in the United States by coating the imported plates. The old amalgama-
tion method with tin-foil and mercury is preferred to any of the more recent inventions, by reason
of the greater whiteness and brilliancy of the reflection and the greater permanence of the coating.
GLUE. All animal tissues contain an adhesive substance which anatomists call histose, in accord-
ance with the name histology given to the study of the formation of these tissues. When they are
boiled in water, the histose is changed into a new substance, called gelatine, dissolved in the water,
from which it may be separated by simple evaporation, when it forms a dry, hard substance, which
has different names corresponding with the various sources of its origin. That obtained from carti-
lage is called chonclm'ne; from bones, hoofs, and hides, glue; from the air-bladder and intestines of
fishes, isz'nglass; and from the less tenacious and adhesive constituents of parchment scraps and
some other animal membranes, size. '
The best kinds of ordinary glueare made from fresh bones, cleared of fat by previous boiling, and
also ofi’al obtained by trimming the skins for tanners. The pieces of dried skin thus obtained are
called glue-pieces. The browner, commoner glue is made from offal from slaughter-houses, cattle—
hoofs, etc. The skin-pieces arc soaked in milk of lime for three weeks, the lime being renewed
every week. They are then put in layers, on a sloping pavement, to drain and dry, and turned over
three times a day. They are afterward soaked in weak lime-water, and washed in baskets under a.
stream of water. They are then drained and exposed to the air, so as to enable the adhering lime
to absorb carbonic acid from the atmosphere, and thus lose its caustic properties, which would do-
stroy part of the glue during the subsequent boiling. If the glue is to be used as gelatine for culi-
nary purposes, only perfectly cleaned, fresh bones are used. Calf bones give a milky glue; those of
the hog produce a blackish foam which mixes in the solution; while the product from those of the
sheep retains always the peculiar odor of the fat of this animal. Beef-bones are preferred, giving a
perfectly transparent glue, sold under the name of gelatine or isinglass. The materials (bones,
skins, etc.) are placed in a flat copper boiler, upon a perforated false bottom, placed at a little dis-
tance over the bottom of the boiler, so as to prevent the solid material from touching the shell, when
it would stick fast and be burned. The boiler is filled two-thirds with water, and heat is applied.
In a few hours, after stirring repeatedly, the liquid is drawn off in successive portions, as soon as it
is perceived that a sample taken out gelatinizes in cooling. Experience has taught that too long
boiling injures the glue. ' The test for this cooled gelatinized material is, that it must be fit to be
cut in slices with a wire. Before drawing off the solution the fire is diminished, so as to stop the
boiling and allow the liquid to clarify by settling. It is then drawn into a deep boiler, where it
settles for the second time, remaining hot from five to six hours.
The principal improvements in glue-making devised by Mr. Peter Cooper consist in the use of
steam-heating of the vessels, and the application of heat under pressure, by which more glue 1s ex-
tracted in a much shorter period of time and with great saving of fuel; and the production of an
opaque porous isinglass, made in winter only, when the frost, by expanding the water in the act of
freezing, separates the glue particles. Being subsequently dried in the frozen state, they keep their
spongy appearance, making them much more easily soluble, and thus better adapted for culinary
purposes. Another improvement is the addition of Paris white (fine chalk) to the glue used by
cabinet-makers. It has the following advantages : 1. It improves the adhesive qualities. 2. It
makes the glue look more white, and thus gives to a browner glue the lighter appearance of a more
expensive quality. 3. It is a pecuniary gain, since a substance costing only 3 or 4 cents per pound
is added to one costing 30 or 40 cents.
Glue is also made-from leather offal and old leather, by means of the action of 15 per cent. of
hydrated lime and water in closed vessels, at a temperature of 250° F., and consequently two atmo-
spheres pressure. In this way the leather is completely decomposed. Its principal constituents
being tannic acid combined with gelatine, the lime takes hold of the tannic acid, forming tannatc of
lime, while the gelatine is set free and dissolves in the water.
The strongest glue is that which is purest and which gelatinizes most completely. Good glue,
properly prepared and well applied, will unite pieces of wood with a degree of strength which leaves
nothing to be desired. The fibres of the hardest and toughest wood will tear asunder before the
glued surfaces will separate, and certainly anything more than this would be unnecessary. Mr.
Bevan found that when two cylinders of dry ash, each an inch and a half in diameter, were glued
together, and then torn asunder after a lapse of 24 hours, it required a force of 1,260 lbs. to sep-
arate them, and consequently the force of adhesion was equal to 715 lbs. per square inch. From a
subsequent experiment on solid glue he found that its cohesion is equal to 4,000 lbs. per square inch.
The precautions necessary in applying glue are, to secure perfect contact of the parts, and to delay
gelatinization of the glue until the joint has been completed. The glue should therefore be used
GOLD-‘BEATING. 953

while very hot, as hot as it will bear, and in very cold weather the wood itself should be warmed.
The glue should be well rubbed in with a stiff brush, and the two surfaces should be rubbed well
together and retained in contact under great pressure until the glue has become somewhat dry.
Complete dryness rarely takes place under several days; but after the lapse of 12 hours the joint
becomes tolerably strong. A joint made in this way is probably as strong as can be made by any
ordinary process. I
Various modes of keeping glue in a liquid state are employed. The addition of a little nitric acid
(10 oz. ofv strong acid to 2 lbs. of dry glue dissolved in water) will prevent the glue from gelatinizing
or becoming solid; and the further addition of a little vinegar, or rather of pyroligneous acid, will
prevent it from moulding. It has been proposed to add sulphate or chloride of zinc to common glue
for the purpose of keeping it liquid. A solution of shellac in alcohol has been used and highly cx-
tollcd as a substitute for common glue. It forms a tolerable liquid cement, but is far inferior to glue.
Maurine glue, which possesses extraordinary adhesive properties, is a preparation of caoutchouc
dissolved in naphtha or oil of turpentine, with the addition of shellac after the solution has by stand-
ing several days acquired the consistence of cream. Two or three parts by weight of shellac are
used for one of the solution.
GOLD—HEATING. The art of preparing what is well known under the name of gold leaf, in
which gold is hammered or beaten into plates, whose average thickness at the present day may be
taken at Tj'g'olijfi of an inch.
To manufacture gold leaf, the metal is required in theory to be in a state of purity. All alloy is at
the expense of malleability. But in practice this is rarely if ever attained, and the usual fineness is
that of coin, which in France and the United States is 90 per cent; in Great Britain, 912% per cent.;
and in Bavaria, where the principal amount of gold-beating in Germany is done, 97% per cent. fine.
In France it was stated about 1820 that the most approved practice was to mix equal parts of old
Spanish coin and pure gold, which would result in an average proportion of 95% per cent. fine.
Below 75 per cent. fine, the manufacture would be, in labor and waste, a losing business.
The principal aim of alloying, when it is done of design, seems to be the production of a variety
of color—silver making the leaf pale, copper deepening the tint. These effects are more particularly
noticed in the article ALLOYS ; they are similar in the leaf as in the more solid masses; only in the
state of tenuity, the green and purple tinge is more easily excited and more vividly displayed. What-
ever may be the character and degree of alloy, the manipulations of the gold-beater are the same in
kind, and will be now briefly described.
1. Casting—The metal is placed, with a little borax to promote fusion, in a black-lead crucible, or
crucibles, and set in a furnace. When perfectly melted, it is poured into cast-iron moulds, 3 or 4
inches long, three-quarters of an inch wide, and about half an inch deep, and holding each about
1,000 grains of metal. These moulds are made with faces a little concave, to allow the cast to draw
easily; and before pouring, they are heated, and rubbed with linseed oil or tallow on the inside, to
drive off moisture and promote an easy separation. When sufficiently cool. the ingot is taken out,
and reheated in an open fire, or a small annealing-furnace, by which it is softened, and the adhering
grease drivenoff.
2. Laminating—In older times this was effected entirely by the hand-hammer; now a fiatting-
mill or laminating rolls are employed. The French still use, however, a preliminary forging upon a
steel anvil (of 3-inch by 4-inch sides), with a hammer of about 3 lbs. weight. The face of this
hammer is about 14,; inch square, and its handle about 6:} inches. \Vith this they bring down the
thickness of the ingot to one-sixth or one-seventh of an inch. The English perform the whole of the
operation in the rolls. As the success of the work and the excellence of the leaf ultimately depend
a good deal upon the uniformity of the lamination, care is taken to use a proper and accurate ma-
chine. These machines have been successively improved, until now there is little if anything left to
be desired. During the hardening processes of lamination and forging, if the latter be employed,
the ribbon has to be frequently annealed, to prevent cracking. Formerly the lamination was thought
sufficient which had brought the thickness down to one-twenty-fifth of an inch, with a width of one
inch; and the balance was done by hand, cutting the ribbon into lengths of 14; inch, piliirr 24 of the
lengths evenly together, and forging them all at once till they came square. This is the practice
with some of the French and German gold-heaters to this day; but others, having access to more
perfect machinery, continue its application to the lamination until the thickness is brought to about
7%“ of an inch. As dimensions like this cease to be appreciable, the degree of lamination is esti-
mated by weight; and the direction usually is, to bring it down until a square inch of ribbon weighs
61,; grains. In this state it is ready for the beating proper.
3. Beating—The implements and fixtures for this are, an anvil, hammers, skins, shears, parting-
knives, etc. The anvil is a. block of marble, weighin<r 250 or 300 lbs. or more, at pleasure, with a
face of 9 inches to 1 foot square, carefully made even and smooth. This is set in a frame of wood-
work, strong and solid, and upon a firm foundation. A ledge, 5 or 6 inches high, runs round three
sides of the frame; to the remaining side an apron of leather is attached, which is lifted by the
workman. The object of all this is to catch and retain fragments of the precious metal. The
hammers are, ordinarily, four in number, varying in weight. Their faces are from 3 to 5 inches in
diameter, and slightly convex. The weight of the first or flat hammer is about 15 lbs; the second
(which the French term the commencing hammer) weighs from 6 to 8 lbs.; the third, or spreading
hammerhwith a smaller face, and more convex, weighs about 5 lbs. only; and the last, or finishing
hammer, is again a heavy one of _10 or 12 lbs., with quite a convex face. The skins are of parch-
ment and vellum and the intestine already spoken of, cut, the two former into squares of about 4
inches, and the last of 5 inches. Besides these, there are packing-boxes, also of parchment, made
on a form, and cemented together, open at two opposite ends, and in pairs, so that one will slip into
the other, by which the open ends are closed. The knives are pieces of cane, set into a frame, both
954 GOLD—BEATING.

four-square and cruciform, with sharpened edges that divide the attenuated leaf better than any
other implement, by pressure downward only. When the leaf becomes very thin, any other motion
would drag it.
Provided with these and other tools that do not requirespecial mention, the workman lays off the
ribbon, which comes from the laminating as nearlyras possible one inch in width, into lengths also
of one inch. This he does with dividers or a scale, and cuts oif afterward with shears. This is on
the supposition that the rolling has been uniform, and equal surfaces therefore should give equal
weights. He then arranges these squares into piles of generally 150 pieces, laying each leaf on a
piece of the vellum before spoken of, as near as may be in the centre, with their edges .even. About
twenty extra vellums are placed on top and at bottom, and the pack is then of proper size to be
pushed smoothly into one of the parchment envelopes, which is then in its turn pushed into its mate,
and the whole thus inclosed on all four sides. The pack is then laid on the marble anvil, and beaten
until the small gold leaf is extended to the size of the vellum. It is in the judicious uniformity of
direction and force of the blows that the skill of the workman is displayed. Great dexterity is, in
fact, attained; the hammer is shifted from hand to hand for relief without interfering with the
regularity of the stroke; and when it is recolleeted that the absolute effect of the average hammer
with the average blow is equivalent to the steady pressure of about 2,800 lbs. on the square inch,
there will be seen to be need for discretion in the application of such a force.
During the beating, the pack is frequently turned, so as to beat on the bottom as well as the top
(as a skillful workman will do without losing the stroke), and also folded or rolled in the hand, to
secure a proper detachment of the surfaces. It is also opened from time to time to watch the effect,
and shift the leaves from the centre to the outsides, that the pressure may be uniform. When the
gold has been extended to the size of the vellums, about sixteen times its original dimensions, it is
taken out, out up into four squares, repacked as before, only with gold-beaters’ skin instead of
vellum, and beaten over until similarly extended again. The caution of folding the pack to loosen
the leaves is even more necessary now than before, and so of opening and shifting. When it has
attained the size of the skins, it is removed, parted into squares again, but this time with the cane,
repacked, and rebeaten as before into leaves of 3 to 31} inches square. It is estimated that the
aggregate surface of the leaves is now 192 times larger than it was originally ; and their thickness
may be taken at main—Um of an inch, which is about the average of English gold leaf, and corresponds
to an extension of about 100 square feet to the ounce. But the operation is frequently carried
further by repeated beatings, till an ounce is extended over 160 square feet, corresponding to a cal-
culated thickness of fixing of an inch nearly. The French gold-heaters claim—and their statement
of weight worked on and number of leaves produced warrants the claim—t0 carry it down ordinarily
much further than this; and our statement at the beginning of 731,157,“ of an inch is probably even
within the average result, and much within the possible limits, of malleability, if these were, without
regard to expense of time and waste of metal, the only points to be reached.
The French workmen are also very precise in the number of pieces, both of leaf and of baudruche
and vellum, which go to the packs in each of the five several steps that comprise their beating. As
the fruit of experience, no doubt, they have ascertained the number which best suits the respective
implements. The English and Germans pack in different numbers, it may be supposed with the
same reason; but the principles of the operation are in all the same.
When the leaf is considered as finished, the last thing is to put it in the square books, such as we
see in commerce. These are made of smooth paper, frequently reddish-colored, on purpose to
heighten the lustre of the gold, and well rubbed with Armenian bole to prevent adhesion. There
are two sizes, one about 4;}, the other 3% inches square. The pack, withdrawn from its parchment
envelopes, is held by one of its angles; and, with a pair of wooden pliers, each leaf is withdrawn,
and laid, aided by the breath, upon a leathern cushion, where, with the cane knives, it is“ parted at
once or successively into four pieces, the size of the book. These pieces are then similarly trans-
ferred to the book, each between separate leaves. rFhe book holds, very uniformly, 25 leaves of
gold. When filled, it is pressed hard with a piece of wood of its own size, so as to bring its edges
close ; and with a piece of linen any projecting pieces of gold leaf are readily wiped off. Afterward
the books are put up in packages of a dozen ordinarily, for sale. The French artists allow between
3 and 4 days for finishing 4 oz. of gold. They estimate the loss in trimmings, waste leaves, etc., at
50 per cent., and consider the remaining 2 oz. (964.6 grains English) as yielding 12,600 leaves of
the smallest size; but there is no authentic experiment of weighings and measurings in this respect.
The parchment employed is used as it comes from the manufacturer, only cutting out of the sheets
those parts, of suitable size, which are softest and of most uniform thickness. The vellum, which is
produced of the finest and softest, is not further treated than by well washing it in cold water, dry-
ing it in the air under a press, and then powder-ing it with finely calcined and reduced selenite.
Whether the implement used for this has any special influence will not be affirmed or denied; but
the uniform practice, in France at least, is to use a home’s feet. I
The preparation of gold-beaters’ skin, from the colon of the ox, has been already spoken of as a
secret maintained by the few who furnish the article. Whatever their processes may be, the gold-
beater is accustomed to test and treat it still further for himself. Thus, he first sweats it, by placing
it between a fold of foolseap; making a pile of many pieces, he treats it to a hearty hammering
until it ceases to give out any grease to the paper. Next, he moistens it with an infusion of nutmeg,
cinnamon, or other spicy aromatics, with the view of preserving it, dries it in the air, moistens again
as often as he sees fit, and finally dries and presses it for use. Since the introduction of creosote,
this (as well as may be judged from the odor of some recent skins) has been applied, and no doubt
more effectually. After the skins have served some time (some '70 or 80 beatings, for instance),
they become inspissated, or wiry, or both, and no longer allow the proper extension of the gold.
This may be cured by laying them a half day between leaves of paper wetted with Rhenish 0r
GONIOMETER. 95,5

Moselle wine, or: even vinegar and water. When thoroughly moistened, they are placed between
, layers of .parehlnent,‘enveloped, and beaten until dry. This beating frequently takes a whole day.
They are then powdered with selenite, and fit for use. While yet fresh, the skins are very liable to
be affected by moisture, which they absorb from the atmosphere. They must be, therefore, always
dried efOre' using, which in France is done by heat in a screw-press. Care is taken not to desiccate
too much, which withers and causes them to crack under the hammer.
The methods which have been described here are also applicable in their measure to silver, copper,
and platinum.
A sort of gold leaf, called party gold leaf, is sometimes used, made with a combination of gold and
silver. Separate leaves are taken of these metals, the silver being about three times as thick as the
gold, heated .and laminated together, so as to produce an alley or welding of their surfaces. The
resulting party-colored ribbon is then beat-en'as if it were all of gold. Its extensibility is, of course,
not so great. There is another false gold leaf, which is better known as Dutch gold leaf. It is, in
fact, a ribbon of brass, wash-gilded, sheared into leaves, and then beaten in the manner, and with
more or less of the precautions, that have been described. When new, it is difficult to be distin-
guished from true gold leaf; but it is soon tarnished by the air, and is unfit for any gilding that is
not to be varnished.
GONIOMETER. An instrument for measuring angles, and more particularly the angles formed
by the faces of crystals. The instrument, chiefly used by mineralogists, was invented by Dr. Wol-
laston. It consists of a brass circle graduated on the edge, and furnished with a vernier, by which
the divisions may be read correct to a minute. The circle moves in a vertical plane, and is supported
on a stand. The axis of the circle is a hollow tube, within which is a smaller axis, fitting so tightly
. that when turned round it carries the other axis, and consequently the wheel, along with it, unless
the latter i s prevented from moving. The interior axis is furnished with a milled head A, Fig. 2194,
and the exterior witha milled head B ; so that when the head A is held and B turned, the circle may
be moved independently of the smaller axis; and when B is held and A turned,
the smaller axis may be turned independently of the circle. Attached to the
end of the smaller axis is a sort of universal joint, capable of being fixed in
different positions by means of screws. The crystal to be examined is attached
' to the joint at C' by a little soft wax, and placed so that its edge shall be par-
allel to the axis of motion; which adjustment is obtained by placing it so that
the image of some horizontal object, as the bar of a window, successively
reflected from the two faces of the crystal, coincides with another horizontal
line seen by direct vi ~i0n. When this adjustment has been made, the instru-
ment is turned till ‘the horizontal object is seen reflected from one of the
faces. The. smaller axis is then-held fast, and the other turned till the index
of the vernier points to the zero of the graduated limb. The circle is then
turned'round, along with the smaller axis, till the same object is seen in the
same position by reflection froni the other face of the crystal ; when the are
passed through by the circle is obviously the supplement of the angle formed by the two faces of the
crystal. In order, however, to avoid calculation, the supplements of the angles are marked on the
limb, so that the angle to be measured is read off immediately.
The name goniometer is also applied to a surveying instrument, somewhat similar to a theodolite.
GOUGE. See LATHE-TOOLS, TURNING.
2194 .


END OF VOLUME 1.
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